Effects of tibolone and continuous combined hormone replacement therapy on parameters in the clotting cascade: a multicenter, double-blind, randomized study.Fertil Steril. 2000 Jul; 74(1):10-9.FS
To determine the effects of tibolone and continuous combined HRT (ccHRT) on parameters in the clotting cascade.
Randomized, double-blind study.
Hemostasis unit of a university hospital clinic in Germany.
Sixty healthy postmenopausal women.
Twenty-nine subjects were treated with tibolone (2.5 mg/d) and 31 with oral ccHRT containing estradiol (2 mg/d) + estriol (1 mg/d) + norethindrone acetate (1 mg/d).
MAIN OUTCOME MEASURE(S)
Effects on parameters in the clotting cascade at baseline and after 12 and 24 weeks of treatment.
Tibolone increased fibrinolysis parameters without significantly altering coagulation parameters. Treatment with ccHRT resulted in a stimulating effect on parameters of both fibrinolysis and coagulation. Tibolone showed a stronger reduction of factor VII activity; less reduction of AT-III, protein C activity, and protein S activity; stronger increase of the activated partial thromboplastin time, plasminogen and plasminogen-antiplasminogen complexes; and less increase of D-Dimer than ccHRT. Both preparations similarly reduced climacteric complaints, whereas tibolone showed less breast complaints than ccHRT.
This study confirms that tibolone, and to a lesser extent also ccHRT, changes hemostasis parameters toward a more fibrinolytic profile, which may diminish the risk of venous thrombosis.