Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
METHERGINE vs Ergometrine / Methylergonovine
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Methylergonovine is an ergot alkaloid that acts as a partial agonist at α-adrenergic receptors in the uterine smooth muscle, causing sustained contractions. It also exhibits serotonergic (5-HT2) and dopaminergic activity.
Ergometrine and methylergonovine are ergot alkaloids that act as partial agonists at alpha-adrenergic, dopaminergic, and serotonergic (5-HT2) receptors. Their primary uterotonic effect is mediated by stimulation of 5-HT2 receptors in uterine smooth muscle, leading to sustained contractions and vasoconstriction.
Prevention and treatment of postpartum hemorrhage due to uterine atony,Management of incomplete abortion
Prevention and treatment of postpartum hemorrhage (FDA approved),Uterine atony (FDA approved),Ovarian hyperstimulation syndrome (off-label),Variceal bleeding (off-label),Migraine headache (off-label)
0.2 mg intramuscularly or intravenously after delivery of placenta and every 2-4 hours as needed, up to a maximum of 5 doses.
0.2 mg intramuscularly or intravenously, repeated every 2-4 hours as needed, up to 5 doses total. Maximum single dose: 0.5 mg. Maximum total dose: 1 mg.
Terminal elimination half-life is approximately 2–3 hours in healthy adults; prolonged in hepatic impairment.
30-120 min (biphasic: initial 10 min, terminal 30-120 min); clinical context: short half-life allows repeated dosing for postpartum hemorrhage but requires monitoring for accumulation
Primarily hepatic via CYP3A4 with significant first-pass metabolism; active metabolite is methylergonovine itself; excreted mainly in bile and urine.
Primarily hepatic via CYP3A4; also undergoes first-pass metabolism. Metabolites are excreted in urine and bile.
Primarily hepatic metabolism; less than 1% excreted unchanged in urine. Biliary/fecal excretion accounts for ~80% of metabolites.
Renal (20% unchanged), biliary/fecal (35% as metabolites and parent compound)
Approximately 93% bound, primarily to albumin and alpha-1-acid glycoprotein.
85-90% (primarily to albumin and α1-acid glycoprotein)
0.6 L/kg (range 0.3–0.8 L/kg), indicating moderate distribution into tissues.
0.4-0.6 L/kg; clinical meaning: moderate tissue distribution, consistent with limited extravascular binding
Oral bioavailability is approximately 10–20% due to extensive first-pass metabolism. Intramuscular administration provides 100% bioavailability.
Oral: 20-40% (due to extensive first-pass metabolism); IM: ~80%
No specific dose adjustment recommended; use with caution in renal impairment due to risk of hypertension.
No specific guidelines; use with caution in severe renal impairment (GFR <30 m L/min) due to risk of accumulation and hypertensive effects.
Contraindicated in severe hepatic impairment (Child-Pugh class C). For Child-Pugh class A or B, use with caution and monitor for signs of toxicity.
Child-Pugh Class A: no adjustment. Child-Pugh Class B: reduce dose by 50% or extend interval. Child-Pugh Class C: avoid use.
Not recommended for pediatric use; safety and efficacy in children have not been established.
0.1-0.2 mg intramuscularly or intravenously every 2-4 hours as needed; maximum single dose 0.2 mg. For postpartum hemorrhage, 0.2 mg IM/IV repeated every 2-4 hours, max 5 doses.
Use with caution in elderly patients due to increased sensitivity to vasoconstrictive effects and higher risk of hypertension and myocardial ischemia.
Use lowest effective dose due to increased sensitivity and higher risk of hypertension and coronary vasospasm; consider 0.1 mg initially and titrate cautiously.
Not for use during pregnancy (except during delivery) due to risk of uterine tetany and fetal hypoxia. Contraindicated in patients with hypertension, preeclampsia, or eclampsia due to risk of severe hypertension and stroke.
Concurrent use with potent CYP3A4 inhibitors (e.g., macrolide antibiotics, protease inhibitors, azole antifungals) may result in acute ergot toxicity (vasospasm, cerebral and peripheral ischemia). Contraindicated in pregnancy for induction of labor due to risk of uterine rupture and fetal harm.
