Sumatriptan: A Selective 5-Hydroxytryptamine Receptor Agonist for the Acute Treatment of Migraine

Abstract

OBJECTIVE: The clinical pharmacology, pharmacokinetics, clinical efficacy, adverse effects, and associated drug interactions of the novel antimigraine drug sumatriptan are reviewed. DATA SOURCES: English-language publications pertaining to sumatriptan were identified via a search of the MEDLINE computerized database. STUDY SELECTION: Open and controlled clinical studies were reviewed in assessing clinical efficacy, although only the results of controlled, randomized trials form the basis for the conclusions pertaining to the effectiveness of sumatriptan. DATA EXTRACTION: The primary measure of drug effectiveness in all clinical studies was significant improvement in headache severity scores. Secondary measures included functional ability, time to relief, rescue medication use, associated symptoms of nausea/vomiting and photo/phonophobia, and, in some studies, headache recurrence rate. These data were obtained from each published clinical trial and used in the overall analysis of sumatriptan efficacy. DATA SYNTHESIS: Sumatriptan is a serotonin agonist that has been studied for the acute treatment of migraine and cluster headache. The drug appears to work via specific serotonin receptors to mediate selective vasoconstriction within the cranial vasculature and to prevent the release of inflammatory mediators from trigeminal nerve terminals. The recommended dose of sumatriptan is 6 mg given subcutaneously at the onset of headache; an oral formulation is under investigation. In the published clinical trials of the oral and subcutaneous dosage forms to date, sumatriptan was effective in reducing headache severity from moderate/severe to mild/absent in approximately 70–80 percent of patients treated with active drug, compared with only 20–30 percent in the placebo groups, and 48 percent in the oral ergotamine tartrate/caffeine (Cafergot)-treated group. Secondary measures of effectiveness also favored sumatriptan. There may be a higher rate of headache recurrence with sumatriptan compared with placebo or Cafergot, although further study is necessary to confirm this observation. Adverse effects associated with sumatriptan administration generally were mild and transient and included tingling, warm/hot sensations, and pressure and tightness in the chest and neck. No significant drug interactions have yet been identified. CONCLUSIONS: Sumatriptan appears to represent a safe and effective alternative to the ergot alkaloids for the abortive treatment of acute migraine. However, further clinical trials, especially those yielding comparative data with current antimigraine agents, are needed to determine the full therapeutic contribution of sumatriptan.