Introduction: Despite numerous reports on injectable ciprofloxacin (CIP) for the treatment of severe infections, the usefulness of CIP with the Japanese dosage regimen (300mg b.i.d) for the treatment of postoperative infections has not been clearly determined. The aim of this study was therefore to compare the efficacy and safety of CIP with injectable Meropenem (MEPM) in patients with postoperative infections.

Methods: Thirty-nine medical centers in Japan participated in the study and enrolled 205 patients from Jun 2005 through May 2008. Patients were randomized to receive either CIP (300 mg, b.i.d) or MEPM (500 mg, b.i.d) for empirical treatment of postoperative infections after elective gastroenterological surgery followed by administration of prophylactic antibiotics. Postoperative infection was defined as: surgical site infection, remote infection, SIRS-positivity, or suspected SIRS-positivity. The primary endpoints were clinical and bacteriological responses and adverse drug reactions. Clinical efficacy was comprehensively assessed based on clinical signs and symptoms and laboratory findings. The secondary endpoints were period of treatment with antibiotics and relapse rate.

Results: There were no significant differences in any 3 primary or 2 secondary endpoints between the two treatment groups. At the end-of-study assessment, the overall clinical response rate for the per-protocol (PP) set was 85.3% (64/75 patients) in the CIP group and 89.6% (69/77 patients) in the MEPM group. Both groups exhibited good clinical response, but it could not demonstrated that CIP is not inferior to MEPM; (difference, -4.3% 95% CI, -14.8 to 6.2%). On bacteriological assessment, a clinically significant pathogen was isolated in 69 of 152 PP patients (45.4%, 36 in CIP group, 33 in MEPM group). Overall bacteriological efficacy was 78.1% (25/32 patients) in the CIP group and 55.2% (16/29 patients) in the MEPM group. The incidence of adverse drug reaction was 7.0% (7/100 patients) in the CIP group and 7.8% (8/103 patients) in the MEPM group. The mean treatment period for PP patients was 8.0 ± 6.1 days (± SD) in the CIP group and 7.3 ± 7.7 days (± SD) in the MEPM group. The rates of relapse of infection after successful treatment was 3.1% (2/64 patients) in the CIP group and 2.9% (2/69 patients) in the MEPM group

Conclusion: The above findings suggested that empirical monotherapy with CIP is useful for postoperative infections after gastroenterological surgery.