Methylergonovine

Following delivery of the placenta, for routine management of uterine atony, hemorrhage and subinvolution of the uterus. For control of uterine hemorrhage in the second stage of labor following delivery of the anterior shoulder.

Methylergonovine maleate acts directly on the smooth muscle of the uterus and increases the tone, rate, and amplitude of rhythmic contractions. Thus, it induces a rapid and sustained tetanic uterotonic effect which shortens the third stage of labor and reduces blood loss. Pharmacodynamics The onset of action after IV administration is immediate, after I.M. administration, 2 to 5 minutes, and after oral administration, 5 to 10 minutes. Pharmacokinetics Pharmacokinetic studies following an IV injection have shown that methylergonovine is rapidly distributed from plasma to peripheral tissues within 2 to 3 minutes or less. The bioavailability after oral administration was reported to be about 60% with no accumulation after repeated doses. During delivery, with intramuscular injection, bioavailability increased to 78%.

Orally The recommended dosage of Methylergonovine Maleate is One tablet, 0.2 mg, orally 3 or 4 times daily in the puerperium for a maximum of 1 week.

Hypertension, toxemia, pregnancy, and hypersensitivity.

General This drug should not be administered I.V. routinely because of the possibility of inducing sudden hypertensive and cerebrovascular accidents. If I.V. administration is considered essential as a lifesaving measure, methylergonovine maleate should be given slowly over a period of no less than 60 seconds with careful monitoring of blood pressure. Intra-arterial or periarterial injection should be strictly avoided. Caution should be exercised in the presence of impaired hepatic or renal function. Coronary artery disease Patients with coronary artery disease or risk factors for coronary artery disease (e.g., smoking, obesity, diabetes, high cholesterol) may be more susceptible to developing myocardial ischemia and infarction associated with methylergonovine-induced vasospasm.

Clinical trials experience Common Adverse Reactions The most common adverse reaction is hypertension associated in several cases with seizure and/or headache. Hypotension has also been reported. Abdominal pain (caused by uterine contractions), nausea and vomiting have occurred occasionally. Rare Adverse Reactions Rarely observed reactions have included: acute myocardial infarction, transient chest pains, vasoconstriction, vasospasm, coronary arterial spasm, bradycardia, tachycardia, dyspnea, hematuria, thrombophlebitis, water intoxication, hallucinations, leg cramps, dizziness, tinnitus, nasal congestion, diarrhea, diaphoresis, palpitation, rash, and foul taste. There have been rare isolated reports of anaphylaxis, without a proven causal relationship to the drug product.

CYP 3A4 Inhibitors (e.g., Macrolide Antibiotics and Protease Inhibitors) There have been rare reports of serious adverse events in connection with the coadministration of certain ergot alkaloid drugs (e.g., dihydroergotamine and ergotamine) and potent CYP 3A4 inhibitors, resulting in vasospasm leading to cerebral ischemia and/or ischemia of the extremities. Although there have been no reports of such interactions with methylergonovine alone, strong and moderate CYP 3A4 inhibitors should not be co-administered with methylergonovine. Examples of some of the strong CYP 3A4 inhibitors include saquinavir, grapefruit juice, nefazodone, macrolide antibiotics (e.g., troleandomycin, clarithromycin), HIV protease or reverse transcriptase inhibitors (e.g., ritonavir, indinavir, nelfinavir) or azole antifungals (e.g., ketoconazole, itraconazole, voriconazole).

Store and Dispense Tablets: Store at 20°C to 25°C (68°F to 77°F), excursions permitted to 15ºC to 30ºC (59ºF to 86ºF).