Efficacy and tolerability of Estraderm MX, a new estradiol matrix patch.

Objectives: To assess the efficacy and tolerability of a new matrix patch delivering 0.05 mg estradiol per day (Estraderm MX 50) in postmenopausal women with moderate to severe postmenopausal symptoms.

Methods: A multicenter, double-blind, randomized, between-patient, placebo controlled trial in 109 postmenopausal women was carried out. Patches were applied twice weekly for 12 weeks. Patients were assessed at 4, 8 and 12 weeks of treatment. The primary efficacy variable was change from baseline in mean number of moderate to severe hot flushes (including night sweats) per 24 h during the last 2 weeks of treatment. Other variables included Kupperman Index, local and systemic tolerability. Plasma concentrations of estradiol (E2), estrone (E1) and estrone sulfate (E1S) were determined before and after treatment.

Results: Estraderm MX was significantly superior to placebo (P < 0.001) in reducing mean number of moderate to severe hot flushes (including night sweats) per 24 h after 4, 8 and 12 weeks of treatment. The estimate of treatment group differences after 12 weeks was 4.2 hot flushes (95% confidence interval: 2.6-5.8). Estraderm MX also significantly reduced Kupperman Index at all time points compared to placebo (P < 0.001). Estraderm MX induced increases in mean E2, E1 and E1S plasma levels as expected (E2: baseline 2.7 pg/ml, 12 weeks 38.9 pg/ml; E1: baseline 18.8 pg/ml, 12 weeks 41.6 pg/ml; E1S: baseline 235.6 pg/ml, 12 weeks 765.1 pg/ml). Overall rates of adverse experiences were similar for Estraderm MX and placebo. The number of patients reporting skin irritation was low and similar in both groups.

Conclusions: Estraderm MX 50, a new matrix patch, offers an effective and well tolerated dosage form for transdermal delivery of 0.05 mg E2 per day.