meth-ill-er-goe-NOE-veen

Therapeutic Classification: oxytocics

Pharmacologic Classification: ergot alkaloids

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

• Directly stimulates uterine and vascular smooth muscle.

• Uterine contraction.

Absorption: Well absorbed following oral or IM administration.

Distribution: Widely distributed to tissues.

Metabolism/Excretion: Probably metabolized by the liver.

Half-life: 30–120 min.

(effects on uterine contractions)

Contraindicated in:

• Hypersensitivity
• Concurrent use of strong CYP3A4 inhibitors
• OB: Should not be used to induce labor
• Lactation: Lactation.

Use Cautiously in:

• Hypertensive or eclamptic patients (more susceptible to hypertensive and arrhythmogenic side effects)
• History of or risk factors for coronary artery disease
• Severe renal impairment
• Severe hepatic impairment
• Sepsis.

Exercise Extreme Caution in:

• OB: Third stage of labor.

CV: arrhythmias, chest pain, heart block, HYPERTENSION, palpitations.

Derm: ↑sweating.

EENT: tinnitus.

GI: nausea, vomiting.

GU: cramps.

Neuro: dizziness, headache, paresthesia, STROKE.

Resp: dyspnea.

Drug-Drug:

• Strong CYP3A4 inhibitors, including erythromycin, clarithromycin, ritonavir, nelfinavir, ketoconazole, itraconazole, or voriconazole, may ↑ levels and ↑ risk of ischemia; concurrent use contraindicated.
• Excessive vasoconstriction may result when used with heavy cigarette smoking (nicotine), other vasopressors, such as dopamine, or beta-blockers.
• Moderate CYP3A4 inhibitors, including nefazodone, fluconazole, fluoxetine, fluvoxamine, zileuton, or clotrimazole, may ↑ levels and risk of toxicity; use concurrently with caution.
• CYP3A4 inducers, including nevirapine and rifampin, may ↓ levels and effectiveness.
• Anesthetics may ↓ its oxytocic properties
• May ↓ the antianginal effects of nitrates.

Drug-Food:

• Grapefruit juice may ↑ levels and risk of toxicity; use concurrently with caution.

• PO (Adults): 0.2–0.4 mg every 6–12 hr for 2–7 days.
• IM, IV (Adults): 0.2 mg every 2–4 hr for up to 5 doses.

(Generic available)

• Tablets: 0.2 mg;
• Injection: 0.2 mg/mL;

• 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).

• If no response to methylergonovine, calcium levels may need to be assessed. Effectiveness of medication is ↓ with hypocalcemia.
  • May cause ↓ serum prolactin levels.

IV Administration:

• IV: IV administration is used for emergencies only. Oral and IM routes are preferred.
• 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.0.2 mg/mL.
• Rate: Administer at a rate of 0.2 mg over at least 1 min.
• Y-Site Compatibility:
  • heparin
  • hydrocortisone
  • potassium chloride
.

• 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.

• Contractions that maintain uterine tone and prevent postpartum hemorrhage.

Methergine