skip to main content

Lithium NSAID interaction — GPhC CRA MCQ

Instant feedback + full explanation. One question, done properly.

ModerateCNS TherapeuticsLithium NSAID interactionGPhC CRA

A 46-year-old man taking lithium carbonate modified-release asks to buy naproxen for acute back pain. His last lithium level was within range. He has no red-flag symptoms. What is the most important interaction to flag?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: D — NSAIDs may increase lithium concentration and toxicity

NSAIDs can reduce renal lithium clearance and increase the risk of lithium toxicity. Toxicity may present with tremor, ataxia, diarrhoea, vomiting, confusion or drowsiness. The patient should avoid self-starting naproxen and discuss safer analgesia and monitoring with a healthcare professional.

Reference: BNF; NICE CKS