Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
METRODIN vs A.P.L.
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.
A. P. L. (Chorionic Gonadotropin) acts as a luteinizing hormone (LH) agonist, binding to LH receptors in the gonads to stimulate testosterone production in males and ovulation in females.
Treatment of infertility: controlled ovarian hyperstimulation in assisted reproductive technology (ART),Ovulation induction in anovulatory women
Induction of ovulation in anovulatory infertile women,Treatment of hypogonadism and cryptorchidism in males,Off-label: Assisted reproductive technology (ART) protocols
750 mg intramuscularly twice weekly for 2-3 weeks; or 500 mg intramuscularly once weekly for 4-6 weeks.
500-1000 mg every 4-6 hours, not to exceed 3000 mg/day in adults.
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: 2.5–3.5 hours (elimination phase); clinical context: requires repeated dosing for sustained effect.
Metabolized via peptidases in the liver and kidneys; metabolites are inactive.
Primarily via glucuronidation (60%) and sulfation (35%) in the liver, with a minor portion (5%) via CYP2E1 oxidation to the toxic metabolite N-acetyl-p-benzoquinone imine (NAPQI), which is normally detoxified by glutathione.
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.
Renal: 10% unchanged; hepatic metabolism to inactive metabolites excreted in urine and feces (90% combined).
Approximately 30% bound to plasma proteins, predominantly albumin.
80–90% bound to sex hormone-binding globulin (SHBG) and albumin.
Apparent volume of distribution is approximately 0.2 L/kg, indicating limited extravascular distribution and confinement primarily to the extracellular fluid space.
0.5–0.9 L/kg, indicating moderate tissue distribution (primarily gonads and liver).
Subcutaneous administration: absolute bioavailability is approximately 75–80% due to partial presystemic degradation; intramuscular administration: bioavailability is similar, approximately 70–80%.
IM: 100%; Subcutaneous: ~80% (relative to IM); Oral: <5% (not clinically used).
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 specific adjustment required for mild to moderate renal impairment. In severe renal impairment (Cr Cl < 10 m L/min), extend dosing interval to every 8 hours.
Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 25%; Child-Pugh C: contraindicated.
Caution in severe hepatic impairment; consider dose reduction or extended interval. Avoid use in active liver disease.
Not recommended in pediatric patients; limited safety data available.
Weight-based: 10-15 mg/kg every 4-6 hours, not to exceed 5 doses per day or 75 mg/kg/day.
Use with caution; dose adjustment based on renal function recommended; monitor for neurotoxicity.
No specific dose adjustment, but consider renal and hepatic function and avoid exceeding 3000 mg/day.
Ovarian hyperstimulation syndrome (OHSS) and multiple births; increased risk of ovarian neoplasms.
No black box warning.
Ovarian hyperstimulation syndrome (OHSS), multiple gestation, ovarian torsion, pulmonary embolism, hypersensitivity reactions, and monitoring of ovarian response via ultrasound and estradiol levels.
May cause fluid retention, ovarian hyperstimulation syndrome (OHSS) in females,Increased risk of thromboembolic events,Precocious puberty in males,Not for use in prepubertal children unless for cryptorchidism
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.
Hypersensitivity to chorionic gonadotropin or any component,Precocious puberty (in males),Prostatic carcinoma or other androgen-dependent neoplasms,Ovarian cyst or enlargement not due to polycystic ovary syndrome
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.
No known food interactions. Avoid alcohol during treatment.
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.
A. P. L. (chorionic gonadotropin) is not expected to increase the risk of congenital anomalies when used in early pregnancy. However, use in the first trimester is generally avoided unless indicated for specific conditions. Data are limited; no increased fetal risk reported in inadvertent exposures. Second and third trimester use is not associated with teratogenicity but may increase risk of multiple gestation (if used for ovulation induction).
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.
Chorionic gonadotropin is not detected in breast milk following maternal administration. M/P ratio not established. Considered compatible with breastfeeding; no adverse effects on infant reported. Use with caution if high doses are administered.
Not applicable; drug is contraindicated in pregnancy. No studies on pharmacokinetic changes. Do not dose during pregnancy.
No pharmacokinetic studies in pregnancy. Dose adjustments are not typically required during pregnancy for standard indications. For ovulation induction, dosing is based on follicular development. In first trimester for luteal support, standard doses are used. No evidence of altered clearance or need for dose changes due to pregnancy.
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).
A. P. L. (chorionic gonadotropin) is used to trigger ovulation in assisted reproductive technology. Administer when follicles are mature (≥18 mm). Risk of ovarian hyperstimulation syndrome (OHSS) increases with higher doses. Monitor for abdominal pain, distension, and weight gain. Use caution in patients with prior thromboembolism.
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.
This medication is given as an injection exactly as prescribed to trigger ovulation.,A single dose is usually sufficient; follow your doctor's timing instructions closely.,Common side effects include headache, fatigue, and injection site reactions.,Seek immediate medical help if you experience severe pelvic pain, nausea, vomiting, or sudden weight gain (signs of OHSS).,Report symptoms of blood clots: leg pain, chest pain, or shortness of breath.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about METRODIN vs A.P.L., 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.. A.P.L. is a Gonadotropin that works by A. P. L. (Chorionic Gonadotropin) acts as a luteinizing hormone (LH) agonist, binding to LH receptors in the gonads to stimulate testosterone production in males and ovulation in females.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between METRODIN and A.P.L. depend on the specific clinical indication. These are both Gonadotropin agents 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 A.P.L. is: 500-1000 mg every 4-6 hours, not to exceed 3000 mg/day in adults.. 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 A.P.L. 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. A.P.L. is classified as Category C. A.P.L. (chorionic gonadotropin) is not expected to increase the risk of congenital anomalies when used in early pregnancy. However, use in the first trimester is generally avoided . Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.