Nephrotoxicity and Ototoxicity of Aztreonam versus Aminoglycoside Therapy in Seriously III Nonneutropenic Patients

A randomized double-blind clinical trial was done of aztreonam versus aminoglycoside therapy for the empiric treatment of seriously ill nonneutropenic patients suspected of aerobic gram-negative bacterial infection. Each patient was treated for =72 h with the study drug. Nephrotoxicity, defined by =50% increase in baseline serum creatinine, occurred in 12 (15%) of 92 patients receiving aminoglycoside therapy and 1 (1%) of 92 patients receiving aztreonam (P <.004). More severe nephrotoxicity, defined by =100% increase in baseline serum creatinine, occurred in 6 (6.5%) of 92 patients receiving aminoglycoside therapy and in 1 of 92 receiving aztreonam (P <.11). Patients with an elevated baseline total bilirubin level were most likely to develop nephrotoxicity. Auditory toxicity occurred in 2 (7%) of 28 evaluatable patients receiving aminoglycoside therapy and in 1 (3%) of 33 receiving aztreonam (P <.58). One patient, who received aminoglycoside, developed vestibular toxicity. In nonneutropenic patients believed to be at increased risk for renal dysfunction, aztreonam is a less toxic alternative to aminoglycoside therapy for treatment of suspected aerobic gram-negative infection.