The efficacy of BMS 180048, a 5HT, agonist in the acute treatment of a migraine headache, was evaluated in 216 patients. Three doses of the study drug were compared to placebo. Patients received a single test dose in the physician’s office while being evaluated with a Holter monitor during a headache-free day. They then treated a migraine headache with a single dose of the study drug as an outpatient. The 150 mg and 200mg doses of BMS were significantly superior to placebo on change in pain intensity at 2 hours. Patients treated with BMS 180048 had a longer duration of response than placebo-treated patients. At the 24hour point, only 24% of the 150mg group and 25% of the 200mg group had relapsed, compared to placebo which had a 42% relapse rate. It is concluded that BMS 180048 is an effective compound for the treatment of migraine headaches with a prolonged duration of response.