Methylergonovine Maleate
Pronouncation: (METH-ill-err-go-NO-veen MAL-ee-ate)Class: Uterine stimulants
Trade Names:
Methergine
- Tablets 0.2 mg
- Injection 0.2 mg/mL
Pharmacology
Acts directly on smooth muscle of the uterus and increases tone, rate, and amplitude of rhythmic contractions, thereby inducing a rapid and sustained tetanic uterotonic effect that shortens the third stage of labor and reduces blood loss.
Pharmacokinetics
Absorption
OralBioavailability is about 60% with no accumulation after repeated doses. C max is 3,243 pg/mL within 1.12 h.
IMBioavailability is about 78%. C max is 5,918 pg/mL observed at 0.41 h. Decreased bioavailability following oral administration is probably caused by first-pass metabolism in liver.
Distribution
Vd about 56.1 L.
IVRapidly distributed to peripheral tissues within 3 min or less.
Metabolism
Plasma Cl about 14.4 L/h. Hepatic metabolism.
Elimination
Hepatic excretion. The decline in plasma concentration is biphasic with a mean elimination t ½ of 3.39 h.
Indications and Usage
Management after delivery of placenta; postpartum atony and hemorrhage; subinvolution; under full obstetric supervision, may be given in second stage of labor following delivery of the anterior shoulder.
Contraindications
Because of the risk of vasospasm leading to cerebral ischemia and ischemia of the extremities, do not use potent CYP3A4 inhibitors (eg, azole antifungal agents, macrolide antibiotics, protease inhibitors) concurrently; hypertension; toxemia; pregnancy; hypersensitivity to any component of product.
Dosage and Administration
AdultsIM/IV 0.2 mg after delivery of anterior shoulder, after delivery of placenta, or during puerperium. May repeat as required at intervals of 2 to 4 h. IV route should not be used routinely (see Precautions).
PO 0.2 mg 3 or 4 times daily in puerperium for a max of 1 wk.
Storage/Stability
Store tablets below 77°F. Store ampules in refrigerator (36° to 46°F). Protect from light.
Drug Interactions
Less potent CYP3A4 inhibitors (eg, clotrimazole, fluconazole, fluoxetine, fluvoxamine, grapefruit juice, nefazodone, saquinavir, zileuton)Because of the increased risk of adverse reactions, including vasospasm, use these agents with caution when administering with methylergonovine.
Potent CYP3A4 inhibitors (eg, azole antifungal agents [eg, itraconazole, ketoconazole, voriconazole], macrolide antibiotics [eg, clarithromycin, erythromycin, troleandomycin]), protease inhibitors [eg, delavirdine, indinavir, nelfinavir, ritonavir])Because of the risk of vasospasm, leading to cerebral ischemia and ischemia of the extremities, use of these agents is contraindicated with methylergonovine.
Laboratory Test Interactions
None well documented.
Adverse Reactions
Cardiovascular
Hypertension; hypotension; acute MI; transient chest pains; palpitation.
CNS
Headache; seizure; hallucinations; dizziness.
Dermatologic
Diaphoresis.
EENT
Tinnitus; nasal congestion.
GI
Nausea; vomiting; diarrhea; foul taste.
Genitourinary
Hematuria.
Hypersensitivity
Anaphylaxis.
Metabolic
Water intoxication.
Musculoskeletal
Leg cramps.
Respiratory
Dyspnea.
Miscellaneous
Thrombophlebitis.
Precautions
Pregnancy
Category C .
Lactation
Small quantity excreted in breast milk.
Children
Safety and efficacy not established.
Elderly
Use with caution because of the greater frequency of decreased hepatic, renal, or cardiac function, and concomitant diseases or other drug therapy.
Special Risk Patients
Use with caution in patients with sepsis, obliterative vascular disease, hepatic or renal involvement, or in second stage of labor.
Retained placenta
Manual removal of retained placenta should occur only rarely with proper technique and adequate allowance of time for spontaneous separation.
IV use
Because of possibility of inducing sudden hypertensive and cerebrovascular accidents, do not use IV administration for routine use. Consider administration as a lifesaving measure and give slowly over a period of at least 60 sec with careful monitoring of BP.
Overdosage
Symptoms
Nausea, vomiting, abdominal pain, numbness, tingling of extremities, rise in BP, hypotension, respiratory depression, hypothermia, convulsions, coma.
Patient Information
- Advise patient that injection will be prepared and administered by a health care provider in a medical setting.
- Advise patient taking tablets to take each dose without regard to meals but to take with food if stomach upset occurs.
- Advise patient to stop taking the medication and notify health care provider if any of the following occur: numbness, tingling, coldness, or paleness in the fingers or toes; muscle pain in arms or legs; weakness in the legs; chest pain, tightness, or pressure; changes in heart rate.
| Link to this page |  |
Printable Version |  |
Email Page |  |
Add to my drug list |
