Best Post-Exposure Prophylaxis (PEP) for This 17-Year-Old Male
The preferred regimen is bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) as a single tablet once daily for 28 days, started immediately 1.
Immediate Action Required
This patient needs nonoccupational post-exposure prophylaxis (nPEP), not PrEP, since the exposure already occurred. The distinction is critical:
- nPEP is recommended for unprotected receptive anal intercourse with a partner of unknown HIV status 1
- Start within 72 hours of exposure—the sooner, the better. Every hour counts for effectiveness 1
- The first dose should be given as soon as possible, ideally at this visit 1
Preferred Regimen Options
The 2025 CDC guidelines provide two preferred regimens for adolescents without contraindications 1:
- Bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) - single tablet daily
- Dolutegravir (DTG) plus (TDF or TAF) plus (FTC or 3TC) - requires multiple pills
Choose BIC/FTC/TAF because it offers:
- Single-tablet regimen (better adherence in adolescents)
- Once-daily dosing
- Excellent tolerability profile
- No food requirements
- Minimal drug interactions
Critical Implementation Steps
Prescribing:
- Provide the full 28-day course immediately at this visit 1
- Do not use "starter packs"—completion rates are better with full prescriptions 2
Baseline Testing (before or concurrent with first dose):
- HIV Ag/Ab combination immunoassay plus diagnostic HIV NAT 1
- Hepatitis B surface antigen 1
- Hepatitis C antibody 1
- Gonorrhea/Chlamydia NAAT (rectal, pharyngeal, urethral) 1
- Serum creatinine 1
Do not delay nPEP while waiting for test results unless acute HIV infection is clinically suspected 1.
Follow-Up Protocol
At 1 month:
- Assess adherence and tolerability
- Repeat HIV testing 1
At 12 weeks post-exposure:
- Final HIV testing using laboratory-based HIV Ag/Ab combination immunoassay AND diagnostic HIV NAT 1
Transition to PrEP
This patient should transition immediately to PrEP after completing nPEP 1. Given his risk profile (MSM with unprotected receptive anal intercourse), he meets clear indications for ongoing prevention:
- Perform HIV testing at nPEP completion
- If negative, start daily oral tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) immediately 3
- For MSM, a double dose (2 tablets) on day 1 provides protection within 24 hours 3
Common Pitfalls to Avoid
Do not:
- Wait for test results to start nPEP—time is critical
- Prescribe only a partial "starter pack"
- Use abacavir-based regimens without HLA-B*5701 testing 4
- Stop nPEP if the source tests HIV-negative 1
- Miss the opportunity to transition to PrEP for ongoing protection
Do:
- Provide enhanced adherence counseling 2
- Schedule the 1-month follow-up before the patient leaves
- Discuss that nPEP does not protect against other STIs
- Address any barriers to medication access or adherence immediately
Age Considerations
At 17 years old, this patient can receive the same adult regimens. The 2025 CDC guidelines explicitly include adolescents in their preferred regimen recommendations 1. There are no special dosing adjustments needed for this age group with normal renal function.