METHYLERGONOVINE MALEATE
Clinical safety rating: avoid
Positive evidence of fetus risks but benefits may outweigh risks in some cases
Ergot alkaloid; partial agonist/antagonist at alpha-adrenergic, serotonin (5-HT2), and dopamine receptors; directly stimulates uterine smooth muscle contractions.
| Metabolism | Hepatic (CYP3A4); extensive first-pass metabolism. |
| Excretion | Renal (approximately 60-80% as metabolites, <1% unchanged); biliary/fecal (minor route, approximately 20-30%) |
| Half-life | Biphasic: initial (alpha) ~10-30 min; terminal (beta) ~2-3 hours in normal subjects; prolonged to ~6-12 hours in hepatic impairment or pregnancy |
| Protein binding | Approximately 65-85% bound to plasma proteins (primarily albumin and α1-acid glycoprotein) |
| Volume of Distribution | 0.4-0.8 L/kg; distributes rapidly into tissues including uterus, liver, and kidney |
| Bioavailability | Oral: approximately 60%; Intramuscular: nearly 100% (due to first-pass metabolism reducing oral availability) |
| Onset of Action | Intravenous: ~30-60 seconds; Intramuscular: ~2-5 minutes; Oral: ~15-30 minutes |
| Duration of Action | Intravenous/Intramuscular: 2-4 hours (uterine contraction); Oral: 3-6 hours; clinical effect on uterine tone persists for 6-8 hours |
0.2 mg intramuscularly or intravenously once, may repeat as needed every 2-4 hours for a maximum of 5 doses.
| Dosage form | TABLET |
| Renal impairment | No specific guidelines; use with caution in severe renal impairment (eGFR <30 mL/min/1.73m2) due to potential for hypertensive effects. |
| Liver impairment | Child-Pugh Class A: no adjustment; Child-Pugh B or C: reduce dose by 50% or avoid use due to increased risk of toxicity. |
| Pediatric use | Not recommended for use in children; safety and efficacy not established. |
| Geriatric use | Use with caution; consider lower initial dose (0.1 mg) due to increased sensitivity to hypertensive effects and potential for cerebrovascular or cardiovascular events. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Strong CYP3A4 inhibitors are contraindicated due to risk of ergotism Contraindicated in hypertension and coronary artery disease.
| Breastfeeding | Methylergonovine is excreted into human breast milk in small amounts. The milk-to-plasma ratio is approximately 0.2-0.5. It is generally considered compatible with breastfeeding when used for short-term management of postpartum hemorrhage. However, it may cause uterine cramping and transient decreases in milk production. Monitor the infant for signs of ergotism (e.g., vomiting, diarrhea, seizures) which are rare. |
| Teratogenic Risk | Methylergonovine maleate is contraindicated during pregnancy due to its oxytocic effects, which can induce uterine contractions and potentially lead to fetal distress, miscarriage, or premature labor. It is classified as FDA Pregnancy Category C. There are no adequate and well-controlled studies in pregnant women. Studies in animals have shown teratogenic effects at high doses, but the relevance to humans is uncertain. Avoid use in the first and second trimesters unless clearly needed for postpartum hemorrhage unresponsive to other therapies. |
■ FDA Black Box Warning
Not for use during pregnancy except for severe hemorrhage; can cause fetal harm. Do not use for elective induction of labor or threatened abortion.
| Common Effects | Nausea |
| Serious Effects |
["Hypertension","Preeclampsia/eclampsia","Ischemic heart disease","Peripheral vascular disease","Severe hepatic or renal impairment","Sepsis","Concurrent therapy with potent CYP3A4 inhibitors (e.g., macrolide antibiotics, azole antifungals, protease inhibitors)"]
| Precautions | ["Risk of severe hypertension, especially in preeclampsia/eclampsia","May cause myocardial ischemia/angina","Caution in patients with coronary artery disease or hypertension","May cause stroke or seizures in susceptible patients","Concurrent use with potent CYP3A4 inhibitors increases toxicity"] |
| Food/Dietary |
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| Fetal Monitoring | Monitor blood pressure, uterine tone and bleeding, fetal heart rate (if still pregnant), and signs of ergotism (hypertension, seizures, peripheral ischemia). For postpartum use, assess lochia and fundal height. Discontinue if signs of excessive uterine stimulation or fetal distress occur. |
| Fertility Effects | No known adverse effects on fertility in humans. However, due to its vasoconstrictive and oxytocic properties, theoretical interference with implantation or early pregnancy maintenance is possible. Use in early pregnancy is contraindicated. |
| Avoid excessive caffeine intake (e.g., coffee, tea, energy drinks) as it may increase the risk of vasoconstriction and hypertensive effects. Grapefruit juice may inhibit CYP3A4 metabolism, increasing methylergonovine levels; avoid concurrent consumption. |
| Clinical Pearls | Methylergonovine maleate is an ergot alkaloid used for prevention and treatment of postpartum hemorrhage caused by uterine atony. It is contraindicated in hypertension, preeclampsia, eclampsia, and during pregnancy (oxytocic effect). Administer after delivery of the placenta. Monitor blood pressure closely; may cause severe hypertension and stroke, especially in patients with preexisting hypertensive disorders. Intravenous administration should be slow over at least 60 seconds to minimize hypertensive effects. Concomitant use with strong CYP3A4 inhibitors (e.g., protease inhibitors, macrolides) or other vasoconstrictors (e.g., triptans) is contraindicated due to risk of ergotism. |
| Patient Advice | This medication is given after childbirth to prevent or treat excessive bleeding by contracting the uterus. · Immediately report symptoms such as severe headache, chest pain, vision changes, or difficulty breathing. · Avoid breastfeeding for at least 8-12 hours after the last dose, as the drug passes into breast milk. · Do not take any other medications, especially ergot derivatives or vasoconstrictors, without consulting your healthcare provider. · This drug is for hospital use only and will be administered by a healthcare professional. |