Leading sexual health physicians have cautiously backed the use of doxycycline as a morning after pill for STI prevention in high-risk gay and bisexual men.

A consensus statement published this month provides new guidance for prescribing doxycycline post-exposure prophylaxis (doxy-PEP) in the form of a single 200mg dose to be taken within 72 hours of condomless sex.

Despite ongoing concerns about antimicrobial resistance, doxy-PEP “should be considered” primarily for syphilis prevention in men who have sex with men (MSM), said doctors led by the Australasian Society for HIV, Viral Hepatitis and Sexual Health Medicine (ASHM).

The group pointed to clinical trial data showing that doxy-PEP reduced the risk of syphilis as much as 80% and chlamydia by up to 90%.