[Bisphosphonate for GnRH therapy]

GnRH therapy is useful for the treatment of various diseases, such as prostate cancer, endometriosis, uterine leiomyoma, based on its reduction of sex steroids. However, it causes osteopenia with high bone turnover in the mechanism similar with ovariectomy or castration. Bisphosphonate potently inhibits bone resorption, which subsequently inhibits elevated metabolic bone markers and osteopenia by GnRH therapy. The intravenous administration of pamidronate markedly inhibited osteopenia induced by GnRH therapy in some reports, but further study is necessary about the usage of bisphosphonate for osteopenia accompanied by GnRH therapy.