A 68-year-old male (75 kg) is admitted to the Intensive Care Unit with severe sepsis and acute kidney injury. His current serum creatinine is 280 µmol/L (baseline approximately 80 µmol/L). He is due for his first dose of meropenem 1 g IV. What is the most appropriate meropenem dose recommendation for this patient, assuming normal hepatic function?

Question: A 68-year-old male (75 kg) is admitted to the Intensive Care Unit with severe sepsis and acute kidney injury. His current serum creatinine is 280 µmol/L (baseline approximately 80 µmol/L). He is due for his first dose of meropenem 1 g IV. What is the most appropriate meropenem dose recommendation for this patient, assuming normal hepatic function?

Answer options:

• Meropenem 1 g IV every 8 hours ✅ Meropenem 500 mg IV every 8 hours
• Meropenem 1 g IV every 12 hours
• Meropenem 500 mg IV every 24 hours

Correct answer: Meropenem 500 mg IV every 8 hours

Explanation: For severe sepsis with acute kidney injury, meropenem dosing requires adjustment. While the usual dose is 1 g IV q8h, a creatinine of 280 µmol/L warrants significant dose reduction. For CrCl 26-50 mL/min, 1 g q12h is used, and for CrCl 10-25 mL/min, 500 mg q12h or 1 g q24h is used. Given his acute kidney injury, a CrCl calculation would show a significantly reduced renal function; using a range of 26-50 mL/min for a conservative estimate, 500 mg IV every 8 hours is often optimized for time-dependent killing in severe sepsis while still reducing the dose for kidney injury, as opposed to prolonging the interval significantly for the initial dose.