Azithromycin or Doxycycline for Chlamydia trachomatis Infection?

For several years, the recommended treatment for urogenital infections from Chlamydia trachomatis has been either doxycycline or azithromycin, although some studies have suggested inferiority of azithromycin.

In the current randomized, noninferiority trial, investigators compared the efficacy of azithromycin (1 g in a single dose) and doxycycline (100 mg twice daily for 7 days) in treating C. trachomatis in 310 youth (age range, 12–21 years; 65% male) in a correctional facility. Doses were administered under direct observation, and treatment success was determined by nucleic acid amplification tests, sexual history, and genotyping of C. trachomatis. Urogenital symptoms were reported in only 25% of males, in contrast with 61% of females, half of whom reported vaginal discharge.

No treatment failures occurred in the doxycycline group, compared with five treatment failures in the azithromycin group (3.2%, 95% confidence interval, 0.4–7.4). Four of the five treatment failures were in male participants. Treatment failure rates differed by 3.2 percentage points with a one-sided 90% confidence interval of 0 to 5.9. The upper limit of 5.9 percentage points exceeded the noninferiority cutoff of 5 percentage points. Adverse events were similar between the two treatment groups and were primarily gastrointestinal problems.