Effects of long-term Org OD 14 administration on blood coagulation in climacteric women.

98 post-menopausal women were randomly allocated to either Org OD 14 [(7 alpha, 17 alpha)-17-hydroxy-7-methyl-19-norpregn-5(10)-en-20-yn-3-one] 2.5 mg/day or placebo. Treatment was continued for up to 6 yr. Any thromboembolic episode that occurred was recorded. Prothrombin time (PT), partial thromboplastin time (PTT), factor VII level and factor X level were measured prior to treatment and at yearly intervals. Antithrombin III level was measured in the last two yr of the study. There was one cerebrovascular accident after 3 months of placebo therapy but no other thromboembolic episodes. No significant difference was found between the effects of Org OD 14 and placebo with regard to any clotting factors at any time interval, although factor VII and factor X levels were consistently lower in the OD 14 group than in the placebo group. Antithrombin III levels measured after 5 and 6 yr were significantly higher (P less than 0.01) in the OD 14 group, suggesting a reduced risk of thrombosis in the treatment group.