Strattera

ADHD Agents, Non-stimulant
Selective Norepinephrine Reuptake Inhibitor Antidepressants, SNeRIs

Oral Administration

Administer as a single daily dose in the morning or in evenly divided doses in the morning and late afternoon/early evening. Patients who have insomnia due to the medication should take the last dose of the day before 6 PM.

Oral Solid Formulations

Administer capsules whole; do not cut, crush, or chew. May give with or without food. If nausea occurs, it may be helpful to administer after a meal.
Do not open the capsules. Atomoxetine is an ocular irritant. If contact with the eye occurs, immediately flush the affected eye with water and seek medical advice. Hands or contaminated surfaces should be washed promptly.

Severe

hepatotoxicity / Delayed / 0-1.0
rhabdomyolysis / Delayed / 0-1.0
suicidal ideation / Delayed / 0.4-0.4
seizures / Delayed / 0.1-0.2
stroke / Early / Incidence not known
myocardial infarction / Delayed / Incidence not known
angioedema / Rapid / Incidence not known
anaphylactoid reactions / Rapid / Incidence not known
hepatic failure / Delayed / Incidence not known
hepatic necrosis / Delayed / Incidence not known

Moderate

constipation / Delayed / 1.0-8.0
impotence (erectile dysfunction) / Delayed / 8.0-8.0
depression / Delayed / 4.0-7.0
urinary retention / Early / 6.0-6.0
ejaculation dysfunction / Delayed / 4.0-4.0
blurred vision / Early / 4.0-4.0
palpitations / Early / 3.0-3.0
conjunctivitis / Delayed / 1.0-3.0
dysuria / Early / 2.0-2.0
prostatitis / Delayed / 0-2.0
orthostatic hypotension / Delayed / 0.2-1.8
hostility / Early / 0.4-1.6
sinus tachycardia / Rapid / 0.3-1.5
chest pain (unspecified) / Early / 0-1.0
hallucinations / Early / 0-0.2
psychosis / Early / 0-0.2
mania / Early / 0-0.2
hypertension / Early / Incidence not known
QT prolongation / Rapid / Incidence not known
peripheral vasoconstriction / Rapid / Incidence not known
priapism / Delayed / Incidence not known
growth inhibition / Delayed / Incidence not known
hepatitis / Delayed / Incidence not known
hyperbilirubinemia / Delayed / Incidence not known
prolonged bleeding time / Delayed / Incidence not known
jaundice / Delayed / Incidence not known
elevated hepatic enzymes / Delayed / Incidence not known

Mild

weight loss / Delayed / 2.0-29.1
nausea / Early / 7.0-26.0
xerostomia / Early / 20.0-20.0
headache / Early / 2.0-19.0
abdominal pain / Early / 7.0-18.0
insomnia / Early / 15.0-15.0
drowsiness / Early / 8.0-11.0
vomiting / Early / 4.0-11.0
fatigue / Early / 6.0-10.0
dizziness / Early / 5.0-8.0
irritability / Delayed / 5.0-6.0
abnormal dreams / Early / 4.0-4.0
dyspepsia / Early / 4.0-4.0
hyperhidrosis / Delayed / 4.0-4.0
paresthesias / Delayed / 0-3.0
dysmenorrhea / Delayed / 3.0-3.0
chills / Rapid / 3.0-3.0
flushing / Rapid / 0-3.0
libido decrease / Delayed / 3.0-3.0
anorexia / Delayed / 3.0-3.0
asthenia / Delayed / 0-2.0
tremor / Early / 0-2.0
emotional lability / Early / 1.0-2.0
restlessness / Early / 0-2.0
agitation / Early / 0-2.0
dysgeusia / Early / 0-2.0
menstrual irregularity / Delayed / 0-2.0
testicular pain / Early / 0-2.0
increased urinary frequency / Early / 0-2.0
urinary urgency / Early / 0-2.0
orgasm dysfunction / Delayed / 0-2.0
mydriasis / Early / 0-2.0
pruritus / Rapid / 0-2.0
urticaria / Rapid / 0-2.0
rash / Early / 0-2.0
muscle cramps / Delayed / 0-2.0
syncope / Early / 0-0.8
anxiety / Delayed / 0.4-0.4
diarrhea / Early / 2.0
back pain / Delayed / 2.0
lethargy / Early / Incidence not known
hypoesthesia / Delayed / Incidence not known
pelvic pain / Delayed / Incidence not known
alopecia / Delayed / Incidence not known

Children, growth inhibition, suicidal ideation

The safety and efficacy of atomoxetine in children less than 6 years of age have not been established. Atomoxetine is not approved for the treatment of major depressive disorder (MDD). An increased risk of suicidal ideation was noted during pediatric ADHD and enuresis studies with atomoxetine, including one suicide attempt but no completed suicides. Co-morbidities occurring with ADHD may increase the risk of suicidal ideation and/or behavior. Pediatric patients should be closely monitored for clinical worsening, as well as agitation, irritability, suicidal thinking or behaviors, and unusual changes in behavior. Such monitoring would generally include at least weekly in-person contact with patients during the first 4 weeks of treatment, then one visit at weeks 6, 8, and 12, then as indicated beyond 12 weeks. Additional contact by telephone may be appropriate between visits. Consideration should be given to changing or stopping the therapeutic regimen in patients who are experiencing symptoms that might be precursors to emerging suicidality, especially if these symptoms are severe, abrupt in onset, or were not part of the patient's presenting symptoms. Periodic reassessment of the need for medication is recommended. Atomoxetine should be prescribed in the smallest quantity consistent with good patient management in order to reduce the risk of overdose. Sudden death has been reported in association with atomoxetine treatment at usual doses in pediatric patients with structural cardiac abnormalities. A large retrospective cohort study including over 1.2 million children and young adults 2—24 years of age did not find an increased risk of serious cardiovascular events, including sudden cardiac death, myocardial infarction, or stroke in current users of drugs for the treatment of ADHD compared to nonusers (adjusted hazard ratio 0.75; 95% CI 0.31—1.85). The authors concluded that although the absolute magnitude of risk appears to be low, a modest increase in risk could not be ruled out. A cardiac assessment should be conducted prior to atomoxetine administration to evaluate appropriateness of treatment; careful screening and monitoring is recommended by the American Heart Association. The potential for growth inhibition in pediatric patients should be monitoring during atomoxetine therapy. Monitor height and weight at treatment initiation and periodically thereafter. Studies are not available to define the impact of atomoxetine on final adult height and weight, but short-term (9-week) studies have shown that up to 3.5% of body weight can be lost, and this loss may be dose-related. Data from open-label trials indicate that in general, the weight and height gain of children treated with atomoxetine lags behind that predicted by normative population data for the first 9—12 months of treatment; subsequently, weight gain rebounds and at about 3 years of treatment, patients have gained slightly more weight (0.5 kg) than predicted by their baseline data. After about 12 months, gain in height stabilizes, and at 3 years, patients have gained only slightly less (0.4 cm) than predicted. Growth patterns are similar regardless of pubertal status; however, mean weight gain has been shown to be slower for poor vs. extensive metabolizers (2.4 kg less vs. 0.2 kg less than predicted, respectively), while height gain is similar between poor and extensive metabolizers (1.1 cm less vs. 0.4 cm less than predicted, respectively). Adverse effects such as aggression and hostility have been observed in some children and adolescents receiving medications for ADHD. Although this has not been a finding of statistical significance with administration of atomoxetine compared to placebo, patients should be closely monitored for potential onset of these effects. It should be noted that not all patients with ADHD will require medication; non-drug measures are often instituted concurrently with drug therapy.

Strattera

Rx

Selective norepinephrine reuptake inhibitor (NRI); lack of abuse potential
Used for attention-deficit hyperactivity disorder (ADHD) in adults and pediatric patients 6 years and older
Boxed warning regarding potential for suicidal ideation and need to monitor for changes in mood and behavior; may increase blood pressure and heart rate

For the treatment of attention-deficit hyperactivity disorder (ADHD). Oral dosage Adults

40 mg/day PO initially. After a minimum of 3 days, titrate to the target dose of 80 mg/day PO. Doses may be given as single dose in the morning or in 2 divided doses. After 2 to 4 weeks, the dose may be further titrated to 100 mg/day PO in 1 or 2 divided doses in patients with suboptimal response. Max: 100 mg/day PO. If the patient is a poor metabolizer of CYP2D6, only increase to the usual target dose of 80 mg/day PO if symptoms fail to improve after 4 weeks and the initial dose is well tolerated. Coadministration of certain drugs may need to be avoided or dosage adjustments may be necessary; review drug interactions. Atomoxetine is an integral part of a total treatment program for ADHD that may include other measures (psychological, educational, social). Maintenance treatment is generally needed in patients with ADHD; however, periodic reassessment is recommended to determine the need for continued therapy. DISCONTINUATION: Can discontinue without tapering.

Children and Adolescents 6 to 17 years weighing more than 70 kg

40 mg/day PO initially. After a minimum of 3 days, titrate to the target dose of 80 mg/day. Doses may be given as single dose in the morning or in 2 divided doses. After 2 to 4 weeks, the dose may be further titrated to 100 mg/day PO in 1 or 2 divided doses in patients with suboptimal response. Max: 100 mg/day PO. If the patient is a poor metabolizer of CYP2D6, only increase to the usual target dose of 80 mg/day PO if symptoms fail to improve after 4 weeks and the initial dose is well tolerated. Coadministration of certain drugs may need to be avoided or dosage adjustments may be necessary; review drug interactions. Treatment strategies must be individualized for patients based on psychosocial and comorbid factors. DISCONTINUATION: Can discontinue without tapering.

Children and Adolescents 6 to 17 years weighing 70 kg or less

0.5 mg/kg/day PO initially. Dose may be increased after a minimum of 3 days to a target dose of 1.2 mg/kg/day and may be given as a single daily dose in the morning or as 2 evenly divided doses in the morning and late afternoon/early evening. Max: 1.4 mg/kg/day (not to exceed 100 mg/day, whichever is less). If the patient is a poor metabolizer of CYP2D6, only increase to the usual target dose of 1.2 mg/kg/day PO if symptoms fail to improve after 4 weeks and the initial dose is well tolerated. Coadministration of certain drugs may need to be avoided or dosage adjustments may be necessary; review drug interactions. ADHD is a chronic condition that will require ongoing management and monitoring. Treatment strategies must be individualized for patients based on psychosocial and comorbid factors. DISCONTINUATION: Can discontinue without tapering.

Hepatic Impairment

Moderate hepatic impairment (Child-Pugh Class B): Reduce initial and target dosage by 50% of normal.
Severe hepatic impairment (Child-Pugh Class C): Reduce initial and target dosage by 75% of normal.

Renal Impairment

Specific guidelines for dosage adjustments in renal impairment are not available; it appears that no dosage adjustments are needed. Renal clearance is not an important predictor of atomoxetine clearance.

