Effect of raloxifene on salivary sex steroid concentrations in premenopausal women

Raloxifene is a selective oestrogen receptor modulator used clinically for the treatment and the prevention of osteoporosis in postmenopausal women. The drug has been evaluated in the Study of Tamoxifen and Raloxifene as an agent to reduce breast cancer incidence in postmenopausal women at high risk. However, about 30% of women who develop breast cancer do so in their premenopausal years. In this pilot study, salivary oestradiol and progesterone were determined throughout the menstrual cycle for a total of 22 subjects, 14 of whom completed pre- and postraloxifene (60 mg daily) salivary collections. The mean concentration. of oestradiol during the menstrual cycle when subjects were taking raloxifene was significantly greater (P<0-001) than during baseline cycles. Neither salivary progesterone and cortisol nor menstrual cycle length were affected by raloxifene treatment. These data demonstrate that raloxifene administered to premenopausal women increases the concentration of oestradiol that diffuses into the salivary glands, and which presumably represents the concentration available to other organs as well. The results reflect increases in serum oestradiol reported earlier.