Local treatment of urogenital atrophy with an estradiol-releasing vaginal ring: a comparative and a placebo-controlled multicenter study. Vaginal Ring Study Group.

Local estrogen substitution has been shown to be more appropriate than any systemic application for the treatment of urogenital symptoms of hormone deficiency. The efficacy, safety and acceptability of a new low-dose drug delivery system consisting of an estradiol-releasing silicone vaginal ring was studied in two multicenter trials. In an open-label comparative trial a total of 219 postmenopausal women were randomized to the estradiol-releasing vaginal ring or to estriol suppositories. In terms of efficacy both treatment arms were shown to be equivalent; however, significantly higher rates of acceptability were found for the vaginal ring. In a double-blinded placebo-controlled study a total of 84 patients were randomized to either treatment arm for a period of 24 weeks. The statistically significant improvement of the vaginal epithelial pH and maturation values demonstrated the efficacy of the estradiol-releasing vaginal ring compared to the placebo ring.