Cefdinir vs cephalexin for the treatment of urinary tract infections: A retrospective evaluation.

PURPOSE: Cefdinir and cephalexin are cephalosporin antibiotics commonly used in the treatment of urinary tract infections (UTIs). Their efficacy depends on achieving sufficient time with concentrations exceeding the minimum inhibitory concentration (MIC). Despite being frequently prescribed for UTIs, cefdinir has markedly lower urine penetration compared to cephalexin. It is possible that differences in pharmacokinetics could result in dissimilar efficacy between these agents; however, comparative studies of cephalosporins in UTIs are lacking. METHODS: This was a retrospective comparative study of patients discharged from emergency departments within a community health system with a diagnosis of acute cystitis who were prescribed cefdinir or cephalexin. Treatment failure rates at 7 and 14 days were compared between the 2 agents using a χ2 or Fisher's exact test, as appropriate. RESULTS: There were no differences in overall treatment failure between the cefdinir and cephalexin groups. Treatment failure at 7 days occurred in 11.6% (n = 14) of patients in the cefdinir group and 8.3% (n = 10) of patients in the cephalexin group (P = 0.389). Treatment failure at 14 days was higher for cefdinir at 20.7% (n = 25) than for cephalexin at 11.8% (n = 14), but this difference was not statistically significant (P = 0.053). There were no differences in the rate of treatment failure in subgroup analyses of uncomplicated or complicated UTIs. CONCLUSION: The results of this study suggest that cefdinir and cephalexin have comparable efficacy for the treatment of lower UTIs. While there was a numerically higher rate of treatment failure with cefdinir, there were no significant differences in treatment failure between the agents.

Impact of reflex fosfomycin susceptibility testing on the utilization of carbapenems for definitive extended-spectrum ß-lactamase Escherichia coli urinary tract infection treatment.

PURPOSE: A protocol was started within a large health system to automatically test all confirmed extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli urine isolates for susceptibility to fosfomycin, an antibiotic not routinely included in such testing in most institutions. This study assessed the effectiveness of the protocol at reducing carbapenem use for the definitive treatment of ESBL E. coli urinary tract infection (UTI) through several endpoints. METHODS: Eighty and 99 patients were compared pre- and postintervention, respectively. The primary outcome was the proportion of patients who received definitive carbapenem therapy. Key secondary outcomes included median total carbapenem days of therapy (DOT), discharge on intravenous UTI antibiotics, and median total antibiotic DOT. RESULTS: Preprotocol vs postprotocol definitive carbapenem use was seen in 59 of 80 patients (73.8%) and 71 of 99 patients (71.7%) (95% confidence interval [CI] for difference, -11.1% to 15.1%; P = 0.76). The rates of step-down to oral agents pre- and postintervention were 15 of 59 (25.4%) and 35 of 71 (49.3%) (P = 0.004). Median carbapenem DOT in those receiving carbapenems decreased from 8 to 4 days (95% CI, -5 to -1 days; P = 0.001). Median total DOT decreased from 10 to 8 days (95% CI, -3 to -1 days; P = 0.002). CONCLUSION: Implementation of a laboratory policy to automatically test ESBL positive E. coli for fosfomycin susceptibility did not reduce the percentage of patients receiving at least 1 dose of carbapenem treatment. It did result in a larger percentage reduction in step-down use of intravenous antibiotics for UTI prior to discharge, reduction in carbapenem DOT, and reduction in total antibiotic DOT.