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amoxicillin
Classes
Penicillinase-Sensitive Penicillin Antibiotics
Administration
Amoxicillin is administered orally.
Chewable tablets: Should be chewed before swallowing; do not swallow whole.
Capsules, chewable tablets, and immediate-release tablets: May be given without regard to meals. The 400 mg chewable tablet and the 875 mg tablet have been studied only when administered at the start of a light meal.
Extended-release tablets: Take within 1 hour of finishing a meal. Do not chew or crush.
In general, amoxicillin oral suspension may be given without regard to meals. The 400mg suspension has been studied only when administered at the start of a light meal.
Shake well prior to each administration. Measure dosage with calibrated spoon, cup, or oral syringe.
The measured dose of suspension may be added to formula, milk, fruit juice, water, ginger ale, or cold drinks for administration. These preparations should be administered immediately and consumed in their entirety to ensure all of the dose is received.
Reconstitution method for oral suspension:
Review the reconstitution instructions for the particular product and package size, as the amount of water required for reconstitution varies from manufacturer to manufacturer.
Prior to reconstitution, tap the bottle several times to loosen the powder. Add approximately 1/3 of the total amount of water as instructed by the manufacturer and shake well. Add the remainder of the water and shake well.
Storage after reconstitution: Store under refrigeration (preferred) or at controlled room temperature for up to 14 days. Discard any unused portion after 14 days.
Adverse Reactions
erythema multiforme / Delayed / Incidence not known
acute generalized exanthematous pustulosis (AGEP) / Delayed / Incidence not known
Stevens-Johnson syndrome / Delayed / Incidence not known
anaphylactic shock / Rapid / Incidence not known
angioedema / Rapid / Incidence not known
anaphylactoid reactions / Rapid / Incidence not known
vasculitis / Delayed / Incidence not known
exfoliative dermatitis / Delayed / Incidence not known
toxic epidermal necrolysis / Delayed / Incidence not known
serum sickness / Delayed / Incidence not known
Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) / Delayed / Incidence not known
hemolytic anemia / Delayed / Incidence not known
thrombotic thrombocytopenic purpura (TTP) / Delayed / Incidence not known
agranulocytosis / Delayed / Incidence not known
odynophagia / Delayed / Incidence not known
C. difficile-associated diarrhea / Delayed / Incidence not known
aseptic meningitis / Delayed / Incidence not known
seizures / Delayed / Incidence not known
candidiasis / Delayed / 2.0-2.0
eosinophilia / Delayed / Incidence not known
anemia / Delayed / Incidence not known
prolonged bleeding time / Delayed / Incidence not known
platelet dysfunction / Delayed / Incidence not known
leukopenia / Delayed / Incidence not known
thrombocytopenia / Delayed / Incidence not known
dysphagia / Delayed / Incidence not known
esophagitis / Delayed / Incidence not known
pseudomembranous colitis / Delayed / Incidence not known
superinfection / Delayed / Incidence not known
confusion / Early / Incidence not known
cholestasis / Delayed / Incidence not known
hepatitis / Delayed / Incidence not known
jaundice / Delayed / Incidence not known
elevated hepatic enzymes / Delayed / Incidence not known
dental fluorosis / Delayed / Incidence not known
crystalluria / Delayed / Incidence not known
rash / Early / 4.0-8.0
diarrhea / Early / 1.7-8.0
dysgeusia / Early / 5.0-5.0
nausea / Early / 1.3-1.3
headache / Early / 1.0-1.0
vomiting / Early / 0.7-0.7
abdominal pain / Early / 0.3-0.3
urticaria / Rapid / Incidence not known
pruritus / Rapid / Incidence not known
tongue discoloration / Delayed / Incidence not known
agitation / Early / Incidence not known
insomnia / Early / Incidence not known
dizziness / Early / Incidence not known
anxiety / Delayed / Incidence not known
tooth discoloration / Delayed / Incidence not known
Jarisch-Herxheimer reaction / Early / Incidence not known
Common Brand Names
Amoxil, Moxatag, Moxilin, Sumox, Trimox
Dea Class
Rx
Description
Oral semisynthetic aminopenicillin similar to ampicillin; not stable to beta-lactamases of either gram-positive or gram-negative bacteria
Used commonly for otitis media, pneumonia, sinusitis, and skin infections
Higher doses necessary for respiratory infections due to S. pneumoniae resistance
Dosage And Indications
1,000 mg PO once daily or 500 mg PO every 12 hours for 10 days. The FDA-approved dosage is 250 mg PO every 8 hours or 500 mg PO every 12 hours for mild to moderate infections and 500 mg PO every 8 hours or 875 mg PO every 12 hours for severe infections.
50 mg/kg/dose (Max: 1,000 mg/dose) PO once daily or 25 mg/kg/dose (Max: 500 mg/dose) PO every 12 hours for 10 days. The FDA-approved dosage is 20 mg/kg/day (Max: 750 mg/day) PO divided every 8 hours or 25 mg/kg/day (Max: 1,000 mg/day) PO divided every 12 hours for mild to moderate infections and 40 mg/kg/day (Max: 1,500 mg/day) PO divided every 8 hours or 45 mg/kg/day (Max: 1,750 mg/day) PO divided every 12 hours for severe infections.
50 mg/kg/dose PO once daily or 25 mg/kg/dose PO every 12 hours for 10 days. The FDA-approved dosage is 30 mg/kg/day PO divided every 12 hours.
50 mg/kg/dose PO once daily or 25 mg/kg/dose PO every 12 hours for 10 days. The FDA-approved dosage is 30 mg/kg/day PO divided every 12 hours.
775 mg PO once daily for 10 days.
775 mg PO once daily for 10 days.
NOTE: Guidelines do not recommend doses less than 80 mg/kg/day PO for the treatment of otitis media. Re-evaluate patients failing to respond within 48 to 72 hours. Amoxicillin; clavulanate is the preferred therapy for children who have received amoxicillin within the past 30 days, who have purulent conjunctivitis, or who have a history of recurrent acute otitis media unresponsive to amoxicillin.
Oral dosage (immediate-release) Adults
500 mg PO every 12 hours or 250 mg PO every 8 hours for mild to moderate disease and 875 mg PO every 12 hours or 500 mg PO every 8 hours for severe disease.
