Fluoroquinolone-based versus β-lactam-based regimens for complicated intra-abdominal infections: a meta-analysis of randomised controlled trials.

Complicated intra-abdominal infections (cIAIs) are common and confer significant morbidity, mortality and costs. In this era of evolving antimicrobial resistance, selection of appropriate empirical antimicrobials is paramount. This systematic review and meta-analysis of randomised controlled trials compared the effectiveness and safety of fluoroquinolone (FQ)-based versus β-lactam (BL)-based regimens for the treatment of patients with cIAIs. Primary outcomes were treatment success in the clinically evaluable (CE) population and all-cause mortality in the intention-to-treat (ITT) population. Subgroup analyses were performed based on specific antimicrobials, infection source and isolated pathogens. Seven trials (4125 patients) were included. FQ-based regimens included moxifloxacin (four studies) or ciprofloxacin/metronidazole (three studies); BL-based regimens were ceftriaxone/metronidazole (three studies), carbapenems (two studies) or piperacillin/tazobactam (two studies). There was no difference in effectiveness in the CE (2883 patients; RR = 1.00, 95% CI 0.95-1.04) or ITT populations (3055 patients; RR = 0.97, 95% CI 0.94-1.01). Mortality (3614 patients; RR = 1.04, 95% CI 0.75-1.43) and treatment-related adverse events (2801 patients; RR = 0.97, 95% CI 0.70-1.33) were also similar. On subset analysis, moxifloxacin was slightly less effective than BLs in the CE (1934 patients; RR = 0.96, 95% CI 0.93-0.99) and ITT populations (1743 patients; RR = 0.94, 95% CI 0.91-0.98). Although FQ- and BL-based regimens appear equally effective and safe for the treatment of cIAIs, limited data suggest slightly inferior results with moxifloxacin. Selection of empirical coverage should be based on local bacterial epidemiology and patterns of resistance as well as antimicrobial stewardship protocols.