Purpose of review
Review of recent data from clinical trials and descriptions of endometrial morphology with administration of selective progesterone receptor modulators (SPRMs).
Recent reports concerning administration of SPRMs, specifically the efficacy of ulipristal acetate in reducing fibroid size and rapid control of menstrual blood loss, have renewed clinical interest in this class of compound. Histological data from studies with SPRMs report that this class of drugs is associated with progesterone receptor modulator-associated endometrial changes. Data on mechanisms of action are lacking. The antagonistic progesterone effect of SPRMs has shown promising results in animal studies with endometriosis. Sex steroid receptor effects of PRMs outside the reproductive tract raise the potential for use in neurology and oncology, and although there are several randomized trials in these areas, there are limited small studies published to date.
The SPRM ulipristal acetate is an effective treatment for preoperative treatment of fibroids and a reliable emergency contraceptive. This class of compounds holds the potential for long-term effective medical management of fibroids and may have utility in the management of other sex steroid-dependent conditions.