Evaluation of the long-term safety and efficacy of 311C90 in the treatment of migraine.

311C90 is an orally active 5-HT1D agonist with both central and peripheral actions that is currently being developed as an acute antimigraine treatment. Several studies have demonstrated the safety and efficacy of 311C90 in the treatment of a single migraine headache. The objectives of this open study are to assess the safety and efficacy of 311C90 when used for a period of up to one year. Patients can treat as many migraine headaches as desired with an oral treatment regimen of 311C90. An initial 5 mg dose for treatment of the migraine headache may be followed with a second 5 mg dose to treat recurrence should it develop. Safety assessments include electrocardiograms, the frequency, intensity and duration of adverse experiences, and routine haematology, urinalysis and clinical chemistry measures. Data presented here are an interim view of the database as of August 1995 and should be considered as preliminary observations. No clinically significant serious adverse experiences have been reported. The adverse experience and efficacy profile appears to be consistent with previous 311C90 studies and this dosing regimen of 311C90 was well tolerated during multiple exposures. Notably, response rates are as good after both initial and repeated exposure (up to 5 migraines).