Methylergonovine
Rapid Review
- Mechanism of Action: Uterotonic agent; increases uterine contraction force and frequency to decrease post-partum hemorrhage and aid in passage of retained products after abortion/miscarriage.
- Indications: Postpartum hemorrhage,
- Contraindications: Allergy to class/drug, pregnancy, hypertension
- Dosage: 0.2 mg IV/IM q 2-4 hours (max five doses)
- Onset: Immediate (IV); 2-5 minutes (IM)
- Duration: 45 minutes (IV); 3 hours (IM)
- Adverse Reactions: Seizures, bradycardia, hypertension, stroke
- Special Considerations: None
Pearls
- Although methylergonovine can be used for uterine atony in post-partum hemorrhage, oxytocin remains the first-line agent.
- Methylergonovine may play a role in treating refractory cluster headaches, though this an off-label use.
Deep Dive
Misoprostol
Rapid Review
- Mechanism of Action: Prostaglandin; binds to myometrial cells and causes strong myometrial contractions.
- Indications: Induction of labor, treatment of post-partum hemorrhage, medical management of miscarriage, medical abortion.
- Contraindications: Allergy to drug/class
- Dosage: 800 mcg PO or 1,000 mcg rectally
- Onset: 8 minutes
- Duration: 2 hours
- Adverse Reactions: Anaphylaxis, uterine rupture, diarrhea, headache.
- Special Considerations: None
Pearls
- Oxytocin is still the first-line uterotonic medication for post-partum hemorrhage, though adding misoprostol may increase the effectiveness.
- Misoprostol additionally provides cytoprotection of the gastrointestinal mucosa, which is why it is FDA approved for the prevention/treatment of NSAID-induced gastric ulcers.
Deep Dive
RhoGAM
Rapid Review
- Mechanism of Action: Immunoglobulin; prevents isoimmunization by suppressing immune response by Rh negative individuals against Rh positive blood cells.
- Indications: Risk of maternal/fetal hemorrhage, ectopic pregnancy, miscarriage
- Contraindications: Allergy to drug, prior sensitization of mother, known Rh-negative father, known Rh-negative fetus.
- Dosage: 50-300mcg (IM)
- Onset: Peak plasma time of 5-10 days (IM)
- Duration: 12 weeks
- Adverse Reactions: Nausea, vomiting, diarrhea, general ill feeling
- Special Considerations: N/A
Pearls
- RhoGam does not need to be administered to Rh + mothers.
- RhoGam reduces the risk of antibody formation from 12% to approximately 1%.
Deep Dive
Emergency Medicine Physician Assistant. Duke University Graduate. Army National Guard PA/Combat Medic. Former Paramedic. Devoted to learning and sharing evidence-based medicine.