CLINICAL STUDY Effects of long-lasting raloxifene treatment on serum prolactin and gonadotropin levels in postmenopausal women

Objective: To evaluate the effects of a 6 month administration of raloxifene hydrochloride, a selective estrogen receptor modulator which was recently approved for the prevention of osteoporosis, on serum gonadotropin and prolactin (PRL) levels and on TRH-stimulated PRL responsiveness in postmenopausal women who have not undergone estrogen replacement therapy. Design and methods: Sixteen healthy postmenopausal women were divided into two groups on the basis of their bone status, evaluated by dual energy X-ray absorptiometry at the lumbar level. Eight women (chronological age 52:4^4:1 (S.D.) years, menopausal age 42:4^3:9 years), in whom T-score L2–L4 was less than 22.5 S.D., were treated with raloxifene (60 mg p.o.) administered daily for 6 months (group 1), while the other eight women (chronological age 52:6^2:5 years, menopausal age 42:1^ 3:6 years), in whom the T-score L2–L4 ranged between 21 and 22.5 S.D., were used as a control group (group 2). Serum PRL, FSH, LH and 17b-estradiol (E2) levels were evaluated at baseline and after 3 and 6 months of treatment. In all subjects, PRL responsiveness to TRH (200mg i.v.) administration was evaluated at baseline and at the end of the study. Results: At baseline, mean PRL, LH and FSH levels were not significantly different in the two group