Highlights & Basics
- Post-exposure HIV prophylaxis must be initiated as soon as possible, ideally within 24 hours, and preferably within 72 hours of exposure.
- Timely access to post-exposure prophylaxis (PEP) is the most crucial factor in PEP effectiveness. The duration of PEP is 28 days.
- Most exposures have only a low risk of HIV transmission even in the absence of PEP.
- PEP reduces the likelihood of HIV seroconversion by approximately 80%.
- PEP regimens are associated with a low risk of toxicity.
Quick Reference
History & Exam
Key Factors
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Definition
Epidemiology
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Citations
World Health Organization. Guidelines for HIV post-exposure prophylaxis. Jul 2024 [internet publication].[Full Text]
British Association for Sexual Health and HIV. Post-exposure prophylaxis. Sep 2021 [internet publication].[Full Text]
Tanner MR, O'Shea JG, Byrd KM, et al. Antiretroviral postexposure prophylaxis after sexual, injection drug use, or other nonoccupational exposure to HIV - CDC recommendations, United States, 2025. May 2025 [internet publication].[Full Text]
Kofman AD, Struble KA, Heneine W, et al. 2025 US Public Health Service guidelines for the management of occupational exposures to human immunodeficiency virus and recommendations for post-exposure prophylaxis in healthcare settings. Infect Control Hosp Epidemiol. 2025 Sep;46(9):863-73.[Full Text]
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