Acetaminophen; Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Due to the potential for additive increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors such as phenylephrine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Acetaminophen; Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Acetaminophen; Chlorpheniramine; Phenylephrine : (Moderate) Due to the potential for additive increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors such as phenylephrine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Acetaminophen; Dextromethorphan; Guaifenesin; Phenylephrine: (Moderate) Due to the potential for additive increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors such as phenylephrine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Acetaminophen; Dextromethorphan; Guaifenesin; Pseudoephedrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Acetaminophen; Dextromethorphan; Phenylephrine: (Moderate) Due to the potential for additive increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors such as phenylephrine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Acetaminophen; Dextromethorphan; Pseudoephedrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Acetaminophen; Guaifenesin; Phenylephrine: (Moderate) Due to the potential for additive increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors such as phenylephrine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Acetaminophen; Phenylephrine: (Moderate) Due to the potential for additive increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors such as phenylephrine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Acetaminophen; Pseudoephedrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Acrivastine; Pseudoephedrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Adagrasib: (Major) Concomitant use of adagrasib and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Alfuzosin: (Moderate) Concomitant use of atomoxetine and alfuzosin may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Amiodarone: (Major) QT prolongation has occurred during therapeutic use of atomoxetine and following overdose. Both atomoxetine and amiodarone are considered drugs with a possible risk of torsade de pointes (TdP); therefore, the combination should be used cautiously and with close monitoring. In addition, because atomoxetine is primarily metabolized by CYP2D6, concurrent use of CYP2D6 inhibitors such as amiodarone may theoretically increase the risk of atomoxetine-induced adverse effects. Monitor for adverse effects, such as dizziness, drowsiness, nervousness, insomnia, and cardiac effects (e.g., hypertension, increased pulse rate, QT prolongation).
Amisulpride: (Major) Monitor ECGs for QT prolongation when amisulpride is administered with atomoxetine. QT prolongation and torsade de pointes have been reported in patients receiving clofazimine in combination with QT prolonging medications. Amisulpride causes dose- and concentration- dependent QT prolongation.
Amoxicillin; Clarithromycin; Omeprazole: (Major) Concomitant use of atomoxetine and clarithromycin increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Amphetamine; Dextroamphetamine Salts: (Moderate) Monitor blood pressure during concomitant amphetamine; dextroamphetamine and atomoxetine use. Because of possible effects on blood pressure, atomoxetine should be used cautiously with other drugs that affect blood pressure, such as amphetamine; dextroamphetamine.
Anagrelide: (Moderate) Concomitant use of atomoxetine and anagrelide may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Apomorphine: (Moderate) Concomitant use of atomoxetine and apomorphine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Aripiprazole: (Moderate) Concomitant use of aripiprazole and atomoxetine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Arsenic Trioxide: (Major) Concomitant use of atomoxetine and arsenic trioxide increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Artemether; Lumefantrine: (Major) QT prolongation has occurred during therapeutic use of atomoxetine and following overdose. Both atomoxetine and artemether; lumefantrine are considered drugs with a possible risk of torsade de pointes (TdP); therefore, the combination should be used cautiously and with close monitoring. In addition, atomoxetine is primarily metabolized by CYP2D6 and lumefantrine is a strong CYP2D6 inhibitor. In children and adolescents up to 70 kg receiving a strong CYP2D6 inhibitor or who are known CYP2D6 poor metabolizers (PMs), atomoxetine should be initiated at 0.5 mg/kg/day and only increased to the usual target dose of 1.2 mg/kg/day if symptoms fail to improve after 4 weeks and the initial dose is well tolerated. In children and adolescents over 70 kg and adults receiving a strong CYP2D6 inhibitor or who are known CYP2D6 poor metabolizers, atomoxetine should be initiated at 40 mg/day and only increased to the usual target dose of 80 mg/day if symptoms fail to improve after 4 weeks and the initial dose is well tolerated. If concurrent use is necessary, monitor for adverse effects, such as dizziness, drowsiness, nervousness, insomnia, and cardiac effects (e.g., hypertension, increased pulse rate, QT prolongation).
Articaine; Epinephrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant epinephrine due to potential effects on blood pressure.
Asenapine: (Major) Concomitant use of asenapine and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Atazanavir; Cobicistat: (Moderate) The plasma concentrations of atomoxetine may be elevated when administered concurrently with cobicistat. Clinical monitoring for adverse effects, such as dizziness, drowsiness, hypertension, and other cardiac adverse events, is recommended during coadministration and dosage adjustments for atomoxetine may be warranted. Cobicistat is a CYP2D6 inhibitor and atomoxetine is a CYP2D6 substrate.
Atropine: (Major) Atropine and atomoxetine should be combined cautiously in patients with known cardiac disease. Atropine or scopolamine may alter the heart rate; the predominant clinical effect is sinus tachycardia. An additive effect on heart rate may occur as atomoxetine may elevate heart rate as well as blood pressure.
Atropine; Difenoxin: (Major) Atropine and atomoxetine should be combined cautiously in patients with known cardiac disease. Atropine or scopolamine may alter the heart rate; the predominant clinical effect is sinus tachycardia. An additive effect on heart rate may occur as atomoxetine may elevate heart rate as well as blood pressure.
Azithromycin: (Major) Concomitant use of azithromycin and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Bedaquiline: (Major) QT prolongation has occurred during therapeutic use of atomoxetine and following overdose. Atomoxetine is considered a drug with a possible risk of torsade de pointes (TdP). Drugs with a possible risk for QT prolongation and TdP that should be used cautiously and with close monitoring with atomoxetine include bedaquiline.
Benzphetamine: (Moderate) Amphetamines increase both systolic and diastolic blood pressure; atomoxetine has been reported to also increase blood pressure and heart rate, probably via inhibition of norepinephrine reuptake. Due to an additive pharmacodynamic effect, amphetamines and atomoxetine should be used together cautiously, particularly in patients with a history of cardiac disease. Consider monitoring heart rate and blood pressure at baseline and regularly throughout treatment if these agents must be used together.
Betrixaban: (Major) Monitor patients closely and promptly evaluate any signs or symptoms of bleeding if betrixaban and selective norepinephrine reuptake inhibitors (SNRIs) are used concomitantly. Coadministration of betrixaban and SNRIs may increase the risk of bleeding.
Bismuth Subcitrate Potassium; Metronidazole; Tetracycline: (Moderate) Concomitant use of metronidazole and atomoxetine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Bismuth Subsalicylate; Metronidazole; Tetracycline: (Moderate) Concomitant use of metronidazole and atomoxetine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Brompheniramine; Dextromethorphan; Phenylephrine: (Moderate) Due to the potential for additive increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors such as phenylephrine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Brompheniramine; Phenylephrine: (Moderate) Due to the potential for additive increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors such as phenylephrine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Brompheniramine; Pseudoephedrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Brompheniramine; Pseudoephedrine; Dextromethorphan: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Bupivacaine; Epinephrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant epinephrine due to potential effects on blood pressure.
Buprenorphine: (Major) Concomitant use of atomoxetine and buprenorphine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Buprenorphine; Naloxone: (Major) Concomitant use of atomoxetine and buprenorphine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Bupropion: (Major) Dosage reduction of atomoxetine is recommended in patients receiving bupropion due to the potential for increased atomoxetine exposure and related adverse effects. In children and adolescents up to 70 kg receiving bupropion, atomoxetine should be initiated at 0.5 mg/kg/day and only increased to the usual target dose of 1.2 mg/kg/day if symptoms fail to improve after 4 weeks and the initial dose is well-tolerated. In children and adolescents over 70 kg and adults receiving bupropion, atomoxetine should be initiated at 40 mg/day and only increased to the usual target dose of 80 mg/day if symptoms fail to improve after 4 weeks and the initial dose is well-tolerated. Bupropion is a strong CYP2D6 inhibitor; atomoxetine is a CYP2D6 substrate. Coadministration of a strong CYP2D6 inhibitor and atomoxetine in extensive metabolizers of CYP2D6, increased atomoxetine steady-state plasma concentrations by approximately 6 to 8-fold. This increase is similar to exposures observed in poor metabolizers. Concurrent use of a strong CYP2D6 inhibitor with atomoxetine in poor metabolizers is not expected to increase atomoxetine exposure.
Bupropion; Naltrexone: (Major) Dosage reduction of atomoxetine is recommended in patients receiving bupropion due to the potential for increased atomoxetine exposure and related adverse effects. In children and adolescents up to 70 kg receiving bupropion, atomoxetine should be initiated at 0.5 mg/kg/day and only increased to the usual target dose of 1.2 mg/kg/day if symptoms fail to improve after 4 weeks and the initial dose is well-tolerated. In children and adolescents over 70 kg and adults receiving bupropion, atomoxetine should be initiated at 40 mg/day and only increased to the usual target dose of 80 mg/day if symptoms fail to improve after 4 weeks and the initial dose is well-tolerated. Bupropion is a strong CYP2D6 inhibitor; atomoxetine is a CYP2D6 substrate. Coadministration of a strong CYP2D6 inhibitor and atomoxetine in extensive metabolizers of CYP2D6, increased atomoxetine steady-state plasma concentrations by approximately 6 to 8-fold. This increase is similar to exposures observed in poor metabolizers. Concurrent use of a strong CYP2D6 inhibitor with atomoxetine in poor metabolizers is not expected to increase atomoxetine exposure.
Cabotegravir; Rilpivirine: (Moderate) Concomitant use of atomoxetine and rilpivirine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP. The degree of QT prolongation associated with rilpivirine is not clinically significant when administered within the recommended dosage range; QT prolongation has been described at 3 times the maximum recommended dose.
Ceritinib: (Major) Avoid coadministration of ceritinib with atomoxetine if possible due to the risk of QT prolongation. If concomitant use is unavoidable, periodically monitor ECGs and electrolytes; an interruption of ceritinib therapy, dose reduction, or discontinuation of therapy may be necessary if QT prolongation occurs. Ceritinib causes concentration-dependent QT prolongation. Prolongation of the QT interval has occurred during therapeutic use of atomoxetine as well as following overdose.
Cetirizine; Pseudoephedrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Chlophedianol; Dexchlorpheniramine; Pseudoephedrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Chloroquine: (Major) Avoid coadministration of chloroquine with atomoxetine due to the increased risk of QT prolongation. If use together is necessary, obtain an ECG at baseline to assess initial QT interval and determine frequency of subsequent ECG monitoring, avoid any non-essential QT prolonging drugs, and correct electrolyte imbalances. Chloroquine is associated with an increased risk of QT prolongation and torsade de pointes (TdP); the risk of QT prolongation is increased with higher chloroquine doses. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose.
Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Due to the potential for additive increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors such as phenylephrine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Chlorpheniramine; Dihydrocodeine; Phenylephrine: (Moderate) Due to the potential for additive increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors such as phenylephrine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Chlorpheniramine; Ibuprofen; Pseudoephedrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Chlorpheniramine; Phenylephrine: (Moderate) Due to the potential for additive increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors such as phenylephrine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Chlorpheniramine; Pseudoephedrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Chlorpromazine: (Major) Concomitant use of atomoxetine and chlorpromazine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Ciprofloxacin: (Moderate) Concomitant use of atomoxetine and ciprofloxacin may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Cisapride: (Contraindicated) Avoid concomitant use of cisapride and atomoxetine due to an increased risk for torsade de pointes (TdP) and QT/QTc prolongation.
Citalopram: (Major) Concomitant use of atomoxetine and citalopram increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Clarithromycin: (Major) Concomitant use of atomoxetine and clarithromycin increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Clofazimine: (Moderate) Concomitant use of clofazimine and atomoxetine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Clomipramine: (Minor) Atomoxetine should be used cautiously with tricyclic antidepressants (TCAs) such as clomipramine as concurrent use may increase the risk of QT prolongation. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose. Tricyclic antidepressants share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
Clozapine: (Moderate) Concomitant use of atomoxetine and clozapine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Cobicistat: (Moderate) The plasma concentrations of atomoxetine may be elevated when administered concurrently with cobicistat. Clinical monitoring for adverse effects, such as dizziness, drowsiness, hypertension, and other cardiac adverse events, is recommended during coadministration and dosage adjustments for atomoxetine may be warranted. Cobicistat is a CYP2D6 inhibitor and atomoxetine is a CYP2D6 substrate.
Codeine; Guaifenesin; Pseudoephedrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Codeine; Phenylephrine; Promethazine: (Moderate) Concomitant use of atomoxetine and promethazine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP. (Moderate) Due to the potential for additive increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors such as phenylephrine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Codeine; Promethazine: (Moderate) Concomitant use of atomoxetine and promethazine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Crizotinib: (Major) Avoid coadministration of crizotinib with atomoxetine due to the risk of QT prolongation. If concomitant use is unavoidable, monitor ECGs for QT prolongation and monitor electrolytes. An interruption of therapy, dose reduction, or discontinuation of therapy may be necessary for crizotinib if QT prolongation occurs. Crizotinib has been associated with concentration-dependent QT prolongation. Prolongation of the QT interval has also occurred during therapeutic use of atomoxetine as well as following overdose.
Dacomitinib: (Major) A lower initial dose of atomoxetine is recommended in patients receiving dacomitinib due to the potential for increased atomoxetine exposure and related adverse effects. In children and adolescents up to 70 kg receiving dacomitinib, atomoxetine should be initiated at 0.5 mg/kg/day and only increased to the usual target dose of 1.2 mg/kg/day if symptoms fail to improve after 4 weeks and the initial dose is well tolerated. In children and adolescents over 70 kg and adults receiving dacomitinib, atomoxetine should be initiated at 40 mg/day and only increased to the usual target dose of 80 mg/day if symptoms fail to improve after 4 weeks and the initial dose is well tolerated. Monitor for adverse effects, such as dizziness, drowsiness, nervousness, insomnia, and cardiac effects (e.g., hypertension, increased pulse rate, QT prolongation). Dacomitinib is a strong CYP2D6 inhibitor; atomoxetine is a CYP2D6 substrate. Coadministration of a strong CYP2D6 inhibitor and atomoxetine in extensive metabolizers of CYP2D6, increased atomoxetine steady-state plasma concentrations by approximately 6 to 8-fold. This increase is similar to exposures observed in poor metabolizers. Concurrent use of a strong CYP2D6 inhibitor with atomoxetine in poor metabolizers is not expected to increase atomoxetine exposure.
Darunavir: (Moderate) The plasma concentrations of atomoxetine may be elevated when administered concurrently with darunavir. Clinical monitoring for adverse effects, such as dizziness, drowsiness, hypertension, and other cardiac adverse events, is recommended during coadministration and dosage adjustments for atomoxetine may be warranted. Darunavir is a CYP2D6 inhibitor, and atomoxetine is a CYP2D6 substrate.
Darunavir; Cobicistat: (Moderate) The plasma concentrations of atomoxetine may be elevated when administered concurrently with cobicistat. Clinical monitoring for adverse effects, such as dizziness, drowsiness, hypertension, and other cardiac adverse events, is recommended during coadministration and dosage adjustments for atomoxetine may be warranted. Cobicistat is a CYP2D6 inhibitor and atomoxetine is a CYP2D6 substrate. (Moderate) The plasma concentrations of atomoxetine may be elevated when administered concurrently with darunavir. Clinical monitoring for adverse effects, such as dizziness, drowsiness, hypertension, and other cardiac adverse events, is recommended during coadministration and dosage adjustments for atomoxetine may be warranted. Darunavir is a CYP2D6 inhibitor, and atomoxetine is a CYP2D6 substrate.
Darunavir; Cobicistat; Emtricitabine; Tenofovir alafenamide: (Moderate) The plasma concentrations of atomoxetine may be elevated when administered concurrently with cobicistat. Clinical monitoring for adverse effects, such as dizziness, drowsiness, hypertension, and other cardiac adverse events, is recommended during coadministration and dosage adjustments for atomoxetine may be warranted. Cobicistat is a CYP2D6 inhibitor and atomoxetine is a CYP2D6 substrate. (Moderate) The plasma concentrations of atomoxetine may be elevated when administered concurrently with darunavir. Clinical monitoring for adverse effects, such as dizziness, drowsiness, hypertension, and other cardiac adverse events, is recommended during coadministration and dosage adjustments for atomoxetine may be warranted. Darunavir is a CYP2D6 inhibitor, and atomoxetine is a CYP2D6 substrate.
Dasatinib: (Moderate) Concomitant use of atomoxetine and dasatinib may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Degarelix: (Moderate) Concomitant use of atomoxetine and androgen deprivation therapy (i.e., degarelix) may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Delavirdine: (Major) Because atomoxetine is primarily metabolized by CYP2D6, concurrent use of CYP2D6 inhibitors such as delavirdine may increase the risk of atomoxetine-induced adverse effects. Monitor for adverse effects, such as dizziness, drowsiness, nervousness, insomnia, and cardiac effects (e.g., hypertension, QT prolongation).
Desflurane: (Major) Concomitant use of atomoxetine and halogenated anesthetics increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Desipramine: (Minor) Atomoxetine should be used cautiously with tricyclic antidepressants (TCAs) such as desipramine as concurrent use may increase the risk of QT prolongation. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose. Tricyclic antidepressants share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
Desloratadine; Pseudoephedrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Desvenlafaxine: (Major) Desvenlafaxine is a serotonin norepinephrine reuptake inhibitor (SNRI) and atomoxetine selectively inhibits norepinephrine reuptake; the drugs have some additive pharmacology that may lead to increases in blood pressure or heart rate. Although clinical studies have shown that desvenlafaxine does not have a clinically relevant effect on CYP2D6 inhibition at doses of 100 mg/day, the manufacturer of desvenlafaxine recommends that the dose of primary substrates of CYP2D6, such as atomoxetine, be reduced by up to one-half if co-administered with desvenlafaxine 400 mg/day. Monitor for adverse effects, such as dizziness, drowsiness, nervousness, insomnia, and cardiac effects (e.g., hypertension, increased pulse rate, QT prolongation) during concurrent use.
Deutetrabenazine: (Minor) The risk of QT prolongation may be increased with coadministration of deutetrabenazine and atomoxetine. Deutetrabenazine may prolong the QT interval, but the degree of QT prolongation is not clinically significant when deutetrabenazine is administered within the recommended dosage range. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose.
Dexbrompheniramine; Pseudoephedrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Dexchlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Dexmedetomidine: (Minor) QT/QTc prolongation can occur with concomitant use of dexmedetomidine and atomoxetine although the risk of developing torsade de pointes (TdP) is low. Additional steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, may be considered in patients with additional risk factors for TdP.
Dextromethorphan; Bupropion: (Major) Dosage reduction of atomoxetine is recommended in patients receiving bupropion due to the potential for increased atomoxetine exposure and related adverse effects. In children and adolescents up to 70 kg receiving bupropion, atomoxetine should be initiated at 0.5 mg/kg/day and only increased to the usual target dose of 1.2 mg/kg/day if symptoms fail to improve after 4 weeks and the initial dose is well-tolerated. In children and adolescents over 70 kg and adults receiving bupropion, atomoxetine should be initiated at 40 mg/day and only increased to the usual target dose of 80 mg/day if symptoms fail to improve after 4 weeks and the initial dose is well-tolerated. Bupropion is a strong CYP2D6 inhibitor; atomoxetine is a CYP2D6 substrate. Coadministration of a strong CYP2D6 inhibitor and atomoxetine in extensive metabolizers of CYP2D6, increased atomoxetine steady-state plasma concentrations by approximately 6 to 8-fold. This increase is similar to exposures observed in poor metabolizers. Concurrent use of a strong CYP2D6 inhibitor with atomoxetine in poor metabolizers is not expected to increase atomoxetine exposure.
Dextromethorphan; Diphenhydramine; Phenylephrine: (Moderate) Due to the potential for additive increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors such as phenylephrine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Dextromethorphan; Guaifenesin; Phenylephrine: (Moderate) Due to the potential for additive increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors such as phenylephrine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Dextromethorphan; Guaifenesin; Pseudoephedrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Dextromethorphan; Quinidine: (Major) If possible, quinidine should be avoided in patients receiving atomoxetine. Coadministration of quinidine with atomoxetine may result in additive QT prolongation and increased exposure to atomoxetine. When administered as quinidine; dextromethorphan, coadministration with atomoxetine is contraindicated. Quinidine is a CYP2D6 inhibitor that is associated with QT prolongation and torsade de pointes (TdP). Atomoxetine is a CYP2D6 substrate. In children and adolescents up to 70 kg receiving quinidine, atomoxetine should be initiated at 0.5 mg/kg/day and only increased to the usual target dose of 1.2 mg/kg/day if symptoms fail to improve after 4 weeks and the initial dose is well tolerated. In children and adolescents over 70 kg and adults receiving quinidine, atomoxetine should be initiated at 40 mg/day and only increased to the usual target dose of 80 mg/day if symptoms fail to improve after 4 weeks and the initial dose is well tolerated. Coadministration of a strong CYP2D6 inhibitor and atomoxetine in extensive metabolizers of CYP2D6, increased atomoxetine steady-state plasma concentrations by approximately 6 to 8-fold. This increase is similar to exposures observed in poor metabolizers. Concurrent use of a strong CYP2D6 inhibitor with atomoxetine in poor metabolizers is not expected to increase atomoxetine exposure.
