HIV Prophylaxis Following Occupational Exposure: Guideline and Commentary

Barry S. Zingman, MD


January 30, 2013

In This Article

Timing of Initiation of PEP


When a potential occupational exposure to HIV occurs, every effort should be made to initiate PEP as soon as possible, ideally within 2 hours. (AII) A first dose of PEP should be offered to the exposed worker while the evaluation is underway.

Decisions regarding initiation of PEP beyond 36 hours post exposure should be made on a case-by-case basis with the realization of diminished efficacy when timing of initiation is prolonged. (AII)

Data from animal models of PEP have shown that effective antiretroviral treatment is most likely to prevent infection when initiated within 24 to 36 hours of exposure.[14,15,16,17,18,19] HIV virions can traverse epithelial barriers in just hours, and many antiretroviral drugs require an intracellular activation step that delays the onset of antiviral activity. Therefore, every effort should be made to initiate PEP as soon as possible and ideally within 2 hours. An absolute elapsed time after which PEP should not be administered cannot be stated with certainty.

Prompt initiation of PEP followed by telephone or in-person consultation with an experienced HIV provider or occupational health clinician experienced in providing PEP is recommended. Expert advice may be obtained from the National Clinicians' Consultation Center PEP Line at 1-888-HIV-4911 (1-888-448-4911). When using the PEP Line, providers from New York State should identify themselves as such.