Doxy-PrEP

Doxy-PrEP is the acronym for: Doxycycline pre- or post-exposure prophylaxis. The term refers to the preventive use of doxycycline before/during or after sexual risk events without contact with a person with diagnosed syphilis or another STI.

In the last two decades, the number of syphilis cases has increased, especially in men who have sex with men (MSM). It has been shown in several randomized controlled trials that prophylactic use of doxycycline in MSM (men who have sex with men) and trans women receiving HIV pre-exposure prophylaxis (HIV-PrEP) or living with HIV infection effectively reduces the risk of syphilis and chlamydia infections (Werner RN et al. 2024). However, questions remain at present, particularly regarding the impact of widespread introduction of prophylactic doxycycline for STI prevention on tetracycline and other antibiotic resistance in bacterial STIs, non-STI-associated bacterial pathogens and the microbiome.

Single dose of 200mg doxycycline within 24 to a maximum of 72 hours after a risk event. A risk event is generally defined as condomless sex.

Doxy-PrEP is the continuous intake of 100mg doxycycline daily to prevent the acquisition of an STI (Bolan RK 2015).

1. Bolan RK et al. (2015) Doxycycline prophylaxis to reduce incident syphilis among HIV-infected men who have sex with men who continue to engage in high-risk sex: a randomized, controlled pilot study. Sex Transm Dis 42:98-103.
2. Werner RN et al. (2024) Schmidt AJ et al. (2024) Position statement of the German STI Society on the prophylactic use of doxycycline to prevent STIs (Doxy-PEP, Doxy-PrEP). J Dtsch Dermatol Ges 22:466-478.