Diethylpropion: (Major) Atomoxetine, an inhibitor of norepinephrine reuptake used for treatment of ADHD, has been shown to increase heart rate and blood pressure. Diethylpropion also inhibits norepinephrine reuptake. The combination of atomoxetine with diethylpropion should be used extremely cautiously, if at all, due to the potential for serious increases in blood pressure and/or heart rate. If these agents must be used concomitantly, consider monitoring blood pressure and heart rate at baseline and regularly throughout treatment.
Diphenhydramine; Phenylephrine: (Moderate) Due to the potential for additive increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors such as phenylephrine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Diphenoxylate; Atropine: (Major) Atropine and atomoxetine should be combined cautiously in patients with known cardiac disease. Atropine or scopolamine may alter the heart rate; the predominant clinical effect is sinus tachycardia. An additive effect on heart rate may occur as atomoxetine may elevate heart rate as well as blood pressure.
Disopyramide: (Major) Concomitant use of disopyramide and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Dobutamine: (Major) Due to the potential for increases in blood pressure and heart rate, atomoxetine should be used cautiously with drugs with sympathomimetic activity, including dobutamine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if sympathomimetics are coadministered with atomoxetine.
Dofetilide: (Major) Concomitant use of atomoxetine and dofetilide increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Dolasetron: (Moderate) Concomitant use of atomoxetine and dolasetron may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Dolutegravir; Rilpivirine: (Moderate) Concomitant use of atomoxetine and rilpivirine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP. The degree of QT prolongation associated with rilpivirine is not clinically significant when administered within the recommended dosage range; QT prolongation has been described at 3 times the maximum recommended dose.
Donepezil: (Moderate) Concomitant use of atomoxetine and donepezil may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Donepezil; Memantine: (Moderate) Concomitant use of atomoxetine and donepezil may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Dopamine: (Major) Due to the potential for additive increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors, such as dopamine. Consider monitoring the patients blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Doxepin: (Minor) Atomoxetine should be used cautiously with tricyclic antidepressants (TCAs) such as doxepin as concurrent use may increase the risk of QT prolongation. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose. Tricyclic antidepressants share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
Dronedarone: (Contraindicated) Avoid concomitant use of dronedarone and atomoxetine due to an increased risk for torsade de pointes (TdP) and QT/QTc prolongation.
Droperidol: (Major) QT prolongation has occurred during therapeutic use of atomoxetine and following overdose. Atomoxetine is considered a drug with a possible risk of torsade de pointes (TdP). Drugs with a possible risk for QT prolongation and TdP that should be used cautiously and with close monitoring with atomoxetine include droperidol.
Droxidopa: (Major) Due to the potential for increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors such as droxidopa. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Edoxaban: (Major) Coadministration of edoxaban with other drugs that affect hemostasis, such as selective norepinephrine reuptake inhibitors (SNRIs), increases the risk of bleeding. If these drugs are administered together, instruct patients to monitor for signs and symptoms of bleeding, and to promptly report any bleeding events to their practitioner.
Efavirenz: (Moderate) Concomitant use of atomoxetine and efavirenz may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Efavirenz; Emtricitabine; Tenofovir Disoproxil Fumarate: (Moderate) Concomitant use of atomoxetine and efavirenz may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Efavirenz; Lamivudine; Tenofovir Disoproxil Fumarate: (Moderate) Concomitant use of atomoxetine and efavirenz may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Eliglustat: (Moderate) Concomitant use of atomoxetine and eliglustat may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Alafenamide: (Moderate) The plasma concentrations of atomoxetine may be elevated when administered concurrently with cobicistat. Clinical monitoring for adverse effects, such as dizziness, drowsiness, hypertension, and other cardiac adverse events, is recommended during coadministration and dosage adjustments for atomoxetine may be warranted. Cobicistat is a CYP2D6 inhibitor and atomoxetine is a CYP2D6 substrate.
Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Disoproxil Fumarate: (Moderate) The plasma concentrations of atomoxetine may be elevated when administered concurrently with cobicistat. Clinical monitoring for adverse effects, such as dizziness, drowsiness, hypertension, and other cardiac adverse events, is recommended during coadministration and dosage adjustments for atomoxetine may be warranted. Cobicistat is a CYP2D6 inhibitor and atomoxetine is a CYP2D6 substrate.
Emtricitabine; Rilpivirine; Tenofovir alafenamide: (Moderate) Concomitant use of atomoxetine and rilpivirine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP. The degree of QT prolongation associated with rilpivirine is not clinically significant when administered within the recommended dosage range; QT prolongation has been described at 3 times the maximum recommended dose.
Emtricitabine; Rilpivirine; Tenofovir Disoproxil Fumarate: (Moderate) Concomitant use of atomoxetine and rilpivirine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP. The degree of QT prolongation associated with rilpivirine is not clinically significant when administered within the recommended dosage range; QT prolongation has been described at 3 times the maximum recommended dose.
Encorafenib: (Major) Concomitant use of encorafenib and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Entrectinib: (Major) Concomitant use of entrectinib with atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Ephedrine: (Major) Due to the potential for increases in blood pressure and heart rate, atomoxetine should be used cautiously with drugs with significant vasopressor effects like ephedrine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Ephedrine; Guaifenesin: (Major) Due to the potential for increases in blood pressure and heart rate, atomoxetine should be used cautiously with drugs with significant vasopressor effects like ephedrine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Epinephrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant epinephrine due to potential effects on blood pressure.
Eribulin: (Major) Concomitant use of atomoxetine and eribulin increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Erythromycin: (Major) Concomitant use of atomoxetine and erythromycin increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Escitalopram: (Moderate) Concomitant use of atomoxetine and escitalopram may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Fexofenadine; Pseudoephedrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Fingolimod: (Moderate) Concomitant use of atomoxetine and fingolimod may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Flecainide: (Major) Concomitant use of atomoxetine and flecainide increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Fluconazole: (Moderate) Concomitant use of atomoxetine and fluconazole may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Fluoxetine: (Major) Monitor for evidence of QT prolongation and increased atomoxetine-related adverse effects during coadministration with fluoxetine. Dosage reduction of atomoxetine is recommended in patients receiving fluoxetine due to the potential for increased atomoxetine exposure and related adverse effects. In children and adolescents up to 70 kg receiving fluoxetine, atomoxetine should be initiated at 0.5 mg/kg/day and only increased to the usual target dose of 1.2 mg/kg/day if symptoms fail to improve after 4 weeks and the initial dose is well-tolerated. In children and adolescents over 70 kg and adults receiving fluoxetine, atomoxetine should be initiated at 40 mg/day and only increased to the usual target dose of 80 mg/day if symptoms fail to improve after 4 weeks and the initial dose is well-tolerated. Fluoxetine is a strong CYP2D6 inhibitor; atomoxetine is a CYP2D6 substrate. Coadministration of a strong CYP2D6 inhibitor and atomoxetine in extensive metabolizers of CYP2D6, increased atomoxetine steady-state plasma concentrations by approximately 6 to 8-fold. This increase is similar to exposures observed in poor metabolizers. Concurrent use of a strong CYP2D6 inhibitor with atomoxetine in poor metabolizers is not expected to increase atomoxetine exposure.
Fluphenazine: (Minor) Use caution if atomoxetine is administered with fluphenazine as concurrent use may increase the risk of QT prolongation. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose. Fluphenazine is also associated with a possible risk for QT prolongation.
Fluvoxamine: (Minor) Coadminister atomoxetine and fluvoxamine with caution as concurrent use may increase the risk of QT prolongation. There may be an increased risk for QT prolongation and torsade de pointes (TdP) during concurrent use of these medications. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose. QT prolongation and TdP have been reported during post-marketing use of fluvoxamine.
Foscarnet: (Major) Concomitant use of atomoxetine and foscarnet increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Fostemsavir: (Moderate) Concomitant use of atomoxetine and fostemsavir may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP. The degree of QT prolongation associated with fostemsavir is not clinically significant when administered within the recommended dosage range; QT prolongation has been described at 4 times the recommended daily dose.
Gemifloxacin: (Moderate) Concomitant use of atomoxetine and gemifloxacin may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Gemtuzumab Ozogamicin: (Moderate) Concomitant use of atomoxetine and gemtuzumab ozogamicin may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Gilteritinib: (Moderate) Concomitant use of atomoxetine and gilteritinib may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Givosiran: (Major) Avoid concomitant use of givosiran and atomoxetine due to the risk of increased atomoxetine-related adverse reactions. If use is necessary, consider reducing the atomoxetine dose. Atomoxetine is a sensitive CYP2D6 substrate. Givosiran may moderately reduce hepatic CYP2D6 enzyme activity because of its pharmacological effects on the hepatic heme biosynthesis pathway.
Glasdegib: (Major) Avoid coadministration of glasdegib with atomoxetine due to the potential for additive QT prolongation. If coadministration cannot be avoided, monitor patients for increased risk of QT prolongation with increased frequency of ECG monitoring. Glasdegib therapy may result in QT prolongation and ventricular arrhythmias including ventricular fibrillation and ventricular tachycardia. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose.
Goserelin: (Moderate) Concomitant use of atomoxetine and androgen deprivation therapy (i.e., goserelin) may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Granisetron: (Moderate) Concomitant use of atomoxetine and granisetron may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Guaifenesin; Phenylephrine: (Moderate) Due to the potential for additive increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors such as phenylephrine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Guaifenesin; Pseudoephedrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Halogenated Anesthetics: (Major) Concomitant use of atomoxetine and halogenated anesthetics increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Haloperidol: (Moderate) Concomitant use of atomoxetine and haloperidol may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP. The intravenous route may carry a higher risk for haloperidol-induced QT/QTc prolongation than other routes of administration.
Histrelin: (Moderate) Concomitant use of atomoxetine and androgen deprivation therapy (i.e., histrelin) may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Hydrocodone; Pseudoephedrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Hydroxychloroquine: (Major) Concomitant use of hydroxychloroquine and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Hydroxyzine: (Moderate) Concomitant use of atomoxetine and hydroxyzine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Ibuprofen; Pseudoephedrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Ibutilide: (Major) Concomitant use of ibutilide and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Iloperidone: (Major) Concomitant use of iloperidone and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk

