Single-dose azithromycin still effective against chlamydia, study finds

Results of a new study published in the New England Journal of Medicine show that the 2 drugs most commonly prescribed to treat urogenital chlamydia have comparable efficacy.

Specifically, a single1-g dose of azithromycin had a cure rate of 97%, and 100 mg doxycycline given twice daily for 7 days had a cure rate of 100%.

Researchers from the University of Alabama at Birmingham and University of Southern California and the Los Angeles County Department of Health Services enrolled 567 male and female subjects ages 12–21 with chlamydia who resided in long-term, sex-segregated youth correctional facilities in Los Angeles. Half were given azithromycin and half doxycycline.

“The design of this study allowed us to control for all the complicated variables that had hindered previous research projects of this nature,” said William M Geisler, MD, professor in the Division of Infectious Diseases in the UAB Department of Medicine and principal investigator of the study, in a University of Alabama press release. “Our study subjects were separated from previous partners and had limited sexual exposure. This approach allowed us to truly understand how well these drugs worked.”

There were 5 treatment failures among those taking azithromycin (3.2%; 95% confidence interval, 0.4% to 7.4%) and no treatment failures among the doxycycline group.

“Our results show that both medications are effective in the treatment of chlamydia, and that while azithromycin had a limited number of treatment failures, the adherence to the drug regimen is likely to be much greater with the single-dose drug as opposed to the multidose doxycycline,” Geisler said.