Methylergonovine maleate
Methylergonovine maleate (Methergine)
Methylergonovine maleate
(meth-ill-er- GON-oh-veen)
Pregnancy Category: C Methergine (Rx)

Classification: Oxytocic agent

Action/Kinetics: Synthetic drug related to ergonovine. Methylergonovine stimulates the rate, tone, and amplitude of uterine contractions. The uterus becomes more sensitive to the drug toward the end of pregnancy. Onset (uterine contractions): PO, 5-10 min; IM, 2-5 min; IV, immediate. t 1/2, IV: 2-3 min (initial) and 20-30 min (final). Duration, PO, IM: 3 hr; IV: 45 min.

Uses: Management and prevention of postpartum and postabortal hemorrhage by producing firm uterine contractions and decreasing uterine bleeding. During the second stage of labor following delivery of the anterior shoulder, but only under full obstetric supervision. Investigational: Ergonovine has been used to diagnose Prinzmetal's angina (variant angina).

Contraindications: Pregnancy, toxemia, hypertension. Ergot hypersensitivity. To induce labor or threatened spontaneous abortions. Administration before delivery of the placenta.

Special Concerns: Use with caution in sepsis, obliterative vascular disease, impaired renal or hepatic function, and during lactation.

Side Effects: CV: Hypertension that may be associated with seizure or headache; hypotension, thrombophlebitis, palpitation. GI: N&V, diarrhea, foul taste. CNS: Dizziness, headache, tinnitus, hallucinations. Miscellaneous: Sweating, chest pain, dyspnea, hematuria, water intoxication, leg cramps, nasal congestion.
NOTE: Use of methylergonovine during labor may result in uterine tetany with rupture, cervical and perineal lacerations, embolism of amniotic fluid as well as hypoxia and intracranial hemorrhage in the infant.

Overdose Management: Symptoms: Initially, N&V, abdominal pain, increase in BP, tingling of extremities, numbness. Symptoms of severe overdose include hypotension, hypothermia, respiratory depression, seizures, coma. Treatment: Induce vomiting or perform gastric lavage. Administer a cathartic; institute diuresis. Maintain respiration, especially if seizures or coma occur. Treat seizures with anticonvulsant drugs. Warm extremities to control peripheral vasospasm.

Drug Interactions: Hypertension may occur if methylergonovine is used with vasoconstrictors.

How Supplied: Injection: 0.2 mg /mL; Tablet: 0.2 mg

Dosage
?IM, IV (Emergencies Only)
0.2 mg q 2-4 hr following delivery of placenta, of the anterior shoulder, or during the puerperium.
?Tablets
0.2 mg t.i.d.-q.i.d. until danger of hemorrhage and uterine atony is over (usually within 2 days, but no more than 1 week).