Risk of severe hypertension, especially in patients with preeclampsia, eclampsia, or hypertension.,Use with caution in patients with sepsis, hepatic or renal impairment, or coronary artery disease.,May cause ergotism with prolonged use or high doses (symptoms: vasospasm, ischemia).,Monitor blood pressure and uterine response during administration.
May cause hypertension, especially in patients with preeclampsia or hypertension. Use with caution in patients with sepsis, hepatic or renal impairment, coronary artery disease, or peripheral vascular disease. Avoid prolonged use. Monitor uterine tone and bleeding.
Hypersensitivity to ergot alkaloids,Pregnancy (for antepartum use),Hypertension, preeclampsia, or eclampsia,Peripheral vascular disease,Coronary artery disease,Severe hepatic or renal impairment,Sepsis
Pregnancy (except for postpartum hemorrhage), hypertension, preeclampsia, eclampsia, coronary artery disease, peripheral vascular disease, Raynaud's phenomenon, sepsis, hypersensitivity to ergot alkaloids, concurrent use of potent CYP3A4 inhibitors.
Avoid grapefruit juice as it may increase serum levels of methylergonovine via CYP3A4 inhibition. No specific food restrictions other than avoiding excessive caffeine intake, which may potentiate vasoconstrictive effects.
No known food interactions.
Methergine (methylergonovine) is contraindicated in pregnancy due to its oxytocic properties and risk of uterine hyperstimulation, fetal distress, and abortion. First trimester: potential teratogenic effects not well studied; avoid use. Second and third trimesters: can cause abruptio placentae, premature labor, and fetal anoxia. It is FDA Pregnancy Category X.
First trimester: Limited human data; animal studies show embryotoxicity and fetotoxicity at high doses due to uterotonic effects, but no structural malformations. Increased risk of spontaneous abortion from uterine hyperstimulation. Second trimester: Uterotonic effects may cause placental abruption, preterm labor, or fetal hypoxia. Third trimester: Contraindicated due to potent uterotonic activity; can cause uterine tetany, fetal distress, and stillbirth. Avoid during pregnancy unless for postpartum hemorrhage.
Methylergonovine is excreted into breast milk in small amounts; the milk-to-plasma ratio is approximately 1.0. Adverse effects in nursing infants are rare but may include diarrhea, vomiting, and hypertension. It is generally considered compatible with breastfeeding when used short-term for postpartum hemorrhage. Avoid prolonged use.
Ergometrine and methylergonovine are excreted into breast milk in small amounts; M/P ratio estimated at 0.2-0.3. Milk concentrations are low (approximately 1-2% of maternal weight-adjusted dose). The American Academy of Pediatrics considers use compatible with breastfeeding, but may cause ergotism in infants (vomiting, diarrhea, seizures) with prolonged use. Short-term use for postpartum hemorrhage is generally acceptable.
Not applicable; the drug is contraindicated during pregnancy. No dose adjustments are recommended for use during pregnancy as it should not be used.
No dose adjustment required for pregnancy because drug is contraindicated during pregnancy due to uterotonic effects. In postpartum use (which is the approved indication), no pharmacokinetic changes necessitate dose adjustment; normal adult dosing applies (0.2 mg IM/IV for ergometrine, 0.2 mg IM for methylergonovine).
METHERGINE (methylergonovine) is an ergot alkaloid used primarily for postpartum hemorrhage due to uterine atony. Do not use for routine induction of labor or for threatened abortion. Avoid in patients with hypertension, preeclampsia, coronary artery disease, or severe hepatic/renal disease. Monitor blood pressure closely during administration. Administer intramuscularly for rapid effect; onset is 2-5 minutes. Intravenous administration should be reserved for emergencies due to risk of hypertensive crisis. Contraindicated in pregnancy except immediately after delivery. Drug interactions: avoid concurrent use with strong CYP3A4 inhibitors (e.g., ketoconazole, macrolides, protease inhibitors) due to risk of ergotism and vasospasm. As of April 2025, there is no generic form; brand METHERGINE only.
Administer intramuscularly or intravenously (slow push over 1 minute) for uterine atony; avoid in hypertension, preeclampsia, and sepsis. Store ampules protected from light; discard if discolored. Contraindicated in impaired hepatic or renal function.
