Methylergometrine maleate is a semi-synthetic ergot alkaloid derivative, primarily used as a potent uterotonic agent for the management of postpartum hemorrhage (PPH) and postpartum uterine atony. It acts as a partial agonist/antagonist at serotonin (5-HT2) receptors and a potent agonist at alpha-adrenergic receptors, leading to sustained, rhythmic uterine contractions with increased basal tone. In the Indian context, it is a critical, cost-effective first-line agent in active management of the third stage of labor (AMTSL) and for treating PPH, a leading cause of maternal mortality.
Adult: **Prevention/Treatment of PPH:** 0.2mg (200 mcg) intramuscularly or 0.2mg in 5ml Normal Saline IV slowly over 60 seconds, after delivery of anterior shoulder or after placental delivery. May repeat once if necessary. **Oral (for subinvolution):** 0.125mg to 0.25mg (125-250 mcg) two to three times daily for up to 7 days postpartum.
Note: **IV Route:** Administer SLOWLY over at least 60 seconds with continuous monitoring of BP and uterine response. Rapid IV injection can cause severe hypertension, CVA, seizures. **IM Route:** Preferred route for prophylaxis. Deep IM injection into a large muscle mass. **Oral:** Take with or after food to minimize GI upset. Do not crush/chew tablets. Use only for short-term postpartum therapy.
Methylergometrine induces sustained uterine contractions by directly stimulating the smooth muscle of the uterus. It increases the frequency, duration, and amplitude of contractions, and significantly elevates the resting tone (basal tonus). This mechanical compression of intramyometrial blood vessels is the key mechanism for controlling postpartum bleeding.
Pregnancy: **US FDA Category: C.** Contraindicated for use during pregnancy EXCEPT for its intended use in the active management of the third stage of labor and treatment of postpartum hemorrhage after delivery of the baby. It can induce uterine contractions and cause fetal distress or abortion if used earlier.
Driving: May cause dizziness, blurred vision, or syncope, especially with IV use or initial oral doses. Patients should be cautioned not to drive or operate machinery until they know how the drug affects them.
| Other Vasoconstrictors (e.g., Sympathomimetics: Epinephrine, Norepinephrine) | Potentiates hypertensive crisis, severe vasoconstriction | Major |
| CYP3A4 Inhibitors (e.g., Macrolides: Erythromycin, Clarithromycin; Azoles: Ketoconazole, Fluconazole; HIV Protease Inhibitors; Grapefruit juice) | Markedly increases Methylergometrine plasma levels, risk of severe toxicity (ergotism, ischemia) | Major |
| Nitrates (e.g., Nitroglycerin, Isosorbide dinitrate) | Potential antagonism of coronary vasodilatory effect of nitrates | Moderate |
| Beta-blockers (e.g., Propranolol) | May enhance vasoconstrictive effects, leading to peripheral ischemia | Moderate |
| Triptans (e.g., Sumatriptan), Other Ergot Alkaloids | Additive vasoconstrictive effects; risk of prolonged vasospasm | Major |
| Dopamine Antagonists (e.g., Metoclopramide, Domperidone) | Theoretical antagonism of uterine effect; clinical significance unclear | Minor |
Same composition (Methylergometrine (0.25mg)), different brands: