Raynaud's phenomenon: pathophysiologic features and treatment with calcium-channel blockers.

Raynaud's phenomenon may be associated with severe pain, functional disability and digital infarction, particularly in patients with underlying vascular disease. The pathophysiologic features of Raynaud's phenomenon are complex although vasospasm contributes to the production of digital ischemia in most cases. Calcium-channel blockers have been shown to produce arteriolar vasodilation and an increase in peripheral blood flow. They have been used to treat patients with Raynaud's phenomenon in several prospective, randomized, double-blind, placebo-controlled trials. Low doses of verapamil were ineffective but both diltiazem and nifedipine produced subjective improvement in 60 to 90% of cases. Objective measures of digital blood flow were not improved. Patients without underlying vascular disease responded more readily to therapy than patients with scleroderma. Adverse effects were uncommon and seldom necessitated discontinuation of therapy. These data suggest that nifedipine and diltiazem provide effective short-term improvement in symptoms for most patients with Raynaud's phenomenon.