80 to 90 mg/kg/day (Usual Max: 4 g/day) PO divided every 12 hours for 5 to 7 days for mild to moderate disease and for 10 days for severe disease as first-line therapy. [53345] The FDA-approved dosage is 20 mg/kg/day (Max: 750 mg/day) PO every 8 hours or 25 mg/kg/day (Max: 1,000 mg/day) PO divided every 12 hours for mild to moderate infections and 40 mg/kg/day (Max: 1,500 mg/day) PO divided every 8 hours or 45 mg/kg/day (Max: 1,750 mg/day) PO divided every 12 hours for severe infections.
80 to 90 mg/kg/day PO divided every 12 hours for 7 days for mild to moderate disease and 10 days for severe disease as first-line therapy.[53345] The FDA-approved dosage is 20 mg/kg/day (Max: 750 mg/day) PO every 8 hours or 25 mg/kg/day (Max: 1,000 mg/day) PO divided every 12 hours for mild to moderate infections and 40 mg/kg/day (Max: 1,500 mg/day) PO divided every 8 hours or 45 mg/kg/day (Max: 1,750 mg/day) PO divided every 12 hours for severe infections.
80 to 90 mg/kg/day PO divided every 12 hours for 10 days as first-line therapy.[53345] The FDA-approved dosage is 20 mg/kg/day PO every 8 hours or 25 mg/kg/day PO divided every 12 hours for mild to moderate infections and 40 mg/kg/day PO divided every 8 hours or 45 mg/kg/day PO divided every 12 hours for severe infections.
80 to 90 mg/kg/day PO divided every 12 hours for 10 days. The FDA-approved dosage is 20 mg/kg/day PO every 8 hours or 25 mg/kg/day PO divided every 12 hours for mild to moderate infections and 40 mg/kg/day PO divided every 8 hours or 45 mg/kg/day PO divided every 12 hours for severe infections.
30 mg/kg/day PO divided every 12 hours.
250 mg PO every 8 hours or 500 mg PO every 12 hours for 5 to 14 days.
20 mg/kg/day (Max: 750 mg/day) PO divided every 8 hours or 25 mg/kg/day (Max: 1,000 mg/day) PO divided every 12 hours for 5 to 14 days.
30 mg/kg/day PO divided every 12 hours for 5 to 14 days.
30 mg/kg/day PO divided every 12 hours for 5 to 14 days.
500 mg PO every 8 hours or 875 mg PO every 12 hours for 5 to 14 days.
40 mg/kg/day (Max: 1,500 mg/day) PO divided every 8 hours or 45 mg/kg/day (Max: 1,750 mg/day) PO divided every 12 hours for 5 to 14 days.
30 mg/kg/day PO divided every 12 hours for 5 to 14 days.
30 mg/kg/day PO divided every 12 hours for 5 to 14 days.
500 mg PO every 8 hours for 7 to 10 days.
875 mg PO every 12 hours or 500 mg PO every 8 hours.
45 mg/kg/day (Max: 1,750 mg/day) PO divided every 12 hours or 40 mg/kg/day (Max: 1,500 mg/day) PO divided every 8 hours.
30 mg/kg/day PO divided every 12 hours.
30 mg/kg/day PO divided every 12 hours.
1 g PO every 8 hours for at least 5 days as monotherapy for outpatients without comorbidities or risk factors for MRSA or P. aeruginosa or as part of combination therapy for persons living with HIV. Guide treatment duration by clinical stability.[34362] [64669]
90 mg/kg/day (Max: 4 g/day) PO in divided doses every 12 hours for 5 to 7 days.[34362] [46963] Consider the addition of a macrolide for patients who do not have clinical, laboratory, or radiologic evidence to distinguish bacterial CAP from atypical CAP.[46963] In persons living with HIV, amoxicillin is recommended as part of combination therapy for outpatients.[34362]
90 mg/kg/day (Max: 4 g/day) PO in divided doses every 12 hours for 5 to 7 days.[46963] Consider the addition of a macrolide for patients 5 years and older who do not have clinical, laboratory, or radiologic evidence to distinguish bacterial CAP from atypical CAP.[46963]
90 mg/kg/day (Max: 4 g/day) in divided doses every 12 hours or 45 mg/kg/day (Max: 4 g/day) in divided doses every 8 hours for 5 to 7 days.[46963]
90 mg/kg/day (Max: 4 g/day) PO in divided doses every 8 hours for 5 to 7 days.[46963] Dividing 90 mg/kg/day into 3 doses/day vs. 2 doses/day increases the probability of reaching a clinical and microbiological cure to 90% compared to 65%, respectively, in patients with pneumococcal pneumonia (MIC = 2 mcg/mL).[51856]
50 to 75 mg/kg/day (Max: 4 g/day) PO in divided doses every 12 hours for 5 to 7 days.[46963]
75 to 100 mg/kg/day (Max: 4 g/day) in divided doses every 8 hours for 5 to 7 days.[46963]
500 mg PO every 8 hours or 875 mg PO every 12 hours for 5 to 10 days as first-line therapy. The FDA-approved dosage is 250 mg PO every 8 hours or 500 mg PO every 12 hours for mild to moderate infections and 500 mg PO every 8 hours or 875 mg PO every 12 hours for severe infections.
45 mg/kg/day (Max: 1,750 mg/day) PO divided every 12 hours for 10 to 14 days for mild to moderate uncomplicated disease in children who do not attend daycare and who have not been treated with an antimicrobial agent in the previous 4 weeks. The FDA-approved dosage is 20 mg/kg/day (Max: 750 mg/day) PO divided every 8 hours or 25 mg/kg/day (Max: 1,000 mg/day) PO divided every 12 hours for mild to moderate infections and 40 mg/kg/day (Max: 1,500 mg/day) PO divided every 8 hours or 45 mg/kg/day (Max: 1,750 mg/day) PO divided every 12 hours for severe infections. Due to the high rates of H. influenzae and beta-lactamase-producing pathogens among upper respiratory tract infections in children, amoxicillin; clavulanic acid (and not amoxicillin alone) is recommended as first-line empiric therapy for acute bacterial sinusitis. However, amoxicillin is an option for children 2 years and older with uncomplicated disease in which antimicrobial resistance is not suspected. Children with moderate to severe disease, attending daycare, or who have recently been treated with antimicrobial therapy should receive high-dose amoxicillin; clavulanic acid.
