Objective: A double-blind, noninferiority trial was conducted to establish the safety and efficacy of a once-daily, 5-day course of levofloxacin 750 mg compared to a twice-daily, 10-day course of ciprofloxacin in complicated urinary tract infections (cUTI) and acute pyelonephritis (AP). This report focuses on subjects with AP.
Research design and methods: Adult male and female subjects with clinical signs and symptoms of AP and laboratory confirmation of their diagnosis were randomized to receive one dose of levofloxacin 750 mg once daily intravenously (i.v.) or orally and one dose of placebo for 5 days, followed by placebo; or ciprofloxacin 400 mg i.v. and/or 500 mg orally twice daily for 10 days.
Main outcome measures: The primary, prospectively defined end point was microbiologic eradication at post-therapy (study days 15-22). Secondary outcomes included clinical response and safety and tolerability.
Results: In the modified intent-to-treat (mITT) population (levofloxacin 94, ciprofloxacin 98), 83% of levofloxacin-treated and 79.6% of ciprofloxacin-treated subjects achieved microbiological eradication (difference -3.4, 95% CI -14.4%, 7.6%). In the microbiologically evaluable (ME) population (levofloxacin 80, ciprofloxacin 76), 92.5% of levofloxacin-treated vs. 93.4% of ciprofloxacin-treated subjects (difference -0.9, 95% CI -7.1%, 8.9%) achieved microbiologic eradication. Clinical success was achieved in 86.2% vs. 80.6% (mITT) and in 92.5% vs. 89.5% (ME) of levofloxacin-treated and ciprofloxacin-treated subjects, respectively. Escherichia coli was the most commonly isolated uropathogen. Few (2.1%) of the pathogens were fluoroquinolone-resistant. Adverse events (AEs) were similar to those seen previously with both agents. Potential limitations are that this analysis is based on a subset of subjects from a larger study and, because of different durations of therapy, the results may be biased against levofloxacin.
Conclusions: High-dose, short-course therapy with levofloxacin in subjects with AP is at least as effective as standard 10-day therapy with ciprofloxacin.