This medication is used to prevent or treat excessive bleeding after childbirth by causing contractions of the uterus.,Report immediately if you experience severe headache, chest pain, vision changes, muscle cramps, or numbness/tingling in the arms or legs.,Avoid breastfeeding within 8 hours after the last dose if possible; if breastfeeding is necessary, pump and discard for 8 hours to reduce infant exposure.,Do not use this medication if you have uncontrolled high blood pressure, heart disease, or liver/kidney disease.,Avoid alcohol and grapefruit juice while on this medication as they may affect blood levels.,Take this medication exactly as prescribed; do not take double doses if a dose is missed.
This medication may cause nausea, vomiting, or headache.,Report severe abdominal pain, chest pain, or difficulty breathing immediately.,Avoid driving or operating machinery if dizziness occurs.,Do not use during pregnancy except for postpartum hemorrhage.,Inform your doctor if you have high blood pressure, heart disease, or are breastfeeding.
No interactions on record
"Coadministration of bromocriptine, a dopamine D2 receptor agonist with vasoconstrictive properties, and ergometrine, an ergot alkaloid that acts as a partial agonist at alpha-adrenergic and serotonin receptors, synergistically increases peripheral vasoconstriction. This additive effect can lead to severe hypertension, myocardial ischemia, cerebral vasospasm, and potentially life-threatening ergotism. Patients may present with headache, chest pain, altered mental status, or peripheral ischemia."
"Nylidrin, a beta-adrenergic agonist, and ergometrine, an ergot alkaloid with vasoconstrictive properties, exhibit a synergistic hypertensive effect. By stimulating beta-2 receptors, nylidrin may cause peripheral vasodilation and reflex tachycardia, while ergometrine induces vasoconstriction via alpha-adrenergic and serotonin receptor activation. This opposing mechanism can lead to unopposed vasoconstriction, potentially resulting in severe hypertension, myocardial ischemia, or stroke."
"Simvastatin, a HMG-CoA reductase inhibitor, may increase the serum concentration of ergometrine, an ergot alkaloid used for postpartum hemorrhage, by inhibiting its metabolism via CYP3A4. This can lead to enhanced vasoconstrictive effects of ergometrine, potentially causing severe hypertension, myocardial ischemia, or peripheral vasospasm. Concomitant use poses a risk of ergotism, manifesting as ischemic complications, and should be approached with caution."
Common clinical questions about METHERGINE vs Ergometrine / Methylergonovine, answered by our medical review team.
METHERGINE is a Ergot Alkaloid Uterotonic that works by Methylergonovine is an ergot alkaloid that acts as a partial agonist at α-adrenergic receptors in the uterine smooth muscle, causing sustained contractions. It also exhibits serotonergic (5-HT2) and dopaminergic activity.. Ergometrine / Methylergonovine is a Ergot Alkaloid Uterotonic that works by Ergometrine and methylergonovine are ergot alkaloids that act as partial agonists at alpha-adrenergic, dopaminergic, and serotonergic (5-HT2) receptors. Their primary uterotonic effect is mediated by stimulation of 5-HT2 receptors in uterine smooth muscle, leading to sustained contractions and vasoconstriction.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between METHERGINE and Ergometrine / Methylergonovine depend on the specific clinical indication. These are both Ergot Alkaloid Uterotonic agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of METHERGINE is: 0.2 mg intramuscularly or intravenously after delivery of placenta and every 2-4 hours as needed, up to a maximum of 5 doses.. The standard adult dose of Ergometrine / Methylergonovine is: 0.2 mg intramuscularly or intravenously, repeated every 2-4 hours as needed, up to 5 doses total. Maximum single dose: 0.5 mg. Maximum total dose: 1 mg.. 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 METHERGINE and Ergometrine / Methylergonovine 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. METHERGINE is classified as Category C. Methergine (methylergonovine) is contraindicated in pregnancy due to its oxytocic properties and risk of uterine hyperstimulation, fetal distress, and abortion. First trimester: po. Ergometrine / Methylergonovine is classified as Category C. First trimester: Limited human data; animal studies show embryotoxicity and fetotoxicity at high doses due to uterotonic effects, but no structural malformations. Increased risk of. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.