Aminoglycoside nephrotoxicity: comparative assessment in critically ill patients

In a prospective trial to determine the incidence of nephrotoxicity with each of three aminoglycoside antibiotics, adults in intensive care units with presumed or proven bacterial infections were treated with intravenous gentamicin, tobramycin, or amikacin. Treatment groups were similar with respect to age, other medical disorders, type of infection, duration of aminoglycoside therapy, additional antibiotics used, other drugs prescribed (notably diuretics and corticosteroids), and rate of superinfection. Nephrotoxicity occurred with gentamicin during 44/121 (36.3%) treatment courses, with tobramycin during 21/92 (22.8%) courses, and with amikacin during 4/16 (25.0%) courses. Although frequent, nephrotoxicity reversed after treatment stopped. Tobramycin nephrotoxicity occurred significantly less often than did gentamicin nephrotoxicity (p less than 0.05). The relative safety of tobramycin may result from lower tissue accumulation during therapy.