Increased risk of renal dysfunction due to interaction of liver disease and aminoglycosides

To determine if aminoglycoside use and liver disease interact to cause an increased risk for renal dysfunction, data from 179 hospitalized patients who had been enrolled in a prospective, randomized trial of nafcillin/tobramycin versus cefotaxime were analyzed. The cefotaxime-treated patients served as a control group not receiving an aminoglycoside. Renal dysfunction occurred in seven of 88 (8 percent) given cefotaxime and 37 of 91 (41 percent) given tobramycin (p <0.001), in 11 of 29 (38 percent) with liver disease and 33 of 150 (22 percent) without liver disease (p <0.08), and occurred in 11 of 15 (73 percent) with both liver disease and tobramycin use and in 0 of 14 (0 percent) with liver disease and cefotaxime use (p <0.001). By logistic regression analysis, the relative odds of renal dysfunction developing during tobramycin treatment in a patient were 6.0 (95 percent confidence interval: 3.8 to 9.5). The relative odds of renal dysfunction developing in a patient receiving tobramycin and having liver disease were 31.8 (95 percent confidence interval: 19.7 to 51.4). This analysis demonstrates an interaction between tobramycin use and liver disease for increasing the risk of renal dysfunction.