Clinical outcomes of flomoxef versus cefmetazole in hospitalized patients with urinary tract infections: combined retrospective analyses of two real-world databases and in vitro data.

BACKGROUND

Flomoxef and cefmetazole have been reported to be effective against broad-spectrum β-lactamase-producing bacteria and have gained attention as a potential alternative to carbapenems. This study aimed to compare the efficacy of these two drugs in treating urinary tract infection (UTI) by integrating in vitro data and two real-world databases.

METHODS

The susceptibility rates of third-generation cephalosporin-resistant Escherichia coli and Klebsiella pneumoniae to flomoxef and cefmetazole were compared using comprehensive national antimicrobial resistance surveillance data. Combined antimicrobial activities against an extended-spectrum beta-lactamase (ESBL)-producing multidrug-resistant bacterial strain were tested by diagonal measurement of n-way drug interactions. The effectiveness of the two drugs in treating UTIs was compared using hospital stay duration data obtained from the Japan Medical Data Center (JMDC) Claims Database.

RESULTS

Third-generation cephalosporin-resistant E. coli and K. pneumoniae, including ESBL-producing strains, were similarly susceptible to flomoxef and cefmetazole. In vitro assessment against an ESBL-producing multidrug-resistant strain revealed similar antimicrobial interaction patterns. JMDC Claims data analysis showed that the median hospital stay was 11 (95% confidence interval [CI]: 11-11) and 4 (95% CI: 3-5) days in the cefmetazole and flomoxef groups, respectively (log-rank test, P < 0.001). Moreover, the flomoxef group demonstrated a significantly lower frequency of adverse events such as C. difficile infection and renal failure.

CONCLUSIONS

The effectiveness of flomoxef is comparable to that of cefmetazole in treating UTIs without major complications. Thus, flomoxef is a viable treatment option for UTIs in locales with a high prevalence of ESBL-producing strains.