A Guide to Primary Care of People with HIV/AIDS - Canadian Public ...

A Guide to Primary Care of People with HIV/AIDS
Chapter 11: Postexposure Prophylaxis
2.
A patient known to be HIV negative 6 months ago comes to the clinic stating that last night he was the
receptive partner of unprotected sexual intercourse with his HIV-positive partner when the condom broke.
His partner has been HIV-positive for 5 years, currently has an undetectable viral load, and is taking
Combivir (zidovudine + lamivudine) and efavirenz (EFV). He has never had a resistance test.
Question: Should the patient take HIV PEP medications?
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Answer:
Although the current recommendations for nonoccupational exposures were released in 1998 and at that
time found that PEP for nonoccupational HIV exposure was still unproven, current data support treating.
Receptive anal intercourse with an HIV-positive partner carries with it a risk of transmission of 0.5%-3.0%.
Your patient’s risk is likely lower because of his partner’s low level of viremia. PEP in nonoccupational
settings is modeled after PEP for HCPs. In this case, the patient had a large exposure from a known HIVpositive
source with an undetectable viral load.
Following the model for PEP for HCPs, the patient should be treated ASAP, ie within 4 to 72 hours but not
more than 72 hours after exposure and receive 2 medications, although some experts would recommend
using 3 medications. It would be reasonable to place the patient on the same combination as his partner
because his partner has exhibited good adherence and good virologic control. Treatment should continue
for 28 days.
The patient should be counseled about medication side effects and the importance of adherence and
followup. Common side effects should be anticipated and pre-empted with counseling and, in some cases,
treatment. Changing medications and/or modifying the dosage regimen may increase the likelihood of
completion of the HIV PEP regimen. And finally, the patient should be educated about the symptoms of
acute HIV infection and advised to return immediately if those symptoms occur.
Question: What lab specimens should be drawn?
Answer:
A baseline HIV Ab should be drawn and repeated at 6 weeks, 3 months, 6 months and 12 months after
exposure, as well as an HBsAg, HBsAb, and HCV Ab. If he were unvaccinated against HAV or HBV then
vaccination should be initiated immediately. Laboratory monitoring for drug toxicity should be performed
at baseline and then 2 weeks after initiating therapy. The medical record of the patient’s partner should
immediately be reviewed, and treatment for HBV, HCV, or other sexually transmitted diseases should occur,
if any of these are found. Expert consultation should be sought if needed.
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U.S. Department of Health and Human Services, Health Resources and Services Administration, HIV/AIDS Bureau