Effects of 4 weeks treatment with chlorpromazine and/or trihexyphenidyl on the pituitary-gonadal axis in male paranoid schizophrenics.

Serum prolactin (PRL), luteinizing hormone (LH) and testosterone (T) levels were estimated in a group of 30 male paranoid schizophrenics before and after 4 weeks treatment with chlorpromazine and/or trihexyphenidyl, and in a group of 14 healthy male individuals. After treatment with chlorpromazine (100 mg t.i.d., p.o.), 10 patients presented a significant increase in serum PRL values and a significant decrease in serum T values. A significant increase in serum PRL values was also found in 10 patients who were treated with chlorpromazine (100 mg t.i.d., p.o.) plus trihexyphenidyl (5 mg t.i.d., p.o.). No significant difference in any of the investigated endocrine parameters was detected in 10 patients after 4 weeks administration of trihexyphenidyl (5 mg t.i.d., p.o.). Following chlorpromazine treatment with or without concomitant administration of trihexyphenidyl, 20 patients showed a significant increase in serum PRL levels and a significant decrease in serum LH and T levels.