Not recommended by guidelines. The FDA-approved dosage is 20 mg/kg/day PO divided every 8 hours or 25 mg/kg/day PO divided every 12 hours for mild to moderate infections and 40 mg/kg/day PO divided every 8 hours or 45 mg/kg/day PO divided every 12 hours for severe infections.
Not recommended by guidelines. The FDA-approved dosage is 30 mg/kg/day PO divided every 12 hours.
Not recommended by guidelines. The FDA-approved dosage is 30 mg/kg/day PO divided every 12 hours.
2,000 mg PO every 12 hours for 5 to 10 days as first-line therapy.
80 to 90 mg/kg/day (Max: 4 g/day) PO divided every 12 hours for 10 to 14 days for children in areas with high rates of S. pneumoniae resistance (more than 10%, including intermediate- and high-level resistance). Due to the high rates of H. influenzae and beta-lactamase-producing pathogens among upper respiratory tract infections in children, amoxicillin; clavulanic acid (and not amoxicillin alone) is recommended as first-line empiric therapy for acute bacterial sinusitis. However, amoxicillin is an option for children 2 years and older with uncomplicated disease in which antimicrobial resistance is not suspected. Children with moderate to severe disease, attending daycare, or who have recently been treated with antimicrobial therapy should receive high-dose amoxicillin; clavulanic acid.
500 mg PO every 12 hours or 250 mg PO every 8 hours. Guidelines recommend against empiric use due to resistance.
20 mg/kg/day (Max: 750 mg/day) PO divided every 8 hours or 25 mg/kg/day (Max: 1,000 mg/day) PO divided every 12 hours.
30 mg/kg/day PO divided every 12 hours.
30 mg/kg/day PO divided every 12 hours.
875 mg PO every 12 hours or 500 mg PO every 8 hours. Guidelines recommend against empiric use due to resistance.
40 mg/kg/day (Max: 1,500 mg/day) PO divided every 8 hours or 45 mg/kg/day (Max: 1,750 mg/day) PO divided every 12 hours.
30 mg/kg/day PO divided every 12 hours.
30 mg/kg/day PO divided every 12 hours.
500 mg PO every 8 hours for 7 days.
40 mg/kg/day (Max: 1,500 mg/day) PO divided every 8 hours for 3 days.
40 mg/kg/day PO divided every 8 hours for 3 days.
500 mg PO every 8 hours for 7 days.
500 mg PO every 8 hours for 7 to 14 days.
40 mg/kg/day (Max: 1,500 mg/day) PO divided every 8 hours or 45 mg/kg/day (Max: 1,750 mg/day) PO divided every 12 hours for 7 to 14 days.
30 mg/kg/day PO divided every 12 hours for 7 to 14 days.
500 mg PO every 8 hours for 14 days.
50 mg/kg/day PO in divided doses every 8 hours (Max: 500 mg/dose) for 14 days.
500 mg PO every 8 hours for 28 days.
50 mg/kg/day PO in divided doses every 8 hours (Max: 500 mg/dose) for 28 days.
500 mg PO every 8 hours for 28 days. A second course of oral antibiotics may be a reasonable alternative for patients in whom synovial proliferation is modest compared to joint swelling and for those who prefer repeating a course of oral antibiotics before considering IV therapy.
50 mg/kg/day PO in divided doses every 8 hours (Max: 500 mg/dose) for 28 days. A second course of oral antibiotics may be a reasonable alternative for patients in whom synovial proliferation is modest compared to joint swelling and for those who prefer repeating a course of oral antibiotics before considering IV therapy.
500 mg PO every 8 hours for 14 to 21 days for patients with mild disease not requiring hospitalization (i.e., first degree AV block with PR interval less than 300 milliseconds) or as appropriate oral stepdown treatment after IV therapy in hospitalized patients with severe disease (i.e., symptomatic, first degree AV block with PR interval 300 milliseconds or greater, second or third degree AV block).
50 mg/kg/day PO in divided doses every 8 hours (Max: 500 mg/dose) for 14 to 21 days for patients with mild disease not requiring hospitalization (i.e., first degree AV block with PR interval less than 300 milliseconds) or as appropriate oral stepdown treatment after IV therapy in hospitalized patients with severe disease (i.e., symptomatic, first degree AV block with PR interval 300 milliseconds or greater, second or third degree AV block).
500 mg PO every 8 hours for 14 days.
50 mg/kg/day PO in divided doses every 8 hours (Max: 500 mg/dose) for 14 days.
500 mg PO every 8 hours for 21 to 28 days.
50 mg/kg/day PO in divided doses every 8 hours (Max: 500 mg/dose) for 21 to 28 days.
500 mg PO three times daily for 7 days as an alternative.
500 mg PO three times daily for 7 days as an alternative.
1 g PO as a loading dose followed by 500 mg PO three times daily for 3 days.
Amoxicillin 250—375 mg PO three times daily with metronidazole (250 mg PO three times daily) for 7—10 days.
2 g PO as a single dose given 30 to 60 minutes before procedure. Prophylaxis is recommended for at-risk cardiac patients undergoing dental procedures that involve manipulation of gingival tissue, manipulation of the periapical region of teeth, or perforation of the oral mucosa.
50 mg/kg/dose (Max: 2 g/dose) PO as a single dose given 30 to 60 minutes before procedure. Prophylaxis is recommended for at-risk cardiac patients undergoing dental procedures that involve manipulation of gingival tissue, manipulation of the periapical region of teeth, or perforation of the oral mucosa.
50 to 100 mg/kg/day PO divided every 6 to 8 hours for 14 days as an alternative. Usual dose: 1 g PO 3 times daily.
50 to 100 mg/kg/day (Max: 3 g/day) PO divided every 6 to 8 hours for 14 days as an alternative.
1,000 mg PO twice daily in combination with clarithromycin and a proton pump inhibitor (PPI) for 14 days.
1,000 mg PO twice daily in combination with clarithromycin and a proton pump inhibitor (PPI) for 14 days.
750 mg PO twice daily in combination with clarithromycin and a proton pump inhibitor (PPI) for 14 days.
