Effect of the serotonin antagonists ritanserin and ketanserin in Cushing's disease

Central serotoninergic regulation could have a role in the course of pituitary-dependent Cusghing's disease. We studied the effect of ritanserin and ketanserin, two related selective 5HT2 receptor antagonists, in 11 patients with Cushing's disease. Treatment lasted from 1 month to 1 year (up to 4 years in one patient). Daily doses were 10-15 mg for ritanserin, and 40-80 mg for ketanserin. Since the two drugs share the same mechanism of action and no qualitative or quantitative differences in response to their administration were observed, the results were pooled together. An inhibitory effect of ritanserin and ketanserin on ACTH and cortisol production in Cushing's disesase appeared to be limited both in terms of duration of response and number of patients with a satisfactory outcome. However, the results may provide a better understanding of serotoninergic modulation in Cushing's disease and lead to therapeutic developments