2020 Volume 35 Issue 1 Pages 22-30
The antimicrobial activity of amikacin sulfate (AMK), an aminoglycoside antibiotic, is maximized when its maximum serum concentration (peak concentration) is maintained above a certain threshold. This concentration should be monitored carefully in patients with an impaired renal function as the degree of renal impairment increases with the minimum serum concentration (trough concentration). Thus, there is a need for a measure to minimize the risk of renal impairment in patients for whom an adjustment of administration intervals alone is not sufficient to select the optimal method of administration. To determine the appropriate use of AMK, we examined whether the trough concentration, which is known to be strongly associated with renal impairment, is associated with the risk of developing renal impairment. We examined data collected from 235 patients who were treated with AMK for infections, including bacterial pneumonia and urinary tract infection. We performed classification and regression tree analysis and selected a threshold of 2.55 and 6.85 μg/mL as the trough concentration. We also included 4.0 μg/mL, which is the reference value according to the Therapeutic Drug Monitoring Guidelines for Antimicrobials, to perform logistic regression analysis. The probabilities of developing renal impairment (mean (95% CI) ) were 2.7% (1.2-5.9), 3.6% (1.8-7.1), and 6.0% (3.3-10.8) at trough concentrations of 2.55, 4.0, and 6.85 μg/mL, respectively. Our findings suggest that instead of using a common cut-off value, the trough concentration should be determined on a per patient basis according to the risk of developing renal impairment when considering the administration of AMK.
