The anti-platelet effect of nifedipine in patients with systemic sclerosis

Abstract

The enhanced platelet reactivity and impaired thrombolysis in patients with systemic sclerosis may contribute to the microvascular insufficiency seen in this disease. Anti-platelet therapy has therefore been suggested for the treatment of Raynaud's phenomenon secondary to systemic sclerosis. Using a novel technique, the Haemostatometer, haemostasis (shear-induced) and thrombolysis (dislodgement of the haemostatic plug) were assessed initially in 15 patients with systemic sclerosis before and 90 minutes after a single oral dose of nifedipine (10 mg), and then at 4-week intervals for 16 weeks in 10 patients on long-term nifedipine (10-20 mg tid). Ninety minutes after a single oral dose of nifedipine in 15 patients with systemic sclerosis, haemostasis was significantly prolonged from 140 +/- 12 sec to 178 +/- 21 sec (mean +/- SE, p less than 0.005). The time until spontaneous thrombolysis occurred was significantly shortened following nifedipine, from an abnormal time of 57.8 +/- 2.8 min to a more normal value of 34.0 +/- 5.1 min (mean +/- SE, p less than 0.01). This improvement in haemostasis and thrombolysis was maintained through 16 weeks on longterm nifedipine treatment. These findings suggest that nifedipine may reduce the risk of developing multiple thrombo-emboli in patients with systemic sclerosis.