Polymyxin B-induced acute kidney injury in a burn patient: a case report and pharmaceutical care

Background: Polymyxin B is increasingly used against multidrug-resistant Gram-negative bacteria but carries a risk of acute kidney injury (AKI). Burn patients are particularly vulnerable. Case summary: A 44-year-old male with 66% TBSA burns and sepsis received polymyxin B (50 mg q12h, then escalated to 100 mg q12h). Serum creatinine rose from 59 to 163 μmol/L within 3 days, meeting KDIGO AKI criteria. No other nephrotoxic agents were used. The Naranjo score was 5, indicating probable polymyxin B-induced AKI. After dose reduction to 50 mg q12h, renal function improved without discontinuing therapy. Conclusion: In burn patients, early renal function monitoring (within 3 days) and dose adjustment based on infection response and renal biomarkers are critical. Therapeutic drug monitoring is recommended when available.