7.3 Contraceptives

General Notes

• Women requiring contraception should be given information about and offered a choice of methods, including long-acting reversible contraception (LARC) methods. Most contraceptive failures are due to poor compliance which is strongly influenced by acceptability. The Faculty of Sexual and Reproductive Healthcare produce eligibility criteria for contraceptive use. The full guidance and a useful summary can be found at http://www.fsrh.org.
• Discontinuation rates of all methods of contraception are high and many women change to a less effective method. Good counselling about risks, side effects and benefits should improve continuation. Long acting reversible methods (LARC), particularly implants and intra-uterine methods, have higher continuation rates and are independent of compliance for their effectiveness. See NICE CG 30.
• When a contraceptive is used for management of gynaecological conditions, such as heavy menstrual bleeding or dysmenorrhoea, the risk/benefit ratio changes and it may be prescribed for women who would have relative contra–indications if they were using it solely for contraception.
• Drug interactions should be considered when prescribing contraceptives. Enzyme-inducing drugs, including rifampicin and rifabutin, may impair the efficacy of hormonal contraceptives. Some drugs may be affected by contraceptives such as lamotrigine, which when prescribed with combined hormonal contraception, can result in reduced serum levels of lamotrigine, leading to increased risk of seizures. For further information see BNF and Faculty of Sexual and Reproductive Healthcare guidance http://www.fsrh.org/ on drug interactions.