Effect of megestrol acetate on flushing and bone metabolism in post-menopausal women

To avoid the risks of oestrogen therapy in post-menopausal women, we have examined the effects of a progestin, megestrol acetate (MA), on hot flushes and bone metabolism. Ten normal post-menopausal women were studied before and after the oral administration of 20, 40 and 80 mg of MA daily for 4 wk at each dose level. Finger temperature and skin resistance were recorded for 8 h as objective indices of flushing and perspiration, respectively. The fasting ratios of urinary calcium: creatinine (Ca/Cr) and hydroxyproline: creatinine (OHPr/Cr) were used as indices of bone resorption. A reduction (P less than 0.01) of flushing episodes was noted on all dose levels of MA, with 56, 11, 6 and 1 flushes occurring on 0, 20, 40 and 80 mg of medication. A decrease (P less than 0.05) of Ca/Cr was noted only with 80 mg of MA, whereas OHPr/Cr remained unchanged. We conclude that progestin therapy may provide an alternative mode of treatment for post-menopausal hot flushes. Definitive demonstration of an effect on post-menopausal bone resorption will require a long-term study of bone density.