sumatriptan succinate

sumatriptan succinate

(sue mah trip' tan)

Imitrex

Pregnancy Category C

Drug classes

Antimigraine drug (triptan)

Serotonin-selective agonist

Therapeutic actions

Binds to serotonin receptors to cause vascular constrictive effects on cranial blood vessels, causing the relief of migraine in selective patients.

Indications

·        Treatment of acute migraine attacks with or without aura (oral, nasal)

·        Acute treatment of cluster headaches (subcutaneous injection)

Contraindications and cautions

·        Contraindicated with allergy to sumatriptan, cerebrovascular or peripheral vascular syndromes, severe hepatic impairment, MAOIs, uncontrolled hypertension, hemiplegic migraine, pregnancy, coronary artery disease.

·        Use cautiously with the elderly, lactation, renal function impairment.

Available forms

Tablets—25, 50, 100 mg; injection—6 mg/0.5 mL; nasal spray—5, 20 mg

Dosages

ADULTS

Oral

25, 50, or 100 mg; additional doses may be repeated in > 2 hr; up to a maximum of 200 mg/day.

Subcutaneous

6 mg, may be repeated in 1 hr. Maximum, 12 mg/24 hr.

Intranasal

5, 10, or 20 mg, may be repeated after 2 hr. Maximum, 40 mg/24 hr.

PEDIATRIC PATIENTS

Safety and efficacy not established.

PATIENTS WITH HEPATIC IMPAIRMENT

Maximum single dose, 50 mg.

Pharmacokinetics

Route	Onset	Peak
SC	Varies	5–20 min
Oral	60–90 min	2–4 hr
Injection	Rapid	90 min

Metabolism: Hepatic; T_1/2: 115 min

Distribution: Crosses placenta; enters breast milk

Excretion: Urine, feces (tablets)

Adverse effects

·        CNS: Dizziness, vertigo, headache, anxiety, malaise or fatigue, weakness, myalgia

·        CV: BP alterations, tightness or pressure in chest

·        GI: Abdominal discomfort, dysphagia

·        Local: Injection site discomfort, nose and throat discomfort (nasal spray)

·        Other: Tingling, warm or hot sensations, burning sensation, feeling of heaviness, pressure sensation, numbness, feeling of tightness, feeling strange, cold sensation

Nasal spray

·        GI: Bad taste in mouth, nausea

Interactions

Drug-drug

·        Prolonged vasoactive reactions with ergot-containing drugs (should not be used within 24 hr of each other)

·        Increased serum levels and toxicity of sumatriptan with MAOIs; avoid this combination and for 2 wk after MAOI discontinuation

Drug-alternative therapy

·        Increased risk of severe reaction if combined with St. John's wort therapy

Nursing considerations

Assessment

·        History: Allergy to sumatriptan; active CAD; uncontrolled hypertension; hemiplegic migraine; pregnancy, lactation

·        Physical: Skin color and lesions; orientation, reflexes, peripheral sensation; P, BP; LFTs, renal function tests

Interventions

·        Administer to relieve acute migraine, not as a prophylactic measure.

·        Administer as subcutaneous injection just below the skin as soon as possible after symptoms begin.

·        Repeat injection only after 1 hr if relief is not obtained; only two injections may be given each 24 hr.

·        Administer PO with fluids; may repeat in 2 hr if no relief.

·        Repeat nasal spray after 2 hr if headache returns or does not respond.

·        Monitor BP of patients with possible CAD; discontinue at any sign of angina, prolonged high BP.

Teaching points

·        Learn to use the autoinjector; injection may be repeated only after 1 hour if relief is not obtained; do not administer more than two injections in 24 hours.

·        Inject just below the skin as soon as possible after onset of migraine; this drug is for an acute attack only, not for use to prevent attacks.

·        Administer nasal spray as a single dose; repeat if needed only after 2 hours.

·        Take oral drug with fluids, may be repeated in 2 hours if no relief or return of headache.

·        This drug should not be taken during pregnancy; if you suspect that you are pregnant, consult your health care provider and stop using drug.

·        Contact your health care provider immediately if you experience severe or continuous chest pain or pressure.

·        You may experience these side effects: Dizziness, drowsiness (avoid driving or the use of dangerous machinery); numbness, tingling, feelings of tightness or pressure.

·        Report feelings of heat, flushing, tiredness, feelings of sickness, swelling of lips or eyelids.

Adverse effects in Italic are most common; those in Bold are life-threatening.