Interest and disparities in awareness and uptake of doxycycline postexposure prophylaxis among US MSM with HIV.

Objective: The CDC recommends doxycycline postexposure prophylaxis (doxyPEP) for MSM with a bacterial sexually transmitted infection (bSTI) in the past year. This study explored determinants of doxyPEP awareness and uptake, and associations with HIV care outcomes, among US MSM with HIV.

Design: Cross-sectional study.

Methods: From October 2023 to October 2024, we enrolled 827 MSM with HIV from 46 states, Washington, DC, and Puerto Rico via a popular geospatial networking app. Adjusted multivariable logistic regression examined determinants of doxyPEP awareness/use and associations with HIV treatment adherence, viral suppression, and care engagement.

Results: Among 827 participants, 13% were currently taking doxyPEP, 46% were aware of doxyPEP but not prescribed it, and 41% had not heard of it. Of 360 participants Centers for Disease Control and Prevention (CDC)-eligible for doxyPEP, 20% were prescribed it, 49% had heard of it but were not on it, and 31% were unaware, 95% of whom expressed interest. Neither awareness nor use of doxyPEP was associated with HIV care outcomes. Both awareness and uptake of doxyPEP were higher among participants with a recent bSTI [adjusted odds ratio (aOR) = 1.15, 95% confidence interval (CI): 1.06-1.25; aOR = 1.11, 95% CI: 1.05-1.17, respectively) and lower in the United States. Midwest, Mountain, and South regions [inverse-variance weighted average (IVW-Avg) aOR = 0.81, 95% CI: 0.76-0.86; IVW-Avg aOR = 0.86, 95% CI: 0.82-0.90, respectively] relative to Pacific states.

Conclusion: High doxyPEP interest underscores unmet demand in integrated HIV/sexual healthcare. Sociodemographic and geographic disparities in doxyPEP implementation necessitate targeted interventions for MSM with HIV to optimize impact on the bSTI epidemic.