Effect of selective estrogen receptor modulators on reproductive tissues other than endometrium

The objective of this paper is to review the published and unpublished knowledge of the effect of selective estrogen receptor modulators on reproductive tissues other than endometrium. Pharmaceutical companies developing or marketing selective estrogen receptor modulators (SERMs) were identified. The investigators at each company responsible for the conduct of investigational trials were contacted and queried about reports of adverse events in any ongoing or completed trials involving SERMs produced by their company. Levormeloxifene and idoxifene trials noted a higher proportion of surgery for pelvic organ prolapse in treated versus untreated women. The development of these pharmaceutical agents was discontinued, primarily for endometrial concerns. However, pelvic organ prolapse was reported to the FDA as an adverse event associated with both drugs. Study weaknesses preclude a definitive association between the agents and pelvic organ prolapse. The treated groups were not necessarily similar for confounding factors such as age, parity, obesity, cigarette smoking, and other risk factors for pelvic organ prolapse. Tamoxifen and raloxifene increase hot flash intensity and frequency. Ovarian cyst formation and uterine fibroid growth have also been reported with some SERMs. The identification and assessment of the impact of current and future SERMs on the pelvic floor and other genital tissues will be important to understanding their potential long-term application in disease treatment and prevention.