Methergine (Methylergonovine) for Postpartum Hemorrhage
For postpartum patients with excessive uterine bleeding due to atony, administer methylergonovine 0.2 mg intramuscularly as a second-line uterotonic after oxytocin, with the option to repeat every 2-4 hours up to a maximum of 5 doses (1 mg total daily), while simultaneously administering tranexamic acid 1 gram IV if within 3 hours of delivery.
Dosing and Administration
- Standard dose: 0.2 mg intramuscularly, which can be repeated every 2-4 hours as needed for persistent uterine atony 1
- Maximum daily dose: 1 mg total (5 doses) 1
- Route: Intramuscular is preferred; intravenous administration should be avoided due to risk of severe hypertension and coronary vasospasm 2
Position in Treatment Algorithm
- First-line therapy: Oxytocin remains the initial uterotonic agent for postpartum hemorrhage 3, 4
- Second-line therapy: Methylergonovine is indicated when oxytocin alone fails to control bleeding from uterine atony 1, 4
- Comparative effectiveness: Methylergonovine demonstrates superior outcomes compared to carboprost, with a 40% reduction in hemorrhage-related morbidity (RR 1.7 for carboprost vs methylergonovine) 1
Concurrent Tranexamic Acid Administration
- Timing is critical: Administer tranexamic acid 1 gram IV within 3 hours of birth alongside methylergonovine for any clinically diagnosed postpartum hemorrhage (>500 mL vaginal delivery or >1000 mL cesarean) 5, 6
- Second dose: Give an additional 1 gram if bleeding continues after 30 minutes or restarts within 24 hours 5
- Mortality benefit: Early tranexamic acid reduces maternal death from hemorrhage and should be considered standard therapy, not reserved for refractory cases 5, 6
- Time-dependent efficacy: Benefit decreases by 10% for every 15-minute delay, with no benefit after 3 hours 5
Critical Contraindications
Absolute contraindications for methylergonovine include:
- Hypertension or preeclampsia: Methylergonovine causes significant vasoconstriction and can precipitate hypertensive crisis 4
- Coronary artery disease or risk factors: Can induce severe coronary vasospasm leading to myocardial ischemia, even with intramuscular administration 2
- Peripheral vascular disease: Ergot alkaloids cause potent vasoconstriction 4
Safety Monitoring
- Cardiovascular complications: Be vigilant for chest pain, as methylergonovine can cause coronary vasospasm even via intramuscular route, requiring immediate sublingual nitroglycerin 2
- Blood pressure monitoring: Check blood pressure before and after administration due to vasoconstrictive effects 4
- Smoking history: Exercise particular caution in smokers, who have increased risk of vasospastic complications 2
Clinical Pitfalls to Avoid
- Do not delay tranexamic acid: The 3-hour window is absolute; giving tranexamic acid beyond this timeframe may be harmful rather than beneficial 5
- Do not give methylergonovine intravenously: This route dramatically increases risk of severe hypertension and coronary vasospasm 2
- Do not use as monotherapy: Methylergonovine should supplement, not replace, oxytocin as the foundation of uterotonic therapy 3, 4
- Do not exceed maximum dosing: Total daily dose should not exceed 1 mg (5 doses of 0.2 mg) 1
Escalation Strategy
If bleeding persists despite maximum methylergonovine dosing:
- Surgical interventions: Proceed to uterine compression sutures, hypogastric artery ligation, or interventional radiology embolization 6
- Massive transfusion protocol: Maintain 1:1:1 ratio of packed red blood cells:fresh frozen plasma:platelets 6
- Fibrinogen monitoring: Target levels >200 mg/dL as hypofibrinogenemia predicts severe hemorrhage 6