Clinical and laboratory effects of nifedipine in Raynaud's phenomenon.

The calcium channel blocking drug nifedipine was shown to be more effective than placebo as a treatment for Raynaud's phenomenon. Given in a dose of 10 mg four times a day it was well tolerated and reduced both the frequency and the severity of vasospastic attacks. There was, however, a large individual variation in response and while approximately half the patients showed marked improvement others showed no improvement at all. Patients with idiopathic Raynaud's phenomenon responded more favourably than those with systemic sclerosis. Nifedipine was shown to inhibit mitogen-induced lymphocyte proliferation but only in patients who responded to the drug clinically. Calcium channel blocking drugs may therefore have potential as immunoregulatory agents.