for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Imatinib: (Major) Administer atomoxetine and imatinib, STI-571 with caution. Because atomoxetine is primarily metabolized by CYP2D6, concurrent use of strong CYP2D6 inhibitors such as imatinib may theoretically increase the risk of atomoxetine-induced adverse effects. In children and adolescents up to 70 kg receiving a strong CYP2D6 inhibitor or who are known CYP2D6 poor metabolizers (PMs), atomoxetine should be initiated at 0.5 mg/kg/day and only increased to the usual target dose of 1.2 mg/kg/day if symptoms fail to improve after 4 weeks and the initial dose is well tolerated. In children and adolescents over 70 kg and adults receiving a strong CYP2D6 inhibitor or who are known CYP2D6 poor metabolizers, atomoxetine should be initiated at 40 mg/day and only increased to the usual target dose of 80 mg/day if symptoms fail to improve after 4 weeks and the initial dose is well tolerated. If concurrent use is necessary, monitor for adverse effects, such as dizziness, drowsiness, nervousness, insomnia, and cardiac effects (e.g., hypertension, increased pulse rate, QT prolongation) during concurrent use.
Imipramine: (Minor) Atomoxetine should be used cautiously with tricyclic antidepressants (TCAs) such as imipramine as concurrent use may increase the risk of QT prolongation. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose. Tricyclic antidepressants share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
Inotuzumab Ozogamicin: (Major) Avoid coadministration of inotuzumab ozogamicin with atomoxetine due to the potential for additive QT prolongation and risk of torsade de pointes (TdP). If coadministration is unavoidable, obtain an ECG and serum electrolytes prior to the start of treatment, after treatment initiation, and periodically during treatment. Inotuzumab has been associated with QT interval prolongation. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose.
Iobenguane I 131: (Major) Discontinue selective norepinephrine reuptake inhibitors for at least 5 half-lives before the administration of the dosimetry dose or a therapeutic dose of iobenguane I-131. Do not restart selective norepinephrine reuptake inhibitors until at least 7 days after each iobenguane I-131 dose. Drugs that reduce catecholamine uptake or deplete catecholamine stores, such as selective norepinephrine reuptake inhibitors, may interfere with iobenguane I-131 uptake into cells and interfere with dosimetry calculations resulting in altered iobenguane I-131 efficacy.
Isocarboxazid: (Contraindicated) The use of selective norepinephrine reuptake inhibitors with monoamine oxidase inhibitors (MAOIs) is contraindicated. At least 2 weeks should elapse between the discontinuation of a drug with MAO inhibiting activity and the start of selective norepinephrine reuptake inhibitors, or vice-versa. Selective norepinephrine reuptake inhibitors potentiate certain catecholamines by inhibiting neuronal reuptake. Reactions with MAOIs may include confusion, seizures, and severe hypertension as well as less severe symptoms.
Isoflurane: (Major) Concomitant use of atomoxetine and halogenated anesthetics increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Isoniazid, INH: (Contraindicated) The use of atomoxetine with monoamine oxidase inhibitors (MAOIs) is contraindicated. Isoniazid (INH) possesses weak MAO-inhibiting activity. Atomoxetine is one of the selective norepinephrine reuptake inhibitors. Since norepinephrine is deaminated by monoamine oxidase, administration of drugs that inhibit this enzyme concurrently with atomoxetine can lead to serious reactions. These reactions may include confusion, seizures, and severe hypertension as well as less severe symptoms. Atomoxetine should not be taken with any MAOI, or within 2 weeks after discontinuing a MAOI and vice versa.
Isoniazid, INH; Pyrazinamide, PZA; Rifampin: (Contraindicated) The use of atomoxetine with monoamine oxidase inhibitors (MAOIs) is contraindicated. Isoniazid (INH) possesses weak MAO-inhibiting activity. Atomoxetine is one of the selective norepinephrine reuptake inhibitors. Since norepinephrine is deaminated by monoamine oxidase, administration of drugs that inhibit this enzyme concurrently with atomoxetine can lead to serious reactions. These reactions may include confusion, seizures, and severe hypertension as well as less severe symptoms. Atomoxetine should not be taken with any MAOI, or within 2 weeks after discontinuing a MAOI and vice versa.
Isoniazid, INH; Rifampin: (Contraindicated) The use of atomoxetine with monoamine oxidase inhibitors (MAOIs) is contraindicated. Isoniazid (INH) possesses weak MAO-inhibiting activity. Atomoxetine is one of the selective norepinephrine reuptake inhibitors. Since norepinephrine is deaminated by monoamine oxidase, administration of drugs that inhibit this enzyme concurrently with atomoxetine can lead to serious reactions. These reactions may include confusion, seizures, and severe hypertension as well as less severe symptoms. Atomoxetine should not be taken with any MAOI, or within 2 weeks after discontinuing a MAOI and vice versa.
Itraconazole: (Moderate) Concomitant use of atomoxetine and itraconazole may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Ivosidenib: (Major) Avoid coadministration of ivosidenib with atomoxetine due to an increased risk of QT prolongation. If concomitant use is unavoidable, monitor ECGs for QTc prolongation and monitor electrolytes; correct any electrolyte abnormalities as clinically appropriate. An interruption of therapy and dose reduction of ivosidenib may be necessary if QT prolongation occurs. Prolongation of the QTc interval and ventricular arrhythmias have been reported in patients treated with ivosidenib. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose.
Ketoconazole: (Contraindicated) Avoid concomitant use of ketoconazole and atomoxetine due to an increased risk for torsade de pointes (TdP) and QT/QTc prolongation. QT prolongation has been reported postmarketing with atomoxetine; ketoconazole is associated with QT prolongation and TdP.
Lansoprazole; Amoxicillin; Clarithromycin: (Major) Concomitant use of atomoxetine and clarithromycin increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Lapatinib: (Moderate) Concomitant use of atomoxetine and lapatinib may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Lefamulin: (Major) Avoid coadministration of lefamulin with atomoxetine as concurrent use may increase the risk of QT prolongation. If coadministration cannot be avoided, monitor ECG during treatment. Lefamulin has a concentration dependent QTc prolongation effect. The pharmacodynamic interaction potential to prolong the QT interval of the electrocardiogram between lefamulin and other drugs that effect cardiac conduction is unknown. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose.
Lenvatinib: (Major) Concomitant use of lenvatinib and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Leuprolide: (Moderate) Concomitant use of atomoxetine and androgen deprivation therapy (i.e., leuprolide) may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Leuprolide; Norethindrone: (Moderate) Concomitant use of atomoxetine and androgen deprivation therapy (i.e., leuprolide) may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Levofloxacin: (Moderate) Concomitant use of levofloxacin and atomoxetine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Levoketoconazole: (Contraindicated) Avoid concomitant use of ketoconazole and atomoxetine due to an increased risk for torsade de pointes (TdP) and QT/QTc prolongation. QT prolongation has been reported postmarketing with atomoxetine; ketoconazole is associated with QT prolongation and TdP.
Levomilnacipran: (Moderate) Levomilnacipran is a serotonin norepinephrine reuptake inhibitor (SNRI) and atomoxetine selectively inhibits norepinephrine reuptake; the drugs have some additive pharmacology that may lead to increases in blood pressure or heart rate.
Lidocaine; Epinephrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant epinephrine due to potential effects on blood pressure.
Linezolid: (Major) Linezolid is an antibiotic that is also a reversible, non-selective MAO inhibitor. Atomoxetine should not be taken with any MAOI, or within 2 weeks after discontinuing a MAOI and vice versa. Atomoxetine, a selective norepinephrine reuptake inhibitor, is contraindicated with the use of any MAOI due to the potential for serious reactions. Clinically, the potential for interaction between linezolid and atomoxetine has not been studied.
Lithium: (Moderate) Concomitant use of atomoxetine and lithium may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Lofexidine: (Moderate) Concomitant use of atomoxetine and lofexidine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Loperamide: (Moderate) Concomitant use of atomoxetine and loperamide may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Loperamide; Simethicone: (Moderate) Concomitant use of atomoxetine and loperamide may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Lopinavir; Ritonavir: (Major) Concomitant use of lopinavir and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Loratadine; Pseudoephedrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Macimorelin: (Major) Avoid concurrent administration of macimorelin with drugs that prolong the QT interval, such as atomoxetine. Use of these drugs together may increase the risk of developing torsade de pointes-type ventricular tachycardia. Sufficient washout time of drugs that are known to prolong the QT interval prior to administration of macimorelin is recommended. Treatment with macimorelin has been associated with an increase in the corrected QT (QTc) interval. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose.
Maprotiline: (Minor) Use caution when administering atomoxetine with maprotiline as concurrent use may increase the risk of QT prolongation. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose. Maprotiline has been reported to prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). Cases of long QT syndrome and torsade de pointes (TdP) tachycardia have been described with maprotiline use, but rarely occur when the drug is used alone in normal prescribed doses and in the absence of other known risk factors for QT prolongation. Limited data are available regarding the safety of maprotiline in combination with other QT-prolonging drugs.
Mefloquine: (Moderate) Concomitant use of atomoxetine and mefloquine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Methadone: (Major) Concomitant use of methadone and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Methamphetamine: (Major) Due to the potential for increases in blood pressure and heart rate, atomoxetine should be used cautiously with drugs with sympathomimetic activity such as methamphetamine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if sympathomimetics are coadministered with atomoxetine.
Methscopolamine: (Moderate) Methscopolamine and atomoxetine should be combined cautiously in patients with known cardiac disease. Methscopolamine may alter the heart rate; the predominant clinical effect is sinus tachycardia. An additive effect on heart rate may occur as atomoxetine may elevate heart rate as well as blood pressure.
Metronidazole: (Moderate) Concomitant use of metronidazole and atomoxetine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Midodrine: (Major) Due to the potential for additive increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors such as midodrine. Consider monitoring the patients blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Midostaurin: (Major) Concomitant use of midostaurin and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Mifepristone: (Major) Concomitant use of atomoxetine and mifepristone increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Mirabegron: (Moderate) Because atomoxetine is primarily metabolized by CYP2D6, concurrent use of CYP2D6 inhibitors such as mirabegron may theoretically increase the risk of atomoxetine-induced adverse effects. Monitor for adverse effects, such as dizziness, drowsiness, nervousness, insomnia, and cardiac effects (e.g., hypertension, QT prolongation).
Mirtazapine: (Moderate) Concomitant use of atomoxetine and mirtazapine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Mobocertinib: (Major) Concomitant use of mobocertinib and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Monoamine oxidase inhibitors: (Contraindicated) The use of selective norepinephrine reuptake inhibitors with monoamine oxidase inhibitors (MAOIs) is contraindicated. At least 2 weeks should elapse between the discontinuation of a drug with MAO inhibiting activity and the start of selective norepinephrine reuptake inhibitors, or vice-versa. Selective norepinephrine reuptake inhibitors potentiate certain catecholamines by inhibiting neuronal reuptake. Reactions with MAOIs may include confusion, seizures, and severe hypertension as well as less severe symptoms.
Moxifloxacin: (Major) Concomitant use of moxifloxacin and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Naproxen; Pseudoephedrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Nicardipine: (Moderate) Monitor for adverse effects, such as dizziness, drowsiness, nervousness, insomnia, and cardiac effects (e.g., hypertension, increased pulse rate, QT prolongation) if concurrent use of nicardipine and atomoxetine is necessary. Because atomoxetine is primarily metabolized by CYP2D6, concurrent use of CYP2D6 inhibitors such as nicardipine may theoretically increase the risk of atomoxetine-induced adverse effects.
Nilotinib: (Major) Concomitant use of atomoxetine and nilotinib increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Nitroglycerin: (Minor) Nitroglycerin can cause hypotension. This action may be additive with other agents that can cause hypotension such as antidepressants. Patients should be monitored more closely for hypotension if nitroglycerin is used concurrently with antidepressants.
Norepinephrine: (Moderate) Due to the potential for additive increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors such as norepinephrine. Consider monitoring blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Nortriptyline: (Minor) Atomoxetine should be used cautiously with tricyclic antidepressants (TCAs) such as nortriptyline as concurrent use may increase the risk of QT prolongation. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose. Tricyclic antidepressants share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
