Post-Exposure Prophylaxis (PEP) Overview

Post-Exposure Prophylaxis (PEP) is an emergency medical treatment intended to reduce the risk of infection after exposure to bloodborne pathogens — especially HIV. When administered promptly and correctly, PEP can significantly reduce the likelihood of seroconversion, but timing is critical. This topic introduces the fundamentals of PEP, its purpose, eligibility, medications involved, and the urgency of initiation.

? What Is PEP?

PEP refers to a short-term course of antiretroviral medications (ARVs) given to an exposed individual after potential contact with a high-risk infectious agent. It is used primarily for HIV exposure, though post-exposure care also includes evaluation for Hepatitis B and C.

PEP is not a vaccine or cure — it is a preventive treatment that must begin as soon as possible after an exposure.

? When Is PEP Recommended?

According to the CDC and U.S. Public Health Service, PEP is indicated when:

  • A healthcare worker experiences a percutaneous injury (e.g., needlestick), mucous membrane, or non-intact skin exposure to HIV-positive blood or body fluids
  • The source patient is known or suspected to have a high HIV risk
  • The exposure is deemed significant based on fluid type and injury mechanism

PEP is typically not indicated for exposures to sweat, tears, urine, or intact skin contact.

 

 

⏱️ Timing Is Critical

  • Initiate PEP within 2 hours of exposure, ideally.
  • It must be started within 72 hours to have any protective effect.
  • Delays beyond this window greatly reduce effectiveness and are not recommended.

? What Does PEP Involve?

HIV Exposure:

  • Standard HIV PEP involves a 28-day course of three-drug antiretroviral therapy (usually a combination of:
    • Tenofovir disoproxil fumarate (TDF)
    • Emtricitabine (FTC)
    • Raltegravir (RAL) or Dolutegravir (DTG))
  • Side effects may include nausea, fatigue, and gastrointestinal upset, but treatment is generally well tolerated.

Hepatitis B Exposure:

  • If the exposed individual is unvaccinated or incompletely vaccinated:
    • Administer Hepatitis B immune globulin (HBIG) and initiate vaccination series
  • If previously vaccinated:
    • Titer (anti-HBs) should be checked
    • Booster dose may be given depending on antibody levels

Hepatitis C:

  • No PEP available
  • The focus is on early detection, serial monitoring, and referral to hepatology if infection develops

 

 

? Follow-Up After PEP Initiation

  • Baseline labs including HIV, HBV, and HCV testing
  • Additional testing at 6 weeks, 3 months, and 6 months post-exposure
  • Supportive counseling and education on:
    • Medication adherence
    • Preventing potential transmission to others during follow-up window

? Key Takeaways:

  • PEP is a race against time — initiate immediately
  • HIV PEP must be taken daily for 28 days and requires full adherence
  • PEP protocols also involve evaluation for Hepatitis B vaccination and monitoring for Hepatitis C
  • Facilities must provide timely access to PEP — delays can have life-changing consequences
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