Ultra-Low-Dose Transdermal Estrogen Therapy in Postmenopausal Urogenital Estrogen Deficiency—A Placebo-Controlled Study

Abstract

Nineteen postmenopausal women with severe urogenital estrogen deficiency were treated in a double-blind, randomized, parallel trial with transdermal administration of 12.5 μg/24 h of 17β-estradiol compared with placebo. Maturation of the vaginal and urethral epithelium was assessed by cytology, expressed as the Maturation Index, pH, clinical examination, and recording of subjective symptoms. After 4 weeks of treatment, a statistically significant maturation of the vaginal epithelium was seen in the group receiving active treatment, as judged by vaginal cytology, pH, and clinical examination. No improvement was found in the placebo group. Urethral cytology showed a similar but less pronounced pattern of maturation in the treatment group. Subjective symptoms such as vaginal dryness and soreness were significantly improved in the treatment group. Other symptoms were too infrequent for evaluation. It was concluded that transdermal administration of the ultra low dose of 12.5 μg/24 h of 17β-estradiol was sufficient to restore urogenital atrophy caused by estrogen deficiency. The form of administration is an interesting alternative to existing treatment regimens. The clinical efficacy for estrogen deficiency-related urological symptoms and the long-term effects on the endometrium should be evaluated in larger, long-term clinical trials.