Usefulness and problems of the urinary tract infection criteria for evaluating drug efficacy for complicated urinary tract infections

We aimed to reveal the usefulness of and problematic points with the Criteria for evaluation of clinical efficacy of antimicrobial agents on urinary tract infection (draft fourth edition) proposed by the UTI Subcommittee of the Clinical Evaluation Guidelines Committee, Japan Society of Chemotherapy, for evaluating antimicrobial agents for complicated urinary tract infections. We conducted a multicenter trial involving 159 patients with complicated urinary tract infections without indwelling urinary catheters. The antimicrobial agents used were cefcapene pivoxil and levofloxacin. "Early evaluation" took place the day after completion of 7 days of therapy; "late evaluation" took place 5-9 days after the end of treatment, and "follow-up evaluation" was done 4-6 weeks after treatment. In the early evaluation, overall clinical efficacy was judged as excellent in 52.9% of the patients, moderate in 26.1%, and poor in 21.0%, and the bacteriological response was judged as "eradicated" for 86.4% of the 198 bacterial strains isolated. Of 96 patients included in the "late evaluation" category in accordance with the draft fourth edition, the clinical outcome was judged as "cured" in 68.4% and the microbiological outcome was judged as "eradicated" in 59.4%. These rates may be low, because 25 patients in whom clinical efficacy was evaluated as "poor" at the end of treatment were separately classified as "failed" at the late evaluation. Of the 49 patients with an excellent clinical response at the end of treatment, symptoms were exacerbated in 18 at the follow-up evaluation. Overall, the draft fourth edition, with some modifications of the third edition criteria, such as the addition of a follow-up evaluation 7 days after the cessation of drug administration, has the potential to play a role in the international standards for evaluating antimicrobial drug efficacy for complicated urinary tract infections.