A randomized, double-blind study comparing single-dose rifalazil with single-dose azithromycin for the empirical treatment of nongonococcal urethritis in men.

OBJECTIVES: To determine the safety and effectiveness of single-dose rifalazil, a new rifamycin, for the treatment of nongonococcal urethritis (NGU).

STUDY DESIGN: Randomized, double-blind trial comparing rifalazil, 2.5, 12.5 or 25 mg, with 1.0 g azithromycin for the treatment of NGU. One hundred and seventy men were evaluated for Chlamydia trachomatis, Ureaplasma urealyticum, and Mycoplasma genitalium infection before therapy and 2- and 5-weeks posttreatment.

RESULTS: C. trachomatis, M. genitalium, and U. urealyticum were present in 42%, 24%, and 28% of subjects, respectively. Microbiologic eradication of C. trachomatis with rifalazil 25 mg at 2- and 5- weeks was 85% and 83%, respectively. Rifalazil was ineffective in eradicating M. genitalium and U. urealyticum. Overall clinical cure rates at 2- and 5-weeks were 86% (95% CI 67-96) and 59% (39-78) in the rifalazil-treated 25 mg group, and 77% (56-91) and 63% (41-81) in the azithromycin-treated group.

CONCLUSIONS: Rifalazil was well tolerated and eradicates C. trachomatis but not M. genitalium and U. ureaplasma in men with NGU.