Testred
Classes
Androgens
Administration
Hazardous Drugs Classification
NIOSH 2016 List: Group 3
NIOSH (Draft) 2020 List: Table 2
Observe and exercise appropriate precautions for handling, preparation, administration, and disposal of hazardous drugs.
Use gloves to handle. Cutting, crushing, or otherwise manipulating tablets/capsules will increase exposure and require additional protective equipment. Oral liquid drugs require double chemotherapy gloves and protective gown. Eye/face and respiratory protection may be needed during preparation and administration.
Administer with food.
Buccal Administration
Place buccal tablet in the upper or lower buccal pouch between the cheek and gum. Allow to dissolve completely; do not swallow.
Advise patients not to eat, drink, chew, or smoke while the buccal tablet is in place. Emphasize the importance of proper oral hygiene after the use of buccal tablets.
Adverse Reactions
anaphylactoid reactions / Rapid / 0-1.0
clitoromegaly / Delayed / Incidence not known
virilization / Delayed / Incidence not known
feminization / Delayed / Incidence not known
new primary malignancy / Delayed / Incidence not known
epididymitis / Delayed / Incidence not known
prostatic hypertrophy / Delayed / Incidence not known
pulmonary embolism / Delayed / Incidence not known
thrombosis / Delayed / Incidence not known
thromboembolism / Delayed / Incidence not known
epiphyseal closure / Delayed / Incidence not known
erythrocytosis / Delayed / Incidence not known
dysphonia / Delayed / Incidence not known
priapism / Early / Incidence not known
fluid retention / Delayed / Incidence not known
peripheral edema / Delayed / Incidence not known
elevated hepatic enzymes / Delayed / Incidence not known
hepatitis / Delayed / Incidence not known
jaundice / Delayed / Incidence not known
peliosis hepatis / Delayed / Incidence not known
hypercalcemia / Delayed / Incidence not known
polycythemia / Delayed / Incidence not known
bleeding / Early / Incidence not known
hypercholesterolemia / Delayed / Incidence not known
depression / Delayed / Incidence not known
headache / Early / 1.0-10.0
amenorrhea / Delayed / Incidence not known
oligomenorrhea / Delayed / Incidence not known
hirsutism / Delayed / Incidence not known
gynecomastia / Delayed / Incidence not known
alopecia / Delayed / Incidence not known
weight gain / Delayed / Incidence not known
acne vulgaris / Delayed / Incidence not known
libido increase / Delayed / Incidence not known
libido decrease / Delayed / Incidence not known
nausea / Early / Incidence not known
vomiting / Early / Incidence not known
anxiety / Delayed / Incidence not known
paresthesias / Delayed / Incidence not known
Common Brand Names
Android, Methitest, Testred, Virilon
Dea Class
Rx, schedule III
Description
Synthetic androgen given orally without loss of bioavailability; has less hepatic metabolism following oral administration when compared to testosterone; has been used in the management of congenital or acquired hypogonadism; pathological, delayed puberty; and as palliative treatment for breast cancer in postmenopausal women. -schedule C-III controlled substance.
Dosage And Indications
The recommended dose is 10 mg PO 3 times per day.
The recommended dose is 5 mg 3 times per day, dissolved in the buccal cavity.
The recommended dose is 5 to 25 mg PO per day for a limited period, usually for 4 to 6 months.
The recommended dose is 2.5 to 12.5 mg per day, dissolved in the buccal cavity, for a limited period, usually for 4 to 6 months.
The recommended dose is 50 mg PO once daily up to 4 times per day. If a suitable response occurs within 2 to 4 weeks, the dose may be reduced to 50 mg 2 times per day.
The recommended dose is 25 mg dissolved in the buccal cavity once daily up to 4 times per day. If a suitable response occurs within 2 to 4 weeks, the dose may be reduced to 25 mg 2 times per day.
NOTE: In the management of erectile dysfunction (ED), methyltestosterone therapy may increase libido and may or may not be effective at improving erectile function in hypogonadal men. Testosterone therapy, however, is not indicated for the treatment of erectile dysfunction in the patient with a normal serum testosterone concentration.
Oral dosage (capsules or tablets) Adult males
The recommended dose is 10 to 50 mg PO per day.
The recommended dose is 5 to 25 mg per day, dissolved in the buccal cavity.
