Purpose: A case of nephrotoxicity possibly caused by tobramycin inhalation solution is presented.
Summary: A 62-year-old Caucasian woman was admitted for treatment of decreased urine output and sepsis secondary to Pseudomonas aeruginosa. Her past medical history was significant for multiple diseases, including chronic renal insufficiency (baseline serum creatinine concentration [SCr] 2 mg/dL). One month postadmission, the patient was diagnosed with health care-associated pneumonia. The patient was initiated on piperacillin-tazobactam and tobramycin 2 mg/kg i.v. She was changed to imipenem-cilastatin with continuation of i.v. tobramycin. A month after discontinuation of her antibiotic regimen, the patient was diagnosed with P. aeruginosa pneumonia. The patient received imipenem-cilastatin, vancomycin, and inhaled tobramycin 300 mg twice daily. At that time, her SCr was 2 mg/dL. Inhaled tobramycin was continued for four weeks, and the patient's SCr steadily rose to a peak of 4.5 mg/dL. During week 1 of treatment, multidrug-resistant P. aeruginosa and methicillin-resistant Staphylococcus aureus were diagnosed. The patient continued to receive i.v. imipenem-cilastatin, vancomycin, and inhaled tobramycin with an SCr of 1.9 mg/dL. However, at the end of week 2, the patient's SCr began to slowly rise (2.3 mg/dL). At week 3, imipenem-cilastatin was discontinued; inhaled tobramycin was continued. The patient's SCr continued to rise (3.2 mg/dL). At week 4, her SCr rose to 4.5 mg/dL, resulting in initiation of hemodialysis and discontinuation of inhaled tobramycin. The patient's SCr never returned to baseline, and renal function was never regained.
Conclusion: Acute renal failure requiring dialysis occurred in a high-risk patient receiving an extended course of treatment with inhaled tobramycin.