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Lithium and ACE inhibitor monitoring — GPhC CRA MCQ

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HardCNS TherapeuticsLithium and ACE inhibitor monitoringGPhC CRA

A patient stabilised on lithium carbonate MR 400 mg twice daily is prescribed ramipril 5 mg daily for hypertension. Her last lithium level was 0.7 mmol/L and eGFR is 58 mL/min/1.73 m2. What monitoring is required?

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Correct answer: B — Arrange lithium level and renal function monitoring after the change

ACE inhibitors can increase lithium concentrations and precipitate toxicity, particularly with reduced renal reserve. Lithium has a narrow therapeutic index, so levels and renal function should be checked after interacting medicines are started or doses changed. The patient should be counselled to seek help for tremor, diarrhoea, ataxia or confusion.

Reference: BNF