What advice should be given to women using hormonal contraception and liver enzyme-inducing drugs?
Combined Hormonal Contraception • Women taking liver enzyme-inducing drugs who wish to use combined oral contraception (COC) should choose a regimen containing at least 50 micrograms ethinylestradiol (EE) daily. Additional contraceptive protection, such as condoms, should be used until 4 weeks after the liver enzyme-inducing drug has been stopped. Information should be given on the use of alternative methods of contraception if liver enzyme-inducing drugs are to be used long term (Grade C). • Breakthrough bleeding does not necessarily indicate low serum EE concentrations and risk of ovulation. Nevertheless, women using liver enzyme-inducing drugs with breakthrough bleeding may increase their dose of EE above 50 micrograms daily (Good Practice Point). • No evidence was identified that supports omitting or reducing the pill-free interval to reduce the risk of ovulation in women using liver enzyme-inducers (Good Practice Point). • Women using liver enzyme-inducing drugs may use a combined
