Nifedipine in the treatment of idiopathic Raynaud's syndrome.

Thirty-nine patients with idiopathic Raynaud's syndrome were randomized into a double-blind controlled trial comparing nifedipine 10 mg TID to placebo during the winter months between November, 1981 and March, 1983. The pills were doubled at 5 weeks in the absence of subjective improvement. Frequency and severity of vasospastic attacks were recorded in a diary. Over the 10-week treatment period, there was a 48.2% reduction in frequency of attacks in the nifedipine group compared to a 24.6% reduction in the placebo group (p less than 0.05). Treatment reduced the frequency of attacks by at least 30% in 10 of 15 patients. The severity of attacks was also significantly improved. Further, analysis suggests a trend towards diminished effectiveness over time. Side effects occurred in all patients taking nifedipine but were usually mild and well tolerated. Nifedipine is effective in reducing the frequency and severity of vasospastic attacks in idiopathic Raynaud's syndrome over a 10-week period.