†Indicates off-label use
Dosing Considerations
Generally, androgen use is contraindicated in patients with severe hepatic dysfunction. Specific guidelines for dosage adjustment in hepatic impairment are not available; use caution in patients with mild to moderate hepatic disease.
Renal ImpairmentSpecific guidelines for dosage adjustments in renal impairment are not available; it appears that no dosage adjustments are needed.
Drug Interactions
Abarelix: (Major) Concomitant use of androgens or estrogens with abarelix is relatively contraindicated, as both could counteract the therapeutic effect of abarelix.
Acarbose: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Alogliptin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Alogliptin; Metformin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Alogliptin; Pioglitazone: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Alpha-glucosidase Inhibitors: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Anticoagulants: (Moderate) Methyltestosterone can increase the effects of anticoagulants through reduction of procoagulant factor. Patients receiving oral anticoagulant therapy should be closely monitored, especially when methyltestosterone treatment is initiated or discontinued.
Antithrombin III: (Moderate) Methyltestosterone can increase the effects of anticoagulants through reduction of procoagulant factor. Patients receiving oral anticoagulant therapy should be closely monitored, especially when methyltestosterone treatment is initiated or discontinued.
Apixaban: (Moderate) Methyltestosterone can increase the effects of anticoagulants through reduction of procoagulant factor. Patients receiving oral anticoagulant therapy should be closely monitored, especially when methyltestosterone treatment is initiated or discontinued.
Argatroban: (Moderate) Methyltestosterone can increase the effects of anticoagulants through reduction of procoagulant factor. Patients receiving oral anticoagulant therapy should be closely monitored, especially when methyltestosterone treatment is initiated or discontinued.
Betrixaban: (Moderate) Methyltestosterone can increase the effects of anticoagulants through reduction of procoagulant factor. Patients receiving oral anticoagulant therapy should be closely monitored, especially when methyltestosterone treatment is initiated or discontinued.
Bivalirudin: (Moderate) Methyltestosterone can increase the effects of anticoagulants through reduction of procoagulant factor. Patients receiving oral anticoagulant therapy should be closely monitored, especially when methyltestosterone treatment is initiated or discontinued.
Canagliflozin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Canagliflozin; Metformin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Cyclosporine: (Moderate) Androgens may increase concentrations of cyclosporine, potentially increasing the risk of nephrotoxicity. Until further data are available, close monitoring of cyclosporine serum concentrations is prudent during coadministration with androgens.
Dabigatran: (Moderate) Methyltestosterone can increase the effects of anticoagulants through reduction of procoagulant factor. Patients receiving oral anticoagulant therapy should be closely monitored, especially when methyltestosterone treatment is initiated or discontinued.
Dalteparin: (Moderate) Methyltestosterone can increase the effects of anticoagulants through reduction of procoagulant factor. Patients receiving oral anticoagulant therapy should be closely monitored, especially when methyltestosterone treatment is initiated or discontinued.
Dapagliflozin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Dapagliflozin; Metformin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Dapagliflozin; Saxagliptin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Darbepoetin Alfa: (Moderate) Androgens are known to stimulate erythropoiesis. Concurrent administration of androgens can increase the patient's response to darbepoetin alfa, reducing the amount required to treat anemia.
Degarelix: (Major) Concomitant use of androgens with degarelix is relatively contraindicated, as androgens could counteract the therapeutic effect of degarelix.
Desirudin: (Moderate) Methyltestosterone can increase the effects of anticoagulants through reduction of procoagulant factor. Patients receiving oral anticoagulant therapy should be closely monitored, especially when methyltestosterone treatment is initiated or discontinued.
Dipeptidyl Peptidase-4 Inhibitors: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Edoxaban: (Moderate) Methyltestosterone can increase the effects of anticoagulants through reduction of procoagulant factor. Patients receiving oral anticoagulant therapy should be closely monitored, especially when methyltestosterone treatment is initiated or discontinued.
Empagliflozin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Empagliflozin; Linagliptin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Empagliflozin; Linagliptin; Metformin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Empagliflozin; Metformin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Enoxaparin: (Moderate) Methyltestosterone can increase the effects of anticoagulants through reduction of procoagulant factor. Patients receiving oral anticoagulant therapy should be closely monitored, especially when methyltestosterone treatment is initiated or discontinued.
