Clinical efficacy of intravenous ciprofloxacin in patients with biliary tract infection: a randomized controlled trial with carbapenem as comparator

Background We conducted a randomized controlled trial (RCT) to evaluate the clinical efficacy of an intravenous fluoroquinolone, ciprofloxacin (CIP), in patients with biliary tract infection requiring biliary drainage using imipenem/cilastatin (IPM/CS) as a control. Methods After the initial collection of bile, patients were randomly assigned to receive CIP at 300 mg twice daily by intravenous drip infusion or IPM/CS at 500 mg twice daily by intravenous drip infusion with the envelope method. Results The characteristics of the 104 patients evaluated for efficacy were well balanced. The clinical response rates were 100.0% (50/50 patients) in the CIP group and 94.4% (51/54) in the IPM/CS group. The difference in clinical response rate between groups (CIP, IPM/CS) was 5.56% (90% confidence interval: -0.26%, 13.95%), and the non-inferiority of CIP to IPM/CS was confirmed. Adverse events for which causal relationships with the study drugs could not be ruled out developed in 5.4% (3/56) of patients in the CIP group and 5.2% (3/58) of patients in the IPM/CS group, and none of them were serious. Conclusions The clinical efficacy of CIP in treating biliary tract infection requiring drainage was comparable to that of IPM/CS. These findings suggest that CIP is useful as a new therapeutic option for biliary tract infection.