What is the recommended HIV post‑exposure prophylaxis regimen for a 17‑year‑old male who had unprotected receptive anal intercourse with a male partner last night, has never been tested for HIV, and does not know the partner’s HIV status?

Recommended HIV Post-Exposure Prophylaxis Regimen

The recommended regimen for this 17-year-old male is bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) as a single daily pill for 28 days, initiated immediately. 1

Why This Regimen is Preferred

The 2025 CDC guidelines establish BIC/FTC/TAF as one of two preferred regimens for adolescents and adults without contraindications 1. This single-pill, once-daily regimen offers several advantages:

• Simplicity: One pill daily improves adherence compared to multi-pill regimens
• Tolerability: Contemporary integrase inhibitors like bictegravir have substantially reduced side effects compared to older antiretrovirals 1
• Renal safety: TAF formulation is safer for patients with renal concerns compared to TDF 2
• Efficacy: Integrase inhibitor-based regimens have become the standard of care, replacing older boosted protease inhibitor regimens 3

The alternative preferred regimen is dolutegravir (DTG) plus (TAF or TDF) plus (FTC or 3TC), but this requires 2-3 pills daily 1.

Critical Timing Considerations

This patient must start nPEP immediately—ideally within hours, not days. The exposure occurred "the night before," placing him well within the 72-hour window, but earlier initiation is strongly associated with better outcomes 1. The median time to treatment in successful PEP programs is 33 hours 4.

nPEP is not recommended if initiated beyond 72 hours post-exposure 1.

Why This Exposure Warrants nPEP

This case clearly meets criteria for nPEP:

• High-risk exposure: Unprotected receptive anal intercourse is the highest-risk sexual exposure for HIV transmission 1, 5
• Unknown source status: The partner's HIV status is unknown, requiring case-by-case determination that favors treatment 1
• Within time window: Exposure occurred <72 hours ago 1
• Not on PrEP: Patient was not taking pre-exposure prophylaxis 1

Required Testing and Follow-Up Protocol

At today's visit:

• Rapid HIV test AND laboratory-based antigen/antibody combination test 1
• Hepatitis B testing (as patient agreed to this)
• STI screening (gonorrhea, chlamydia, syphilis)
• Baseline renal and hepatic function, pregnancy test if applicable
• Assess for contraindications to BIC/FTC/TAF

Follow-up testing schedule:

• 4-6 weeks: HIV Ag/Ab test PLUS diagnostic HIV NAT (may be deferred if started within 24 hours and no missed doses) 1
• 12 weeks: Final HIV Ag/Ab test PLUS diagnostic HIV NAT 1

Common Pitfalls to Avoid

1. Delaying initiation: Do not wait for baseline test results to start nPEP—give the first dose today 1
2. Incomplete course: 20% of patients discontinue prematurely 3. Emphasize the importance of completing all 28 days
3. Inadequate counseling: This patient needs risk-reduction counseling and should be assessed for transition to PrEP after completing nPEP, given his risk profile 1
4. Missing follow-up: Ensure scheduled appointments for adherence monitoring, toxicity assessment, and HIV testing

Special Considerations for Adolescents

At age 17, this patient may face unique barriers:

• Confidentiality concerns: Ensure privacy and discuss consent laws in your jurisdiction
• Adherence challenges: Younger age is associated with lower completion rates 3. Provide intensive adherence support
• Transition to PrEP: MSM adolescents with ongoing risk should transition to PrEP after completing nPEP 1, 6

If Contraindications Exist

Before prescribing, assess for:

• Severe renal dysfunction (adjust or use alternative regimen)
• Hepatic impairment
• Drug interactions with current medications 1
• Known hypersensitivity to components

If BIC/FTC/TAF is contraindicated, use the alternative preferred regimen: DTG + (TAF or TDF) + (FTC or 3TC) 1.

Stop nPEP If...

Discontinue the 28-day course only if the source partner is definitively determined to be HIV-negative 1.