Controlled Comparison of Amikacin and Gentamicin

Amikacin or gentamicin was used to treat 174 patients with suspected severe gram-negative infections in a prospective, randomized, double-blind trial. Enteric gram-negative bacilli were pathogenic in 71 cases (39 treated with amikacin, and 32 with gentamicin). Amikacin was effective in 10 of 12 bacteremias, 21 of 24 urinary-tract infections, two of five pneumonias and four of six other serious tissue infections. The total favorable response rate was 77 per cent for amikacin and 78 per cent for gentamicin. Nephrotoxicity and auditory toxicity could be evaluated in 124 and 67 cases respectively. Definite nephrotoxicity developed in five of 62 (8 per cent) receiving amikacin and seven of 62 (11 per cent) given gentamicin, and possible nephrotoxicity developed in four patients in both groups. Definite ototoxicity developed in two of 34 (6 per cent) and three of 30 (10 per cent) respectively. These differences were not statistically significant (by chi-square analysis, P>0.05). The results indicate that amikacin is effective against severe gram-negative infections and is not more and not less ototoxic or nephrotoxic than gentamicin. (N Engl J Med 296: 349–353, 1977 Infections caused by enteric gram-negative bacilli are a major cause of morbidity and mortality in hospitalized patients.¹ Although gentamicin is the drug currently used most frequently to treat these infections, it is nephrotoxic and ototoxic,² and an increasing number of enterobacteriaceae and pseudomonas are becoming resistant.³ Amikacin, a semisynthetic aminoglycoside with pharmacokinetic properties similar to those of kanamycin,^{4 5 6} is effective in vitro against most enterobacteriaceae and pseudomonas, including many strains that are resistant to gentamicin.^{7 8 9 10} Initial clinical trials have suggested that amikacin is effective therapy for serious gram-negative infections, including those due to gentamicin-resistant organisms.^{11 12 13 14} However, these studies have not.