Assessment and Plan for HIV Post-Exposure Prophylaxis (PEP)
HIV PEP should be initiated as soon as possible, ideally within hours but no later than 72 hours after exposure, using a full 28-day course of antiretroviral therapy with TDF + 3TC (or FTC) as the backbone regimen plus a third drug such as LPV/r or ATV/r for all individuals with exposures that have potential for HIV transmission. 1, 2
Initial Assessment
Exposure Risk Evaluation
Bodily fluids that pose risk:
- Blood, blood-stained saliva, breast milk, genital secretions
- Cerebrospinal, amniotic, peritoneal, synovial, pericardial, or pleural fluids 1
Exposure routes warranting PEP:
- Mucous membrane exposure (sexual exposure, splashes to eye, nose, oral cavity)
- Parenteral exposures (needlestick, sharps injuries) 1
Exposures NOT requiring PEP:
- When exposed individual is already HIV positive
- When source is confirmed HIV negative
- Exposures to tears, non-blood-stained saliva, urine, and sweat 1
Immediate Actions
Provide immediate care to exposure site:
- Wash wounds and skin with soap and water
- Flush mucous membranes with water 1
Perform HIV testing of exposed person:
PEP Regimen Selection
Preferred Regimen for Adults and Adolescents
- Backbone regimen: TDF + 3TC (or FTC) 1, 2
- Third drug: LPV/r or ATV/r 1
- Alternative third drugs: RAL, DRV/r, or EFV (avoid EFV in women of childbearing age) 1, 2
Preferred Regimen for Children ≤10 years
- Backbone regimen: ZDV + 3TC 1
- Alternative backbones: ABC + 3TC or TDF + 3TC (or FTC) 1
- Third drug: LPV/r 1
- Alternative third drugs: ATV/r, RAL, DRV, EFV, or NVP 1
PEP Administration
Timing and Duration
- Initiate PEP as soon as possible after exposure, ideally within hours 1, 2
- Complete full 28-day course of antiretroviral drugs 1
- Provide full 28-day prescription at initial visit rather than starter packs 1
Adherence Support
- Provide enhanced adherence counseling for all individuals starting PEP 1
- Discuss potential side effects and management strategies
- Consider adherence tools: pill boxes, smartphone reminders, check-ins 1
Follow-up and Monitoring
Initial Follow-up
- Schedule follow-up within 72 hours of exposure for reevaluation 1, 2
- Reassess exposure risk based on any new information about source
- Adjust regimen if needed based on source's treatment history or drug resistance 1
Laboratory Monitoring
- Baseline testing: HIV antibody, hepatitis B and C serology, creatinine, liver enzymes
- Follow-up HIV testing: at 6 weeks, 3 months, and 6 months post-exposure 1
- Monitor for drug toxicity: especially in patients with risk factors for kidney injury 2
Special Considerations
- If source is later determined to be HIV-negative, PEP can be discontinued 2
- For pregnant individuals, evaluate risk/benefit with special consideration of drug safety in pregnancy 2
- If exposed person completes PEP for non-occupational exposure, assess for ongoing HIV risk and consider transition to PrEP without interruption 1
Common Pitfalls and Caveats
Delayed initiation: Effectiveness decreases with time; start PEP as soon as possible and never beyond 72 hours 1
Incomplete course: Poor adherence reduces effectiveness; provide full 28-day prescription and adherence support 1
Inadequate follow-up: Ensure follow-up within 72 hours to reassess risk and adjust regimen if needed 1
Failure to consider drug resistance: When source person's virus is known or suspected to be resistant, select drugs to which resistance is unlikely 1
Overlooking transition to PrEP: For individuals with ongoing HIV exposure risk, transition directly from PEP to PrEP without a gap 1
The most recent and highest quality evidence from the World Health Organization (2015) supports a three-drug regimen for all PEP cases, with TDF + 3TC (or FTC) as the backbone plus a third drug, which represents an evolution from earlier guidelines that recommended stratification based on exposure severity 1.