2017-12-19T13:06:11
Doxycycline After Condomless Sex Lowers STI Risk in High-Risk Men
Use of doxycycline after condomless sex lowers the risk for some sexually transmitted infections (STIs) among high-risk men who have sex with men (MSM), according to a substudy of an HIV prevention trial in the Lancet Infectious Diseases.
Over 230 high-risk MSM in France were randomized to receive post-exposure prophylaxis (PEP) with doxycycline or no PEP. For PEP, participants were advised to take two 100-mg doxycycline pills within 24 hours after condomless oral or anal sex, not to exceed six pills weekly. (As part of the main study protocol, all participants were taking tenofovir/emtricitabine as pre-exposure prophylaxis against HIV).
During roughly 9 months' follow-up, the primary outcome — first occurrence of syphilis, chlamydia, or gonorrhea — was significantly lower with PEP (9-month probability, 22% vs. 42%). When examined by STI type, PEP significantly lowered the incidence of chlamydia and syphilis, but not gonorrhea.