Effects of raloxifene, one of the selective estrogen receptor modulators, on pituitary-ovary axis and prolactin in postmenopausal women

To investigate the clinical effects of raloxifene, one of the selective estrogen receptor modulators (SERMs), on the pituitary-ovary axis and prolactin, a prospective, randomized, double-blinded study on 59 healthy postmenopausal women was performed. Forty-eight women received raloxifene 60 mg daily. The other 11 received combined conjugated equine estrogen 0.625 mg and medroxyprogesterone acetate 5 mg daily (CCEP) as active controls. Serum follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), and prolactin were measured at baseline and 1 yr after treatment. The mean levels of FSH and LH were significantly decreased in the raloxifene group (FSH: -10.7%; p < 0.01, LH: -10.3%; p < 0.05) and CCEP group (FSH: -53.7%, p < 0.001; LH: -46.8%, p < 0.001). The prolactin level decreased in the raloxifene group but not in the CCEP group (-17.0%; p < 0.001 vs +13.3%, p = no significance; NS). Consequently, long-term administration of raloxifene up to 1 yr decreases serum prolactin level significantly and may be a therapeutic alternative for postmenopausal osteoporotic women with hyperprolactinemia.