Effect of cyproterone acetate on platelet aggregability, fibrinolytic activity and fibrinolytic capacity in normal men.

Nine healthy men were treated with a daily dose of 5 or 10 mg of the anti-androgen cyproterone acetate. Platelet aggregability was increased in 6 of 9 men; fibrinolytic activity decreased in 7 of 7 and the fibrinolytic capacity decreased in 5 of 7 volunteers. We conclude that platelet aggregability, fibrinolytic activity and capacity may be modified by anti-androgen treatment and therefore attention should be paid to the coagulation parameters when cyproterone acetate is used.