Randomized controlled trial of moxifloxacin compared with piperacillin-tazobactam and amoxicillin-clavulanate for the treatment of complicated intra-abdominal infections.

Objective: To compare the safety and efficacy of sequential intravenous (IV) to oral (PO) moxifloxacin treatment against a standard antimicrobial regimen of IV piperacillin-tazobactam followed by PO amoxicillin-clavulanate for the treatment of adults with complicated intra-abdominal infection (cIAI).

Summary Background Data: cIAIs are commonly due to mixed aerobic and anaerobic bacteria and require both source control and broad-spectrum antibiotic therapy.

Methods: A prospective, double-blind, randomized, phase III comparative trial. Patients with cIAI were stratified by disease severity (APACHE II score) and randomized to either IV/PO moxifloxacin (400 mg q24 hours) or comparator (IV piperacillin-tazobactam [3.0/0.375 g q6 hours] +/- PO amoxicillin-clavulanate [800 mg/114 mg q12 hours]), each for 5 to 14 days. The primary efficacy variable was clinical cure rate at the test-of-cure visit (days 25-50). Bacteriologic outcomes were also determined.

Results: : Of 656 intent-to-treat patients, 379 (58%) were valid to assess efficacy (183 moxifloxacin, 196 comparator). Demographic and baseline medical characteristics were similar between the 2 groups. Clinical cure rates at test-of-cure were 80% (146 of 183) for moxifloxacin versus 78% (153 of 196) for comparator (95% confidence interval, -7.4%, 9.3%). The clinical cure rate at test-of-cure for hospital-acquired cIAI was higher with moxifloxacin (82%, 22 of 27) versus comparator (55%, 17 of 31; P = 0.05); rates were similar for community-acquired infections (80% [124 of 156] versus 82% [136 of 165], respectively). Bacterial eradication rates were 78% (117 of 150) with moxifloxacin versus 77% (126 of 163) in the comparator group (95% confidence interval, -9.9%, 8.7%).

Conclusions: Once daily IV/PO moxifloxacin monotherapy was as least as effective as standard IV piperacillin-tazobactam/PO amoxicillin-clavulanate dosed multiple times daily for the treatment of cIAIs.