Acute Kidney Injury After Nephrotoxic Antibiotic Therapy in Patients with Infective Endocarditis

Background: Acute kidney injury (AKI) due to antibiotic nephrotoxicity is a complication that can be avoided or managed properly if diagnosed early. Objectives: We aimed to determine the incidence and risk factors of AKI and to assess the possible effects of nephrotoxic antibiotic therapy on its development in a large group of patients with infective endocarditis (IE). Methods: Patients with definite or possible IE diagnosed based on the Duke criteria were included in this retrospective cohort study at a tertiary referral center from 2007 to 2017. Data were derived from the single-center Iranian Registry of Infective Endocarditis (IRIE). Baseline risk factors for AKI were assessed via repeated serum creatinine measurements. Patients (n = 22) with end-stage renal failure undergoing dialysis were excluded. AKI was defined and staged in accordance with the Kidney Disease: Improving Global Outcomes (KDIGO) classification. Results: Totally, 498 patients at a mean age of 45 16 years were studied. The baseline creatinine level was 1.26 0.72 mg/dL. AKI occurred in 126 (26.3%) patients 1 week after the initiation of antibiotic therapy. There was a significant relationship between AKI and the use of gentamicin (P = 0.01) and gentamicin and vancomycin concomitantly (P = 0.01). At the end of the treatment, after dose adjustment and additional treatments, the incidence of AKI decreased to 22.7%, whereas this improvement was less remarkable in the patients with prior renal failure. Some independent variables, including age (P = 0.04), diabetes (P 0.0001), prior renal failure (creatinine 2 mg/dL), anemia (P = 0.003), left-sided IE (P = 0.04), and positive blood cultures with Staphylococcus aureus (P = 0.04) had a statistically significant association with AKI. Conclusions: Close monitoring of the renal function is essential in IE patients receiving treatment with nephrotoxic antibiotics, especially patients with advanced age, diabetes, chronic renal failure, anemia, and left-sided IE.