Low-dose intravaginal estradiol delivery using a Silastic vaginal ring for estrogen replacement therapy in postmenopausal women: a review.

OBJECTIVES

The aim of this study was to review the potential of the intravaginal ring to be an effective low-dose estrogen delivery system for the treatment of postmenopausal women.

METHODS

The data were extracted from the literature using the computerized MEDLINE system. The soft and flexible ring (Estring(R)) is made of silicone rubber with a 55-mm outer diameter and 9.5-mm cross-sectional diameter, contains 2 mg 17beta-estradiol in the core section with the release specification limit of 6.5-9.5 microg/24 h and maintains a continuous plasma estradiol concentration of 20-30 pmol/l for 3 months when inserted in women.

RESULTS

Comparative clinical trials have demonstrated that treatment with the intravaginal ring is excellent at alleviating subjective and objective symptoms of estrogen deficiency, restores vaginal mucosa, induces a high maturation index of mucosal cells and reduces vaginal pH to < 5.5 in postmenopausal women. No major side-effects or endometrial proliferation have been observed during treatment. The majority of patients prefer using the vaginal ring to other currently available vaginal steroid delivery systems. The sustained low-dose estrogen therapy is also found to improve the serum lipid profile in elderly women.

CONCLUSIONS

It is suggested that the low-dose estradiol intravaginal ring is safe, effective and well accepted for the treatment of estrogen deficiency symptoms in postmenopausal women.