A multicenter comparative trial of tobramycin and ticarcillin vs moxalactam and ticarcillin in febrile neutropenic patients.

During a multicenter prospective randomized trial in febrile neutropenic patients (neutrophil count, less than 1,000/cu mm), 103 episodes were treated with tobramycin sulfate plus ticarcillin disodium (TT) while 117 were treated with moxalactam plus ticarcillin disodium (MT). The majority of patients had an underlying diagnosis of leukemia (60%) and most (62.8%) had granulocyte counts of less than 100/cu mm at the start of therapy. The response rates for clinically or microbiologically documented episodes were 38 of 60 (55.1%) for TT and 38 of 64 (59.4%) for MT. The MT regimen appeared to be more effective for gram-positive infections (56% vs 33%) while TT appeared more effective for gram-negative infections (64% vs 40%). Nephrotoxicity attributable to study drugs occurred in only 2.3% of cases (one on each treatment arm). Prolongation of the prothrombin time was observed in only six of 78 (7.7%) in the TT arm as compared with 39 of 103 (38%) in the MT arm. Neither regimen was adequate for the unusually high frequency of gram-positive pathogens seen during this study.