Objectives. To compare the efficacy and safety of ertapenem, a new once-daily parenteral beta-lactam, with that of ceftriaxone for the initial empiric treatment of adults with complicated urinary tract infections (cUTIs).

Methods. In a multicenter, prospective, double-blind study, patients with cUTIs were stratified as to whether they had acute pyelonephritis or other cUTIs (without pyelonephritis) and randomized to receive ertapenem, 1 g once a day, or ceftriaxone, 1 g once a day. After 3 days, patients with a satisfactory clinical response could be switched to an oral antimicrobial agent.

Results. Of 258 randomized patients, 97 (55.4%) in the ertapenem group and 53 (63.9%) in the ceftriaxone group were evaluated microbiologically. Almost all patients in each treatment group were switched to oral therapy. The mean duration of therapy was similar in both treatment groups: parenteral, approximately 4 days; total, approximately 13 days. The most common pathogen was Escherichia coli. At the primary efficacy endpoint, 5 to 9 days after treatment, 85.6% of patients who received ertapenem and 84.9% who received ceftriaxone had a favorable microbiologic response, indicating that the two treatment groups were equivalent. The frequency and severity of drug-related adverse events were generally similar in both treatment groups.

Conclusions. In this study, ertapenem was as effective as ceftriaxone for the initial treatment of cUTI in adults, was generally well tolerated, and had a similar safety profile.