Verapamil in migraine prophylaxis--a five-year review.

Verapamil is a papaverine derivative calcium channel blocking drug that has been effectively utilized in the prophylaxis of migraine. This paper reviews the clinical pharmacology as it applied to headache and the current research on the clinical use of verapamil in migraine prophylaxis. Included are three double-blind, placebo-controlled studies. Ten of 12 patients, eight of 14 patients, and 20 of 23 patients showed improvement, with all studies finding verapamil significantly more effective than placebo in migraine prophylaxis. Research comparing 240 mg/day with 320 mg/day dosing found 320 mg/day significantly more effective in reducing migraine frequency. Review of 133 refractory headache-clinic patients, treated with verapamil and additional drugs reported excellent (100% improvement) or good results (greater than 50% reduction in migraine frequency) in 5% and 40% of patients, respectively. Fair response (less than 50% improvement) was observed in 50% of patients, and poor response was seen in 5% of patients. Analysis of this information reveals that verapamil is a safe, well-tolerated and effective agent for migraine prophylaxis.