Clinical efficacy of ceftazidime. Treatment of serious infection due to multiresistant Pseudomonas and other gram-negative bacteria.

Ceftazidime, a beta-lactamase stable cephalosporin, was administered to 57 patients. Substantial underlying disease was present in the majority of patients, and 50% were in critical or poor condition. Ceftazidime inhibited all initial isolates of Enterobacteriaceae at 8 mg/L or less, regardless of resistance to other antibiotics and the majority of Pseudomonas aeruginosa at 12 mg/L or less. The mean serum level after infusion of 1 g during 30 minutes was 62 mg/L. Overall clinical response was 84%, and the bacteriological response was 72% excluding cystic fibrosis patients. No major adverse effects were encountered. Resistance developed in Pseudomonas from patients with cystic fibrosis and in Enterobacter from two other patients. Ceftazidime was an effective, safe therapy for serious infection due to multiply resistant Pseudomonas and other aerobic gram-negative bacilli including aminoglycoside-resistant Serratia and Klebsiella.