skip to main content

Metformin renal function — GPhC CRA MCQ

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

ModerateRenal and Hepatic ImpairmentMetformin renal functionGPhC CRA

A 71-year-old taking metformin 1 g twice daily has an acute vomiting illness and reduced oral intake. His latest eGFR is usually 42 mL/min/1.73 m². His daughter asks whether to continue his medicines. What is the most appropriate action?

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

Reveal the answer and explanation

Correct answer: E — Advise temporary withholding and urgent clinical review if unwell

Acute illness with dehydration increases the risk of acute kidney injury and metformin-associated lactic acidosis. Sick-day advice commonly includes temporarily withholding metformin during significant vomiting, diarrhoea or dehydration and seeking review if symptoms persist or worsen. Dose escalation would increase risk. A pharmacist should not switch diabetes therapy without appropriate clinical assessment.

Reference: BNF; NICE CKS