Cefdinir vs cephalexin: Which is a better step-down therapy in severe UTI?

Treatment with cefdinir and cephalexin results in comparable failure rates, but patients on cephalexin tend to have more unplanned clinic and emergency visits, a study has shown.

Patients admitted to three hospitals for severe urinary tract infections (UTIs) over a 1-year period were included in this retrospective study. Participants were identified using ICD-10 codes N10, N39.0, and A41.9. Those who received intravenous antibiotics for >24 h and completed treatment with either cephalexin or cefdinir were included in the analysis.

A composite of death, rehospitalization for UTI in 30 days, unplanned clinic or emergency visit for UTI in 30 days, hospitalization for any reason in 90 days, or Clostridoides difficile infection was the primary outcome. Secondary outcomes were the individual element of the composite outcome.

Of the patients, 135 received cephalexin and 75 cefdinir. Eligible participants had similar baseline characteristics. The cephalexin group showed numerically higher rates of pyelonephritis (46.7 percent vs 30.2 percent; p=0.024) and composite failure (14.1 percent vs 8 percent; p=0.193).

No between-group difference was observed in secondary outcomes, except for clinic or emergency visits, which were higher among users of cephalexin (7.2 percent vs 0 percent; p=0.028).

In logistic regression, no significant associations with treatment failure were noted, except for cephalexin use, which correlated with clinic or emergency visits for UTI (r², 0.075).

“Cephalosporins are increasingly used to treat severe UTI due to rising resistance with standard antibiotics,” the investigators said. “When switching from intravenous to oral cephalosporins, there is limited clinical outcome data to guide selection.”