Vaginal rings for continuous low-dose release of oestradiol in the treatment of urogenital atrophy.

Silicone vaginal rings for the continuous release of 17 beta-oestradiol (E2) with 2 constant in vitro release rates were used for the treatment of symptoms of urogenital atrophy in 2 groups of postmenopausal women. The very low dose of 7 micrograms/24 h was found to alleviate atrophic symptoms effectively and to induce significant maturation of vaginal and urethral epithelium. After a brief initial peak, the serum levels of E2 over 3 mth of treatment remained close to the detection limit. The 'undetectable' E2 release pattern was reflected only in increased levels of oestrone sulphate. There was no evidence of a systemic metabolic response and patient acceptance of the method was excellent. Continuous low-dose release of E2 via vaginal rings consequently offers an alternative means of administering local oestrogen therapy which may be particularly suitable for geriatric patients.