Efficacy and safety of a seven-day, transdermal estradiol drug-delivery system: comparison with conjugated estrogens and placebo. The Transdermal Estradiol Patch Study Group.

OBJECTIVE

To evaluate the efficacy and safety of a new, seven-day, transdermal estradiol system in healthy postmenopausal women with hot flushes.

METHODS

Two studies are described. In the first study, subjects were randomized to treatment with a 0.05 mg/day estradiol patch, a 0.1 mg/day estradiol patch, or a placebo patch; and in the second study, to treatment with either of the two estradiol patches or oral conjugated estrogens (as Premarin) 0.625 mg/day. Efficacy was evaluated on the basis of diary entries recording hot-flush frequency and severity. Subjects' and investigators' global assessments of treatment efficacy were recorded at follow-up visits.

RESULTS

In Study 1, both the 0.05-mg and 0.1-mg estradiol patches were significantly more effective than placebo in reducing hot flushes and were associated with higher global assessments. In Study 2, all three active treatments produced a significant reduction in the number of hot flushes compared with base-line. There were no statistically significant between-group differences, although the response to the 0.1-mg estradiol patch was greater, and to the 0.05-mg estradiol patch less, than the response to conjugated estrogens. The patches were generally well tolerated. Skin irritation from the patch was the most common adverse experience in both studies.

CONCLUSIONS

The new, seven-day, transdermal system effectively and safely treats post-menopausal vasomotor symptoms.