Nifedipine in primary Raynaud's phenomenon and in scleroderma: oral versus sublingual hemodynamic effects.

In 16 patients with Raynaud's phenomenon a placebo-controlled single-dose study was performed on the hemodynamic effects of 10 mg nifedipine, sublingually administered, followed by an open eight-week study on the therapeutic efficacy of chronic oral nifedipine, 10 mg qid. After the acute sublingual nifedipine administration, a pronounced objective improvement of finger skin (P = .013) and forearm muscle blood flow (P = .04) during a standard finger-cooling test was found. During the chronic oral study the improvement in objective efficacy parameters disappeared, except for laser Doppler estimated shunt flow (P = .07). The acute hemodynamic effects did not predict the long-term results in individual patients. Patients with systemic sclerosis reacted as well as patients with primary Raynaud's phenomenon. This study shows that orally administered nifedipine does not convey long-term objective benefit to patients with Raynaud's phenomenon. The apparent increase in vasodilation during acute administration suggests that sublingual nifedipine prophylactically or during a vasospastic attack may be more useful.