5-HT2-receptor blockade in the treatment of heart failure. A preliminary study.

Ketanserin (R 41 468), a quinazoline derivative, has been shown to be a selective blocker of 5-HT2 receptors. The drug was administered intravenously (10 mg given over a 3 min period) to 8 patients with severe cardiac failure already treated with digitalis, diuretics, and, in 4 cases, vasodilators. R 41 468 produced a significant fall in right-atrial, pulmonary-artery, pulmonary-wedge, and systemic arterial pressures. Systemic dynamic and total pulmonary vascular resistances were also reduced. Cardiac and stroke-work indices both increased, Heart rate remained unchanged. The platelet aggregation index, assessed in 2 patients, was initially low and was nearly normal 15 min after administration of a single dose of R 41 468.