Oral contraceptives venous thromboembolism with

Cyproterone acetate in combination with ethinylestra-diol is indicated for the treatment of women with severe acne and moderately severe hirsutism. This product has been associated with a greater risk of venous thromboembolism than oral contraceptives. However, in a rigorous case-control study the risk of venous thromboembolism with cyproterone acetate + ethinylestradiol was not significantly greater than the risk in women who took conventional oral contraceptives (25). 

Douketis JD, Ginsberg JS, Holbrook A, et al. A reevaluation of risk for venous thromboembolism with use of oral contraception and hormone replacement. Arch Intern Med 1997 157 1522-1530. 

Cilest contains ethinylestradiol and norgestimate whereas Yasmin contains ethinylestradiol in combination with drospirenone. Both are combined oral contraceptives available as tablets, which have to be taken once daily for 21 days. Both are contraindicated in patients with venous thromboembolic diseases. 

England that the Committee on Safety of Medicines had written to prescribers in 1995 stating that three unpublished studies on the safety of combined oral contraceptives in relation to venous thromboembolism had indicated about a two-fold increase in the risk of such conditions compared with the preceding generation of products. This issue of a two-fold increase became crucial to the case. For reasons of causation, as the Judge put it, the claimants had accepted the burden of proving that the increase in risk was not less than two-fold. 

Jick H, Kaye JA, Vasilakis-Scaramozza C, Jick SS. Risk of venous thromboembolism among users of third generation oral contraceptives compared with users of oral contraceptives with levonorgestrel before and after 1995 cohort and case-control analysis. BMJ 2000 321(7270) 1190-5. 

Jick H, Jick SS, Gurewich V, Myers MW, Vasilakis C. Risk of idiopathic cardiovascular death and nonfatal venous thromboembolism in women using oral contraceptives with differing progestagen components. Lancet 1995 346(8990) 1589-93. 

The current consensus is that the contemporary low-dose preparations pose minimal risks in women who have no predisposing risk factors and, in fact, may provide certain beneficial health effects (e.g., protection against endometrial and ovarian cancer). Oral contraceptive pills have been associated with increased risk for myocardial infarction, stroke, and venous thromboembolism. However, studies have been published that suggest that these risks are minimal in appropriately chosen low-risk women. 

Stroke is a very uncommon event in childbearing women, occurring in approximately 11 per 100,000 women over a 1-year period of time. Therefore, even a doubling of this risk with oral contraceptive pills would have minimal effect on attributable risk. The estimated risk of myocardial infarction associated with oral contraceptive pill use in nonsmokers is 3 per million women over 1 year. The estimated risk of venous thromboembolism attributable to oral contraceptive pills is less than 3 per 10,000 women per year. However, the risk may be increased in women who smoke or have other predisposing factors to thrombosis or thromboembolism. In fact, it should be emphasized that the risk of serious cardiovascular side effects is particularly marked in women over 35 years of age who are heavy smokers (e.g., more than 15 cigarettes per day). Additionally, the literature suggests that there may be an increased risk of breast cancer associated with long-term oral contraceptive pill use in women under the age of 35. However, because the incidence of breast cancer is so relatively low in this population, the attributable risk of breast cancer from birth control pill use is small. 

Thrombosis in the dural sinuses or cerebral veins is much less common than cerebral arterial thromboembolism. It causes a variety of clinical syndromes, which often do not resemble stroke (Bousser and Ross Russell 1997). While ischemic arterial stroke and cerebral venous thrombosis share some causes (Southwick et al. 1986), others are specific to cerebral venous thrombosis (Table 29.1). A particularly high index of suspicion is required in women on the oral contraceptive pill (Saadatnia and Tajmirriahi 2007) and in the puerperium. In the past, cerebral venous thrombosis was strongly associated with otitis media and mastoiditis, lateral sinus thrombosis or otitic hydrocephalus, but the most common causes are now pregnancy and the puerperium, which cause 5-20% of the cerebral venous thrombosis in the developed world, the oral contraceptive pill, malignancy, dehydration, inflammatory disorders and hereditary coagulation disorders. No cause is found in around 20% of cases. 

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