Endometrial safety and tolerability of AERODIOL(R) (intranasal estradiol) for 1 year.

Objective: the purpose of this study was to assess the endometrial safety and patient acceptability of a pulsed estrogen therapy provided by S21400 (intranasal 17 beta-estradiol) in the treatment of postmenopausal symptoms.

Design: postmenopausal women (n=408) entered an open-label, community based, multicentre trial. Patients received S21400 plus sequential (>90% of patients) or continuous progestogen. Treatment was initiated with a standard daily dose of 300 microg but dose adaptation was possible every 3 months from 150 to 600 microg daily. Endometrial biopsies were performed at entry and at 12 months, and bleeding patterns were recorded at 3-monthly intervals throughout the trial.

Results: 71% of patients received 300 microg per day S21400 throughout the study, 3% had their dose decreased, 19% had their dose increased and 7% had their dose both decreased and increased. Three hundred and eleven biopsies were obtained after 12 months of treatment, there were no cases of endometrial hyperplasia. The 95% confidence interval [CI] for the rate of incidence was 0-1.2%. Cyclical bleeding occurred in 82% of sequential treatment cycles. Unexpected bleeding occurred in 5% of the treatment cycles. Presence of unexpected bleeding varied according to the treatment regimen, 15 and 4% of the cycles with combined continuous and sequential regimen, respectively. Unexpected bleeding was mostly spotting. Nasal treatment was well accepted. Nasal symptoms (itching sensation, rhinorrhea and sneezing) were mostly mild in intensity and they led to treatment withdrawal in approximately 3% of patients. The rate of treatment continuation was 85% at 1 year.

Conclusions: S21400, in combination with continuous or sequential progestogen, exhibits good endometrial safety and patient acceptability in postmenopausal women.