Evaluating the incidence of acute kidney injury and gentamicin synergy dosing for endocarditis

Abstract

Abstract Objectives Current infective endocarditis guidelines recommend two different gentamicin synergy dosing strategies for selected Gram-positive organisms. The purpose of this analysis was to evaluate the incidence of acute kidney injury (AKI) with gentamicin synergy dosing, comparing divided-daily and once-daily dosing strategies for infective endocarditis (IE). Methods Groups were split into patients who received gentamicin divided-daily dosing and once-daily (3 mg/kg) dosing for Gram-positive IE. The primary outcome was the incidence of AKI defined by RIFLE (risk, injury, failure, loss, end-stage renal disease) criteria after starting gentamicin. A multivariable logistic regression analysis was performed to identify possible independent predictors of developing AKI. Notable secondary outcomes included hospital length of stay, need for gentamicin dose adjustments based on therapeutic drug monitoring, and assessment of each case of AKI using the Naranjo algorithm. Results The incidence of AKI was significantly higher in the divided-daily group compared with the once-daily group (52.5% versus 13%, P < 0.01). The divided-dosing group had significantly longer median [IQR] hospital length of stay (19 days [12:29] versus 13.5 days [9:22], P < 0.01) and a greater number of patients who required dose adjustments (76.2% versus 21.7%, P < 0.01). The multivariable regression analysis showed that the divided-dosing strategy, duration and institution were independently associated with incidence of AKI. Conclusions This analysis suggests a lower incidence of AKI in the treatment of endocarditis with gentamicin synergy dosed once-daily compared with a divided-daily dosing. Further studies are warranted to assess if there is a difference in efficacy between gentamicin synergy dosing strategies and in gentamicin compared with no gentamicin regimens for IE.