Infections in cancer patients.Results with gentamicin sulfate therapy

Gentamicin was administered to 101 cancer patients during 122 episodes of infection. Sixty-two (51%) infections responded. The drug was most effective for the treatment of urinary tract infection and cellulitis and ineffective against infections involving multiple body sites. Most of the infections were caused by Serratia marcescens, Pseudomonas aeruginosa, and Klebsiella sp. The response to gentamicin therapy was related to the patients' neutrophil counts. Only five of the 23 (22%) infections occurring in patients with less than 100 neutrophils per mm3 responded favorably, whereas 29 of the 51 (57%) infections occurring in patients with more than 1000 neutrophils per mm3 responded favorably. Fourteen (11%) superinfections occurred while patients were receiving gentamicin. Nephrotoxicity occurred in 30% of patients with normal renal function at the onset of gentamicin therapy.