Hormone serum levels during oral cimetidine treatment of patients with peptic ulcers.

Radioimmunoassayable basal serum levels of luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin (hPRL), 17 beta-estradiol (E2) and testosterone (T) were estimated in a total of 68 patients, who were treated because of peptic ulcer with 1 g cimetidine per day. 37 patients were male and 31 were female subjects, respectively. Hormone serum levels were assayed before and 4 to 6 weeks after start of therapy. A significant increase of LH serum levels (p less than 0.025) and a significant decrease of hPRL (p less than 0.025) was noted in the male subjects during therapy. Similarly, a decrease of hPRL serum levels (p less than 0.001) was registered in the female subjects during treatment with 1 g cimetidine per day. All other hormone serum levels in both female and male subjects remained unchanged. The present data combine to suggest that 1 g cimetidine per day does not provoke hyperprolactinemia. In addition, cimetidine at the dose used does not interfere with other hormones of the hypothalamus-pituitary-gonadal axis and therefore, cannot be considered, responsible for endocrine disorders during treatment with cimetidine.