Nifedipine in the prophylaxis of classic migraine: a crossover, double-masked, placebo-controlled study of headache frequency and side effects.

Twenty-four patients with classic migraine attacks were treated with either nifedipine or placebo for up to 12 weeks. No significant differences were observed between the nifedipine (2.1 +/- 0.2) and placebo (2.3 +/- 0.2) treatment groups in the monthly frequency of headaches. However, the incidence of side effects was significantly greater (p less than 0.001) in the nifedipine (54% of patients) than in the placebo (8% of patients) treatment groups.