Metformin renal impairment — GPhC CRA MCQ

Correct answer: D — Withhold lithium and arrange urgent medical assessment

This patient has clinical features of lithium toxicity, and both dehydration and recent ACE-inhibitor initiation can reduce lithium clearance. The immediate priority is to withhold lithium and obtain urgent medical assessment; management must not be delayed merely because the sample was not a standard 12-hour trough. Dose reduction or routine repeat testing is unsafe in a symptomatic patient.

Reference: https://www.pharmacyregulation.org/students-and-trainees/pharmacist-education-and-training/registration-assessment