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Theophylline interaction — GPhC CRA MCQ

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HardRespiratory TherapeuticsTheophylline interactionGPhC CRA

A 68-year-old weighing 72 kg takes levetiracetam for focal seizures. Creatinine clearance normalised to 1.73 m² is 44 mL/min, and the prescriber asks which listed maintenance regimen falls within the authorised adult range for this renal category. Which is correct?

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Correct answer: C — Levetiracetam 500 mg twice daily

Creatinine clearance 30–49 mL/min/1.73 m² is moderate renal impairment. For adults and adolescents over 50 kg, the SmPC range is 250–750 mg twice daily, so 500 mg twice daily is within range. One gram twice daily exceeds the renal range. The once-daily regimens do not match the authorised frequency for this category; once-daily maintenance is reserved for end-stage renal disease on dialysis, with a post-dialysis supplement. The exact dose within the range is individualised to seizure control and tolerability.

Reference: Levetiracetam Sandoz 500 mg tablets SmPC. https://www.medicines.org.uk/emc/product/13455/smpc