methylergonovine

methylergonovine

 [meth″il-er″go-no´vin]

an oxytocic used as the maleate salt especially to prevent or combat postpartum hemorrhage or atony.

Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

methylergonovine

(meth-ill-er-goe-noe-veen) ,

Methergine

(trade name)

Classification

Therapeutic: oxytocic
Pharmacologic: ergot alkaloids

Pregnancy Category: C

Indications

Prevention and treatment of postpartum or postabortion hemorrhage caused by uterine atony or subinvolution.

Action

Directly stimulates uterine and vascular smooth muscle.

Therapeutic effects

Uterine contraction.

Pharmacokinetics

Absorption: Well absorbed following oral or IM administration.

Distribution: Unknown. Enters breast milk in small quantities.

Metabolism and Excretion: Probably metabolized by the liver.

Half-life: 30–120 min.

Time/action profile (effects on uterine contractions)

ROUTE	ONSET	PEAK	DURATION
PO	5–15 min	unknown	3 hr
IM	2–5 min	unknown	3 hr
IV	immediate	unknown	45 min–3 hr

Contraindications/Precautions

Contraindicated in: Hypersensitivity; Obstetric: Should not be used to induce labor; Lactation: Do not breast feed during treatment and for 12 hours after the last doseConcurrent use of potent CYP3A4 inhibitors

Use Cautiously in: Hypertensive or eclamptic patients (more susceptible to hypertensive and arrhythmogenic side effects);History of or risk factors for coronary artery diseaseSevere hepatic or renal disease;Sepsis.Concurrent use of moderate CYP3A4 inhibitors

Exercise Extreme Caution in: Obstetric: Third stage of labor.

Adverse Reactions/Side Effects

Central nervous system

• stroke (life-threatening)
• dizziness
• headache

Ear, Eye, Nose, Throat

• tinnitus

Respiratory

• dyspnea

Cardiovascular

• hypertension (life-threatening)
• arrhythmias
• AV block
• chest pain
• palpitations

Gastrointestinal

• nausea (most frequent)
• vomiting (most frequent)

Genitourinary

• cramps (most frequent)

Dermatologic

• diaphoresis

Neurologic

• paresthesia

Miscellaneous

• allergic reactions

Interactions

Drug-Drug interaction

Excessive vasoconstriction may result when used with heavy cigarette smoking (nicotine ), other vasopressors, such as dopamine, or beta-blockers.Potent CYP3A4 inhibitors, including erythromycin, clarithromycin, troleandomycin, ritonavir, indinavir, nelfinavir, delavirdine, ketoconazole, itraconazole, or voriconazole may ↑ levels and ↑ risk of ischemia; concurrent use contraindicatedModerate CYP3A4 inhibitors including saquinavir, nefazodone, fluconazole, fluoxetine, fluvoxamine, zileuton, or clotrimazole may ↑ levels; use with cautionCYP3A4 inducers including nevirapine and rifampin may ↓ levelsAnesthetics may ↓ its oxytocic propertiesMay ↓ the antianginal effects of nitrates Grapefruit juice may ↑ levels; use with caution

Route/Dosage

Oral (Adults) 200–400 mcg (0.2–0.4 mg) q 6–12 hr for 2–7 days.

Intramuscular Intravenous (Adults) 200 mcg (0.2 mg) q 2–4 hr for up to 5 doses.

Availability (generic available)

Tablets: 200 mcg (0.2 mg)

Injection: 200 mcg (0.2 mg)/mL

Nursing implications

Nursing assessment

• Monitor BP, heart rate, and uterine response frequently during medication administration. Notify health care professional promptly if uterine relaxation becomes prolonged or if character of vaginal bleeding changes.
• Assess for signs of ergotism (cold, numb fingers and toes, chest pain, nausea, vomiting, headache, muscle pain, weakness).
• Lab Test Considerations: If no response to methylergonovine, calcium levels may need to be assessed. Effectiveness of medication is ↓ with hypocalcemia.
  • May cause ↓ serum prolactin levels.

Potential Nursing Diagnoses

Acute pain (Side Effects)

Implementation

• Intravenous Administration

• Intravenous: IV administration is used for emergencies only. Oral and IM routes are preferred.
• Diluent: May be given undiluted or diluted in 5 mL of 0.9% NaCl and administered through Y site. Do not add to IV solutions. Do not mix in syringe with any other drug. Refrigerate; stable for storage at room temperature for 60 days; deteriorates with age. Use only solution that is clear and colorless and that contains no precipitate.Concentration: 0.2 mg/mL.
• Rate: Administer at a rate of 0.2 mg over at least 1 min.
• Y-Site Compatibility: heparin, hydrocortisone sodium succinate, potassium chloride, vitamin B complex with C

Patient/Family Teaching

• Instruct patient to take medication as directed; do not skip or double up on missed doses. If a dose is missed, omit it and return to regular dose schedule.
• Advise patient that medication may cause menstrual-like cramps.
• Caution patient to avoid smoking, because nicotine constricts blood vessels.
• Instruct patient to notify health care professional if infection develops, as this may cause increased sensitivity to the medication.
• Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care professional before taking other medications.

Evaluation/Desired Outcomes

• Contractions that maintain uterine tone and prevent postpartum hemorrhage.

Drug Guide, © 2015 Farlex and Partners