WHAT IS POST-EXPOSURE PROPHYLAXIS?
Prophylaxis means disease prevention. Post-exposure prophylaxis (PEP) means taking antiretroviral medications (ARVs) to prevent HIV infection as soon as possible after exposure to HIV. These medications are only available with a prescription.
WHO SHOULD USE PEP?
Workplace exposure: PEP has been standard procedure since 1996 for healthcare workers exposed to HIV. People who have been exposed start taking medications within a few hours of exposure. Usually the exposure is from a needlestick, when a healthcare worker accidentally gets jabbed with a needle containing blood that may be contaminated with HIV or other bloodborne viruses. PEP reduces the rate of HIV infection from workplace exposures by 79%. However, it is still possible for healthcare workers who take PEP to get HIV infection.
Other exposure: In 2005, the Centers for Disease Control and Prevention (CDC) reviewed information on PEP. They concluded that it should also be available for use after HIV exposures that are not work-related. People can be exposed to HIV during unsafe sexual activity, when a condom breaks during sex, or if they share needles for injecting drugs. Infants can be exposed if they drink breast milk from a parent with HIV.
PEP MUST BE STARTED WITHIN 72 HOURS OF POSSIBLE EXPOSURE TO HIV
Talk right away with a healthcare provider, emergency room clinician, or urgent care provider about PEP if you think you’ve recently been exposed to HIV through any of the following scenarios:
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- During sex (for example, if the condom broke)
- You have shared needles, syringes, or other equipment to inject drugs (for example, cookers)
- If you’ve been sexually assaulted.
The sooner you start PEP, the better. Every hour counts. PEP must be started within 72 hours (3 days) of a possible exposure. If you’re prescribed PEP, you’ll need to take it daily for 28 days.
PEP IS FOR EMERGENCY SITUATIONS
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- PEP is given after a possible exposure to HIV.
- PEP is not a substitute for regular use of other HIV prevention.
- PEP is not the right choice for people who may be exposed to HIV frequently.
- If you are at ongoing risk for HIV, such as through repeated exposures to HIV, talk to your healthcare provider about pre-exposure prophylaxis (PrEP).
HOW IS PEP TAKEN?
PEP isn’t just a one-time pill—it’s a regimen where you take many pills over many weeks. If your healthcare provider gives you PEP, you’ll need to take medicine 1-2 times a day for at least 28 days (4 weeks). It’s important that you take every pill as directed and don’t skip doses, otherwise PEP may not work as well.
PEP isn’t 100% effective, and it won’t prevent future HIV infections like PrEP can, so it’s important to keep protecting yourself and others from HIV while you’re on PEP. Use condoms every time you have sex. If you inject drugs, don’t share needles or works. This helps protect you from being exposed to HIV again. And it lowers the chances of giving HIV to others if you do have it.
HOW WELL DOES PEP WORK?
If taken within 72 hours after possible exposure, PEP is highly effective at preventing HIV. But to be safe, you should take other actions to protect your partners while you are taking PEP. This includes always using condoms with sexual partners and not sharing needles, syringes, or other equipment to inject drugs.
WHAT ARE THE SIDE EFFECTS?
The most common side effects from PEP medications are nausea and generally not feeling well. Other possible side effects include headaches, fatigue, vomiting, and diarrhea. In almost all cases, these side effects can be treated and aren’t life-threatening. Talk with your healthcare provider if you have side effects that are really bothering you.
If PEP doesn’t work, you may have symptoms of the first stage of HIV infection, like a fever or rash. If you have these symptoms while you’re on PEP, or within a month after finishing PEP, call your healthcare provider.
WHAT HAPPENS AFTER I TAKE PEP?
You need to visit your healthcare provider for follow-up testing after you finish PEP. You’ll get another HIV test 4-6 weeks after you were first exposed to HIV, and then you’ll be tested again 3 months later. Depending on your situation, your healthcare provider may recommend another HIV test 6 months later.
It’s really important to get these follow-up tests to make sure PEP worked. In the meantime, keep protecting yourself and others from HIV by using condoms when you have sex and not sharing needles or works.
HOW CAN I PAY FOR PEP?
Depending on the reason you are prescribed PEP, you may qualify for free or low-cost PEP medicines.
Paying for PEP after sexual assault:
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- You may qualify for partial or total reimbursement for medicines and clinical care costs.
- Find resources available in your area.
Paying for PEP after workplace exposure:
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- Your workplace health insurance or workers’ compensation will usually pay for PEP.
Paying for PEP for another reason:
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- If you cannot get insurance coverage, your healthcare provider can apply for free PEP medicines through medication assistance programs run by the manufacturers. These requests for assistance can be handled urgently in many cases to avoid a delay in getting medicine.
- Enrollment applications from several manufacturers can be completed online, over the phone, or by fax:
THE BOTTOM LINE
Post-exposure prophylaxis (PEP) is the use of antiretroviral medications (ARVs) as soon as possible after exposure to HIV to prevent HIV infection. PEP can reduce the rate of infection in healthcare workers exposed to HIV by 79%.
PEP is a four-week program of several ARVs, taken 1-2 times a day. The medications have side effects, but they usually aren’t dangerous and can be treated. PEP is not 100% effective; it cannot guarantee that exposure to HIV will not become a case of HIV infection.
MORE INFORMATION
HIV.gov: Post-Exposure Prophylaxis
HIVinfo.NIH.gov: Post-Exposure Prophylaxis
CDC: PEP 101 Consumer Info Sheet
Reviewed June 2024
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