LOW-DOSE 17-BETA-ESTRADIOL DURING MAINTENANCE THERAPY - A PHARMACOKINETIC AND PHARMACODYNAMIC STUDY

The vaginal absorption of oestradiol was studied during maintenance th erapy with low-dose oestradiol. Six women with severe vaginal atrophy due to oestrogen deficiency were treated with a vaginal tablet contain ing 25 mu g 17 beta-oestradiol. Initially, a daily dose was given for 2 weeks, followed by maintenance therapy with twice weekly treatment f or another 10 weeks. The plasma concentrations of unconjugated oestron e and oestradiol were measured before oestrogen treatment was started at the beginning of the study. After 3 months of treatment frequent pl asma sampling over a period of 24 h was performed. Gonadotrophins, vag inal and urethral cytology, clinical findings and subjective symptoms were assessed at the beginning and end of the study. Plasma concentrat ions of unconjugated oestradiol were at all times within the limits of postmenopausal values, but showed a slight but not statistically sign ificant elevation after 3 months compared to pretreatment values. Plas ma concentrations of unconjugated oestrone were in the low postmenopau sal range throughout the study. LH levels were unaffected during the s tudy, while FSH was somewhat lowered, but still well within the postme nopausal range. Vaginal and urethral cytology showed maturation with a lmost complete disappearance of parabasal cells. Clinical and subjecti ve improvement was statistically significant during the treatment peri od.