Piperacillin/tazobactam compared with cefuroxime/metronidazole in the treatment of intra-abdominal infections

Objective: To assess the effect of piperacillin/tazobactam compared with cefuroxime/metronidazole in the treatment of patients with intra-abdominal infections. Design: Randomised open study. Setting: 16 Swedish and 6 Norwegian hospitals. Subjects: 269 patients with intra-abdominal infections were randomised and treated with at least one dose of each study drug. 205 patients, 105 treated with piperacillin/tazobactam and 100 with cefuroxime, were clinically evaluable for follow up (had been given the full course of treatment). Intervention: Patients were given piperacillin 4g/tazobactam 0.5 g every 8 hours or cefuroxime 1.5 g every 8 hours plus metronidazole 1.5 g every 24 hours. Each patient was to be treated for a minimum of 3 days and not more than 10 days. Main outcome measures: Clinical evaluation of infection at the end of and 4-6 weeks after treatment. Evaluation of safety and tolerance to the drugs and bacteriological susceptibility to the treatment drugs. Results: In the intention to treat analysis treatment was equally successful for piperacillin/tazobactam (103/140, 74%) and the cefuroxime/metronidazole groups (90/129, 70%) (p = 0.6). Corresponding figures for the clinically evaluable group were 102/105 (97%) and 94/100 (94%) for piperacillin/tazobactam and cefuroxime/metronidazole groups, respectively, at the end of treatment. At late follow up, 92/105 (88%) and 83/100 (83%) in the two groups, respectively, remained free of infection. The side effects of the treatment were mild and evenly distributed between the two groups. Most pathogens were susceptible to the drugs in both treatment groups. Conclusion: Both piperacillin/tazobactam and cefuroxime/metronidazole are well suited to the treatment of patients with intraabdominal infections, and we found no significant difference between the two. The drugs were safe and well tolerated in the regimens used.