Methysergide Maleate

A to Z Drug Facts

 Action Semisynthetic ergot derivative possessing no intrinsic vasoconstrictor activity; believed to work by antagonizing effects of serotonin in lowering pain threshold.

 Indications Prevention or reduction of intensity of severe and frequent (once weekly or more) vascular headaches; prophylaxis of vascular headache. Not for management of acute attack.

 Contraindications Pregnancy; peripheral vascular disease; severe arteriosclerosis; severe hypertension; coronary artery disease; phlebitis or cellulitis in lower limbs; ulmonary disease; collagen disease or fibrotic processes; impaired liver or renal function; valvular heart disease; debilitated states; serious infections.

 Route/Dosage

ADULTS: PO 4–8 mg daily with meals. There must be drug-free interval of 3–4 wk after 6 mo of treatment.

 Interactions

Beta blockers: May result in peripheral ischemia, manifested by cold extremities with possible peripheral gangrene.

 Lab Test Interferences None well documented.

 Adverse Reactions

CV: Encroachment of retroperitoneal fibrosis on aorta, inferior vena cava and common iliac branches may cause vascular insufficiency of lower limbs; fibrotic thickening of cardiac valves; murmurs; bruits; arterial vasoconstriction causing chest pain; coldness, numbness or pain in extremities; diminished or absent pulse; ischemic tissue damage; orthostatic hypotension; tachycardia; eripheral edema. CNS: Insomnia; drowsiness; mild euphoria; dizziness; ataxia; weakness; lightheadedness; yperesthesia; hallucinatory dissociation; parasthesias. DERM: Facial flush; telangiectasia; rash; initial increased hair loss. GI: Nausea; vomiting; diarrhea; heartburn; abdominal pain; constipation. HEMA: Neutropenia; eosinophilia. RESP: Pleuropulmonary fibrosis. OTHER: Arthralgia; myalgia; weight loss.

 Precautions

Pregnancy: Contraindicated in pregnancy due to oxytocic properties. Lactation: Excreted in breast milk. Children: Not recommended for children. Fibrosis: Long-term methylsergide therapy may cause retroperitoneal fibrosis, pleuropulmonary fibrosis and fibrotic complications within cardiovascular system. These may be reversible. This drug should be reserved for prophylaxis of frequent, severe or uncontrollable vascular headaches under close supervision. To reduce fibrotic risks, continuous use should not exceed 6 mo. Reduce dosage gradually over 2–3 wk to avoid “rebound headache.” Provide 3–4 wk drug-free interval between each 6-mo course of therapy. Tartrazine sensitivity: Contains tartrazine, which may cause allergic reactions in susceptible people.

 Administration/Storage

• Administer as supplied; do not crush.
• Give with meals.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies. Note tartrazine sensitivity.
• Obtain cardiac and renal function studies, blood count and sedimentation rate before administration and monitor throughout therapy.
• Palpate for diminished or absent peripheral pulses, changes in extremity color/temperature or peripheral edema throughout prolonged therapy.
• Implement appropriate safety precautions, as patient may be at risk for falls due to insomnia, lightheadedness, hyperesthesia or hallucinatory experiences.
• Notify physician of orthostatic hypotension or tachycardia, chest or flank pain, leg cramps or shortness of breath.

 Patient/Family Education

• Caution patient that this medication must not be taken during pregnancy or when pregnancy is possible. Advise patient to use reliable form of birth control while taking this drug.
• Explain that medication can be taken with food or milk if GI upset occurs.
• Tell patient that medication may cause drowsiness and to use caution while driving or performing other tasks requiring mental alertness, coordination, dexterity.
• Instruct patient or family member to check regularly for cold or numb extremities.
• Advise patient to report these symptoms to physician immediately: eg cramps, chest pain, flank pain, shortness of breath or painful urination.
• Caution patient to avoid sudden position changes to prevent orthostatic hypotension.
• Tell patient to consult physician after 6 mo of therapy regarding tapering of regimen.
• Explain that medication should not be discontinued abruptly; which may cause rebound headache.
• Educate patient to report rapid weight gain and to check for peripheral edema. Explain benefits of low salt, reduced calorie diet if necessary.

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Copyright © 2003 Facts and Comparisons
David S. Tatro
A to Z Drug Facts