Cost effectiveness of ciprofloxacin plus metronidazole versus imipenem-cilastatin in the treatment of intra-abdominal infections.

Objective: To compare the cost effectiveness of sequential intravenous (i.v.) to oral ciprofloxacin plus metronidazole (CIP/MTZ i.v./PO) with that of i.v. ciprofloxacin plus i.v. metronidazole (CIP/MTZ i.v.) and i.v. imipenem-cilastatin (IMI i.v.) in patients with intra-abdominal infections.
Design and Participants: Patients enrolled in a double-blind randomised clinical trial were eligible for inclusion into this cost-effectiveness analysis. Decision analysis was used to characterise the economic outcomes between groups and provide a structure upon which to base the sensitivity analyses. 1996 cost values were used throughout.
Setting: The economic perspective of the analysis was that of a hospital provider.
Main Outcome Measures and Results: Among 446 economically evaluable patients, 176 could be switched from i.v. to oral administration. The 51 patients randomised to CIP/MTZ i.v./PO who received active oral therapy had a success rate of 98%, mean duration of therapy of 9.1 days and mean cost of $US7678. There were 125 patients randomized to either CIP/MTZ i.v. or IMI i.v. who received oral placebo while continuing on active i.v. antibacterials; their success rate was 94%, mean duration of therapy was 10.1 days and mean cost was $US8774 (p = 0.029 vs CIP/MTZ i.v./PO). Of the 270 patients who were unable to receive oral administration, 97 received IMI i.v. and had a success rate of 75%, mean duration of therapy of 13.8 days and a mean cost of $US12,418, and 173 received CIP/MTZ i.v. and had a success rate of 77%, mean duration of therapy of 13.4 days and mean cost of $US12,219 (p = 0.26 vs IMI i.v.).
Conclusions: In patients able to receive oral therapy, sequential i.v. to oral treatment with ciprofloxacin plus metronidazole was cost effective compared with full i.v. courses of ciprofloxacin plus metronidazole or imipenem-cilastatin. In patients unable to receive oral therapy, no difference in mean cost was found between i.v. imipenem-cilastatin or i.v. ciprofloxacin plus i.v. metronidazole.