Dose-response efficacy of a new estradiol transdermal matrix patch for 7-day application: a randomized, double-blind, placebo-controlled study

New estradiol (E-2) transdermal matrix patches developed for once-a-week ap plication, releasing 25 mu g E-2 (7D-25) or 50 mu g E-2 (7D-50) daily, were investigated in comparison with a placebo patch and the twice-weekly paren t patch releasing 50 mu g E-2 (Derm-50) daily. Three hundred and eleven pos tmenopausal patients suffering at least seven hot flushes daily were random ly assigned to the four parallel groups and treated continuously for 12 wee ks without progestin opposition. The daily number of hot flushes significantly decreased in all groups. At t he 12th week the decrease from a baseline average of eight to nine episodes per day was 78% with 7D-25, 93% and 97% respectively with 7D-50 and Derm-5 0, and significantly (p < 0.001) lower with placebo (59%). Comparable effic acy was observed in terms of severity of hot flushes, Kupperman Index and p atient self-rated overall efficacy. Minor systemic adverse events occurred in 10.0%, 8.8%, 16.9% and 13.5% pati ents in the placebo, 7d-25, 7D-50 and Derm-50 groups respectively Occasional mild and transient itching and/or erythema at the site of applic ation was reported by a few patients, with no difference between groups or between once-weekly or twice-weekly application. In conclusion all E-2 patches were significantly more effective than placeb o in relieving climacteric symptoms in a dose-dependent fashion and all wer e well tolerated.