[Mechanism of action of dydrogesterone in dysmehorrhea. Prostaglandin levels in menstrual blood].

Menstrual blood was collected from seven dysmenorrhoeic volunteers age 20-35, during nine cycles. After three control-cycles the women were treated with dydrogesteron ( Duphaston ) 2 X 10 mg/die, day 5-25, for a period of six months. Blood loss was constant over the study period. Estradiol excretion was significantly reduced during dydrogesteron treatment, whereas oestron excretion remained unchanged. Progesteron excretion was significantly higher during the treatment period (2p less than or equal to 0,05). Consequently PG F2 alpha was significantly reduced (2p less than 0,05), there was a marked reduction in 6-keto PG F1 alpha excretion, but no change was noticed in PG E2 excretion. The estradiol/ progesteron ratio in dysmenorrhoeic patients was raised, as was the PG F2 alpha/6-keto-PG F1 alpha and PG F2 alpha/PG E2 ratio. As a steroid dependant prevalence of PG F2 alpha in the uterus appears to play a role in the aetiology of dysmenorrhoea, therapeutic treatment should go for regulation of the hormonal, resp. prostaglandin imbalance. Dydrogesteron is capable of normalizing the disturbed hormonal balance and in this way is effective in the treatment of dysmenorrhoeic complaints.