500 mg PO twice daily in combination with clarithromycin and a proton pump inhibitor (PPI) for 14 days.
1,000 mg PO twice daily in combination with clarithromycin, a nitroimidazole, and a proton pump inhibitor (PPI) for 10 to 14 days.
1,000 mg PO twice daily in combination with clarithromycin, metronidazole, and a proton pump inhibitor (PPI) for 14 days.
750 mg PO twice daily in combination with clarithromycin, metronidazole, and a proton pump inhibitor (PPI) for 14 days.
500 mg PO twice daily in combination with clarithromycin, metronidazole, and a proton pump inhibitor (PPI) for 14 days.
1,000 mg PO twice daily in combination with a proton pump inhibitor (PPI) for 5 to 7 days, followed by clarithromycin, a nitroimidazole, and a PPI for 5 to 7 days.
1,000 mg PO twice daily in combination with a proton pump inhibitor (PPI) for 5 days, followed by clarithromycin, metronidazole, and a PPI for 5 days.
750 mg PO twice daily in combination with a proton pump inhibitor (PPI) for 5 days, followed by clarithromycin, metronidazole, and a PPI for 5 days.
500 mg PO twice daily in combination with a proton pump inhibitor (PPI) for 5 days, followed by clarithromycin, metronidazole, and a PPI for 5 days.
1,000 mg PO twice daily in combination with levofloxacin and a proton pump inhibitor (PPI) for 10 to 14 days.
1,000 mg PO twice daily in combination with metronidazole and a proton pump inhibitor (PPI) for 14 days.
750 mg PO twice daily in combination with metronidazole and a proton pump inhibitor (PPI) for 14 days.
500 mg PO twice daily in combination with metronidazole and a proton pump inhibitor (PPI) for 14 days.
1,000 mg PO twice daily in combination with rifabutin and a proton pump inhibitor (PPI) for 10 days.
1,000 mg PO 3 times daily or 750 mg PO 4 times daily in combination with a proton pump inhibitor (PPI) for 14 days.
1,000 mg PO twice daily in combination with a proton pump inhibitor (PPI) for 7 days, followed by 1,000 mg PO twice daily in combination with clarithromycin, a nitroimidazole, and a PPI for 7 days.
1,000 mg PO twice daily in combination with a proton pump inhibitor (PPI) for 5 to 7 days, followed by levofloxacin, a nitroimidazole, and a PPI for 5 to 7 days.
1,500 mg PO twice daily in combination with metronidazole and a proton pump inhibitor (PPI) for 14 days.
1,000 mg PO twice daily in combination with metronidazole and a proton pump inhibitor (PPI) for 14 days.
750 mg PO twice daily in combination with metronidazole and a proton pump inhibitor (PPI) for 14 days.
1,000 mg PO twice daily in combination with bismuth subsalicylate, a proton pump inhibitor (PPI), and clarithromycin, levofloxacin, metronidazole, or tetracycline for 10 to 14 days.
1,000 mg PO twice daily in combination with levofloxacin and a proton pump inhibitor (PPI) for 14 days.
1 g PO every 8 hours as an alternative for penicillin-susceptible strains for patients who cannot take first-line agents (i.e., ciprofloxacin, doxycycline) or if first-line agents are unavailable. Treat for 7 to 10 days for naturally acquired infection. For a bioterrorism-related event, treat for a total duration of 60 days. Following initial treatment for severe anthrax infection, amoxicillin as a single agent may also be used as follow-up treatment.
75 mg/kg/day PO divided every 8 hours (Max: 1 g/dose) as an alternative for penicillin-susceptible strains. Treat for 7 to 10 days for naturally acquired infection. For a bioterrorism-related event, continue treatment for 60 days. As oral follow-up combination therapy after initial IV therapy for severe anthrax (non-CNS infection), use amoxicillin in combination with a protein synthesis inhibitor (i.e., clindamycin, doxycycline, linezolid). Continue therapy to complete a treatment course of at least 14 days; additional prophylaxis to complete an antimicrobial course of up to 60 days may be required.
75 mg/kg/day PO divided every 8 hours as an alternative for penicillin-susceptible strains. Treat for 7 to 10 days for naturally acquired infection. For a bioterrorism-related event, continue treatment for 60 days. As oral follow-up combination therapy after initial IV therapy for severe anthrax (non-CNS infection), use amoxicillin in combination with a protein synthesis inhibitor (i.e., clindamycin, linezolid). Continue therapy to complete a treatment course of at least 14 days; additional prophylaxis to complete an antimicrobial course of up to 60 days may be required.
50 mg/kg/day PO divided every 12 hours as an alternative for penicillin-susceptible strains. Treat for 7 to 10 days for naturally acquired infection. For a bioterrorism-related event, continue treatment for 60 days. As oral follow-up combination therapy after initial IV therapy for severe anthrax (non-CNS infection), use amoxicillin in combination with a protein synthesis inhibitor (i.e., clindamycin, linezolid). Continue therapy to complete a treatment course of at least 14 days; additional prophylaxis to complete an antimicrobial course of up to 60 days may be required.
1 g PO every 8 hours for 60 days after exposure as an alternative for penicillin-susceptible strains for patients who cannot take first-line agents (i.e., fluoroquinolones, doxycycline) or if first-line agents are unavailable.
75 mg/kg/day (Max: 3 g/day) PO divided every 8 hours for 60 days after exposure for penicillin-susceptible strains.
75 mg/kg/day PO divided every 8 hours for 60 days after exposure for penicillin-susceptible strains.
75 mg/kg/day PO divided every 8 hours for 60 days after exposure for penicillin-susceptible strains.
50 mg/kg/day PO divided every 12 hours for 60 days after exposure for penicillin-susceptible strains.
250 mg PO every 8 hours in combination with oral erythromycin for 5 days as step-down therapy after 48 hours of IV therapy, or alternatively, as a single agent for 5 days if azithromycin was part of initial therapy. A 7-day course of antibiotics is recommended for pregnant persons with preterm PROM who are less than 34 0/7 weeks gestation. Persons with preterm PROM who are candidates for group B streptococcal (GBS) intrapartum prophylaxis should receive GBS prophylaxis to prevent vertical transmission regardless of earlier treatments.
