Morphine metabolites in renal impairment — FRCA Primary MCQ
Instant feedback + full explanation. One question, done properly.
Educational content. Not a substitute for clinical judgement or local policy.
Reveal the answer and explanation
Correct answer: C — Accumulation of pharmacologically active morphine metabolites
The best answer is “Accumulation of pharmacologically active morphine metabolites”. Morphine metabolites, particularly morphine-6-glucuronide, are pharmacologically active and can accumulate in renal impairment, producing prolonged sedation and respiratory depression. Reduced free drug, esterase clearance, volatile conversion and receptor-affinity loss do not explain this classic presentation.
Reference: Morphine 10 mg/5 mL oral solution, Summary of Product Characteristics: https://www.medicines.org.uk/emc/product/3427/smpc