Pseudomonas Bacteremia: Pharmacologic and Other Bases for Failure of Treatment with Gentamicin

Abstract

The species Pseudomonas aeruginosa is sensitive to gentamicin, but among 21 patients treated for pseudomonas bacteremia, only six were cured and 15 (71%) died. Seven patients with a rapidly fatal underlying disease died; five of eight considered to have ultimately fatal diseases died, and three of six patients with nonfatal primary diseases died. The dose was not predictive of the level in serum, and most patients received a suboptimal dose. The concentration in the serum was directly related to eradication of bacteremia and survival of the patient. The protective level in serum corroborated the in-vitro sensitivity tests. Gentamicin had a slow maximal bactericidal rate on Pseudomonas. Leukemic leukocytes in leukemic serum were less effective than normal leukocytes in normal serum in killing P. aeruginosa. The high fatality rate from pseudomonas bacteremia results from inadequate treatment, resistance of the organism to killing, and defective defense mechanisms in the patients. Proper use of gentamicin should cure patients if they do not have fatal underlying diseases.