250 mg PO every 8 hours in combination with oral erythromycin for 5 days as step-down therapy after 48 hours of IV therapy, or alternatively, as a single agent for 5 days if azithromycin was part of initial therapy. A 7-day course of antibiotics is recommended for pregnant persons with preterm PROM who are less than 34 0/7 weeks gestation. Persons with preterm PROM who are candidates for group B streptococcal (GBS) intrapartum prophylaxis should receive GBS prophylaxis to prevent vertical transmission regardless of earlier treatments.
100 mg/kg/day PO divided every 6 to 8 hours plus probenecid for 4 to 6 weeks. Usual dose: 2 g PO 3 times daily.
75 to 100 mg/kg/day (Max: 6 g/day) PO divided every 6 to 8 hours plus probenecid for 4 to 6 weeks.
250 to 500 mg PO every 12 hours for at least 14 days to 21 days.
10 to 20 mg/kg/dose (Max: 1,000 mg/dose) PO every 24 hours for at least 14 to 28 days.
1 g PO every 8 hours for 14 days as second-line therapy.
500 mg PO every 6 hours or 1,000 mg PO every 12 hours for 7 days as alternative therapy for mild or moderate disease.
30 to 40 mg/kg/day PO divided every 6 hours or 50 mg/kg/day PO divided every 12 hours (Max: 2 g/day) for 7 to 10 days as alternative therapy for mild or moderate disease.
NOTE: Routine antimicrobial prophylaxis for patients age 2 to 24 months with vesicoureteral reflux is not supported by currently available data; however, antimicrobial prophylaxis is still utilized and has biological plausibility.
Oral dosage (immediate-release) Infants younger than 2 months
10 to 15 mg/kg/dose PO once daily. Guidelines recommend antibiotic prophylaxis for all grades of vesicoureteral reflux in all children younger than 1 year.
10 to 15 mg/kg/dose PO once daily. Guidelines recommend antibiotic prophylaxis for all grades of vesicoureteral reflux in all children younger than 1 year.
500 mg PO every 6 hours for 6 to 12 months after IV therapy. Shorter courses may be appropriate for less extensive infections.
50 to 100 mg/kg/day (Max: 4 g/day) PO divided every 8 hours. Treat for a total duration of 3 to 4 weeks (parenteral plus oral) for uncomplicated cases. A longer course (i.e., 4 to 6 weeks or longer) may be needed for severe or complicated infections.
50 to 100 mg/kg/day PO divided every 8 hours. Treat for a total duration of 4 to 6 weeks (parenteral plus oral). A longer course (several months) may be needed for severe or complicated infections.
15 mg/kg/dose PO every 12 hours. Treat for a total duration of 4 to 6 weeks (parenteral plus oral). A longer course (several months) may be needed for severe or complicated infections.
50 to 100 mg/kg/day (Max: 4 g/day) PO divided every 8 hours. Treat for a total duration of 2 to 3 weeks (parenteral plus oral) for uncomplicated cases. A longer course (i.e., 4 to 6 weeks or longer) may be needed for septic hip arthritis or severe or complicated infections.
50 to 100 mg/kg/day PO divided every 8 hours. Treat for a total duration of 4 to 6 weeks (parenteral plus oral). A longer course (several months) may be needed for severe or complicated infections.
15 mg/kg/dose PO every 12 hours. Treat for a total duration of 4 to 6 weeks (parenteral plus oral). A longer course (several months) may be needed for severe or complicated infections.
500 mg PO every 8 hours.
500 mg PO every 8 hours for 14 days.
40 to 45 mg/kg/day (Max: 1,500 mg/day) PO divided every 8 hours for 14 days.
250 to 500 mg PO once daily for at least 1 to 2 years post-splenectomy. Lifelong prophylaxis may be warranted in certain populations.
20 to 40 mg/kg/day (Max: 500 mg/day) PO divided once or twice daily for at least 1 to 2 years post-splenectomy. Lifelong prophylaxis may be warranted in certain populations.
20 to 40 mg/kg/day (Max: 500 mg/day) PO divided once or twice daily until at least age 5 years. Lifelong prophylaxis may be warranted in certain populations.
†Indicates off-label use
Dosing Considerations
No dosage adjustment needed; amoxicillin is not appreciably metabolized in the liver and does not undergo biliary secretion.
Renal ImpairmentAdult patients
CrCl more than 30 mL/minute: no dosage adjustment needed.
CrCl 10 to 30 mL/minute: 250 to 500 mg PO every 12 hours, depending on the severity of the infection.
CrCl less than 10 mL/minute: 250 to 500 mg PO every 24 hours, depending on the severity of the infection.
Pediatric patients (non-neonatal)†
The following renal dosage adjustments are based on a usual amoxicillin dose in pediatric patients of 25 to 50 mg/kg/day PO divided every 8 hours (standard-dose) or 80 to 90 mg/kg/day PO divided every 12 hours (high-dose):
CrCl 30 mL/minute/1.73 m2: no dosage adjustment needed.
CrCl 10 to 29 mL/minute/1.73 m2: 8 to 20 mg/kg/dose PO every 12 hours (standard-dose) or 20 mg/kg/dose PO every 12 hours (high-dose); Max: 500 mg/dose.
CrCl less than 10 mL/minute/1.73 m2: 8 to 20 mg/kg/dose PO every 24 hours (standard-dose) or 20 mg/kg/dose PO every 24 hours (high-dose); Max: 500 mg/dose.
Intermittent hemodialysis
Adult patients
250 to 500 mg PO every 24 hours, depending on the severity of the infection. An additional dose should be given both during and at the end of a dialysis session.
Pediatric patients†
8 to 20 mg/kg/dose PO every 24 hours (standard-dose) or 20 mg/kg/dose PO every 24 hours (high-dose) after dialysis; Max: 500 mg/dose.
Peritoneal dialysis†
Adult patients
250 mg PO every 12 hours.
Pediatric patients
8 to 20 mg/kg/dose PO every 24 hours (standard-dose) or 20 mg/kg/dose PO every 24 hours (high-dose); Max: 500 mg/dose.
