Methylergonovine (Methergine)
Methergine
Ergot alkaloid uterotonic (semi-synthetic)
Direct uterine smooth muscle stimulant — potent + sustained contraction. Also vasoconstrictor (especially coronary + cerebral arteries) → CONTRAINDICATED in HTN, preeclampsia, CAD.
Indications
- •Postpartum hemorrhage from uterine atony — second-line after oxytocin
- •Subinvolution of uterus postpartum
Dosing
| Context | Adult | Pediatric |
|---|---|---|
| Postpartum hemorrhage | 0.2 mg IM q2-4 h max (slow IV 0.2 mg over 1 min — generally avoided due to severe HTN) | — |
Pharmacokinetics
Onset IM 2-7 min, IV 1-5 min. Duration ~3 h. Hepatic metabolism.
Hemodynamic effects
↑BP (significant — vasoconstriction). Coronary spasm + cerebral vasoconstriction reported. Avoid IV if alternatives available.
Side effects
- !Severe HYPERTENSION (especially with rapid IV)
- !Coronary vasospasm + MI
- !Cerebral vasoconstriction + stroke (with IV bolus)
- !Nausea + vomiting
- !Headache
Contraindications
- ×HYPERTENSION (any) — absolute
- ×Preeclampsia/eclampsia
- ×Coronary artery disease
- ×Peripheral vascular disease
- ×Concurrent CYP3A4 inhibitors (severe vasospasm reported)
Clinical pearls
- ★PPH stepwise: oxytocin → METHYLERGONOVINE → carboprost → misoprostol → mechanical/surgical.
- ★HYPERTENSION + PREECLAMPSIA — major contraindication. Skip to carboprost or misoprostol.
- ★Give IM, NOT IV (severe HTN with IV bolus). IV reserved for life-threatening hemorrhage when other agents unavailable.
- ★Prepare antihypertensive (labetalol, nicardipine) ready when given.
- ★Avoid in patients with HIV protease inhibitors, azole antifungals, macrolides (CYP3A4 inhibitors → severe vasospasm).
Education only — confirm against current package inserts and institutional protocols. Doses assume normal organ function unless otherwise noted.