Hemostatic effects of smoking and oral contraceptive use

This review addresses current knowledge of;the effects of lower dose oral c ontraceptives (containing 35, 30, or 20 mu g of ethinyl estradiol) on hemos tasis in smoking and nonsmoking women. Evidence suggests that formulations containing 30 and 35 mu g ethinyl estradiol induce a significant activation of coagulation, whereas oral contraceptive preparations with 20 mu g ethin yl estradiol appear to have a negligible effect or no effect. In nonsmokers who take oral contraceptives any procoagulatory effects that may occur are counterbalanced by fibrinolytic effects. In smokers, however, compensatory fibrinolytic effects to offset the procoagulatory effects seen with 30-mu g ethinyl estradiol oral contraceptive formulations are absent, shifting th e hemostatic profile toward a hypercoagulable state. This suggests that a f ormulation with the lowest dose of ethinyl estradiol may be most suitable f or smokers who wish to use this form of contraception.