What is the recommended treatment for Post-Exposure Prophylaxis (PEP) in young individuals exposed to sex?

Post-Exposure Prophylaxis (PEP) for Young Individuals After Sexual Exposure

Initiate PEP immediately with bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) as a single daily tablet for 28 days, starting within 24 hours but no later than 72 hours after sexual exposure to HIV. 1

Immediate Actions (Do Not Delay)

• Start PEP as soon as possible, ideally within 24 hours of exposure, but it can be initiated up to 72 hours post-exposure 1, 2
• Perform a rapid HIV antibody test or laboratory-based antigen/antibody combination test at the point of care before starting PEP 1, 2
• Do not wait for test results to initiate the first dose of PEP 1, 2
• Do not delay for source person risk assessment or testing 1

Preferred Medication Regimens for Young Patients

The 2025 CDC guidelines prioritize two first-line options for adolescents and young adults 1:

Option 1 (Single-tablet regimen):

• Bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) - one tablet daily for 28 days 1, 2

Option 2 (Multi-tablet regimen):

• Dolutegravir (DTG) PLUS (tenofovir alafenamide [TAF] OR tenofovir disoproxil fumarate [TDF]) PLUS (emtricitabine [FTC] OR lamivudine [3TC]) for 28 days 1

These integrase inhibitor-based regimens have replaced older zidovudine-based regimens due to superior tolerability and adherence rates 2

When PEP Is Indicated

PEP is recommended when 1:

• Anal or vaginal intercourse occurred without a condom within the past 72 hours 1
• The source person has HIV without sustained viral suppression OR their HIV/viral suppression status is unknown 1
• The exposed person was not taking PrEP as recommended 1

When PEP Is NOT Routinely Recommended

• Oral-genital sexual contact without a condom (case-by-case determination may be considered) 1
• Intact condom was used during intercourse 1
• Source person has sustained viral suppression 1
• More than 72 hours have passed since exposure (though some experts argue for case-by-case consideration) 1

Baseline Testing Protocol

Before initiating PEP, perform 1, 2:

• Rapid HIV test or laboratory-based fourth-generation antigen/antibody (Ag/Ab) test to rule out pre-existing infection 1, 2
• Test for other sexually transmitted infections 1, 2
• Critical pitfall to avoid: Never use oral fluid rapid tests in the PEP context, as they are less sensitive for acute/recent infection 2

Source Person Testing

• If possible, test the source person with a fourth-generation HIV antigen/antibody test, which detects infection several weeks earlier than standard antibody tests 1, 2
• If the source tests negative and has no signs of acute HIV infection, PEP can be discontinued 1, 2

Follow-Up Testing Schedule

The 2025 CDC guidelines specify 1, 2:

• 24 hours post-initiation: Remote or in-person visit with medical provider 1
• 4-6 weeks post-exposure: Laboratory-based HIV Ag/Ab test AND diagnostic HIV nucleic acid testing (NAT) 1, 2
• 12 weeks post-exposure: Final conclusive testing with both laboratory-based HIV Ag/Ab combination immunoassay AND diagnostic HIV NAT 1, 2

Important consideration: The 4-6 week testing may be omitted for persons who started PEP within 24 hours of exposure and did not miss any doses 2

Monitoring and Adherence

• Evaluate patients within 72 hours after starting PEP and monitor for drug toxicity for at least 2 weeks 2
• Counsel patients to seek immediate medical evaluation for any acute illness during follow-up, as this may indicate acute retroviral syndrome 2
• Completion rates are higher in older patients, men who have sex with men, and those with known HIV-infected source partners 3
• Youth represent a particularly vulnerable group requiring targeted adherence support 3, 4

Critical Pitfalls to Avoid

• Never delay PEP initiation while awaiting laboratory results or source person information 1, 2
• Antiretroviral medications (PEP or PrEP) can suppress viral load and delay antibody formation, potentially reducing HIV detection ability 2
• Do not test discarded needles or syringes for virus contamination 2

Transition to Long-Term Prevention

• Offer PrEP to young individuals with anticipated repeat or ongoing potential HIV exposures 1, 2
• An immediate transition from PEP to PrEP can occur after completion of the 28-day course with HIV testing at completion 1, 2
• This is particularly important for youth and men who have sex with men who have higher rates of repeat exposures 3

Additional Considerations for Young Patients

• Young age is associated with lower PEP completion rates and decreased condom use, necessitating enhanced counseling and support 3
• Risk-reduction counseling should be provided to prevent recurrent exposures 1
• Counsel on precautions to prevent secondary transmission during the follow-up period 2