Sildenafil in the Treatment of Raynaud’s Phenomenon Resistant to Vasodilatory Therapy

Abstract

Vasodilatory therapy of Raynaud's phenomenon represents a difficult clinical problem because treatment often remains inefficient and may be not tolerated because of side effects. To investigate the effects of sildenafil on symptoms and capillary perfusion in patients with Raynaud's phenomenon, we performed a double-blinded, placebo-controlled, fixed-dose, crossover study in 16 patients with symptomatic secondary Raynaud's phenomenon resistant to vasodilatory therapy. Patients were treated with 50 mg sildenafil or placebo twice daily for 4 weeks. Symptoms were assessed by diary cards including a 10-point Raynaud's Condition Score. Capillary flow velocity was measured in digital nailfold capillaries by means of a laser Doppler anemometer. While taking sildenafil, the mean frequency of Raynaud attacks was significantly lower (35+/-14 versus 52+/-18, P=0.0064), the cumulative attack duration was significantly shorter (581+/-133 versus 1046+/-245 minutes, P=0.0038), and the mean Raynaud's Condition Score was significantly lower (2.2+/-0.4 versus 3.0+/-0.5, P=0.0386). Capillary blood flow velocity increased in each individual patient, and the mean capillary flow velocity of all patients more than quadrupled after treatment with sildenafil (0.53+/-0.09 versus 0.13+/-0.02 mm/s, P=0.0004). Two patients reported side effects leading to discontinuation of the study drug. Sildenafil is an effective and well-tolerated treatment in patients with Raynaud's phenomenon.