Drug Interactions
Acetaminophen; Aspirin, ASA; Caffeine: (Minor) Due to the high protein binding of aspirin, it could displace or be displaced from binding sites by other highly protein-bound drugs, such as penicillins. Also, aspirin may compete with penicillin for renal tubular secretion, increasing penicillin serum concentrations. Overall, this combination should be used with caution and patients monitored for increased side effects.
Acetaminophen; Aspirin: (Minor) Due to the high protein binding of aspirin, it could displace or be displaced from binding sites by other highly protein-bound drugs, such as penicillins. Also, aspirin may compete with penicillin for renal tubular secretion, increasing penicillin serum concentrations. Overall, this combination should be used with caution and patients monitored for increased side effects.
Acetaminophen; Aspirin; Diphenhydramine: (Minor) Due to the high protein binding of aspirin, it could displace or be displaced from binding sites by other highly protein-bound drugs, such as penicillins. Also, aspirin may compete with penicillin for renal tubular secretion, increasing penicillin serum concentrations. Overall, this combination should be used with caution and patients monitored for increased side effects.
Allopurinol: (Minor) Use of amoxicillin with allopurinol can increase the incidence of drug-related skin rash.
Aspirin, ASA: (Minor) Due to the high protein binding of aspirin, it could displace or be displaced from binding sites by other highly protein-bound drugs, such as penicillins. Also, aspirin may compete with penicillin for renal tubular secretion, increasing penicillin serum concentrations. Overall, this combination should be used with caution and patients monitored for increased side effects.
Aspirin, ASA; Butalbital; Caffeine: (Minor) Due to the high protein binding of aspirin, it could displace or be displaced from binding sites by other highly protein-bound drugs, such as penicillins. Also, aspirin may compete with penicillin for renal tubular secretion, increasing penicillin serum concentrations. Overall, this combination should be used with caution and patients monitored for increased side effects.
Aspirin, ASA; Caffeine: (Minor) Due to the high protein binding of aspirin, it could displace or be displaced from binding sites by other highly protein-bound drugs, such as penicillins. Also, aspirin may compete with penicillin for renal tubular secretion, increasing penicillin serum concentrations. Overall, this combination should be used with caution and patients monitored for increased side effects.
Aspirin, ASA; Caffeine; Orphenadrine: (Minor) Due to the high protein binding of aspirin, it could displace or be displaced from binding sites by other highly protein-bound drugs, such as penicillins. Also, aspirin may compete with penicillin for renal tubular secretion, increasing penicillin serum concentrations. Overall, this combination should be used with caution and patients monitored for increased side effects.
Aspirin, ASA; Carisoprodol: (Minor) Due to the high protein binding of aspirin, it could displace or be displaced from binding sites by other highly protein-bound drugs, such as penicillins. Also, aspirin may compete with penicillin for renal tubular secretion, increasing penicillin serum concentrations. Overall, this combination should be used with caution and patients monitored for increased side effects.
Aspirin, ASA; Carisoprodol; Codeine: (Minor) Due to the high protein binding of aspirin, it could displace or be displaced from binding sites by other highly protein-bound drugs, such as penicillins. Also, aspirin may compete with penicillin for renal tubular secretion, increasing penicillin serum concentrations. Overall, this combination should be used with caution and patients monitored for increased side effects.
Aspirin, ASA; Citric Acid; Sodium Bicarbonate: (Minor) Due to the high protein binding of aspirin, it could displace or be displaced from binding sites by other highly protein-bound drugs, such as penicillins. Also, aspirin may compete with penicillin for renal tubular secretion, increasing penicillin serum concentrations. Overall, this combination should be used with caution and patients monitored for increased side effects.
Aspirin, ASA; Dipyridamole: (Minor) Due to the high protein binding of aspirin, it could displace or be displaced from binding sites by other highly protein-bound drugs, such as penicillins. Also, aspirin may compete with penicillin for renal tubular secretion, increasing penicillin serum concentrations. Overall, this combination should be used with caution and patients monitored for increased side effects.
Aspirin, ASA; Omeprazole: (Minor) Due to the high protein binding of aspirin, it could displace or be displaced from binding sites by other highly protein-bound drugs, such as penicillins. Also, aspirin may compete with penicillin for renal tubular secretion, increasing penicillin serum concentrations. Overall, this combination should be used with caution and patients monitored for increased side effects.
Aspirin, ASA; Oxycodone: (Minor) Due to the high protein binding of aspirin, it could displace or be displaced from binding sites by other highly protein-bound drugs, such as penicillins. Also, aspirin may compete with penicillin for renal tubular secretion, increasing penicillin serum concentrations. Overall, this combination should be used with caution and patients monitored for increased side effects.
Butalbital; Aspirin; Caffeine; Codeine: (Minor) Due to the high protein binding of aspirin, it could displace or be displaced from binding sites by other highly protein-bound drugs, such as penicillins. Also, aspirin may compete with penicillin for renal tubular secretion, increasing penicillin serum concentrations. Overall, this combination should be used with caution and patients monitored for increased side effects.
Caffeine; Sodium Benzoate: (Moderate) Antibiotics that undergo tubular secretion such as penicillins may compete with phenylacetlyglutamine and hippuric acid for active tubular secretion. The overall usefulness of sodium benzoate; sodium phenylacetate is due to the excretion of its metabolites. An increase in metabolite concentrations could contribute to failed treatment and worsening of the patient's clinical status. This combination should be used with caution.
Choline Salicylate; Magnesium Salicylate: (Minor) Due to high protein binding, salicylates could be displaced from binding sites, or could displace other highly protein-bound drugs such as penicillins, and sulfonamides. An enhanced effect of the displaced drug may occur.
Desogestrel; Ethinyl Estradiol: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Dichlorphenamide: (Moderate) Use dichlorphenamide and amoxicillin together with caution. Dichlorphenamide increases potassium excretion and can cause hypokalemia and should be used cautiously with other drugs that may cause hypokalemia including amoxicillin. Measure potassium concentrations at baseline and periodically during dichlorphenamide treatment. If hypokalemia occurs or persists, consider reducing the dose or discontinuing dichlorphenamide therapy.
Dienogest; Estradiol valerate: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Digoxin: (Minor) Displacement of penicillins from plasma protein binding sites by highly protein bound drugs like digoxin will elevate the level of free penicillin in the serum. The clinical significance of this interaction is unclear. It is recommended to monitor these patients for increased adverse effects.