Epoetin Alfa: (Moderate) Androgens are known to stimulate erythropoiesis. Concurrent administration of androgens can increase the patient's response to epoetin alfa, reducing the amount required to treat anemia. Because adverse reactions have been associated with an abrupt increase in blood viscosity, this drug combination should be avoided, if possible. Further evaluation of this combination needs to be made.
Ertugliflozin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Ertugliflozin; Metformin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Ertugliflozin; Sitagliptin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Fondaparinux: (Moderate) Methyltestosterone can increase the effects of anticoagulants through reduction of procoagulant factor. Patients receiving oral anticoagulant therapy should be closely monitored, especially when methyltestosterone treatment is initiated or discontinued.
Glipizide; Metformin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Glyburide; Metformin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Goserelin: (Major) Avoid concurrent use of androgens with gonadotropin releasing hormone (GnRH) agonists such as goserelin. Goserelin inhibits steroidogenesis; concomitant use with androgens may counteract this therapeutic effect.
Heparin: (Moderate) Methyltestosterone can increase the effects of anticoagulants through reduction of procoagulant factor. Patients receiving oral anticoagulant therapy should be closely monitored, especially when methyltestosterone treatment is initiated or discontinued.
Histrelin: (Major) Avoid concurrent use of androgens with gonadotropin releasing hormone (GnRH) agonists such as histrelin. Histrelin inhibits steroidogenesis; concomitant use with androgens may counteract this therapeutic effect.
Imipramine: (Minor) Coadministration of methyltestosterone with imipramine has led to dramatic paranoia in a limited number of patients.
Incretin Mimetics: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Insulins: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Leuprolide: (Major) Leuprolide inhibits steroidogenesis. While no drug interactions have been reported with leuprolide, therapy with androgens would be relatively contraindicated and would counteract the therapeutic effect of leuprolide.
Leuprolide; Norethindrone: (Major) Leuprolide inhibits steroidogenesis. While no drug interactions have been reported with leuprolide, therapy with androgens would be relatively contraindicated and would counteract the therapeutic effect of leuprolide.
Linagliptin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Linagliptin; Metformin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Meglitinides: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Metformin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Metformin; Repaglinide: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Metformin; Rosiglitazone: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Metformin; Saxagliptin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Metformin; Sitagliptin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Methotrexate: (Moderate) Methyltestosterone has been associated with hepatotoxicity; caution is recommended in combining 17-alpha-alkylated androgens in combination with other medications that have potential hepatotoxic effects (e.g., methotrexate). Monitor liver function periodically; if liver function becomes abnormal or clinical symptoms (e.g., jaundice) develop, discontinue the androgen and determine the etiology. Androgen-induced jaundice is reversible whtih medication discontinuation.
Methoxy polyethylene glycol-epoetin beta: (Moderate) Androgens are known to stimulate erythropoiesis. Despite the fact that endogenous generation of erythropoietin is depressed in patients with chronic renal failure, other tissues besides the kidney can synthesize erythropoietin, albeit in small amounts. Concurrent administration of androgens can increase the patient's response to MPG-epoetin beta, reducing the amount required to treat anemia. Because adverse reactions have been associated with an abrupt increase in blood viscosity, this drug combination should be avoided, if possible. Further evaluation of this combination needs to be made.
Miglitol: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Nafarelin: (Major) Gonadotropin releasing hormone (GnRH) agonists (i.e.,nafarelin) inhibit steroidogenesis, therefore the concomitant use of these agents with androgens may counteract this therapeutic effect. Avoid concurrent use of androgens with GnRH agonists.
Pentosan: (Moderate) Methyltestosterone can increase the effects of anticoagulants through reduction of procoagulant factor. Patients receiving oral anticoagulant therapy should be closely monitored, especially when methyltestosterone treatment is initiated or discontinued.
Pioglitazone; Metformin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Pramlintide: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Rivaroxaban: (Moderate) Methyltestosterone can increase the effects of anticoagulants through reduction of procoagulant factor. Patients receiving oral anticoagulant therapy should be closely monitored, especially when methyltestosterone treatment is initiated or discontinued.
Saw Palmetto, Serenoa repens: (Major) Drug interactions with Saw palmetto, Serenoa repens have not been specifically studied or reported. Saw palmetto extracts appear to have antiandrogenic effects. The antiandrogenic effects of Saw palmetto, Serenoa repens would be expected to antagonize the actions of androgens; it would seem illogical for patients taking androgens to use this herbal supplement.
