Update on Raloxifene: mechanism of action, clinical efficacy, side effects and contraindications

Raloxifene is the only SERM approved for long-term treatment in the prevention of osteoporotic fractures and for the reduction of invasive breast cancer risk in postmenopausal women. The demonstrated beneficial effects on bone and mammalian tissue led clinical and molecular research to focus mainly on these organs, giving less attention to all other systemic effects. The aim of this review is to evaluate all described systemic effects of raloxifene, investigating its molecular and tissutal mechanism of action. A literature research was carried out in electronic databases MEDLINE, EMBASE Sciencedirect and the Cochrane Library in interval time between 2000-2012. Outcomes were considered in relation to positive/side effects concerning bone metabolism, lipid metabolism, coagulation pattern, menopausal symptoms, breast cancer onset and endometrial cancer onset. Raloxifene acts as an estrogen agonist or antagonist depending on the tissue. This feature is related to specific actions on at least two distinct estrogen receptors, whose proportions vary according to tissue type. Rraloxifene is an excellent drug for the treatment of osteoporosis and for the prevention of estrogen receptors positive breast cancer since it guarantees an excellent safety profile on the endometrium. Raloxifene is furthermore an effective therapy in women with increased levels of plasma cholesterol. Raloxifene treatment shifts the coagulation pattern towards pro-thrombosis and the patients should be exhaustively informed about the risks associated with therapy. Raloxifene does not show to affect memory and cognition. Finally, it is noteworthy that quality-of-life studies demonstrated some favourable effects of Raloxifene.