Drospirenone: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Drospirenone; Estetrol: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Drospirenone; Estradiol: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Drospirenone; Ethinyl Estradiol: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Drospirenone; Ethinyl Estradiol; Levomefolate: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Elagolix; Estradiol; Norethindrone acetate: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Estradiol; Levonorgestrel: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Estradiol; Norethindrone: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Estradiol; Norgestimate: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Ethacrynic Acid: (Minor) Ethacrynic acid may compete with penicillin for renal tubular secretion, increasing penicillin serum concentrations. This combination should be used with caution and patients monitored for increased side effects.
Ethinyl Estradiol; Norelgestromin: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Ethinyl Estradiol; Norethindrone Acetate: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Ethinyl Estradiol; Norgestrel: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Ethynodiol Diacetate; Ethinyl Estradiol: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Etonogestrel; Ethinyl Estradiol: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Furosemide: (Minor) Furosemide may compete with penicillin for renal tubular secretion, increasing penicillin serum concentrations. This combination should be used with caution and patients monitored for increased side effects.
Indomethacin: (Minor) Indomethacin may compete with penicillin for renal tubular secretion, increasing penicillin serum concentrations. This combination should be used with caution and patients monitored for increased side effects.
Lesinurad; Allopurinol: (Minor) Use of amoxicillin with allopurinol can increase the incidence of drug-related skin rash.
Leuprolide; Norethindrone: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Levonorgestrel: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Levonorgestrel; Ethinyl Estradiol: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Levonorgestrel; Ethinyl Estradiol; Ferrous Bisglycinate: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Levonorgestrel; Ethinyl Estradiol; Ferrous Fumarate: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Mafenide: (Minor) Sulfonamides may compete with amoxicillin for renal tubular secretion, increasing amoxicillin serum concentrations. Use this combination with caution, and monitor patients for increased side effects.
Magnesium Salicylate: (Minor) Due to high protein binding, salicylates could be displaced from binding sites, or could displace other highly protein-bound drugs such as penicillins, and sulfonamides. An enhanced effect of the displaced drug may occur.
Methotrexate: (Major) Avoid concomitant use of methotrexate with penicillins due to the risk of severe methotrexate-related adverse reactions. If concomitant use is unavoidable, closely monitor for adverse reactions.
Mycophenolate: (Moderate) Drugs that alter the gastrointestinal flora may interact with mycophenolate by disrupting enterohepatic recirculation. Amoxicillin;Clavulanic Acid may decrease normal GI flora levels and thus lead to less free mycophenolate available for absorption. The effect of amoxicillin without clavulantic acid on mycophenolate kinetics is unclear.
Norethindrone Acetate; Ethinyl Estradiol; Ferrous fumarate: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Norethindrone: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Norethindrone; Ethinyl Estradiol: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Norethindrone; Ethinyl Estradiol; Ferrous fumarate: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Norgestimate; Ethinyl Estradiol: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated wi
Norgestrel: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Oral Contraceptives: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Probenecid: (Minor) Probenecid competitively inhibits renal tubular secretion and causes higher, prolonged serum levels of penicillins. In general, this pharmacokinetic interaction is not harmful and can be used therapeutically if needed.
Probenecid; Colchicine: (Minor) Probenecid competitively inhibits renal tubular secretion and causes higher, prolonged serum levels of penicillins. In general, this pharmacokinetic interaction is not harmful and can be used therapeutically if needed.
Relugolix; Estradiol; Norethindrone acetate: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Salsalate: (Minor) Due to high protein binding, salicylates could be displaced from binding sites or could displace other highly protein-bound drugs such as penicillins. An enhanced effect of the displaced drug may occur.
Segesterone Acetate; Ethinyl Estradiol: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Sodium Benzoate; Sodium Phenylacetate: (Moderate) Antibiotics that undergo tubular secretion such as penicillins may compete with phenylacetlyglutamine and hippuric acid for active tubular secretion. The overall usefulness of sodium benzoate; sodium phenylacetate is due to the excretion of its metabolites. An increase in metabolite concentrations could contribute to failed treatment and worsening of the patient's clinical status. This combination should be used with caution.
Sodium picosulfate; Magnesium oxide; Anhydrous citric acid: (Major) Prior or concomitant use of antibiotics with sodium picosulfate; magnesium oxide; anhydrous citric acid may reduce efficacy of the bowel preparation as conversion of sodium picosulfate to its active metabolite bis-(p-hydroxy-phenyl)-pyridyl-2-methane (BHPM) is mediated by colonic bacteria. If possible, avoid coadministration. Certain antibiotics (i.e., tetracyclines and quinolones) may chelate with the magnesium in sodium picosulfate; magnesium oxide; anhydrous citric acid solution. Therefore, these antibiotics should be taken at least 2 hours before and not less than 6 hours after the administration of sodium picosulfate; magnesium oxide; anhydrous citric acid solution.
Sulfadiazine: (Minor) Sulfonamides may compete with amoxicillin for renal tubular secretion, increasing amoxicillin serum concentrations. Use this combination with caution, and monitor patients for increased side effects.
Sulfamethoxazole; Trimethoprim, SMX-TMP, Cotrimoxazole: (Minor) Sulfonamides may compete with amoxicillin for renal tubular secretion, increasing amoxicillin serum concentrations. Use this combination with caution, and monitor patients for increased side effects.
Sulfasalazine: (Minor) Sulfonamides may compete with amoxicillin for renal tubular secretion, increasing amoxicillin serum concentrations. Use this combination with caution, and monitor patients for increased side effects.
Sulfonamides: (Minor) Sulfonamides may compete with amoxicillin for renal tubular secretion, increasing amoxicillin serum concentrations. Use this combination with caution, and monitor patients for increased side effects.
Tetracyclines: (Minor) Consider additional monitoring or alternative antimicrobial therapy for patients with infections in which clinical response is highly dependent upon the rapid, bactericidal activity of penicillins. Bacterostatic antibacterials like tetracyclines may antagonize the bactericidal effects of penicillins which may reduce their efficacy. The clinical relevance of this interaction is poorly defined and for many infections the benefits of combination therapy are likely to outweigh the potential risks.
