[Effect of a single dose of nifedipine on the CO transfer capacity in patients with scleroderma].

The calcium antagonists are currently used in the treatment of Raynaud's syndrome for patients with scleroderma. The effect on the pulmonary vasculature in these patients is little understood. The study reported here is based on 15 patients with scleroderma. In each patient lung volumes, expiratory flow and transfer factor (DLCO) were carried out in a basal state and one hour after the administration of sub lingual nifedipine. Nine patients showed a diminution in the DLCO before taking the product but the mean variation after nifedipine was not significant. Different mechanisms may explain the absence of any effect: irreversible vascular disease or the absence of pulmonary arterial hypertension or hypoxic constriction, the latter conditions were previously associated with the efficacy of nifedipine. Thus it does not seem that nifedipine, in acute tests, has an effect on the pulmonary localisation of scleroderma, at least in the absence of pulmonary arterial hypertension.