Sexually Transmitted Illnesses (STI) are still occurring in our society. Prevention is recommended. Always using barrier contraception is very important. But what should you do if you forget or decide not to use one?
The CDC has come out with a strong recommendation that people at risk should consider taking an oral antibiotic (doxycycline 200 mg) within 72 hours of oral, anal, or vaginal sex. It has been shown to substantially reducing the risk of developing a bacterial STI.
Who is at risk? The CDC considers men who have sex with men and trans men who have had an STI within the past 12 months are the at-risk group. The sexual behavior includes oral, anal and/or vaginal sex.
People who are considering this form of prevention should be aware of the risks and benefits. Doxycycline given as a single oral dose has few side effects, which are usually mild. It can lead to antibiotic resistance in some cases. However, it has been shown to substantially reduce the risk of a bacterial STI.
There have been a few cases of “intimate partner violence after discovery of doxycycline PEP (post-exposure prophylaxis) use” [CDC].
It is an open question whether heterosexual people with repeated STIs should be offered this prophylaxis treatment after sex.
The CDC recommends that individuals at risk should have testing for STIs every 3-6 months.
This overview is from an article by Floes and colleagues in JAMA.2025; 333 (3): 248-249.
Peter M. Hartmann, MD
Family Medicine & Psychiatry
