Estradiol/progesterone-releasing vaginal rings for hormone replacement therapy in postmenopausal women

In order to investigate whether vaginal rings delivering estradiol and progesterone could prevent endometrial hyperplasia and relieve climacteric symptoms, two variants of rings were used in 20 postmenopausal women with intact uteri for 4 months. One ring designated as PI-002 (n = 8) delivered in vitro estradiol 160 microg/day and progesterone 20 mg/day, while the other (PI-003; n = 12) delivered the same dosage of estradiol but only half the progesterone (10 mg/day). Serum estrone, estradiol and progesterone were measured at pretreatment, weekly for 4 weeks, and then monthly for 4 months. The incidence of hot flushes, frequency of night sweats, mood scores, vaginal discharge and bleeding profiles were recorded. Endometrial thickness was monitored by ultrasonography. The mean estrone level was 50 pg/ml for 16 weeks. The mean serum estradiol level was 75 pg/ml for the first 4 weeks and gradually decreased to 50 pg/ml at 16 weeks. The mean progesterone level with the PI-002 ring was 5 ng/ml for the first 4 weeks and decreased to 3.5 ng/ml at 16 weeks. With the PI-003 ring, the mean progesterone level was initially 3.5 ng/ml and then decreased to 2.5 ng/ml thereafter. Significant decreases in the incidence of hot flushes and night sweats as well as a striking improvement in mood scores were noted as early as 2 weeks after insertion. Three of the 20 women discontinued the treatment, owing to ring expulsion. Increased vaginal discharge was observed with both rings in the first 6 weeks. Vaginal bleeding was more frequently apparent among users of the PI-002 ring, although bleeding and spotting were confined to the first 6 weeks. Ultrasonographic monitoring of the endometrium constantly revealed a thickness of < 3 mm for both variants throughout use for 16 weeks. An estradiol/progesterone-releasing vaginal ring is a potential alternative to long-term hormone replacement therapy with minimum attention required. It provides effective protection against endometrial hyperplasia.