A randomized study of ceftazidime compared to ceftazidime and tobramycin for the treatment of infections in cancer patients

Three hundred and twenty-one febrile episodes in cancer patients were treated with ceftazidime alone or in combination with tobramycin. Patients were grouped according to their neutrophil count into neutropenic and non-neutropenic (< 1000 and > 1000/mm³) respectively. Two hundred and seventy-five episodes were evaluated. The overall response rate in 83 episodes of infection treated with ceftazidime alone was 60 and 73% in those who received the combination. In those bacteriologically proven the response rate was 72% in both groups of the study. The overall response rate in septicaemia was 75% with ceftazidime alone and 85% with the combination. High response rates were obtained in Gram-negative bacillary septicaemias in both groups even in neutropenic patients treated with ceftazidime alone. Pneumonias in neutropenic patients responded equally well. However, patients with adequate neutrophil counts responded better to the combination than to single-agent therapy. The response rate for Gram-positive infections was 41% for ceftazidime alone and 57% for the combination, which was inferior to the results obtained for Gram-negative infections (P = 0.001). The rates of superinfection and toxicity were very low. Ceftazidime is a useful antibiotic against Gram-negative infections in cancer patients. It should be combined with an agent active against Gram-positive pathogens in neutropenic patients.