Sumatriptan in the treatment of migraine

The headache phase of the migraine attack is thought to be associated with a dilation of cranial blood vessels, particularly those in the dura mater, and an accompanying localized sterile inflammatory response. Serotonin, or 5-hydroxytryptamine (5-HT), is considered a possible mediator of this syndrome. Receptors for 5-hydroxytryptamine are present in cranial arteries and are widely distributed in the CNS. Studies indicate that sumatriptan, a 5-HT1 receptor agonist, is effective in treating acute migraine attacks. The mechanism of sumatriptan's therapeutic action is not completely understood. Evidence from animal and human studies suggests that sumatriptan constricts dural vessels and inhibits neuropeptide release from trigeminal nerve endings by activating 5-HT1 receptors. Clinically, sumatriptan is rapidly effective against all features of the headache phase in migraine in up to 80% of patients. The headache may recur, however, within 24 hours in about one third of patients, but this can be treated effectively with a subsequent dose of sumatriptan. Treatment with sumatriptan has been well tolerated with only minor, transient, acute side effects reported. At present, only limited information is available regarding long-term tolerability, safety, and efficacy. Sumatriptan should not be prescribed to patients with a cardiovascular history.