Typhoid Vaccine: (Major) Antibiotics which possess bacterial activity against salmonella typhi organisms may interfere with the immunological response to the live typhoid vaccine. Allow 24 hours or more to elapse between the administration of the last dose of the antibiotic and the live typhoid vaccine.
Warfarin: (Moderate) The concomitant use of warfarin with many classes of antibiotics, including penicillins, may result in an increased INR thereby potentiating the risk for bleeding. Inhibition of vitamin K synthesis due to alterations in the intestinal flora may be a mechanism; however, concurrent infection is also a potential risk factor for elevated INR. Monitor patients for signs and symptoms of bleeding. Additionally, increased monitoring of the INR, especially during initiation and upon discontinuation of the antibiotic, may be necessary.
How Supplied
Amoxicillin/Amoxicillin Trihydrate/Amoxil Oral Tab Chew: 125mg, 250mg
Amoxicillin/Amoxicillin Trihydrate/Amoxil Oral Tab: 500mg, 875mg
Amoxicillin/Amoxicillin Trihydrate/Amoxil/Moxilin/Sumox/Trimox Oral Cap: 250mg, 500mg
Amoxicillin/Amoxicillin Trihydrate/Amoxil/Moxilin/Sumox/Trimox Oral Pwd F/Recon: 5mL, 125mg, 200mg, 250mg, 400mg
Moxatag Oral Tab ER: 775mg
Maximum Dosage
1,750 mg/day PO is FDA-approved maximum; however, doses up to 3 g/day PO have been used off-label.
Geriatric1,750 mg/day PO is FDA-approved maximum; however, doses up to 3 g/day PO have been used off-label.
Adolescents45 mg/kg/day (Max: 1,750 mg/day) PO is FDA-approved maximum; however, doses up to 100 mg/kg/day (Max: 4 g/day) PO have been used off-label.
Children45 mg/kg/day (Max: 1,750 mg/day) PO is FDA-approved maximum; however, doses up to 100 mg/kg/day (Max: 4 g/day) PO have been used off-label.
Infants4 to 11 months: 45 mg/kg/day PO is FDA-approved maximum; however, doses up to 100 mg/kg/day PO have been used off-label.
1 to 3 months: 30 mg/kg/day PO is FDA-approved maximum; however, doses up to 100 mg/kg/day PO have been used off-label.
30 mg/kg/day PO is FDA-approved maximum; however, doses up to 75 mg/kg/day PO have been used off-label.
Mechanism Of Action
Beta-lactam antibiotics such as amoxicillin are mainly bactericidal. Like other penicillins, amoxicillin inhibits the third and final stage of bacterial cell wall synthesis by preferentially binding to specific penicillin-binding proteins (PBPs) that are located inside the bacterial cell wall. Penicillin-binding proteins are responsible for several steps in the synthesis of the cell wall and are found in quantities of several hundred to several thousand molecules per bacterial cell. Penicillin-binding proteins vary among different bacterial species. Thus, the intrinisic activity of amoxicillin, as well as the other penicillins, against a particular organism depends on their ability to gain access to and bind with the necessary PBP. The aminopenicillins are able to penetrate gram-negative bacteria more readily than are the natural penicillins or penicillinase-resistant penicillins due to the presence of a free amino group within the structure. Like all beta-lactam antibiotics, amoxicillin's ability to interfere with PBP-mediated cell wall synthesis ultimately leads to cell lysis. Lysis is mediated by bacterial cell wall autolytic enzymes (i.e., autolysins). The relationship between PBPs and autolysins is unclear, but it is possible that the beta-lactam antibiotic interferes with an autolysin inhibitor.
Penicillin-resistant strains of S. pneumoniae are increasing in number. The mechanism of resistance is mediated via the development of altered PBPs and the penicillin-resistant strains will generally be resistant to amoxicillin. The addition of clavulanic acid does not overcome this type of resistance. Increased dosages of amoxicillin may be necessary to overcome resistant S. pneumoniae. Community resistance patterns may determine the likelyhood of amoxicillin efficacy against S. pneumoniae.
Pharmacokinetics
Amoxicillin is administered orally. Approximately 20% of the circulating drug is protein-bound. Amoxicillin is widely distributed into most body tissues and fluids, excluding the brain and spinal fluid except when meninges are inflamed. Amoxicillin does cross the placenta. A small percentage is excreted in breast milk. The unchanged drug and its metabolites are excreted into the urine primarily via tubular secretion and glomerular filtration. Approximately 60% of an orally administered dose is excreted in the urine within 6 to 8 hours; concurrent administration of probenecid prolongs urinary excretion. In patients with normal renal function, the elimination half-life of amoxicillin is 1 to 1.5 hours.
Affected cytochrome P450 isoenzymes: none
Amoxicillin is stable against gastric acid and is rapidly absorbed. Oral bioavailability ranges from 74% to 92%. Amoxicillin is more completely absorbed than ampicillin and, for this reason, is often the preferred oral aminopenicillin.
Immediate-release formulations
Peak concentrations are reached 1 to 2 hours after administration.
Extended-release formulation
Administration of the extended-release formulation results in slower amoxicillin absorption compared to immediate-release products; peak concentrations are reached approximately 3 hours after administration. Amoxicillin exposure (AUC) achieved with the extended-release formulation is similar to that observed after oral administration of a comparable dose of immediate-release amoxicillin suspension. Food decreases the rate, but does not alter the extent of absorption.
Pregnancy And Lactation
Available data from amoxicillin use during human pregnancy have not established drug-associated risks of major birth defects, miscarriage, or adverse maternal or fetal outcomes. No adverse developmental effects were observed in animal reproduction studies with administration of amoxicillin to pregnant mice and rats at doses up to 12.5 and 25 times the recommended human dose.
43096Amoxicillin is excreted in breast milk in small amounts. Penicillins may cause diarrhea (due to disruption of GI flora), candidiasis, and skin rash in breast-feeding infants. Small studies assessing adverse events in breastfed infants exposed to antibiotics have found adverse event rates of 7.5% to 8.3% after exposure to amoxicillin. The adverse events reported included diarrhea, rash, and somnolence. There are no data on the effects of amoxicillin on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for amoxicillin and any potential adverse effects on the breast-fed child from amoxicillin or from the underlying maternal condition.