Etidronate and hormone replacement therapy (HRT) for postmenopausal women with osteoporosis despite HRT.

Hormone replacement therapy (HRT) is effective treatment for postmenopausal bone loss and osteoporosis. However, postmenopausal women with low bone mass fail to respond after a few years of HRT and some postmenopausal women show no bone response to HRT. In these cases, additive therapy is necessary. Bisphosphonates are highly effective in postmenopausal osteoporosis. We investigated the effects of adding etidronate, a bisphosphonate, to HRT. The addition of etidronate to HRT improved bone density (4.40+/-1.12% increase per year) in patients showing no increase or even a decrease after at least 1 year of HRT (5.39+/-2.40% decrease per year).