How should I counsel a patient regarding the efficacy and side effects of different emergency contraceptive methods?

Emergency contraceptive methods include the copper intrauterine device (Cu-IUD), ulipristal acetate, and levonorgestrel tablets.

Efficacy: The Cu-IUD is the most effective emergency contraception method and should be offered first if insertion criteria are met and the woman accepts it.

Ulipristal acetate is effective if taken as soon as possible after unprotected sexual intercourse (UPSI), ideally within 120 hours, but efficacy decreases with time and it is less effective if taken beyond 72 hours.

Levonorgestrel is less effective than ulipristal acetate and the Cu-IUD, and its efficacy also decreases with time after UPSI.

Side effects: The Cu-IUD may cause menstrual abnormalities such as unscheduled bleeding, mild lower abdominal pain, and discomfort during intercourse; women should be advised on how to check for IUD threads and to seek medical advice if symptoms persist or complications arise.

Levonorgestrel can cause headache, lower abdominal pain, fatigue, dizziness, diarrhoea, and breast tenderness.

Ulipristal acetate may have side effects but specific adverse effects are less commonly reported; however, it should not be used with liver enzyme-inducing drugs as efficacy may be reduced.

Counselling points: Inform the woman about the mode of action, timing, and efficacy of each method, including that the Cu-IUD provides ongoing contraception and is unaffected by enzyme-inducing drugs, unlike oral methods.

Advise that none of these methods protect against sexually transmitted infections (STIs), so barrier methods should be used for STI prevention.

Discuss any contraindications, current medications, breastfeeding status, and timing since UPSI to guide method choice.

Offer referral for Cu-IUD insertion if appropriate, and provide oral emergency contraception in the meantime if needed.

Ensure confidentiality, especially for women under 16, and provide information on local services and ongoing contraception options.

This approach supports informed choice and maximises efficacy while minimising risks and side effects.

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