Action of hormonal contraceptives on the coagulation system and some of its inhibitors
Misz, M.; Beck, P.
Acta Medica Hungarica 43(3): 301-310
1986
ISSN/ISBN: 0236-5286 PMID: 2438639 Document Number: 351977
Inhibitors of the coagulation system were measured in 71 women taking 4 oral contraceptives for 1-8 years, 2 combined pills, Bisecurin and Ovidon, a low-dose combined pill, Rigevidon, and a biphasic, Anteovin. The article begins with a review of the clinical significance and recent research on serine protease inhibitors. The pill formulations were: Bisecurin, 50 mcg, ethinyl estradiol and 1 mg ethinodiol diacetate; Ovidon, 50 mcg, ethinyl estradiol and 250 mcg, d-norgestrel; Rigevidon, 30 mcg ethinyl estradiol and 150 mcg, d-norgestrel; Antiovin 50 mcg, ethinyl estradiol and 50 mcg, d-norgestrel for 11 days and with 125 mcg d-norgestrel for 10 days. Thromboelastographic values r and I, indicating hypercoagulation, were significantly higher for pill users compared to 28 controls. No change was seen in prothrombin time (PT), and partial prothrombin time (PTT), fibrinogen values or ethanol gelation. Antithrombin III biological activity and quantity assayed immunologically decreased as much as 20%. The fixed dose pills significantly enhanced alpha 1-antitrypsin, a possible biochemical risk factor for thromboembolic disease. Alpha 2-macroglobulin levels did not change. The results showed that the increased coagulability and enhanced incidence of thromboembolic disorders associated with oral contraception may be caused by a decrease in thrombin inhibitors as well as increased alpha 1 antitrypsin, which inhibits the fibrinolytic system.