A patient with chronic kidney disease has a glomerular filtration rate of 40 mL/min. You intend to prescribe amoxicillin-clavulanate. What should you do?

Correct answer: C. Reduce the dose or extend the dosing interval

• A. Antibiotics are not contraindicated — they simply require appropriate dose adjustment.
• B. Increasing the dose in renal impairment produces accumulation and toxicity — the reasoning is backwards.
• C. Correct. Amoxicillin and clavulanate are eliminated principally by the KIDNEY. With a reduced GFR, drug and metabolites accumulate and toxicity risk rises, so the dose is reduced and/or the interval lengthened. A GFR of 40 mL/min places this patient in CKD stage 3b. General rule: renally cleared drugs need dose adjustment; hepatically cleared drugs generally do not.
• D. An unchanged dose risks accumulation; adjustment is mandatory at this level of impairment.