Aims: Several studies have reported that critically ill patients who require amikacin for the treatment of severe infection require therapeutic drug monitoring (TDM) to prevent acute kidney injury. Moreover, studies so far have mainly focused on patients with critical illnesses; therefore, the probability of occurrence of nephrotoxicity in noncritically ill patients is less known and tends to be overestimated. Recently, with the emergence of multidrug resistant bacteria, the need for aminoglycosides has resurfaced. Therefore, the aim of this study was to investigate the nephrotoxicity and tolerability of amikacin in noncritically ill patients.
Materials and methods: This was a retrospective study that included 224 patients who were administered amikacin. Relevant data on patients' clinical course of disease, comorbidities, and clinical laboratory measurements were statistically analyzed. Nephrotoxicity was defined as a serum creatinine level increase by ≥ 0.3 mg/dL or ≥ 50% after therapy initiation.
Results: The mean (SD) daily amikacin dose was 13.04 (4.21) mg/kg. The mean (SD) duration of treatment was 12.09 (12.89) days. The incidence rate (95% CI) of amikacin-induced nephrotoxicity was 1.076/person-year (0.46 - 2.12) for the total person-time (3.44 years). In the risk analysis, no risk factor associated with nephrotoxicity could be found. However, an increasing trend of AKI risk was observed in patients with low baseline estimated glomerular filtration rate.
Conclusion: In noncritically ill patients, the incidence of amikacin-induced nephrotoxicity was lower than that reported in previous studies. The initial monitoring for kidney function in clinical laboratories may be useful, and therapeutic drug monitoring (TDM) may not be necessary in patients with normal kidney function.