The efficacy of the calcium-channel blocker nicardipine in the treatment of Raynaud's phenomenon was assessed in a prospective, double-blind, randomized, crossover trial in 20 patients. Each patient received nicardipine 20 mg or placebo three times a day for two weeks and then was crossed over for two weeks. Nicardipine significantly decreased the frequency and severity of Raynaud's phenomenon as compared with placebo. The authors conclude that nicardipine is effective in the treatment of Raynaud's phenomenon.