Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
METHERGINE vs ERGOSTAT
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.
Ergostat (ergotamine) is a serotonin (5-HT) receptor agonist, specifically at 5-HT1B and 5-HT1D receptors, leading to cranial vasoconstriction and inhibition of neurogenic inflammation. It also has partial agonist/antagonist activity at alpha-adrenergic receptors.
Prevention and treatment of postpartum hemorrhage due to uterine atony,Management of incomplete abortion
FDA-approved: Acute treatment of migraine headache with or without aura,Off-label: Cluster headache, vascular headache
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 every 2-4 hours for maximum 5 doses; not to exceed 1 mg total dose.
Terminal elimination half-life is approximately 2–3 hours in healthy adults; prolonged in hepatic impairment.
Terminal half-life is 2–3 hours (intravenous) and 2–4 hours (oral). Short half-life necessitates frequent dosing; duration of action limited to 2–4 hours.
Primarily hepatic via CYP3A4 with significant first-pass metabolism; active metabolite is methylergonovine itself; excreted mainly in bile and urine.
Primarily hepatic via CYP3A4. Undergoes extensive first-pass metabolism.
Primarily hepatic metabolism; less than 1% excreted unchanged in urine. Biliary/fecal excretion accounts for ~80% of metabolites.
Primarily hepatic (biliary-fecal) elimination: ~90% of a dose is excreted in feces as metabolites; renal excretion accounts for <5% unchanged drug.
Approximately 93% bound, primarily to albumin and alpha-1-acid glycoprotein.
~65% bound to plasma albumin. Metabolites are less extensively bound.
0.6 L/kg (range 0.3–0.8 L/kg), indicating moderate distribution into tissues.
Approximately 0.2–0.3 L/kg, indicating primarily extracellular and peripheral tissue distribution with limited CNS penetration.
Oral bioavailability is approximately 10–20% due to extensive first-pass metabolism. Intramuscular administration provides 100% bioavailability.
Oral: ~10–20% (extensive first-pass metabolism); Sublingual: ~50–60% (avoids portal circulation); Rectal: ~30–40% (variable).
No specific dose adjustment recommended; use with caution in renal impairment due to risk of hypertension.
No specific adjustment; use with caution in severe renal impairment (GFR <30 m L/min) due to potential accumulation.
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%; Child-Pugh Class C: avoid use.
Not recommended for pediatric use; safety and efficacy in children have not been established.
Intravenous: 0.1 mg/m² body surface area every 2-4 hours, maximum 0.5 mg total; intramuscular: 0.2 mg every 2-4 hours, maximum 1 mg.
Use with caution in elderly patients due to increased sensitivity to vasoconstrictive effects and higher risk of hypertension and myocardial ischemia.
Start at 0.1 mg intramuscularly or intravenously; monitor for hypertension with higher doses.
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.
Concomitant use with strong CYP3A4 inhibitors (e.g., protease inhibitors, macrolide antibiotics, azole antifungals) can lead to serious and/or life-threatening peripheral ischemia and vasospasm. Avoid coadministration.
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.
Risk of ischemia (peripheral, cerebral, coronary) especially with prolonged use or overdose,Fibrotic complications (cardiac valvulopathy, pulmonary, retroperitoneal fibrosis) with chronic use,Medication overuse headache (MOH) with frequent use, Avoid in patients with uncontrolled hypertension, coronary artery disease, or peripheral vascular disease,Do not exceed recommended dosage; may cause ergotism
Hypersensitivity to ergot alkaloids,Pregnancy (for antepartum use),Hypertension, preeclampsia, or eclampsia,Peripheral vascular disease,Coronary artery disease,Severe hepatic or renal impairment,Sepsis
Concurrent use of potent CYP3A4 inhibitors (e.g., boceprevir, clarithromycin, ketoconazole, ritonavir)
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.
Avoid grapefruit juice as it may increase ergonovine levels. No other significant 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.
Ergostat (ergonovine) is contraindicated in pregnancy due to its potent uterotonic effects, which can cause uterine tetany, fetal hypoxia, and placental abruption. It is classified as FDA Pregnancy Category X. Use in the first trimester may increase the risk of spontaneous abortion; in the second and third trimesters, it can precipitate preterm labor and fetal distress. There is no evidence of structural teratogenicity from direct drug effects, but the potential for ischemic injury to the fetus due to uterine hyperstimulation exists.
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.
Ergonovine is excreted into breast milk. The M/P ratio is not well established, but small amounts are detectable. It may cause adverse effects in the nursing infant, including vomiting, diarrhea, and transient hypertension. Because of the risk of ergotism in the infant, breastfeeding is generally not recommended during therapy. A decision should be made to discontinue breastfeeding or discontinue the drug, considering the importance of the drug to the mother.
Not applicable; the drug is contraindicated during pregnancy. No dose adjustments are recommended for use during pregnancy as it should not be used.
No dosing adjustments are recommended or studied because use in pregnancy is contraindicated. If exposure occurs accidentally or for life-threatening indications (e.g., severe postpartum hemorrhage), the same doses used in non-pregnant adults (0.2 mg IM or IV) may be employed, but with extreme caution due to heightened sensitivity to uterotonic effects. No pharmacokinetic studies in pregnancy exist; however, increased plasma volume and altered hepatic metabolism may require careful titration, but no specific evidence supports dose changes.
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.
ERGOSTAT (ergonovine) is an ergot alkaloid used for postpartum hemorrhage. It causes sustained uterine contraction. Contraindicated in hypertension, preeclampsia, and vascular disease. Administer IM or IV slowly over 1 minute to avoid severe vasoconstriction. Monitor blood pressure and uterine tone closely. Do not use in patients with hypersensitivity to ergot alkaloids.
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 is given to control bleeding after childbirth.,It may cause nausea, vomiting, or dizziness.,Report severe headache, chest pain, or vision changes immediately.,Avoid smoking or using nicotine products while on this drug.,Do not breastfeed within 12 hours after the last dose; discuss with your doctor.
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 METHERGINE vs ERGOSTAT, 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.. ERGOSTAT is a Ergot Alkaloid Antimigraine that works by Ergostat (ergotamine) is a serotonin (5-HT) receptor agonist, specifically at 5-HT1B and 5-HT1D receptors, leading to cranial vasoconstriction and inhibition of neurogenic inflammation. It also has partial agonist/antagonist activity at alpha-adrenergic receptors.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between METHERGINE and ERGOSTAT 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 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 ERGOSTAT is: 0.2 mg intramuscularly or intravenously every 2-4 hours for maximum 5 doses; not to exceed 1 mg total dose.. 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 ERGOSTAT 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. ERGOSTAT is classified as Category C. Ergostat (ergonovine) is contraindicated in pregnancy due to its potent uterotonic effects, which can cause uterine tetany, fetal hypoxia, and placental abruption. It is classified. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.