Postexposure prophylaxis against STIs

Postexposure prophylaxis with a single dose of doxycycline up to 72 hours after sexual exposure (also known as Doxy-PEP) reduced the incidence of chlamydia, gonorrhoea and syphilis in gay, bisexual and other men who have sex with men, and transgender women in open-label trials in the United Sates of America and FranceBachmann, 2024Cornelisse, 2024Luetkemeyer, 2023. In Australia, postexposure prophylaxis with doxycycline is likely to be less effective in preventing gonorrhoea because of high rates of tetracycline resistanceCornelisse, 2024. Doxycycline is likely to have the greatest benefit when used to prevent syphilisCornelisse, 2024.

Consider postexposure prophylaxis with doxycycline in gay, bisexual and other men who have sex with men, and transgender women with any of the following risk factorsCornelisse, 2024:

  • a recent syphilis diagnosis (within the previous 6 to 12 months)
  • 2 or more other bacterial sexually transmissible infections (STIs) within the last 12 months
  • a planned period of increased STI risk (eg attendance at a sex event)
  • concurrent male1 and female2 sexual partners.

Additional health benefits of syphilis, gonorrhoea and chlamydia prevention include reducing the risk of adverse pregnancy and reproductive health outcomes in female sexual partnersCornelisse, 2024.

Data are preliminary and potential harms associated with doxycycline administration for the individual and wider community are unknown. If postexposure prophylaxis against STIs with doxycycline is considered, discuss the potential benefits and harms of antibiotic therapy (eg adverse effects, potential for antimicrobial resistance in the patient and community) with the patient3Bachmann, 2024Bell, 2024Cornelisse, 2024. Postexposure prophylaxis against STIs does not replace the need to screen, test and treat patients for STIsBachmann, 2024.

Note: Postexposure prophylaxis against STIs does not replace the need to screen, test and treat patients for STIs.

For a detailed description of the evidence base and prescribing advice for postexposure prophylaxis against STIs with doxycycline, see the Australasian Society for HIV, Viral Hepatitis and Sexual Health Medicine (ASHM) 2023 Consensus statement on doxycycline prophylaxis (Doxy-PEP).

1 In this topic, the term ‘male’ is used to include all people presumed male at birth.Return
2 In this topic, the term ‘female’ is used to include all people presumed female at birth.Return
3 A decision aid for consumers to support discussions about the use of doxycycline for postexposure prophylaxis against STIs is available from the New South Wales (NSW) Health website.Return