Nearly 3.2 million people in this country receive aminoglycoside antibiotics annually. Gentamicin sulfate and tobramycin sulfate continue to demonstrate ototoxicity and nephrotoxicity in both animal and clinical studies. In this study, 62 patients with confirmed initial normal renal function and treated with 2 to 5 mg/kg/day of gentamicin sulfate or tobramycin sulfate for a minimum of seven days were followed up prospectively for the development of aminoglycoside-related renal failure, defined as at least a one-third reduction in renal function. In these 62 patients, no other causes for renal failure could be identified. Five of 33 (15%) of the tobramycin-treated patients and 16 of 29 (55.2%) of the gentamicin-treated patients had renal failure. Thus, gentamicin was associated with renal failure more than three times as often as was tobramycin.