Ofloxacin: (Moderate) Concomitant use of ofloxacin and atomoxetine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Olanzapine: (Moderate) Concomitant use of atomoxetine and olanzapine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Olanzapine; Fluoxetine: (Major) Monitor for evidence of QT prolongation and increased atomoxetine-related adverse effects during coadministration with fluoxetine. Dosage reduction of atomoxetine is recommended in patients receiving fluoxetine due to the potential for increased atomoxetine exposure and related adverse effects. In children and adolescents up to 70 kg receiving fluoxetine, atomoxetine should be initiated at 0.5 mg/kg/day and only increased to the usual target dose of 1.2 mg/kg/day if symptoms fail to improve after 4 weeks and the initial dose is well-tolerated. In children and adolescents over 70 kg and adults receiving fluoxetine, atomoxetine should be initiated at 40 mg/day and only increased to the usual target dose of 80 mg/day if symptoms fail to improve after 4 weeks and the initial dose is well-tolerated. Fluoxetine is a strong CYP2D6 inhibitor; atomoxetine is a CYP2D6 substrate. Coadministration of a strong CYP2D6 inhibitor and atomoxetine in extensive metabolizers of CYP2D6, increased atomoxetine steady-state plasma concentrations by approximately 6 to 8-fold. This increase is similar to exposures observed in poor metabolizers. Concurrent use of a strong CYP2D6 inhibitor with atomoxetine in poor metabolizers is not expected to increase atomoxetine exposure. (Moderate) Concomitant use of atomoxetine and olanzapine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Olanzapine; Samidorphan: (Moderate) Concomitant use of atomoxetine and olanzapine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Ondansetron: (Major) Concomitant use of ondansetron and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Oritavancin: (Moderate) Atomoxetine is metabolized by CYP2D6; oritavancin is a weak CYP2D6 inducer. Plasma concentrations and efficacy of atomoxetine may be reduced if these drugs are administered concurrently.
Osilodrostat: (Moderate) Concomitant use of atomoxetine and osilodrostat may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Osimertinib: (Major) Concomitant use of osimertinib and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Oxaliplatin: (Major) Concomitant use of oxaliplatin and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Ozanimod: (Major) In general, do not initiate ozanimod in patients taking atomoxetine due to the risk of additive bradycardia, QT prolongation, and torsade de pointes (TdP). Increased blood pressure or hypertensive crisis may also be possible, as atomoxetine may increase heart rate and blood pressure. If treatment initiation is considered, seek advice from a cardiologist. Ozanimod initiation may result in a transient decrease in heart rate and atrioventricular conduction delays. Ozanimod has not been studied in patients taking concurrent QT prolonging drugs; however, QT prolonging drugs have been associated with TdP in patients with bradycardia. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose.
Pacritinib: (Major) Concomitant use of pacritinib and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Paliperidone: (Major) Concomitant use of paliperidone and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Panobinostat: (Major) The co-administration of panobinostat and atomoxetine is not recommended. If concomitant use cannot be avoided, closely monitor patients for signs and symptoms of atomoxetine toxicity. Panobinostat is a CYP2D6 inhibitor and atomoxetine is a CYP2D6-sensitive substrate. When a single-dose of a CYP2D6-sensitive substrate was administered after 3 doses of panobinostat (20 mg given on days 3, 5, and 8), the CYP2D6 substrate Cmax increased by 20% to 200% and the AUC value increased by 20% to 130% in 14 patients with advanced cancer; exposure was highly variable (coefficient of variance > 150%).
Paroxetine: (Major) Dosage reduction of atomoxetine is recommended in patients receiving paroxetine due to the potential for increased atomoxetine exposure and related adverse effects. In children and adolescents up to 70 kg receiving paroxetine, atomoxetine should be initiated at 0.5 mg/kg/day and only increased to the usual target dose of 1.2 mg/kg/day if symptoms fail to improve after 4 weeks and the initial dose is well-tolerated. In children and adolescents over 70 kg and adults receiving paroxetine, atomoxetine should be initiated at 40 mg/day and only increased to the usual target dose of 80 mg/day if symptoms fail to improve after 4 weeks and the initial dose is well-tolerated. Paroxetine is a strong CYP2D6 inhibitor; atomoxetine is a CYP2D6 substrate. Coadministration of a strong CYP2D6 inhibitor and atomoxetine in extensive metabolizers of CYP2D6 increased atomoxetine steady-state plasma concentrations by approximately 6 to 8-fold. This increase is similar to exposures observed in poor metabolizers. Concurrent use of a strong CYP2D6 inhibitor with atomoxetine in poor metabolizers is not expected to increase atomoxetine exposure.
Pasireotide: (Moderate) Concomitant use of atomoxetine and pasireotide may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Pazopanib: (Major) Concomitant use of pazopanib and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Peginterferon Alfa-2b: (Moderate) Monitor for adverse effects associated with increased exposure to atomoxetine if peginterferon alfa-2b is coadministered. Peginterferon alfa-2b is a CYP2D6 inhibitor, while atomoxetine is a CYP2D6 substrate.
Pentamidine: (Major) Concomitant use of pentamidine and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Perphenazine: (Minor) Use caution when administering atomoxetine with perphenazine as concurrent use may increase the risk of QT prolongation. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose. Additionally, perphenazine is associated with a possible risk for QT prolongation.
Perphenazine; Amitriptyline: (Minor) Use caution when administering atomoxetine with perphenazine as concurrent use may increase the risk of QT prolongation. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose. Additionally, perphenazine is associated with a possible risk for QT prolongation.
Phendimetrazine: (Major) Due to the potential for increases in blood pressure and heart rate, atomoxetine should be used cautiously with drugs with sympathomimetic activity such as phendimetrazine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if sympathomimetics are coadministered with atomoxetine.
Phenelzine: (Contraindicated) The use of selective norepinephrine reuptake inhibitors with monoamine oxidase inhibitors (MAOIs) is contraindicated. At least 2 weeks should elapse between the discontinuation of a drug with MAO inhibiting activity and the start of selective norepinephrine reuptake inhibitors, or vice-versa. Selective norepinephrine reuptake inhibitors potentiate certain catecholamines by inhibiting neuronal reuptake. Reactions with MAOIs may include confusion, seizures, and severe hypertension as well as less severe symptoms.
Phenobarbital; Hyoscyamine; Atropine; Scopolamine: (Major) Atropine and atomoxetine should be combined cautiously in patients with known cardiac disease. Atropine or scopolamine may alter the heart rate; the predominant clinical effect is sinus tachycardia. An additive effect on heart rate may occur as atomoxetine may elevate heart rate as well as blood pressure. (Moderate) Scopolamine and atomoxetine should be combined cautiously in patients with known cardiac disease. Scopolamine may alter the heart rate; the predominant clinical effect is sinus tachycardia. An additive effect on heart rate may occur as atomoxetine may elevate heart rate as well as blood pressure.
Phentermine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant phentermine due to potential effects on blood pressure.
Phentermine; Topiramate: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant phentermine due to potential effects on blood pressure.
Phenylephrine: (Moderate) Due to the potential for additive increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors such as phenylephrine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Pimavanserin: (Major) Concomitant use of pimavanserin and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Pimozide: (Contraindicated) Avoid concomitant use of pimozide and atomoxetine due to an increased risk for torsade de pointes (TdP) and QT/QTc prolongation.
Pitolisant: (Major) Concomitant use of pitolisant and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Ponesimod: (Major) In general, do not initiate ponesimod in patients taking atomoxetine due to the risk of additive bradycardia, QT prolongation, and torsade de pointes (TdP). If treatment initiation is considered, seek advice from a cardiologist. Ponesimod initiation may result in a transient decrease in heart rate and atrioventricular conduction delays. Ponesimod has not been studied in patients taking concurrent QT prolonging drugs; however, QT prolonging drugs have been associated with TdP in patients with bradycardia. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose.
Posaconazole: (Moderate) Concomitant use of atomoxetine and posaconazole may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Prilocaine; Epinephrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant epinephrine due to potential effects on blood pressure.
Primaquine: (Moderate) Concomitant use of atomoxetine and primaquine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Procainamide: (Major) Concomitant use of procainamide and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Procarbazine: (Contraindicated) Procarbazine is a weak monoamine oxidase inhibitor (MAOI). The use of atomoxetine with monoamine oxidase inhibitors (MAOIs) is contraindicated. Atomoxetine should not be taken with any MAOI, or within 2 weeks after discontinuing a MAOI and vice versa. Atomoxetine is one of the selective norepinephrine reuptake inhibitors (SNRIs). Since norepinephrine is deaminated by monoamine oxidase, administration of drugs that inhibit this enzyme concurrently with atomoxetine can lead to serious reactions. These reactions may include confusion, seizures, and severe hypertension as well as less severe symptoms.
Prochlorperazine: (Minor) Use atomoxetine with caution in combination with prochlorperazine as concurrent use may increase the risk of QT prolongation. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose. Prochlorperazine is also associated with a possible risk for QT prolongation.
Promethazine: (Moderate) Concomitant use of atomoxetine and promethazine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Promethazine; Dextromethorphan: (Moderate) Concomitant use of atomoxetine and promethazine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Promethazine; Phenylephrine: (Moderate) Concomitant use of atomoxetine and promethazine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP. (Moderate) Due to the potential for additive increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors such as phenylephrine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if vasopressors are coadministered with atomoxetine.
Propafenone: (Major) Concomitant use of propafenone and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Protriptyline: (Minor) Atomoxetine should be used cautiously with tricyclic antidepressants (TCAs) such as protriptyline as concurrent use may increase the risk of QT prolongation. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose. Tricyclic antidepressants share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
Pseudoephedrine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Pseudoephedrine; Triprolidine: (Moderate) Use atomoxetine with caution and monitor blood pressure in patients receiving concomitant pseudoephedrine due to potential effects on blood pressure.
Quetiapine: (Major) Concomitant use of atomoxetine and quetiapine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Quinidine: (Major) If possible, quinidine should be avoided in patients receiving atomoxetine. Coadministration of quinidine with atomoxetine may result in additive QT prolongation and increased exposure to atomoxetine. When administered as quinidine; dextromethorphan, coadministration with atomoxetine is contraindicated. Quinidine is a CYP2D6 inhibitor that is associated with QT prolongation and torsade de pointes (TdP). Atomoxetine is a CYP2D6 substrate. In children and adolescents up to 70 kg receiving quinidine, atomoxetine should be initiated at 0.5 mg/kg/day and only increased to the usual target dose of 1.2 mg/kg/day if symptoms fail to improve after 4 weeks and the initial dose is well tolerated. In children and adolescents over 70 kg and adults receiving quinidine, atomoxetine should be initiated at 40 mg/day and only increased to the usual target dose of 80 mg/day if symptoms fail to improve after 4 weeks and the initial dose is well tolerated. Coadministration of a strong CYP2D6 inhibitor and atomoxetine in extensive metabolizers of CYP2D6, increased atomoxetine steady-state plasma concentrations by approximately 6 to 8-fold. This increase is similar to exposures observed in poor metabolizers. Concurrent use of a strong CYP2D6 inhibitor with atomoxetine in poor metabolizers is not expected to increase atomoxetine exposure.
Quinine: (Major) QT prolongation has occurred during therapeutic use of atomoxetine and following overdose. Both atomoxetine and quinine are considered drugs with a possible risk of torsade de pointes (TdP); therefore, the combination should be used cautiously and with close monitoring. In addition, because atomoxetine is primarily metabolized by CYP2D6, concurrent use of CYP2D6 inhibitors such as quinine may theoretically increase the risk of atomoxetine-induced adverse effects. Monitor for adverse effects, such as dizziness, drowsiness, nervousness, insomnia, and cardiac effects (e.g., hypertension, increased pulse rate, QT prolongation).
