Doxycycline post-exposure prophylaxis as prevention of STIs - the golden bullet?

Doxycycline post-exposure prophylaxis ('doxyPEP') is an emerging strategy to prevent bacterial sexually transmitted infections (STIs). Users take 200 mg of doxycycline up to 72 hours after condomless sex, and data from randomized controlled trials and real-world implementation have shown doxyPEP to be effective in preventing syphilis, chlamydia, and to a lesser extent gonorrhea, in gay, bisexual, and other men-who-have-sex-with-men (GBMSM) and transgender women.

We discuss the potential benefits, risks, and important considerations for doxyPEP implementation, drawing on published literature and our own perspectives.

Is doxyPEP the golden bullet? DoxyPEP provides significant benefits through STI prevention and holistic improvements in sexual health and wellbeing. Concerns over emergent antimicrobial resistance need to be weighed against STI-related morbidity and contextualized within society's overuse of antibiotics. Inequities in the doxyPEP evidence-base and implementation will undermine its ability to end the syphilis epidemic and reduce chlamydia associated morbidity in cisgender women. Moreover, contexts in which doxyPEP proves effective for gonorrhea prevention initially are unlikely to see a long-lasting impact. Rather than a golden bullet, doxyPEP is a bridge to the next set of STI prevention tools.