Awareness and acceptability of doxycycline post-exposure prophylaxis among men who have sex with men

Objectives: Doxycycline post-exposure prophylaxis (Doxy-PEP) has emerged as a complementary strategy for the prevention of bacterial sexually transmitted infections (STIs).In Portugal, data regarding awareness and acceptability of Doxy-PEP among men who have sex with men (MSM) are scarce.This study aimed to assess awareness and acceptability of Doxy-PEP among MSM attending a hospital-based STI clinic, describe sexual and preventive practices, and explore the relationship between human immunodeficiency virus (HIV) pre-exposure prophylaxis (HIV-PrEP), previous bacterial STIs, and willingness to use Doxy-PEP.Methods: A cross-sectional single-center study was conducted using an anonymous questionnaire administered to MSM attending a hospital-based STIs clinic between April and September 2025.Statistical analysis was performed using the Statistical Package for the Social Sciences version 29.0.1.Results: Fifty-four valid questionnaires were included.Participants had a median age of 31.5 years (range: 19-57 years).HIV infection was present in 20.4% (11/54) of participants.Among HIV-negative participants, 44.2% (19/43) were using HIV-PrEP.Overall, 66.7% (36/54) reported at least one bacterial STI episode in the previous 12 months.Previous awareness of Doxy-PEP was reported by 57.4% (31/54), mainly through peers (51.6%).After a brief explanation regarding Doxy-PEP, 83.3% (45/54) stated that they would be willing to use it if available.A statistically significant association was found between the number of sexual partners during the previous 6 months and Doxy-PEP acceptability (Spearman's correlation coefficient = 0.395; p = 0.0054).Among HIV-negative participants, bacterial STI burden and Doxy-PEP acceptability were higher among HIV-PrEP users compared with non-users.Conclusion: Doxy-PEP acceptability among MSM attending an STI clinic was high, despite limited baseline awareness.HIV-PrEP users represented a subgroup with higher STI burden and greater acceptability of Doxy-PEP, suggesting that implementation strategies may be particularly relevant within HIV-PrEP clinics.Educational interventions, regular STI screening, antimicrobial stewardship, and antimicrobial resistance surveillance should accompany this prophylactic strategy.