Drugs in the peri-operative period: 3--Hormonal contraceptives and hormone replacement therapy.

Women taking combined hormonal contraceptives or hormone replacement therapy (HRT) have an increased risk of developing venous thromboembolism, compared to non-users. Surgery itself carries a risk of thromboembolism, the incidence of which varies with the nature of the procedure. In this article, the third in our series on drug therapy in the peri-operative period, we review the thromboembolic effects of oral contraceptives and HRT and consider how these affect management around the time of surgery.