Saxagliptin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
SGLT2 Inhibitors: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Sitagliptin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Sotagliflozin: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Soy Isoflavones: (Moderate) Theoretically, the soy isoflavones may counteract the activity of the androgens.
Sulfonylureas: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Thiazolidinediones: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
Triptorelin: (Major) Gonadotropin releasing hormone (GnRH) agonists (i.e.,triptorelin) inhibit steroidogenesis, therefore the concomitant use of these agents with androgens may counteract this therapeutic effect. Avoid concurrent use of androgens with GnRH agonists.
Warfarin: (Moderate) Methyltestosterone can increase the effects of anticoagulants through reduction of procoagulant factor. Patients receiving oral anticoagulant therapy should be closely monitored, especially when methyltestosterone treatment is initiated or discontinued.
How Supplied
Android/Methyltestosterone/Testred/Virilon Oral Cap: 10mg
Methitest/Methyltestosterone Oral Tab: 10mg
Maximum Dosage
The maximum dosage is dependent on indication for therapy.
ElderlyThe maximum dosage is dependent on indication for therapy.
AdolescentsThe maximum dosage is dependent on indication for therapy.
ChildrenSafety and efficacy have not been established.
Mechanism Of Action
Mechanism of Action: The function of androgens in male development begins in the fetus, is crucial during puberty, and continues to play an important role in the adult male. Women also secrete small amounts of androgen from the ovaries. The secretion of androgens from the adrenal cortex is insufficient to maintain male sexuality.Normally, endogenous androgens stimulate RNA polymerase, increasing protein production. These proteins are responsible for normal male sexual development, including the growth and maturation of the prostate, seminal vesicle, penis, and scrotum. During puberty, androgens cause a sudden increase in growth and development of muscle, with a redistribution of body fat. Changes associated with endogenous androgens also take place in the larynx and vocal cords, deepening the voice. Puberty is completed with beard development and growth of body hair. Fusion of the epiphyses and termination of growth is governed by the androgens, as is the maintenance of spermatogenesis. Androgens have a high lipid solubility, enabling them to rapidly enter cells of target tissues. Increased androgen plasma levels suppress gonadotropin-releasing hormone, reducing endogenous testosterone, luteinizing hormone, and follicle-stimulating hormone through a negative-feedback mechanism. Exogenous replacement therapy stimulates the above process when endogenous supply is inadequate.
Pharmacokinetics
Methyltestosterone is administered orally or via the buccal cavity. Methyltestosterone has an elimination half-life of 2.5—3.5 hours, somewhat longer than that of testosterone. Excretion of glucuronide and sulfate conjugates is primarily renal; there is little excretion of unchanged drug. Small amounts are eliminated in the feces.
Oral RouteBioavailability is roughly 50% after oral administration. Peak serum concentrations are achieved about 2 hours after tablet administration.
Other Route(s)Buccal Route
After administration of methyltestosterone via the buccal cavity, first-pass hepatic metabolism is bypassed.
Pregnancy And Lactation
Methyltestosterone is classified as FDA pregnancy category X; its use is absolutely contraindicated during pregnancy because of probable adverse effects on the fetus. Androgens have caused virilization of the external genitalia of the female fetus, including clitoromegaly, abnormal vaginal development, and fusion of genital folds to form a scrotal-like structure. The degree of masculinization is dependent on the amount of drug given and the age of the fetus; these effects are most likely to occur in the female fetus when the drugs are given in the first trimester. Females of childbearing potential should use adequate methods of contraception, and should commence therapy during menstruation to ensure a nonpregnant state. If pregnancy occurs, the drug should be immediately discontinued and the patient should be counseled concerning the potential risks to the fetus.
Methyltestosterone distribution into breast milk has not been determined, but exposure to this androgen via breast-feeding may have adverse androgenic effects on the infant and the drug may also interfere with proper establishment of lactation in the mother. Because methyltestosterone is both structurally and mechanistically similar to testosterone, and testosterone products are to be avoided in lactating women, methyltestosterone should also be avoided in lactating women. Alternative methods to breast-feeding are recommended if methyltestosterone therapy is necessary. Historically, testosterone/androgens have been used adjunctively for lactation suppression.