Monotherapy in serious hospital-acquired infections: a clinical trial of ceftazidime versus imipenem/cilastatin

The clinical and bacteriological efficacy and safety of the antibiotics ceftazidime or imipenem/cilastatin in seriously ill patients with nosocomial infections were compared in a prospective, open, evaluator-blind, multicentre comparative trial. The study was performed in 26 European centres, the majority being intensive care units. Subjects were randomized to receive either ceftazidime 2 g bid or imipenem cilastatin 0·5 g qid given for at least five days after stratification for pneumonia, septicaemia or urinary tract infection (UTI). Three hundred and ninety-three patients with serious nosocomial infections (254 with pneumonia; 91 with septicaemia and 48 UTI were treated between February 1988 and January 1990 and their clinical and bacteriological response to antibiotic treatment assessed. There were no significant differences between ceftazidime and imipenem/cilastatin in clinical efficacy. The failure rates in evaluable patients were 22 and 26% in pneumonia, 23 and 19% in septicaemia and 0 and 5% respectively in those with UTI. Overall there was no significant difference between the two antibiotics for bacteriological response in the three infection strata. However, in patients with pneumonia ceftazidime was significantly more effective than imipenem/cilastatin in clearing patients of Pseudomonas spp.: 3/17 and 11/19 patients respectively had persistent growth of Pseudomonas spp. post-treatment (P = 0·004), and in one ceftazidime failure resistance emerged compared to six imipenem/cilastatin failures in which resistance emerged. Few drug-related adverse events were recorded in either treatment group. Monotherapy with either ceftazidime (2 g bid) or imipenem/cilastatin (0·5 g qid) is safe and effective and could be considered as an alternative to combination therapy for the treatment of serious hospital-acquired infection