Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
METRODIN vs DANAZOL
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Gonadotropin-releasing hormone (Gn RH) agonist; initially stimulates pituitary gonadotropin release, then downregulates Gn RH receptors, suppressing LH and FSH secretion.
Danazol is a synthetic androgen derived from ethisterone that suppresses pituitary-ovarian axis by inhibiting gonadotropin release, leading to decreased estrogen and progesterone levels. It also has weak androgenic and progestational activity.
Treatment of infertility: controlled ovarian hyperstimulation in assisted reproductive technology (ART),Ovulation induction in anovulatory women
FDA: Treatment of endometriosis, fibrocystic breast disease, hereditary angioedema,Off-label: Idiopathic thrombocytopenic purpura, precocious puberty, gynecomastia
750 mg intramuscularly twice weekly for 2-3 weeks; or 500 mg intramuscularly once weekly for 4-6 weeks.
300-600 mg orally twice daily; maximum 800 mg/day
Terminal elimination half-life is approximately 35 hours (range 28–48 hours) in patients with normal renal function; prolonged in renal impairment, requiring dose adjustment.
Terminal elimination half-life is 4-4.5 hours; clinical context: requires multiple daily dosing to maintain therapeutic levels.
Metabolized via peptidases in the liver and kidneys; metabolites are inactive.
Primarily hepatic: undergoes oxidation and conjugation via CYP3A4, with metabolites excreted in urine and feces.
Primarily renal, with approximately 75% of a dose excreted unchanged in urine within 24 hours; biliary/fecal excretion accounts for less than 5% of elimination.
Primarily hepatic metabolism; approximately 60% excreted in feces, 30% in urine as metabolites.
Approximately 30% bound to plasma proteins, predominantly albumin.
Highly protein bound: 97-99%, primarily to albumin.
Apparent volume of distribution is approximately 0.2 L/kg, indicating limited extravascular distribution and confinement primarily to the extracellular fluid space.
Approximately 1.5 L/kg; indicates extensive distribution into tissues, exceeding total body water.
Subcutaneous administration: absolute bioavailability is approximately 75–80% due to partial presystemic degradation; intramuscular administration: bioavailability is similar, approximately 70–80%.
Oral bioavailability is approximately 100% due to extensive absorption, but first-pass metabolism reduces systemic availability to about 70-80%.
GFR 10-50 m L/min: reduce dose to 500 mg intramuscularly twice weekly; GFR <10 m L/min: 500 mg intramuscularly once weekly.
No adjustment required for GFR ≥10 m L/min; avoid use in GFR <10 m L/min due to fluid retention risk
Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 25%; Child-Pugh C: contraindicated.
Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: contraindicated
Not recommended in pediatric patients; limited safety data available.
2-5 mg/kg/dose orally twice daily; maximum 400 mg/day
Use with caution; dose adjustment based on renal function recommended; monitor for neurotoxicity.
Start at low end of adult dose, titrate cautiously due to increased risk of fluid retention and thromboembolism
Ovarian hyperstimulation syndrome (OHSS) and multiple births; increased risk of ovarian neoplasms.
Danazol may cause thrombotic events, including pulmonary embolism and thrombophlebitis. It is contraindicated in patients with a history of thrombosis.
Ovarian hyperstimulation syndrome (OHSS), multiple gestation, ovarian torsion, pulmonary embolism, hypersensitivity reactions, and monitoring of ovarian response via ultrasound and estradiol levels.
Hepatotoxicity (monitor LFTs), pseudotumor cerebri (benign intracranial hypertension), androgenic effects (hirsutism, acne, voice deepening), lipid changes (decreased HDL, increased LDL), thromboembolic events, and premature closure of epiphyses in children.
Hypersensitivity to Gn RH or similar compounds, ovarian enlargement or cyst not due to polycystic ovary syndrome (PCOS), undiagnosed vaginal bleeding, primary ovarian failure, estrogen-dependent tumors (e.g., breast cancer), and pregnancy.
Pregnancy, lactation, porphyria, severe hepatic/renal/cardiac disease, undiagnosed abnormal genital bleeding, history of thromboembolic disorders, androgen-dependent tumors.
Avoid all alcoholic beverages and any foods or medications containing alcohol (e.g., vinegar sauces, kombucha, some desserts) during therapy and for 48 hours post-treatment to prevent disulfiram-like reaction. No other significant food interactions.
Take with food or milk to minimize gastrointestinal irritation. Avoid grapefruit juice as it may alter drug metabolism. Limit alcohol consumption due to increased risk of hepatotoxicity.
Pregnancy Category X. In first trimester, risk of major congenital malformations including neural tube defects, cardiovascular anomalies, and orofacial clefts. Second and third trimester exposure associated with fetal growth restriction, oligohydramnios, and neonatal hypotonia. Avoid throughout pregnancy.
Danazol is contraindicated in pregnancy. First trimester exposure is associated with virilization of female fetus including clitoromegaly, labioscrotal fusion, and urogenital sinus abnormalities. Risk in second and third trimesters is also significant due to androgenic effects; fetal growth restriction and preterm birth may occur. No safe gestational period exists.
