Background
The current IDSA treatment guidelines recommend beta-lactam antibiotics as alternative, rather than first-line agents, for the treatment of uncomplicated UTI (uUTI). Cephalexin is a commonly prescribed first-generation cephalosporin with excellent bioavailability and urinary penetration; however, little data exist to support optimal dosing for uUTI.
Methods
This retrospective, multicenter, cohort study included adult female patients who received 5-7 days of cephalexin for symptomatic uUTI with a cefazolin-susceptible urine culture. The primary objective was to compare uUTI treatment failure (e.g., continued or recurrent symptoms within 30 days) between patients treated with cephalexin 500 mg twice daily (BID Group) versus 500 mg four times daily (QID Group) in the outpatient setting. Secondary outcomes included time to treatment failure, reported adverse events within 7 days of treatment, and occurrence of C. difficile within 30 days of treatment.
Results
A total of 261 patients were included (BID Group, n = 173; QID Group, n = 88). Baseline characteristics were similar between groups. Escherichia coli was the most commonly isolated pathogen (85.4%). There was no difference in treatment failure observed between groups (BID Group 12.7% vs QID Group 17%, p = 0.343), including failure while on therapy (BID Group 2.3% vs QID Group 5.7%, p = 0.438) or recurrence within 30 days (BID Group 10.4% vs QID Group 11.3%, p = 0.438). No differences in reported adverse events (BID Group 4.6% vs QID Group 5.6%, p = 0.103) were observed between groups.
Conclusion
Twice daily cephalexin is as effective as four times daily dosing for uUTI. A twice daily dosing strategy may improve patient adherence.