Serotonin antagonism in the treatment of cardiac insufficiency

One approach in the therapy of cardiac insufficiency is the administration of vasodilator substances for afterload reduction. Ketanserin selectively blocks the serotonin-2 receptors and thus inhibits the vasoconstrictor effect of serotonin. A hypotensive action of ketanserin has been documented in several studies. In 10 patients with coronary heart disease and cardiac insufficiency we investigated the haemodynamic effects of ketanserin after 24 h of intravenous administration (4 mg/h) and after 4 weeks of oral therapy (80 mg/day). Five patients received ketanserin for 12 months and were then re-examined. The resting mean arterial pressure dropped from 97.1 to 89.3 mm Hg after intravenous administration (p less than 0.05) and to 89.3 mm Hg after 4 weeks of oral intake (p less than 0.05). The resting mean pulmonary arterial pressure dropped from 15.2 to 12.0 mm Hg after intravenous administration (p less than 0.05) and to 11.7 mm Hg after 4 weeks of oral ingestion (p less than 0.01). Under exercise the pressure dropped from 35.3 to 28.1 mm Hg after intravenous administration (p less than 0.0025) and to 29.9 mm Hg after 4 weeks of oral intake (p less than 0.0025). Heart rate and cardiac output did not show any significant differences. The measured values after 12 months (in 5 patients) did not differ significantly from those measured after 4 weeks. In view of its low side effect liability ketanserin could be used as an afterload-lowering agent in patients with cardiac insufficiency.