Doxycycline, an antibiotic widely used to combat acne, malaria and Lyme disease, has been recommended by the CDC for use in the United States by gay and bisexual men and transgender women after having unprotected sex to ward off sexually transmitted infections (STIs).
Post-exposure prophylaxis (PEP) treatment with a 200 mg dose of doxycycline is recommended within 72 hours of having unprotected oral, vaginal or anal sex and comes as infections for syphilis, gonorrhea and chlamydia are on the rise in the U.S., disproportionally affecting men who have sex with men and transgender women.
Three trials have shown that post-exposure prophylaxis (PEP) use of doxycycline can reduce the risk of syphilis or gonorrhea infection by more than 70% and chlamydia infection by 50%, the CDC said.
Doxycyline comes in pill form and users should limit use to a 200 mg dose over a 24-hour period. The strategy is referred to as doxy PEP and is similar to post-exposure regimens for the prevention of HIV.
The CDC recommends that at-risk individuals acquire prescriptions, allowing them to self-administer doxycycline as soon as possible after engaging in unprotected sex.
The agency's guidelines say that those who are prescribed doxy PEP should undergo bacterial STI testing and be reassessed every three to six months
In 2022, more than 2.51 million cases of syphilis, gonorrhea and chlamydia were reported in the U.S., up from 2.37 million cases in 2017. The rise of syphilis—which was nearly stamped out 20 years ago—has become increasingly troubling, with infections up 79% from 2018 to 2022. Over that period, gonorrhea infections were up 11%.