methylergonovine

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.

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

Contraind./Precautions ⬆ ⬇

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.

OB: Third stage of labor.

Adv. Reactions/Side Effects ⬆ ⬇

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

Derm: ↑sweating

EENT: tinnitus

GI: nausea, vomiting

GU: cramps

Neuro: dizziness, headache, paresthesia, STROKE

Resp: dyspnea

Interactions ⬆ ⬇

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.

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

Route/Dosage ⬆ ⬇

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.

Availability ⬆ ⬇

(Generic available)

Tablets: 0.2 mg
Injection: 0.2 mg/mL

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.

Implementation ⬆ ⬇

IV Administration:

IV: 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.

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.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