Hormonal changes induced by a partial opiate antagonist, nalorphine. Evaluation of PRL, GH, TSH, LH, FSH and cortisol secretion.

The effects of nalorphine 5 mg i. m., a partial opiate antagonist, on circulating levels of PRL, GH, TSH, LH, FSH and cortisol were studied in six healthy men. Nalorphine produced a produced a prompt and sharp increase in serum PRL and a small, delayed rise in serum GH. Serum LH and cortisol decreased after drug administration and no change in serum FSH and TSH was observed. These findings are discussed and a possible site of action of nalorphine is suggested.