Quizartinib: (Major) Concomitant use of quizartinib and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Racepinephrine: (Major) Due to the potential for additive increases in blood pressure and heart rate, atomoxetine should be used cautiously with sympathomimetic agents such as racepinephrine. If a patient is taking atomoxetine, then they should seek health care professional advice prior to the use of racepinephrine. Consider monitoring the patients blood pressure and heart rate at baseline and regularly if racepinephrine inhalation is medically necessary in a patient coadministered atomoxetine.
Ranolazine: (Moderate) Concomitant use of atomoxetine and ranolazine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Rasagiline: (Contraindicated) The use of selective norepinephrine reuptake inhibitors (such as atomoxetine) with monoamine oxidase inhibitors (MAOIs) is contraindicated. At least 2 weeks should elapse between the discontinuation of a drug with MAO inhibiting activity and the start of selective norepinephrine reuptake inhibitors, or vice-versa. Selective norepinephrine reuptake inhibitors potentiate certain catecholamines by inhibiting neuronal reuptake. Reactions with MAOIs may include confusion, seizures, and severe hypertension as well as less severe symptoms.
Relugolix: (Moderate) Concomitant use of atomoxetine and androgen deprivation therapy (i.e., relugolix) may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Relugolix; Estradiol; Norethindrone acetate: (Moderate) Concomitant use of atomoxetine and androgen deprivation therapy (i.e., relugolix) may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Ribociclib: (Major) Concomitant use of ribociclib and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Ribociclib; Letrozole: (Major) Concomitant use of ribociclib and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Rilpivirine: (Moderate) Concomitant use of atomoxetine and rilpivirine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP. The degree of QT prolongation associated with rilpivirine is not clinically significant when administered within the recommended dosage range; QT prolongation has been described at 3 times the maximum recommended dose.
Risperidone: (Moderate) Concomitant use of atomoxetine and risperidone may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Rivaroxaban: (Major) Coadministration of rivaroxaban with other drugs that affect hemostasis, such as selective norepinephrine reuptake inhibitors (SNRIs), increases the risk of bleeding. If these drugs are administered together, instruct patients to monitor for signs and symptoms of bleeding, and to promptly report any bleeding events to their practitioner.
Rolapitant: (Major) Use caution if atomoxetine and rolapitant are used concurrently, and monitor for atomoxetine-related adverse effects. Atomoxetine is a CYP2D6 substrate and rolapitant is a moderate CYP2D6 inhibitor; the inhibitory effect of rolapitant is expected to persist beyond 28 days for an unknown duration. Exposure to another CYP2D6 substrate, following a single dose of rolapitant increased about 3-fold on Days 8 and Day 22. The inhibition of CYP2D6 persisted on Day 28 with a 2.3-fold increase in the CYP2D6 substrate concentrations, the last time point measured.
Romidepsin: (Moderate) Concomitant use of atomoxetine and romidepsin may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Safinamide: (Contraindicated) The use of selective norepinephrine reuptake inhibitors (such as atomoxetine) with monoamine oxidase inhibitors (MAOIs) is contraindicated. At least 2 weeks should elapse between the discontinuation of a drug with MAO inhibiting activity and the start of selective norepinephrine reuptake inhibitors, or vice-versa. Selective norepinephrine reuptake inhibitors potentiate certain catecholamines by inhibiting neuronal reuptake. Reactions with MAOIs may include confusion, seizures, and severe hypertension as well as less severe symptoms.
Saquinavir: (Major) Concomitant use of saquinavir and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Scopolamine: (Moderate) Scopolamine and atomoxetine should be combined cautiously in patients with known cardiac disease. Scopolamine may alter the heart rate; the predominant clinical effect is sinus tachycardia. An additive effect on heart rate may occur as atomoxetine may elevate heart rate as well as blood pressure.
Selegiline: (Contraindicated) Selective norepinephrine reuptake inhibitors are contraindicated for use with selegiline because of a possible increased risk of hypertensive crisis. At least 14 days should elapse between discontinuation of selegiline and initiation of treatment with a selective norepinephrine reuptake inhibitor. After stopping treatment with the reuptake inhibitor, a time period equal to 4 to 5 half-lives of the reuptake inhibitor or any active metabolite should elapse before starting therapy with selegiline.
Selpercatinib: (Major) Concomitant use of selpercatinib and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Sertraline: (Moderate) Concomitant use of atomoxetine and sertraline may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP. The degree of QT prolongation associated with sertraline is not clinically significant when administered within the recommended dosage range; QT prolongation has been described at 2 times the maximum recommended dose.
Sevoflurane: (Major) Concomitant use of atomoxetine and halogenated anesthetics increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Siponimod: (Major) Concomitant use of siponimod and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Sodium Stibogluconate: (Moderate) Concomitant use of sodium stibogluconate and atomoxetine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Solifenacin: (Moderate) Concomitant use of atomoxetine and solifenacin may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Sorafenib: (Major) Concomitant use of sorafenib and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Sotalol: (Major) Concomitant use of atomoxetine and sotalol increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Sunitinib: (Moderate) Concomitant use of atomoxetine and sunitinib may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Tacrolimus: (Moderate) Concomitant use of atomoxetine and tacrolimus may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Tamoxifen: (Moderate) Concomitant use of tamoxifen and atomoxetine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Tapentadol: (Major) Caution is advised when tapentadol is coadministered with selective norepinephrine reuptake inhibitors. The combined use of these drugs may result in excessive concentrations of norepinephrine, increasing the risk of adverse cardiac effects. If concomitant treatment is clinically warranted, careful observation of the patient is advised, especially during initiation of the second therapy and after dosage adjustments (increases) of either agent.
Telavancin: (Moderate) Concomitant use of atomoxetine and telavancin may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Terbinafine: (Major) Dosage reduction of atomoxetine is recommended in patients receiving terbinafine due to the potential for increased atomoxetine exposure and related adverse effects. In children and adolescents up to 70 kg receiving terbinafine, atomoxetine should be initiated at 0.5 mg/kg/day and only increased to the usual target dose of 1.2 mg/kg/day if symptoms fail to improve after 4 weeks and the initial dose is well tolerated. In children and adolescents over 70 kg and adults receiving terbinafine, atomoxetine should be initiated at 40 mg/day and only increased to the usual target dose of 80 mg/day if symptoms fail to improve after 4 weeks and the initial dose is well tolerated. Terbinafine is a strong CYP2D6 inhibitor; atomoxetine is a CYP2D6 substrate. Coadministration of a strong CYP2D6 inhibitor and atomoxetine in extensive metabolizers of CYP2D6, increased atomoxetine steady-state plasma concentrations by approximately 6 to 8-fold. This increase is similar to exposures observed in poor metabolizers. Concurrent use of a strong CYP2D6 inhibitor with atomoxetine in poor metabolizers is not expected to increase atomoxetine exposure.
Tetrabenazine: (Major) Concomitant use of tetrabenazine and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Thioridazine: (Contraindicated) Avoid concomitant use of thioridazine and atomoxetine due to an increased risk for torsade de pointes (TdP) and QT/QTc prolongation.
Tipranavir: (Major) Dosage reduction of atomoxetine is recommended in patients receiving tipranavir due to the potential for increased atomoxetine exposure and related adverse effects. In children and adolescents up to 70 kg receiving tipranavir, atomoxetine should be initiated at 0.5 mg/kg/day and only increased to the usual target dose of 1.2 mg/kg/day if symptoms fail to improve after 4 weeks and the initial dose is well tolerated. In children and adolescents over 70 kg and adults receiving tipranavir, atomoxetine should be initiated at 40 mg/day and only increased to the usual target dose of 80 mg/day if symptoms fail to improve after 4 weeks and the initial dose is well tolerated. Tipranavir is a strong CYP2D6 inhibitor; atomoxetine is a CYP2D6 substrate. Coadministration of a strong CYP2D6 inhibitor and atomoxetine in extensive metabolizers of CYP2D6, increased atomoxetine steady-state plasma concentrations by approximately 6 to 8-fold. This increase is similar to exposures observed in poor metabolizers. Concurrent use of a strong CYP2D6 inhibitor with atomoxetine in poor metabolizers is not expected to increase atomoxetine exposure.
Tolterodine: (Moderate) Use caution when coadministering atomoxetine and tolterodine as concurrent use may increase the risk of QT prolongation. Tolterodine has been associated with dose-dependent prolongation of the QT interval, especially in poor CYP2D6 metabolizers. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose.
Toremifene: (Major) Concomitant use of toremifene and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Tranylcypromine: (Contraindicated) The use of selective norepinephrine reuptake inhibitors with monoamine oxidase inhibitors (MAOIs) is contraindicated. At least 2 weeks should elapse between the discontinuation of a drug with MAO inhibiting activity and the start of selective norepinephrine reuptake inhibitors, or vice-versa. Selective norepinephrine reuptake inhibitors potentiate certain catecholamines by inhibiting neuronal reuptake. Reactions with MAOIs may include confusion, seizures, and severe hypertension as well as less severe symptoms.
Trazodone: (Major) Concomitant use of atomoxetine and trazodone increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Triclabendazole: (Moderate) Concomitant use of triclabendazole and atomoxetine may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interva l prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Trifluoperazine: (Minor) Use atomoxetine with caution in combination with trifluoperazine as concurrent use may increase the risk of QT prolongation. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose. Trifluoperazine is associated with a possible risk for QT prolongation.
Trimipramine: (Minor) Atomoxetine should be used cautiously with tricyclic antidepressants (TCAs) such as trimipramine as concurrent use may increase the risk of QT prolongation. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose. Tricyclic antidepressants share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
Triptorelin: (Moderate) Concomitant use of atomoxetine and androgen deprivation therapy (i.e., triptorelin) may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Vandetanib: (Major) Concomitant use of vandetanib and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Vardenafil: (Moderate) Concomitant use of atomoxetine and vardenafil may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Vemurafenib: (Major) QT prolongation has occurred during therapeutic use of atomoxetine and following overdose. Both atomoxetine and vemurafenib are considered drugs with a possible risk of torsade de pointes (TdP); therefore, the combination should be used cautiously and with close monitoring. In addition, because atomoxetine is primarily metabolized by CYP2D6, concurrent use of CYP2D6 inhibitors such as vemurafenib may theoretically increase the risk of atomoxetine-induced adverse effects. Monitor for adverse effects, such as dizziness, drowsiness, nervousness, insomnia, and cardiac effects (e.g., hypertension, increased pulse rate, QT prolongation).
Venlafaxine: (Moderate) The concomitant use of atomoxetine and venlafaxine may lead to additive effects on blood pressure, heart rate, or QT interval prolongation. Venlafaxine is a serotonin norepinephrine reuptake inhibitor (SNRI) and atomoxetine selectively inhibits norepinephrine reuptake; the drugs have some additive pharmacology that may lead to increases in blood pressure or heart rate. Venlafaxine is associated with a possible risk of QT prolongation; torsade de pointes (TdP) has been reported with postmarketing use. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose.
Viloxazine: (Major) Avoid concomitant use of atomoxetine and viloxazine. This combination may represent duplicate therapy and additive toxicities may occur. Additionally, atomoxetine exposure may increase. Atomoxetine is a CYP2D6 substrate and viloxazine is a weak CYP2D6 inhibitor.
Voclosporin: (Moderate) Concomitant use of atomoxetine and voclosporin may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP. The degree of QT prolongation associated with voclosporin is not clinically significant when administered within the recommended dosage range; QT prolongation has been described at 3 times the maximum recommended dose.
Vonoprazan; Amoxicillin; Clarithromycin: (Major) Concomitant use of atomoxetine and clarithromycin increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.
Voriconazole: (Moderate) Concomitant use of atomoxetine and voriconazole may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Vorinostat: (Moderate) Concomitant use of atomoxetine and vorinostat may increase the risk of QT/QTc prolongation and torsade de pointes (TdP) in some patients. Consider taking steps to minimize the risk of QT/QTc interval prolongation and TdP, such as avoidance, electrolyte monitoring and repletion, and ECG monitoring, especially in patients with additional risk factors for TdP.
Ziprasidone: (Major) Concomitant use of ziprasidone and atomoxetine increases the risk of QT/QTc prolongation and torsade de pointes (TdP). Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary.

