Drug Guide

Generic Name

Methylergonovine Maleate

Brand Names Methergine

Classification

Therapeutic: Uterotonics; Ergot Alkaloids

Pharmacological: Alpha-adrenergic agonist, serotonin receptor agonist

FDA Approved Indications

  • Prevention and treatment of postpartum hemorrhage due to uterine atony

Mechanism of Action

Stimulates alpha-adrenergic and serotonin receptors on uterine smooth muscle, causing vasoconstriction and increased uterine tone, thus reducing bleeding.

Dosage and Administration

Adult: 0.2 mg IM every 2-4 hours as needed, max 5 doses within 24 hours

Pediatric: Not generally used in children

Geriatric: Use with caution, dose adjustments not specifically established

Renal Impairment: Use cautiously; no specific dosage adjustment available

Hepatic Impairment: Use cautiously; no specific dosage adjustment available

Pharmacokinetics

Absorption: Rapid IM absorption

Distribution: Widely distributed, crosses the placenta and enters breast milk

Metabolism: Hepatic metabolism

Excretion: Eliminated mainly in feces, minor renal excretion

Half Life: About 3-4 hours

Contraindications

  • Uncontrolled hypertension
  • History of ergot alkaloid sensitivity
  • Vascular disease
  • Pregnancy

Precautions

  • Monitor blood pressure closely, especially in hypertensive patients; use with caution in cardiovascular disease

Adverse Reactions - Common

  • Hypertension (Common)
  • Nausea, vomiting (less common) (Less common)

Adverse Reactions - Serious

  • Vasospasm, acute hypertension, stroke (Rare)
  • Uterine rupture (rare) (Rare)

Drug-Drug Interactions

  • Other vasoconstrictors or adrenergic drugs, which may increase hypertension risk

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor blood pressure, uterine tone, bleeding, and signs of vasospasm

Diagnoses:

  • Risk for hypertension
  • Ineffective tissue perfusion

Implementation: Administer as ordered, monitor response, and assess for adverse effects

Evaluation: Effectiveness in reducing bleeding, maintaining safe blood pressure levels

Patient/Family Teaching

  • Report chest pain, severe headache, high blood pressure, or signs of allergic reaction
  • Do not use in pregnancy unless prescribed by a healthcare provider for postpartum hemorrhage

Special Considerations

Black Box Warnings:

  • Potential for serious and life-threatening hypertension and vasospasm

Genetic Factors: None established

Lab Test Interference: None

Overdose Management

Signs/Symptoms: Severe hypertension, vasospasm, cold, clammy extremities, decreased pulse

Treatment: Discontinue drug, provide supportive care, treat hypertensive crisis with antihypertensive agents as needed

Storage and Handling

Storage: Store at room temperature, protect from light and moisture

Stability: Stable under recommended storage conditions for the specified shelf life

This guide is for educational purposes only and is not intended for clinical use.