Doxycycline superior to azithromycin for rectal chlamydia in MSM, study shows
Click Here to Manage Email Alerts
A week-long regimen of doxycycline was superior to a single-dose of azithromycin for the treatment of rectal chlamydia among men who have sex with men, or MSM, according to study results.
The randomized, double-blind trial, which was published in The New England Journal of Medicine, included 625 men from five clinics in Australia.
“Our results suggest that doxycycline should replace azithromycin as the first-line treatment for rectal chlamydia. Clinicians should use doxycycline as first-line treatment for chlamydia infection at any infection site — including for urogenital and rectal infections, particularly given that most women with a urogenital infection will also have rectal chlamydia,” Jane Hocking, MPH, PhD, NHMRC professorial fellow at the Melbourne School of Population and Global Health, told Healio. “However, azithromycin will still have a place for treating chlamydia infection in pregnant women where doxycycline is contraindicated, in those with an allergy to doxycycline and for those where there are serious concerns about adherence to a 7-day regimen.”
Hocking and colleagues randomly assigned 314 of the men 100 mg of doxycycline twice daily for 7 days and 311 of the men a 1 g single dose of azithromycin. They assessed whether the participants were cured of chlamydia at 4 weeks via nucleic acid amplification test (NAAT).
At 4 weeks, test results were available for 290 (92.4%) of men who were given doxycycline and 297 (95.5%) of men who were given azithromycin. According to the researchers, 96.9% (n = 281/290; 95% CI, 94.9%-98.9%) of men in the doxycycline group and 76.4% (n = 227/297; 95% CI, 73.8%-79.1%) of men in the azithromycin group were cured.
Hocking said that one of the study’s major limitations was that it included only MSM.
However, “rectal chlamydia organism load is similar between the sexes, and observational data show similar treatment efficacy in men and women — suggesting our results will also apply to women,” Hocking said. “Only men with asymptomatic chlamydia were eligible to participate, but given over 85% of rectal chlamydia in men is asymptomatic, our results will apply to the majority of those with infection.”
Perspective
Back to Top
The study by Lau and colleagues from Melbourne, Australia, is an important randomized controlled trial that will undoubtedly influence the STD treatment guidelines. Current CDC guidelines recommend doxycycline or azithromycin as first-line agents for treating rectal chlamydia infection. However, observational data suggest that doxycycline is more effective than azithromycin.
The findings from this study are similar to those of a smaller study recently published in Clinical Infectious Diseases in which microbiologic cure occurred in 100% of those who received doxycycline and 74% of those who received azithromycin. I think these two studies conclusively prove that 1 week of doxycycline is more effective than a single dose of azithromycin for the treatment.
Reference:
Dombrowski JC, et al. Clin Infect Dis. 2021;doi:10.1093/cid/ciab153.
Collapse
Click Here to Manage Email Alerts