HIV Prophylaxis: Recommended Approaches
HIV prophylaxis should be initiated as soon as possible after exposure, ideally within 24 hours but no later than 72 hours, and continued for a full 28 days using a three-drug regimen of bictegravir/emtricitabine/tenofovir alafenamide or dolutegravir plus tenofovir with emtricitabine/lamivudine. 1, 2
Types of HIV Prophylaxis
There are two main approaches to HIV prophylaxis:
1. Post-Exposure Prophylaxis (PEP)
- Indicated when there has been a potential exposure to HIV within the past 72 hours 3, 1
- Should be initiated as early as possible, ideally within 24 hours of exposure 1, 2
- Exposures warranting PEP include contact with blood, blood-stained saliva, breast milk, genital secretions, and other high-risk bodily fluids 3
- Not recommended when the exposed individual is already HIV-positive or when the source is confirmed HIV-negative 3
2. Pre-Exposure Prophylaxis (PrEP)
- Recommended for individuals with ongoing risk of HIV exposure 4
- Transition from PEP to PrEP should be considered for persons with anticipated repeat or ongoing HIV exposure risk 1, 2
- Has been shown to be cost-effective in high-risk populations 5
Recommended PEP Regimens
Adults and Adolescents
- Preferred regimens: 1, 2
- Bictegravir/emtricitabine/tenofovir alafenamide (single-tablet regimen)
- Dolutegravir plus (tenofovir alafenamide or tenofovir disoproxil fumarate) plus (emtricitabine or lamivudine)
Children ≤10 years
- Preferred backbone: Zidovudine (ZDV) + lamivudine (3TC) 3
- Preferred third drug: Lopinavir/ritonavir (LPV/r) 3
- Alternative regimens include abacavir + lamivudine or tenofovir + lamivudine/emtricitabine 3
PEP Implementation Protocol
- Perform rapid HIV testing using antigen/antibody combination test
- Assess for medical comorbidities, current medications, and allergies
- Do not delay first dose while awaiting test results
- Start PEP as soon as possible after exposure, ideally within 24 hours
- PEP must be initiated within 72 hours of exposure for effectiveness
- Complete full 28-day course of antiretroviral therapy
- Provide the full 28-day prescription at initial assessment to improve completion rates
- Interim HIV testing at 4-6 weeks post-exposure
- Final HIV testing at 12 weeks post-exposure using laboratory-based HIV Ag/Ab combination immunoassay and diagnostic HIV NAT
Special Populations
Pregnant Women
- PEP should be administered to pregnant women as for other adults 3
- TMP-SMZ is the recommended prophylactic agent for opportunistic infections; dapsone is an alternative 3
- Some providers may withhold prophylaxis during the first trimester due to theoretical concerns about teratogenicity 3
Sexual Assault Survivors
- PEP should be offered promptly without waiting for risk assessment results 2, 6
- Enhanced adherence support is crucial as many survivors have difficulties completing the full PEP course 6
- Consultation with a sexual assault forensic examiner or nurse is recommended when available 6
HIV-Exposed Infants
- Infants born to HIV-infected mothers should receive prophylaxis with antiretroviral drugs 3
- For infants born to women who have not received prepartum or intrapartum ARV therapy, prophylaxis with 6 weeks of zidovudine is recommended 3
Common Pitfalls and Considerations
- Delayed initiation: Effectiveness decreases significantly when PEP is started beyond 72 hours after exposure 1, 2
- Incomplete adherence: The full 28-day course must be completed for maximum effectiveness 1, 3
- Drug interactions: Always assess for potential interactions with the patient's current medications 1
- Inadequate follow-up: Proper monitoring for medication adherence and toxicity is essential 1
- Stigma concerns: Stigma has been identified as a major barrier to PEP acceptance and adherence, particularly in certain populations 7