Combined monophasic oral contraceptives with a constant daily dose of a combination of an estrogen and a progesterone agent are the most commonly utilized form of birth control pills.
The progestogen agent is the anti-ovulatory agent.
The estrogen in most cases is ethinylestradiol.
Second generation progestogens (levonorgestrel) and third generation progestogens (desogestrel, gestodene) are utilized.
Not recommended for women with the following medical conditions: pregnancy, breast cancer, hypertension, certain heart and liver diseases, long-standing or complicated diabetes mellitus, history of thromboembolic disease, stroke, migraine headaches with focal neurologic symptoms, less than 6 weeks postpartum, breastfeeding, older than 35 years who smoke more than 15 cigarettes per day.
Commonly can cause hypertension.
Should be avoided in smokers over the age of 35 years doing due to increased thrombotic risk along with hypertension, which may precipitate myocardial infarction or stroke.
Increase the risk for thromboembolism.
In women with inherited clotting defects venous thromboses occur more often and sooner in onset when they use oral contraceptives.
Incidence of venous thromboembolism 12-20 cases per 100,000 women per year.
Large studies have identified the risk of deep vein thrombosis at baseline in reproductive age do women to be approximately 2 to 10 per 10,000 women years.
The risk associated with combined hormonal contraception is approximately 7 to 10 venous thrombotic events per 10,000 women years.
The risk of venous thromboembolism is substantially greater in pregnancy.
Most common cause of venous thrombosis in young women..
Risk of venous thrombosis highest in the first year of use, reaching an absolute risk of 12 per 10,000 women per year.
The risk of venous thrombosis is immediately reversed to baseline shortly after discontinuation.
Increase procoagulants Factors VII, IX, X, fibrinogen, thrombin generation, activated protein C resistance.
Decreases Antithrombin, protein S, fibrinolysis inhibitor, alpha-2-plasmin.
Even in the lowest doses the increased risk of arterial and venous thrombosis is 2-5 fold.
Agents containing the third generation progestogens desogestrel and gestodene have a 2 fold higher risk of venous thrombosis in patients than users of other formulations.
Effects on the coagulation system are more pronounced when they contain desogestrel or gestodene than in those containing levonorgestrel, leading to a more pronounced prothrombotic state.
Containing cyproteronacetate increases the risk of venous thrombosis, higher than the risk for third generation oral contraceptives.
For most women hormonal contraception can be safely provided on the basis of a careful review of the medical history and blood pressure measurement.
Increase myocardial infarction four fold in young women.
Increased risk among women who smoke heavily.
Higher risk of thromboembolism in older women, obese women and women with prothrombotic abnormalities.
Obesity doubles risk of thrombosis with BMI over 30 kg/m2 and when they use oral contraceptives they have a 10 fold increased risk.
Greatly increase risk of thrombosis in familial thrombophilia, deficiencies of protein S, C or antithrombin.
Patients who are factor V Leiden carriers or prothrombin 20210A carriers have a 15-30 fold increased risk of thrombosis when they use oral contraceptives.
Rifampin and to a lesser extent tetracycline and penicillins may impair the effectiveness of oral contraceptives and lead to their failure when used in combination.
Use is known to reduce the incidence of endometrial cancer.
Oral contraceptives reduce the risk of endometrial cancer by 30-40%, and their longer use is associated with increased protection, which can persist for decades after cessation.
Increased risk of breast cancer among women currently using OC’s are suggested, and risk reduction for ovarian, endometrial, and likely colo-rectal cancers are associated with increasing duration of OC use.