PH7.7 | PH7.7 | Contraceptive Pharmacology — SDL Guide — Summary & Reflection

KEY TAKEAWAYS

Contraceptive Pharmacology — Key Takeaways:

• COC mechanisms: Ovulation suppression (primary — suppresses LH surge) + cervical mucus thickening + endometrial thinning.
• COC absolute contraindications (WHO MEC 4): VTE history, ischaemic heart disease, stroke, migraine with aura, smoking ≥35 years, uncontrolled hypertension, active liver disease, breast cancer.
• Oestrogen + breastfeeding = reduced milk supply — use progestin-only methods in breastfeeding women.
• Enzyme inducers (rifampicin, phenytoin, carbamazepine): accelerate OCP metabolism → contraceptive failure. Add condom; continue 28 days post-course.
• Emergency contraception windows: Levonorgestrel 1.5 mg ≤72 hours (effective to 120 hr with declining efficacy). Ulipristal acetate ≤120 hours (more effective than LNG at 72–120 hr). Copper IUD ≤120 hours — most effective EC.
• Levonorgestrel EC is NOT abortifacient — works primarily by preventing/delaying ovulation.
• Male condom = only STI prevention method — counsel on correct use at every sexual health consultation.
• VTE with COC: 3–4× relative risk increase vs non-users; absolute risk low. Progestin-only methods do not significantly increase VTE risk.

REFLECT

Consider the scenario of a 30-year-old woman who asks you 'Is the morning-after pill the same as an abortion pill?' How would you explain the pharmacological difference between emergency contraception (levonorgestrel/ulipristal) and medical termination agents (mifepristone + misoprostol) in clear, non-judgmental, patient-friendly language? Write three sentences addressing: (1) what emergency contraception does (its timing of action), (2) what medical termination does (when it is used), (3) why they are not the same drug or the same concept. Reflect on how pharmacological accuracy enables sensitive and factually correct patient counselling.