Effects of low and high dose oral cimetidine on hormone serum levels in patients with peptic ulcers.

Luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin (hPRL) and testosterone (T) were assayed in a total of 131 patients with peptic ulcer. Initial oral treatment was performed with 1000 mg cimetidine per day for 6 to 12 weeks. After healing was confirmed endoscopically, the patients were switched to a maintenance dose of 400 mg per day cimetidine for 3 years. Serum hormone levels before and during the two regimens were estimated in 48 male, 22 postmenopausal and 5 premenopausal subjects. Comparison between the two cimetidine doses was possible in 76 male, 44 postmenopausal and 6 premenopausal patients. In all patients hormone parameters assayed before therapy were within the normal ranges. FSH was noted to increase significantly in all but the premenopausal group but remained within the normal range. In contrast, hPRL declined significantly in all groups of subjects except for premenopausal females during cimetidine treatment. LH and T did not change during treatment and no differences of hormone serum levels were noted between the two regimens. Present data combine to suggest that an initial treatment with 1000 mg of cimetidine per day did not provoke hyperprolactinemia, and a switch from an initial high dose to a maintenance dose of 400 mg per day did not cause further changes in hormone serum levels. Changes of LH, FSH, hPRL and T recorded in the present study are too small to be considered responsible for possible endocrine disorders observed during cimetidine therapy.