Doxycycline post-exposure prophylaxis (doxyPEP) for prevention of sexually transmitted infections (STIs) has been big news at recent AIDS conferences, but for people who have sex often, daily doxycycline pre-exposure prophylaxis (doxyPrEP) may also be an option. DoxyPEP is a single 200 milligram dose of the antibiotic taken within 72 hours after sex. DoxyPrEP, in contrast, involves taking half that dose every day.

 

In a study of 52 HIV-positive gay and bisexual men in Toronto and Vancouver, daily doxycycline reduced the incidence of chlamydia by 92%, syphilis by 79% and gonorrhea by 68% compared with a placebo. Another study of 40 women sex workers seen at a clinic in Tokyo found that those who used doxycycline every day saw a 67% decline in overall STI incidence. In both studies, daily doxycycline was safe and generally well tolerated.

 

“We need to provide patients with choice,” says Troy Grennan, MD, of the British Columbia Centre for Disease Control. “One of the assumptions we often make is that we know what patients will prefer, but we just don’t know.”