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Lithium toxicity with NSAID and dehydration — GPhC CRA MCQ

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HardCNS TherapeuticsLithium toxicity with NSAID and dehydrationGPhC CRA

A 79-year-old woman takes lithium carbonate modified-release tablets. She has vomiting and diarrhoea, feels tremulous and unsteady, and started ibuprofen for back pain two days ago. Her daughter asks whether to collect the repeat prescription. What is the most important interaction to flag?

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Correct answer: D — Do not supply until urgent same-day lithium toxicity assessment is arranged.

Vomiting, diarrhoea, tremor and ataxia are concerning for lithium toxicity, and NSAIDs plus dehydration can increase lithium levels. This requires urgent clinical assessment and serum lithium/electrolyte testing. Continuing supply without escalation could cause serious harm.

Reference: https://www.pharmacyregulation.org/registration-assessment#stage-8-order-90