Atomoxetine/Atomoxetine Hydrochloride/Strattera Oral Cap: 10mg, 18mg, 25mg, 40mg, 60mg, 80mg, 100mg

Adults

100 mg/day PO.

Geriatric

Safety and efficacy have not been evaluated.

Adolescents

Weighing more than 70 kg: 100 mg/day PO.
Weighing 70 kg or less: 1.4 mg/kg/day PO (Max: 100 mg/day PO).

Children

6 to 12 years weighing more than 70 kg: 100 mg/day PO.
6 to 12 years weighing 70 kg or less: 1.4 mg/kg/day PO (Max: 100 mg/day PO).
1 to 5 years: Safety and efficacy have not been established.

Infants

Safety and efficacy have not been established.

Neonates

Safety and efficacy have not been established.

Although the precise mechanism by which atomoxetine produces beneficial effects in Attention-Deficit/Hyperactivity Disorder (ADHD) is unknown, it is thought that the drug exerts its effect through selective inhibition of the pre-synaptic norepinephrine (NE) transporter. Atomoxetine, the R(-) isomer, selectively inhibits the neuronal reuptake of norepinephrine (NE). Atomoxetine binding sites in the brain are consistent with the known distribution of NE-containing neurons. It is hypothesized that the atomoxetine-induced increase in NE in the prefrontal cortex, a region involved in attention and memory, mediates the therapeutic effect of atomoxetine in ADHD. Increased concentrations of NE ultimately result in desensitization of beta-adrenoreceptors. Atomoxetine has minimal to no affinity for other neurotransmitter transporter or receptor sites (e.g., dopamine or serotonin).
 
With once-daily dosing of atomoxetine, plasma drug concentrations are low in most patients by late afternoon. How the drug's clinical effects persist with once-daily dosing despite low drug concentrations is uncertain. One investigator suggests that brain pharmacokinetics may be different than plasma, or neuroregulatory changes may exist beyond the time the drug is at the receptor site.

Atomoxetine is administered orally. Extensive metabolizers (EM) of CYP2D6 metabolized drugs are those with a normal metabolic pathway. Poor metabolizers (PM) of CYP2D6 metabolized drugs (roughly 7% of Caucasians and 2% of African Americans) have reduced activity via this pathway, leading to elevated levels of atomoxetine. Bioavailability is roughly 94% in PM and 63% in EM. In PM, the AUC is increased roughly 10-fold, and peak plasma concentrations and half-life are elevated 5-fold compared to EMs.  Coadministration of atomoxetine with potent inhibitors of CYP2D6 isoenzymes in extensive metabolizers (EM) results in elevated plasma concentrations of atomoxetine. In vivo data indicate that administration of paroxetine, a potent CYP2D6 inhibitor, to PMs of 2D6 does not further decrease the clearance of atomoxetine compared to EMs receiving paroxetine. Thus, it can be concluded that coadministration of potent CYP2D6 inhibitors and atomoxetine produces a similar pharmacokinetic profile to 2D6 poor metabolizers in CYP2D6-mediated inhibition of atomoxetine conversion. The major oxidative metabolite of atomoxetine is 4-hydroxyatomoxetine, regardless of CYP2D6 status; however, 4-hydroxyatomoxetine is formed at a slower rate by several other CYP isoenzymes in poor metabolizers. 4-Hydroxyatomoxetine is as potent as atomoxetine, but circulates in much lower concentrations (i.e., 1% of atomoxetine concentration in EM and 0.1% in PM). A second metabolite, N-desmethylatomoxetine, is formed by CYP2C19 and other isoenzymes, but has substantially less pharmacological activity compared with atomoxetine and circulates in plasma at lower concentrations (5% of atomoxetine concentration in EMs and 45% of atomoxetine concentration in PMs). Plasma clearance of atomoxetine in adult EMs is 0.35L/hr/kg and the elimination half-life is 6—8 hours, but in PMs the clearance drops to 0.03 L/hr/kg and the half-life increases to 19 hours. Accumulation of atomoxetine occurs in PMs but not EMs. Biotransformation is extensive, with < 3% of a dose being excreted as the parent drug. Atomoxetine is excreted primarily in the urine (> 80%) as 4-hydroxyatomoxetine-O-glucuronide and is excreted to a lesser extent in the feces (< 17%).
 
With once-daily dosing of atomoxetine, plasma drug concentrations are low in most patients by late afternoon (half-life of 4 hours in extensive metabolizers). How the drug's clinical effects persist with once-daily dosing despite low drug concentrations is uncertain. One investigator suggests that brain pharmacokinetics may be different than plasma pharmacokinetics, or neuroregulatory changes may exist beyond the time the drug is at the receptor site.
 
Affected cytochrome P450 isoenzymes and drug transporters: CYP2D6
Atomoxetine is a primary substrate of CYP2D6. Atomoxetine has not been shown to inhibit or induce CYP enzymes 1A2, 3A, 2D6, or 2C9. Dosage adjustments are not recommended for other drugs metabolized by the 2D6 or 3A4 enzyme system when coadministered. However, dosage adjustments of atomoxetine are recommended in pediatric and adult patients who are either receiving a strong CYP2D6 inhibitor or who are 2D6 poor metabolizers (PM).
 

Oral Route

Atomoxetine is rapidly absorbed from the GI tract. Drugs that elevate gastric pH have not been shown to affect atomoxetine bioavailability. The Cmax occurs 1—2 hours after dosing. Food does not effect the overall extent of absorption (AUC) of atomoxetine in adults, but does reduced the rate of absorption, reducing Cmax by 37% and Tmax by 3 hours. The volume of distribution is roughly 0.85 L/kg indicating that atomoxetine distributes primarily into total body water. Atomoxetine is 98% protein-bound, primarily to albumin.

Pregnancy

Available published studies with atomoxetine use during pregnancy are insufficient to establish a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. Atomoxetine should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. In rabbit organogenesis studies, decreases in live fetuses, increases in early resorption and slight increases in the incidences of atypical origin of the carotid artery and absent subclavian artery. These effects were observed at plasma levels (AUC) 3 times and 0.4 times the human plasma levels in extensive and poor metabolizers receiving the maximum recommended human dose (MRHD), respectively. The no-effect dose for these findings was 30 mg/kg/day. In rats dosed prior to mating and during organogenesis a decrease in fetal weight (female only) and an increase in the incidence of incomplete ossification of the vertebral arch in fetuses were observed at a dose approximately 5 times the MRHD (mg/m2 basis). In one of 2 studies in which rats were dosed prior to mating through the periods of organogenesis and lactation, decreased pup weight and decreased pup survival were observed at doses corresponding to 5 to 6 times the MRHD (mg/m2 basis). No adverse fetal effects were seen in pregnant rats dosed during the organogenesis period. Rat studies have not shown impairment of fertility during use of atomoxetine doses 6 times the MHRD. According to one brief correspondence, 3 pregnancies have occurred during adult clinical trials of atomoxetine, with 2 pregnancies resulting in healthy newborns, and 1 unknown outcome because the patient was lost to follow-up. There is a pregnancy registry that monitors pregnancy outcomes in women exposed to ADHD medications, including atomoxetine, during pregnancy. Healthcare providers are encouraged to register patients by calling the National Pregnancy Registry for ADHD Medications at 1-866-961-2388 or by visiting the worldwide web at https://womensmentalhealth.org/adhd-medications/. The effect of atomoxetine on labor and delivery is unknown.

There are no data on the presence of atomoxetine or its metabolite in human milk, the effects on the breastfed child, or the effects on milk production. Atomoxetine is present in animal milk. When a drug is present in animal milk, it is likely that the drug will be present in human milk. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. Limited data exist; reports from the manufacturer found no serious adverse effects in two breastfed infants. Consider if an alternate drug would be preferred, especially while the woman is nursing a newborn or preterm infant. If atomoxetine therapy cannot be avoided during breast-feeding, the nursing infant should be monitored for signs of potential toxicity, such as poor feeding, irritability, or changes in sleep patterns. Although methylphenidate may be considered as an alternative to other ADHD medications during lactation and breast-feeding due to low excretion into breastmilk, the medical use of stimulant medications during breast-feeding has not been formally evaluated.