Clinical efficacy of intravenous doripenem in patients with acute biliary tract infection: a multicenter, randomized, controlled trial with imipenem/cilastatin as comparator.

Background: We conducted a randomized controlled trial to evaluate the clinical efficacy and safety of intravenous doripenem (DRPM) in patients with biliary tract infection requiring biliary drainage in comparison with imipenem/cilastatin (IPM/CS).
Methods: After the initial collection of bile, patients were randomly assigned by the registration system of the Clinical Research Organization to receive intravenous drip infusion of DRPM 0.5 g or IPM/CS 0.5 g three times daily in a randomized, open-label manner.
Results: A total of 127 patients were enrolled in the trial (DRPM 62, IPM/CS 65). The characteristics of the 122 patients evaluated for efficacy were well balanced, except for the percentage of patients previously receiving antimicrobials, which was higher in the DRPM group than in the IPM/CS group. The clinical response rate was not significantly different between the DRPM group (93.1 %, 54/58 patients) and the IPM/CS group (93.8 %, 60/64). Non-inferiority assessment using confidence intervals demonstrated the non-inferiority of DRPM-IPM/CS. The incidence of adverse events, for which a causal relationship with either treatment was not ruled out, was 3.3 % (2/60) in the DRPM group and 3.1 % (2/65) in the IPM/CS group, and none was serious.
Conclusions: The clinical efficacy of DRPM in treating moderate or severe biliary tract infection requiring drainage was comparable to that of IPM/CS. DRPM was associated with no serious adverse events and a low incidence of adverse events. The results of this trial demonstrate that DRPM is a useful therapeutic option for moderate or severe biliary tract infection.