[Selective estrogen receptor modulators in treatment of postmenopausal osteoporosis]

Postmenopausal osteoporosis is associated with lack of estrogens, therefore, understandably one of the treatment options in osteoporosis is a group of medicines known as selective estrogen receptor modulators (SERMs). They can act as an estrogen receptor agonist in some tissues, whereas as an antagonist in others. In relation to this antago-antagonistic action, SERMs have a positive effect on bones, the serum lipid profile and the cardio-vascular system. Moreover, they can protect against some estrogen-dependent neoplasm development. The first used SERM was tamoxifen, but due to its negative effect on endometrium it is not indicated in osteoporosis. Raloxifen, which is currently in use, besides the reduction of vertebral fractures risk, has beneficial influence on endometrial and breast neoplasm development risk as well. On the other hand, raloxifen intensifies vasomotor symptoms and its bone-protecting effect is limited. At present, new SERMs (ospemifen, lasofoxifen, bazedoxifen, arzoxifen) are being researched in clinical trials. In the current stage of investigations they reveal beneficial influence on skeletal as well as extraskeletal tissues. Implementation of SERMs in combined therapy of osteoporosis is currently under research as well. SERM with parathormone or SERM with bisphosphonate might prove to be an advantageous treatment option for women with severe or resistant osteoporosis. An addition of SERM to conventional hormonal replacement therapy did not bring the anticipated benefits. Future studies on SERMs may result in new preparations adjusted to individual needs of the patients.