Methergin
Methergin - General Information
A homolog of ergonovine containing one more CH2 group. (Merck Index, 11th ed)
Pharmacology of Methergin
Methergin is a semisynthetic ergot alkaloid and a derivative of ergonovine and is used for the prevention and control of postpartum and post-abortion hemorrhage. In general, the effects of all the ergot alkaloids appear to results from their actions as partial agonists or antagonists at adrenergic, dopaminergic, and tryptaminergic receptors. The spectrum of effects depends on the agent, dosage, species, tissue, and experimental or physiological conditions. All of the alkaloids of ergot significantly increase the motor activity of the uterus. After small doses contractions are increased in force or frequency, or both, but are followed by a normal degree of relaxation. As the dose is increased, contractions become more forceful and prolonged, resting tonus is markedly increased, and sustained contracture can result.
Methergin for patients
Some blood-vessel disorders and certain infections make the use of Methergine dangerous. Make sure your doctor is aware of any medical conditions you may have. You should not take Methergine if you are allergic to it, if you are pregnant, or if you have high blood pressure or toxemia (poisons circulating in the blood). It may be dangerous to take Methergine if you have an infection, certain blood vessel disorders, or a liver or kidney problem. Inform your doctor if you think you have any such condition. Your doctor will use intravenous Methergine only when necessary, because of the possibility of a sudden rise in blood pressure or a stroke.
Methergin Interactions
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, potent CYP 3A4 inhibitors should not be coadministered with methylergonovine. Examples of some of the more potent CYP 3A4 inhibitors include macrolide antibiotics (e.g., erythromycin, troleandomycin, clarithromycin), HIV protease or reverse transcriptase inhibitors (e.g., ritonavir, indinavir, nelfinavir, delavirdine) or azole antifungals (e.g., ketoconazole, itraconazole, voriconazole). Less potent CYP 3A4 inhibitors should be administered with caution. Less potent inhibitors include saquinavir, nefazodone, fluconazole, grapefruit juice, fluoxetine, fluvoxamine, zileuton, and clotrimazole. These lists are not exhaustive, and the prescriber should consider the effects on CYP 3A4 of other agents being considered for concomitant use with methylergonovine.
No pharmacokinetic interactions involving other cytochrome P450 isoenzymes are known.
Caution should be exercised when Methergine® (methylergonovine maleate) is used concurrently with other vasoconstrictors or ergot alkaloids.
Methergin Contraindications
Hypertension; toxemia; pregnancy; and hypersensitivity.
Additional information about Methergin
Methergin Indication: For the prevention and control of excessive bleeding following vaginal childbirth
Mechanism Of Action: Methergin acts directly on the smooth muscle of the uterus and increases the tone, rate, and amplitude of rhythmic contractions through binding and the resultant antagonism of the dopamine D1 receptor. Thus, it induces a rapid and sustained tetanic uterotonic effect which shortens the third stage of labor and reduces blood loss.
Drug Interactions: Not Available
Food Interactions: Not Available
Generic Name: Methylergonovine
Synonyms: Methylergometrine; Methylergonovin; Methylergometrin; Methylergobrevin; Methylergobasine; Methylergobasin; methylergonovine maleate
Drug Category: Oxytocics
Drug Type: Small Molecule; Approved
Other Brand Names containing Methylergonovine: Basofortina; Metenarin; Methergen; Methergin; Methergine; Norforms; Partergin; Ryegonovin; Spametrin-M;
Absorption: Absorption is rapid after oral (60% bioavailability) and intramuscular (78% bioavailability) administration.
Toxicity (Overdose): Signs and symptoms of overexposure: hypertension, seizures, headache, hypotension, nausea, and vomiting.
Protein Binding: Not Available
Biotransformation: Hepatic, with extensive first-pass metabolism.
Half Life: 3.39 hours
Dosage Forms of Methergin: Tablet Oral
Solution Intramuscular
Solution Intravenous
Chemical IUPAC Name: Not Available
Chemical Formula: C20H25N3O2
Methylergonovine on Wikipedia: https://en.wikipedia.org/wiki/Methylergonovine
Organisms Affected: Humans and other mammals
