Ospemifene (brand names Osphena and Senshio produced by Shionogi) is an oral medication indicated for the treatment of dyspareunia – pain during sexual intercourse – encountered by some women, more often in those who are post-menopausal. Ospemifene is a selective estrogen receptor modulator (SERM) acting similarly to an estrogen on the vaginal epithelium, building vaginal wall thickness which in turn reduces the pain associated with dyspareunia. Dyspareunia is most commonly caused by "vulvar and vaginal atrophy. "The medication was approved by the FDA in February 2013 and by the European Commission for marketing in the EU in January 2015. Medical uses
Ospemifene is used to treat dyspareunia. In the US it is indicated for the treatment of moderate to severe dyspareunia, a symptom of vulvar and vaginal atrophy (VVA), due to menopause. In the EU it is indicated for the treatment of moderate to severe symptomatic VVA in post-menopausal women who are not candidates for local vaginal oestrogen therapy. Contraindications
Women with "undiagnosed abnormal genital bleeding; known or suspected estrogen-dependent neoplasia; active or history of deep vein thrombosis; pulmonary embolism; arterial thromboembolic disease; and are or may become pregnant" or "with known or suspected breast cancer or those with extreme hepatic impairment" should not take ospemifene. This is not a full list of contraindications. Side effects
Side effects associated with ospemifene include vaginal discharge, hot flashes, and diaphoresis. More serious adverse effects are similar to those of estrogens and estrogen receptor modulators.
Estradiol was used as a positive control and raloxifene was used because it is in the same drug class as ospemifene. Multiple doses of oral ospemifene were tested. 10 mg/kg/day of Ospemifene was found to cause a greater increase in vaginal weight and vaginal epithelial height than 10 mg/kg/day of raloxifene. Vaginal weight had a 1.46x increase after a two-week treatment of 10 mg/kg/day of ospemifene. The number of progesterone receptors was increased in the vaginal stroma and epithelium, which indicates that ospemifene has "estrogenic activity. "Two 12-week phase 3 clinical trials were performed for ospemifene. One evaluated the effects of Ospemifene on vaginal tissue thickness, composition and vaginal pH. The other evaluated the effects of Ospemifene on vaginal tissue and on symptoms of dyspareunia. Between the two trials, 4 signs and symptoms were measured. These included three tissue-related signs, two of which represented histological changes in the vaginal tissue (change in percent parabasal cells and change in percent superficial cells) and the third was "change in vaginal pH". Dyspareunia was evaluated in one of the trials. It was defined as "change in most bothersome symptom" of discomfort during sexual activity and further limited to symptoms of either vaginal dryness or vaginal pain." Ospemifene produced more changes in vaginal tissue and greater reduction in dyspareunia symptoms than placebo. A dose-response also was observed in the trial; ospemifene 60 mg had greater efficacy than ospemifene 30 mg. Safety was also evaluated in these phase 3 trials.