What is the recommended post-exposure treatment for a patient recently exposed to Human Immunodeficiency Virus (HIV)?

HIV Post-Exposure Prophylaxis

Initiate a 28-day course of three-drug antiretroviral therapy immediately (ideally within 2 hours, but up to 72 hours) after substantial-risk HIV exposure from a known HIV-positive source. 1, 2

Timing is Critical

• Start PEP as soon as possible after exposure—the sooner treatment begins, the more likely it is to prevent HIV infection. 1
• PEP should be initiated within 72 hours of exposure, though efficacy decreases significantly after 48 hours. 1
• For exposures presenting serious transmission risk, clinicians may consider PEP even beyond 72 hours if the potential benefit outweighs risks, though this is not formally recommended. 1

Recommended Regimens

Preferred three-drug HAART regimens include: 1

• Efavirenz + lamivudine (or emtricitabine) + zidovudine or tenofovir (NNRTI-based regimen)
• Lopinavir/ritonavir (Kaletra) + zidovudine + lamivudine (or emtricitabine) (PI-based regimen)

The three-drug approach maximally suppresses viral replication during the critical days after exposure when local infection could otherwise become disseminated. 1

Alternative Considerations

• While no evidence proves three-drug regimens superior to two-drug regimens, the three-drug approach is recommended based on the principle of maximal viral suppression. 1
• If adherence or toxicity concerns are significant, a two-drug regimen (two reverse transcriptase inhibitors) may be considered, though this represents a compromise. 1

Source Patient Evaluation

When the source patient is available: 1

• Obtain their antiretroviral medication history and most recent viral load measurement
• Consider drawing blood for viral load and resistance testing to guide regimen selection and avoid prescribing drugs to which the source virus is likely resistant
• This information can modify the initial PEP regimen if results are obtained promptly

Unknown Source Status

For exposures from sources of unknown HIV status: 1

• No formal recommendation exists either for or against PEP
• Evaluate risk and benefits on a case-by-case basis
• Consider that prescribing antiretrovirals subjects patients to risks that may not be balanced by benefit if the source is actually HIV-negative

Monitoring and Follow-Up

Testing schedule: 2, 3

• Baseline HIV testing at initial evaluation
• Follow-up HIV antibody testing at 6 weeks, 3 months, and 6 months post-exposure
• Evaluate patients taking PEP within 72 hours after exposure and monitor for drug toxicity for at least 2 weeks 1, 2

During follow-up: 1, 2

• Advise patients to use precautions to prevent secondary transmission during the 6-month follow-up period
• Instruct patients to seek immediate medical evaluation for any acute illness compatible with acute retroviral syndrome

Additional Considerations

Concurrent STI and hepatitis management: 1

• Test for and provide prophylaxis for other sexually transmitted infections, as STIs increase HIV acquisition risk
• Test for hepatitis and vaccinate for hepatitis B if not immune 1
• For women of reproductive capacity with genital semen exposure, discuss emergency contraception 1

Adherence support: 1

• Counsel patients about potential side effects and adverse events requiring immediate medical attention
• Consider prescribing antiemetics or antimotility agents to manage symptoms and improve adherence
• The 28-day course must be completed for maximum effectiveness

Common Pitfalls to Avoid

• Do not delay PEP initiation while awaiting source patient test results—start immediately and modify later if needed 1, 2
• Do not test discarded needles or syringes for virus contamination—this is not recommended and delays care 1
• Do not use PEP for negligible-risk exposures (e.g., saliva not contaminated with blood, intact skin exposure) 1
• Do not forget immediate wound care: wash wounds and skin with soap and water; flush mucous membranes with water 1, 2