Emergency Contraception (except Cu-IUD)
Levonorgestrel (Levonelle)
Absolute Contraindications
- Hypersensitivity to levonorgestrel
Main Side Effects
- Nausea, vomiting
- Irregular bleeding (before next period)
- Fatigue, headache
Main Interactions
- Enzyme inducers (e.g., rifampicin, carbamazepine) reduce efficacy – double the dose (3 mg) if required
Main Monitoring Requirements
- None required, but consider pregnancy test if period is delayed >7 days
Pregnancy & Breastfeeding
- Pregnancy: Not effective if pregnant but no harm to fetus
- Breastfeeding: Safe; avoid breastfeeding for 8 hours after taking
Indications for Dose Increase of Levonorgestrel in Emergency Contraception
1.Body Weight or BMI:
Indication: A higher body weight (>70 kg) or BMI (>26 kg/m²) may reduce the efficacy of levonorgestrel.
Recommendation: Consider increasing the dose (doubling to 3 mg) or using an alternative emergency contraceptive (e.g., ulipristal acetate or a copper IUD).
2.Enzyme-Inducing Drugs:
Indication: If the patient has been using enzyme-inducing drugs (e.g., carbamazepine, rifampicin, or St. John’s wort) within the past 4 weeks.
Recommendation: Double the standard dose of levonorgestrel (from 1.5 mg to 3 mg).
Ulipristal Acetate (EllaOne)
Absolute Contraindications
- Known or suspected pregnancy
- Severe asthma poorly controlled by glucocorticoids
Main Side Effects
- Nausea, abdominal pain
- Headache, dizziness
Main Interactions
- Enzyme inducers (reduce efficacy)
- Hormonal contraception (e.g., COC) – delay initiation for 5 days
Main Monitoring Requirements
- Consider pregnancy test if period is delayed >7 days or unusual bleeding occurs
Pregnancy & Breastfeeding
- Pregnancy: Not effective if pregnant but no known teratogenic risk
- Breastfeeding: Avoid breastfeeding for 1 week; express and discard milk