Comparison of ciprofloxacin (7 days) and trimethoprim-sulfamethoxazole (14days) for acute uncomplicated pyelonephritis in women - A randomized trial

Context The optimal antimicrobial regimen and treatment duration for acute uncomplicated pyelonephritis are unknown. Objective To compare the efficacy and safety of a 7-day ciprofloxacin regim en and a 14-day trimethoprim-sulfamethoxazole regimen for the treatment of acute pyelonephritis in women. Design Randomized, double-blind comparative trial conducted from October 19 94 through January 1997. Setting Twenty-five outpatient centers in the United States. Patients Of 378 enrolled premenopausal women aged at least 18 years with cl inical diagnosis of acute uncomplicated pyelonephritis, 255 were included i n the analysis. Other individuals were excluded for no baseline causative o rganism, inadequate receipt of study drug, loss to follow-up, no appropriat e cultures, and other reasons. Interventions Patients were randomized to oral ciprofloxacin, 500 mg twice per day for 7 days (with or without an initial 400-mg intravenous dose) fol lowed by placebo for 7 days (n = 128 included in analysis) vs trimethoprim- sulfamethoxazole, 160/800 mg twice per day for 14 days (with or without int ravenous ceftriaxone, 1 g) (n = 127 included in the analysis). Main Outcome Measure Continued bacteriologic and clinical cure, such that a lternative antimicrobial drugs were not required, among evaluable patients through the 4- to 11-day posttherapy visit, compared by treatment group. Results At 4 to 11 days posttherapy, bacteriologic cure rates were 99% (112 of 113) for the ciprofloxacin regimen and 89% (90 of 101) for the trimetho primsulfamethoxazole regimen (95% confidence interval [CI] for difference, 0.04-0.16; P =.004). Clinical cure rates were 96% (109 of 113) for the cipr ofloxacin regimen and 83% (92 of 111) for the trimethoprim-sulfamethoxazole regimen (95% CI, 0.06-0.22; P =.002), Escherichia coli, which caused more than 90% of infections, was more frequently resistant to trimethoprim-sulfa methoxazole (18%) than to ciprofloxacin (0%; P<.001). Among trimethoprim-su lfamethoxazole-treated patients, drug resistance was associated with greate r bacteriologic and clinical failure rates (P<.001 for both). Drug-related adverse events occurred in 24% of 191 ciprofloxacin-treated patients and in 33% of 187 trimethoprim-sulfamethoxazole-treated patients, respectively (9 5% CI, -0.001 to 0.2). Conclusions In our study of outpatient treatment of acute uncomplicated pye lonephritis in women, a 7-day ciprofloxacin regimen was associated with gre ater bacteriologic and clinical cure rates than a 14-day trimethoprim-sulfa methoxazole regimen, especially in patients infected with trimethoprim-sulf amethoxazole-resistant strains.