Effects of tibolone and continuous combined hormone replacement therapy on parameters in the clotting cascade: a multicenter, double-blind, randomized study

Abstract

Objective: To determine the effects of tibolone and continuous combined HRT (ccHRT) on parameters in the clotting cascade.

Design: Randomized, double-blind study.

Setting: Hemostasis unit of a university hospital clinic in Germany.

Patient(s): Sixty healthy postmenopausal women.

Intervention(s): 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.

Result(s): 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.

Conclusion(s): 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.