Methylergometrine maleate is a semi-synthetic ergot alkaloid derivative used primarily in obstetrics and gynecology as a potent uterotonic agent. It acts as a partial agonist/antagonist at serotonin (5-HT2) receptors and a partial agonist at alpha-adrenergic receptors in uterine smooth muscle, leading to sustained, rhythmic contractions. It is a first-line agent in the Indian context for the prevention and treatment of postpartum hemorrhage (PPH), a leading cause of maternal mortality.
Adult: **Prevention/Treatment of PPH:** 0.125mg to 0.2mg (1 to 1.6 ml of 0.125mg/ml solution) intramuscularly or intravenously after delivery of the anterior shoulder, after delivery of the placenta, or during puerperium. May be repeated every 2-4 hours as needed. **Oral:** 0.125mg to 0.25mg two to four times daily for up to 7 days postpartum for uterine involution.
Note: For IM/IV use: Administer slowly over at least 60 seconds. Rapid IV injection can cause severe hypertension, cerebrovascular accident, and seizures. Oral tablets should be taken with or without food. Strict aseptic technique for parenteral administration. Monitor vital signs, especially blood pressure, and uterine response closely.
Methylergometrine produces sustained tonic contraction of uterine smooth muscle by directly stimulating the alpha-adrenergic and serotonin (5-HT2) receptors. Unlike oxytocin, it increases both the frequency and amplitude of uterine contractions, and its effect persists for several hours. It also has moderate vasoconstrictive properties.
Pregnancy: **Category X.** Contraindicated for use during pregnancy except for its approved use in the management of the third stage of labor and postpartum hemorrhage. Can cause fetal distress, hypoxia, or death due to uterine tetany and vasoconstriction of the uteroplacental vessels if used before delivery.
Driving: May cause dizziness, blurred vision, or hypotension. Patients should be cautioned against driving or operating machinery until they know how the drug affects them.
| CYP3A4 Inhibitors (e.g., Clarithromycin, Erythromycin, Ketoconazole, Itraconazole, Ritonavir) | Markedly increased plasma levels of methylergometrine, leading to severe toxicity (ergotism, vasospasm, hypertension). | Major - Contraindicated or use with extreme caution. |
| Other Vasoconstrictors (e.g., Sumatriptan, Ergotamine, Norepinephrine) | Additive vasoconstrictive effects, increasing risk of severe hypertension and ischemia. | Major |
| Beta-blockers (e.g., Propranolol) | Potentiation of vasoconstrictive effects, may lead to peripheral ischemia. | Moderate |
| Nitrates (e.g., Nitroglycerin) | Nitrates may counteract the vasoconstrictive effects of methylergometrine. | Moderate |
| Dopamine Agonists (e.g., Bromocriptine) | Increased risk of vasospasm and hypertension. | Moderate |
Same composition (Methylergometrine (0.125mg)), different brands: