What should be done before starting post-exposure prophylaxis (PEP) after a condom break?

Pre-PEP Assessment After Condom Breakage

Before starting HIV post-exposure prophylaxis (PEP) after a condom break, you must perform rapid HIV testing on the exposed person, assess the source's HIV status and viral suppression, and initiate PEP within 72 hours (ideally within 24 hours) if indicated—do not delay the first dose for pending laboratory results. 1

Immediate Actions at Initial Visit

HIV Testing of Exposed Person

• Perform rapid point-of-care HIV test at the initial visit to rule out pre-existing HIV infection 2, 1
• Simultaneously order a laboratory-based HIV antibody/antigen (Ag/Ab) combination test 2, 1
• If the person has used long-acting injectable PrEP in the past 12 months, add a diagnostic HIV nucleic acid test (NAT) 1
• Do not delay PEP initiation while waiting for laboratory results if rapid test is negative and no symptoms of acute HIV infection are present 2, 1

Source Assessment

• Determine the HIV status of the source partner if possible 2
• If source is HIV-positive, assess their viral suppression status and antiretroviral treatment history 1
• PEP is recommended when the source has HIV without sustained viral suppression or their viral suppression status is unknown 1
• If source HIV status is completely unknown, make a case-by-case determination based on epidemiologic likelihood of HIV infection 2, 1

Clinical Evaluation

• Assess for symptoms of acute HIV infection (fever, rash, lymphadenopathy) which would require HIV RNA testing before starting PEP 2
• Document medical comorbidities that may affect drug selection, particularly kidney disease 1
• Review current medications to identify potential drug interactions 1
• Document allergies to antiretroviral medications 1

Additional Baseline Testing

STI Screening

• Screen for gonorrhea and chlamydia using nucleic acid amplification testing at all anatomic sites of exposure (genital, rectal, pharyngeal) 2
• Perform syphilis serology 2
• Test for hepatitis B and C 2
• Consider pregnancy testing if applicable 2

Laboratory Monitoring

• Obtain baseline creatinine and calculate estimated creatinine clearance, especially if using tenofovir-containing regimens 2
• Baseline liver function tests if hepatitis co-infection is suspected 2

Timing Considerations

PEP must be initiated as soon as possible after exposure, ideally within 24 hours but no later than 72 hours 2, 1. Animal studies demonstrate that PEP is substantially less effective when started more than 24-36 hours post-exposure 2. However, if the exposure represents a serious transmission risk, consider initiating PEP even beyond 72 hours, as the exact time limit for benefit is undefined 2.

Critical Pitfall to Avoid

Never delay PEP initiation to wait for laboratory results, source testing, or specialist consultation 2. Start with the preferred regimen immediately and modify later if needed based on additional information 2.

Counseling Before Starting PEP

• Explain that PEP is a 28-day course of antiretroviral medications 2, 1
• Discuss common side effects (nausea, fatigue, diarrhea) and their management 2, 3
• Emphasize the importance of medication adherence for the full 28 days 2
• Provide risk reduction counseling including safer sex practices 2
• Schedule follow-up within 72 hours to reassess, review test results, and monitor adherence 2

When PEP is NOT Recommended

PEP should not be initiated if 1:

• The exposure occurred more than 72 hours ago (though exceptions may be considered for high-risk exposures) 2
• The source is confirmed HIV-negative 2
• The exposed person tests HIV-positive at baseline 2, 1
• The exposure presents negligible transmission risk 2

If the source is later determined to be HIV-negative after PEP has started, discontinue PEP immediately 2.