No data on M/P ratio. Excretion into breast milk unknown. Due to potential for serious adverse reactions (CNS depression, respiratory depression) in breastfed infants, breastfeeding is contraindicated during therapy and for at least 7 days after last dose.
Danazol is excreted in human milk; M/P ratio not determined. Potential for adverse effects in breastfed infant (e.g., androgenization). Use is contraindicated during breastfeeding due to risk of virilization and other hormonal effects.
Not applicable; drug is contraindicated in pregnancy. No studies on pharmacokinetic changes. Do not dose during pregnancy.
Danazol is contraindicated in pregnancy; no dose adjustment recommendations exist. If inadvertently used during pregnancy, discontinue immediately and monitor for fetal effects. Pharmacokinetic changes in pregnancy are not studied; dose modifications are not applicable due to contraindication.
METRODIN (metronidazole) is a nitroimidazole antibiotic effective against anaerobic bacteria and protozoa. It achieves high concentrations in CNS and bone. Use with caution in patients with Cockayne syndrome due to risk of severe hepatotoxicity. Monitor INR closely in patients on warfarin as metronidazole potentiates anticoagulant effect. Dose adjustment required in severe hepatic impairment (Child-Pugh C).
Monitor liver function tests; androgenic effects (acne, hirsutism, voice deepening) may occur; use with caution in patients with cardiac or renal impairment; may potentiate warfarin; effective for hereditary angioedema prophylaxis; check pregnancy test before initiation due to teratogenicity.
Take exactly as prescribed; do not miss doses. Complete the full course even if you feel better.,Avoid alcohol and any products containing alcohol (e.g., mouthwash, cough syrup) during treatment and for at least 48 hours after last dose to prevent disulfiram-like reaction (nausea, vomiting, headache).,May cause metallic taste, dark urine, or gastrointestinal upset; these are usually harmless.,Inform your doctor if you have a history of liver disease, Cockayne syndrome, or are taking blood thinners (warfarin).,If you experience numbness/tingling in hands/feet, seizures, or confusion, seek medical attention immediately.
Do not take if pregnant or planning pregnancy; use effective contraception.,Report symptoms of liver toxicity (jaundice, dark urine, abdominal pain) immediately.,Avoid alcohol as it may increase hepatotoxicity risk.,May cause weight gain, acne, or voice changes; report if bothersome.,Take with food to reduce GI upset.,Use sunscreen due to photosensitivity risk.,Do not discontinue abruptly; taper under medical supervision.
No interactions on record
"Formestane, an aromatase inhibitor, reduces estrogen synthesis, while danazol, a synthetic androgen, possesses weak androgenic and anabolic activity. Concomitant use may lead to additive fluid retention due to danazol's mineralocorticoid-like effects and formestane's potential to cause fluid retention through estrogen withdrawal. This can result in peripheral edema, hypertension, or exacerbation of heart failure in susceptible patients."
"Danazol, a synthetic androgen with weak androgenic activity, may reduce the therapeutic efficacy of vildagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor used for glycemic control in type 2 diabetes. The proposed mechanism involves danazol-induced activation of cytochrome P450 enzymes (particularly CYP3A4) and potential upregulation of glucagon counter-regulatory pathways, leading to increased vildagliptin clearance and diminished inhibition of DPP-4. Clinically, this interaction may result in elevated postprandial glucose levels and reduced HbA1c reduction, compromising glycemic management."
"Danazol, an androgenic steroid, can induce hepatic microsomal enzymes, particularly CYP2C9, which accelerates the metabolism of glipizide, a sulfonylurea antidiabetic agent. This increased clearance reduces glipizide's plasma concentrations, diminishing its insulinotropic effect and potentially leading to hyperglycemia and loss of glycemic control in patients with type 2 diabetes mellitus."
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about METRODIN vs DANAZOL, answered by our medical review team.
METRODIN is a Gonadotropin that works by Gonadotropin-releasing hormone (Gn RH) agonist; initially stimulates pituitary gonadotropin release, then downregulates Gn RH receptors, suppressing LH and FSH secretion.. DANAZOL is a Androgen/Antigonadotropin that works by Danazol is a synthetic androgen derived from ethisterone that suppresses pituitary-ovarian axis by inhibiting gonadotropin release, leading to decreased estrogen and progesterone levels. It also has weak androgenic and progestational activity.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between METRODIN and DANAZOL depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of METRODIN is: 750 mg intramuscularly twice weekly for 2-3 weeks; or 500 mg intramuscularly once weekly for 4-6 weeks.. The standard adult dose of DANAZOL is: 300-600 mg orally twice daily; maximum 800 mg/day. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between METRODIN and DANAZOL in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. METRODIN is classified as Category C. Pregnancy Category X. In first trimester, risk of major congenital malformations including neural tube defects, cardiovascular anomalies, and orofacial clefts. Second and third tri. DANAZOL is classified as Category C. Danazol is contraindicated in pregnancy. First trimester exposure is associated with virilization of female fetus including clitoromegaly, labioscrotal fusion, and urogenital sinus. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.