The effect of tranexamic acid on measured menstrual loss and endometrial fibrinolytic enzymes in dysfunctional uterine bleeding.

Fibrinolytic activity of the menstrual fluid is increased in dysfunctional uterine bleeding (DUB). We measured the effect of tranexamic acid on the menstrual blood loss and endometrial fibrinolytic enzymes in women with DUB (> 80 ml menstrual loss/cycle). Endometrial biopsies were taken between 24 and 36 hours after the onset of menstruation. Enzyme activity was assayed by measuring the rate of conversion of Glu-plasminogen to plasmin, using a chromogenic plasmin substrate. Antigen levels were measured using an enzyme linked immunoassay (ELISA) technique. Tranexamic acid reduced menstrual blood loss by 58% (p < 0.05). Endometrial tissue plasminogen activator activity and antigen and plasminogen activator inhibitor--type 1 antigen levels were significantly decreased by tranexamic acid. The effect of tranexamic acid on the fibrinolytic enzymes at local endometrial level may be responsible for its success in the treatment of menorrhagia.