Because of the increasing problem of HIV infection from needle sticks, The Centers for Disease Control now recommends treating HIV exposure with what it calls post-exposure prophylaxis (PEP) for those workers thought to be exposed to HIV in the workplace.
What is Post Exposure Prophylaxis (PEP)?PEP is just what the name suggests; prophylaxis (preventative) medications given after an HIV or suspected HIV exposure in hopes of decreasing the likelihood of HIV infection from the exposure. The PEP medication combinations used depends on the degree of exposure and the HIV status of the source of the exposure. But before any medications are prescribed, it has to be determined if PEP is indicated and appropriate.
When is PEP Indicated?The following scenarios warrant PEP.
- Two Drug PEP Recommended
- exposure to asymptomatic HIV+ person by solid needle stick or superficial injury that break the skin
- a mucous membrane exposure to a large volume of HIV infected blood that's source is asymptomatic (consider for a lesser volume, a few drops)
- a mucous membrane exposure to a small volume of HIV infected blood that's source is symptomatic.
- Three Drug PEP Recommended
- exposure to asymptomatic HIV+ person via deep puncture from a large bore hollow needle
- a puncture from a needle with visible blood on the needle
- a puncture from a needle used in a patient's vein or artery.
- Three or More Drug PEP Recommended
- any needle stick exposure from any type needle used on a symptomatic HIV+ person
- a mucous membrane exposure to a large volume of HIV infected blood whose source is symptomatic.
- Possibility of Two Drug PEP under Certain Circumstances
- needle stick with any type needle and any degree of exposure if the source has an unknown HIV status but has HIV risk factors
- needle stick with any type needle and any degree of exposure if the source has an unknown HIV status and unknown risk factors but a setting in which exposure to HIV+ persons is likely
- a mucous membrane exposure to any volume of blood whose source has an unknown HIV status but has HIV risk factors
- a mucous membrane exposure to any volume of blood whose source has an unknown HIV status but is in a setting where where HIV exposure is likely
- No PEP Warranted
- any needle stick injury involving a known HIV negative source
- a mucous membrane exposure to any volume of HIV negative blood
What Medication Combination is Used?PEP regimens are chosen depending on the type of exposure. Typically regimens are prescribed for a four week period. PEP should be started within hours of the potential exposure not days. The sooner PEP is began the better.
Preferred Two-Drug Regimen
- Option 1 - Retrovir (zidovudine, AZT)+ Epivir (lamivudine) twice daily. Combivir (Retrovir + Epivir)twice daily is typically substituted for ease of administration. This twice a day regimen is a bit harder to take but is recommended in pregnancy.
- Option 2 - Truvada (tenofovir + emtricitabine) taken once daily. This one drug regimen is easier to take but does have the risk of liver toxicity.
Preferred Three-Drug Expanded Regimen
- Basic two drug regimen option 1 or 2 above with the addition of Kaletra (lopinavir + ritonavir) twice daily.
Concerns Associated with PEPWhile the benefits of PEP have been documented, there are some concerns as well. It's these concerns that cause practitioners to consider the need for PEP thoroughly before prescribing it. PEP is not without risk and should only be given in those people that absolutely need it. That being said concerns associated with PEP include:
- Adherence Issues and the Problem of Resistance - It's no secret that HIV medications have some unpleasant side effects. Because of these side effects the people who have been exposed find it difficult to take their PEP regimen as prescribed and/or complete the four week course. Both of these barriers result in poor adherence. And as in the case of HIV+ people on medication, poor adherence leads to viral resistance and poor control of HIV. That could make the difference between the PEP being successful or not.
The Last Word on PEPPEP is a viable option for occupational exposures to HIV. While it is not without it's downfalls, it is effective in reducing the risk of HIV infection from a needle stick. But, without addressing the problem of needle sticks, more people are going to become infected by this route, health care cost will continue to rise and the epidemic will continue to grow.
Department of Health and Human Services; "MMWR - Morbidity and Mortality Weekly Report"; Vol. 54; No. RR-9; 30 Sept 2005.
Raphael J. Landovitz, M.D., and Judith S. Currier, M.D.; "Post-exposure Prophylaxis for HIV Infection"; New England Journal of Medicine; Volume 361:1768-1775; Number 18; 29 Oct 2009.