Central and regional hemodynamic effects of nitrendipine in normotensive patients with chronic obstructive lung...

Central and regional hemodynamic studies were performed before and after administration of nitrendipine, a recently introduced calcium-channel blocker, in 10 normotensive patients with chronic obstructive pulmonary disease. None of them had a mean pulmonary artery pressure higher than 20 mm Hg. Ninety minutes after oral intake of 20 mg nitrendipine, cardiac output increased by 22%, heart rate increased by 12%, mean arterial pressure decreased by 7%, and pulmonary artery pressures as well as filling pressures of the heart did not change. Venous admixture and alveolar to arterial PO2 gradients increased by 54% and 22%, respectively. Hepatic blood flow increased by 33%. Renal blood flow remained unchanged and glomerular filtration rate decreased by 11%. Thus, in normotensive patients, nitrendipine administration induces systemic vasodilatation with an apparently reflex increase in cardiac output. These effects are accompanied by a deterioration in pulmonary gas exchange, increase in hepatic perfusion, no change in renal perfusion, and possibly a slight deterioration in renal function.