Effects of treatment with various doses of haloperidol on the pituitary-gonadal axis in male schizophrenic patients.

Fifteen male paranoid schizophrenics underwent an initial 4-week therapy with haloperidol 7.5 mg/day, and a subsequent 4-week treatment with haloperidol 15 mg/day, p.o. (group I). Another 15 male paranoid schizophrenics received an initial 4-week treatment with haloperidol 30 mg/day, and a subsequent 4-week therapy with haloperidol 60 mg/day, p.o. (group II). In each group of patients, serum prolactin (PRL), luteinizing hormone (LH) and testosterone (T) levels were measured before treatment and at the end of the two consecutive periods of treatment. A dose-related increase in serum PRL levels was found in both groups of medicated patients. Serum LH levels were not significantly affected by haloperidol treatment. A significant decrease in serum T levels was detected only in group II medicated patients, i.e., in the patients who were treated with relatively high daily doses (30 or 60 mg/day) of haloperidol.