What are the next steps after taking Post-Exposure Prophylaxis (PEP) for HIV exposure?

Next Steps After Taking HIV Post-Exposure Prophylaxis (PEP)

Complete the full 28-day course of PEP without interruption, attend follow-up appointments for HIV testing at 4-6 weeks and 12 weeks post-exposure, and monitor for medication side effects and symptoms of acute HIV infection. 1, 2

Immediate Actions: Complete Your Medication Course

• Take all PEP medications for the full 28 days, even if you later learn the source person does not have HIV or has an undetectable viral load. 1, 2
• Do not stop PEP early—incomplete adherence significantly reduces effectiveness and increases the risk of HIV transmission. 2, 3
• If you experience side effects, contact your healthcare provider immediately rather than stopping medications on your own. 1

Follow-Up HIV Testing Schedule

The CDC's 2025 guidelines have updated the testing timeline to be more comprehensive:

Interim Testing (4-6 weeks after exposure):

• Get both a laboratory-based HIV antigen/antibody (Ag/Ab) combination test AND an HIV nucleic acid test (NAT). 1, 2
• This testing may be deferred only if you started PEP within 24 hours of exposure and have not missed any doses. 1

Final Testing (12 weeks after exposure):

• Get both a laboratory-based HIV Ag/Ab combination immunoassay AND an HIV NAT test. 1, 2
• This 12-week timeline represents an update from older 6-month protocols when using modern fourth-generation testing. 1, 4

Extended Follow-Up (12 months):

• Required only if you become infected with hepatitis C (HCV) after exposure to a source coinfected with HIV and HCV. 1, 5

Monitoring for Side Effects

• Attend a clinical evaluation within 72 hours of starting PEP to assess for drug toxicity. 2
• Report any new symptoms immediately, as medication side effects are common with antiretroviral regimens. 1
• Baseline laboratory testing should have been done before starting PEP; follow-up labs will monitor for renal, hepatic, and hematologic toxicity. 1, 2

Watch for Acute HIV Infection Symptoms

Seek immediate medical evaluation if you develop any acute illness during the follow-up period, regardless of the timeline since exposure. 1

Symptoms of acute retroviral syndrome include:

• Fever, fatigue, rash
• Sore throat, swollen lymph nodes
• Muscle aches, headache
• These symptoms warrant immediate HIV testing, even outside the scheduled testing intervals. 1, 5, 2

Prevent Secondary Transmission During Follow-Up

Until you complete testing at 12 weeks and confirm you are HIV-negative:

• Use condoms during any sexual activity. 1, 2
• Do not share needles or injection equipment. 1
• Do not donate blood, plasma, organs, tissue, or semen. 1
• Consider delaying pregnancy or breastfeeding until HIV status is confirmed. 1

Consider Transitioning to PrEP

If you have ongoing or anticipated repeat HIV exposures, transition immediately from PEP to pre-exposure prophylaxis (PrEP) after completing the 28-day PEP course. 1, 2

• Perform HIV testing at completion of PEP before starting PrEP. 1, 2
• This transition is particularly important for individuals with high-risk sexual behaviors or injection drug use. 1
• The same medications used for PEP (bictegravir/emtricitabine/tenofovir alafenamide) can be continued as PrEP. 1, 2

Common Pitfalls to Avoid

• Do not skip follow-up appointments—many people feel reassured after starting PEP and fail to return for testing, missing potential early HIV infection. 1
• Do not assume you are protected after completing PEP—you must complete the full testing schedule to confirm HIV-negative status. 1, 2
• Do not stop PEP due to side effects without consulting your provider—alternative regimens may be available, and stopping early dramatically reduces effectiveness. 2, 3
• Do not rely on rapid tests alone—the 2025 guidelines specifically require both Ag/Ab testing AND NAT testing for comprehensive detection. 1

When to Seek Expert Consultation

Contact an infectious disease specialist or HIV expert if:

• You are pregnant or breastfeeding. 1, 2
• You have significant kidney or liver disease. 2
• You are taking other medications that may interact with PEP. 1, 2
• The source person has known drug-resistant HIV. 1, 2
• You received long-acting injectable PrEP in the past 12 months (requires additional NAT testing at baseline). 1, 2

Resources for consultation include the PEPline at 888-448-4911 or http://www.ucsf.edu/hivcntr/Hotlines/PEPline. 1