Effects of Serotonin Antagonists in Normal Subjects and Patients with Carcinoid Tumors

Abstract

The pathogenesis of flushing attacks in patients with malignant carcinoid tumors is attributed to the direct pharmacologic effect of excessive amounts of circulating serotonin. It was hoped that potent serotonin antagonists might relieve symptoms of the carcinoid syndrome in the inoperable patient. The nature of flushing attacks was studied in carcinoid patients and the influence thereon of 3 serotonin antagonists, a benzyl analog of serotonin, bromo-lysergic acid diethylamide, and chlorpromazine. The systemic, subjective, and vascular effects of these antagonists in normal subjects were also investigated.