Nephrotoxicity due to combination antibiotic therapy with vancomycin and aminoglycosides in septic critically ill patients

The aim of this prospective observational study was to evaluate the incidence of nephrotoxicity due to combination therapy with vancomycin and aminoglycosides in septic critically ill patients admitted to the intensive care unit. METHODS: Thirty consecutive critically ill patients were treated with vancomycin concurrent with aminoglycosides for sepsis. Inclusion criteria were: the need for mechanical ventilation and the presence of severe infection due to bacteria susceptible to vancomycin and aminoglycosides. Exclusion criteria were: age <18 years, impaired renal function (24-hour creatinine clearance <90 ml/min) or previous adverse reaction to either drug. Serum creatinine and urea concentrations, creatinine clearance, 24-hour urinary excretion of proteins, beta2-microglobulin and enzymes were measured immediately before starting therapy and at different times thereafter. RESULTS: Eleven of the 30 patients had a transient and modest increase in serum urea, 15 patients presented with urinary excretion of beta2-microglobulin and tubular enzymes, and 14 patients had urinary proteins.In the only patient with severe acute renal failure (serum creatinine 8.2 mg/dl), the clinical course was complicated by prolonged hypotension. CONCLUSION: Concurrent administration of vancomycin and aminoglycosides to critically ill septic patients with normal renal function at baseline induced mainly slight and transient toxic tubular effects. The only clinically significant nephrotoxic event occurred in a patient with septic shock.