If you think that you’ve been accidentally exposed to HIV, either through sex or other high-risk modes of transmission, there are medications you can take—called post-exposure prophylaxis (PEP)—that can significantly reduce your risk of infection if started in a timely manner.
Examples of high-risk exposure include:
- Unprotected sex
- A condom that has slipped or burst
- Shared needles or other drug paraphernalia
- Rape or sexual assault
What Is PEP?
PEP consists of a 28-day course of antiretroviral drugs that must be taken completely and without interruption. In order to minimize the risk of infection, PEP must be started as soon as possible—ideally within one to 36 hours of exposure.
While PEP can be administered within 72 hours of exposure, the chances of averting an infection are best the sooner you start. The more time that passes, the more the virus is able to migrate from the site of the exposure to nearby cells and tissues.
If you think you have been exposed to HIV, do not wait. Go immediately to your nearest emergency room or walk-in clinic. Do not wait until the morning to call your healthcare provider.
HIV Doctor Discussion Guide
Get our printable guide for your next doctor’s appointment to help you ask the right questions.
Once you arrive at the hospital or clinic, you will be asked about the exposure incident by a doctor, nurse, or dedicated staff member. Do not be embarrassed to describe what happened. The aim of the interview is to ascertain if the incident poses a viable risk of transmission. This can help you avoid taking drugs you don’t actually need.
On the other hand, PEP may not be viable if you have waited too long to seek treatment.
- If you are HIV-positive, it means that you have HIV. A second test will then be given to confirm the results, after which a trained healthcare worker will discuss your results and explain how HIV is diagnosed and treated.
- If you are HIV-negative, it means there is no evidence of the virus in your blood. The healthcare worker will explain what a negative result does and does not mean and walk you through the steps of PEP.
If PEP is authorized, you will be advised about how to take the drugs, what side effects may occur, and the importance of treatment adherence.
PEP is not recommended if you delay for more than 72 hours from the time of the exposure. This does not mean you will get HIV—only that the potential benefits of PEP will have been lost.
How PEP Is Prescribed
In the past, PEP consisted of either one, two, or three antiretroviral drugs based on the severity of the exposure. Part of the reason for this was that earlier drugs were more toxic and often caused intolerable side effects. Newer-generation antiretrovirals used for PEP are far more tolerable and tend to cause few, if any, side effects.
PEP can be used for both adults and adolescents. The CDC recommends several options, two of which are preferred and an alternate if the preferred drugs aren’t available.
|Preferred Option 1||Truvada (tenofovir + emtricitabine) once daily plus Tivicay (dolutegravir) once daily|
|Preferred Option 2||Truvada (tenofovir + emtricitabine) once daily plus Isentress (raltegravir) twice daily|
|Alternative Option||Truvada (tenofovir + emtricitabine) once daily plus Prezista (darunavir) once daily plus Norvir (ritonavir) once daily|
A follow-up HIV test would then be scheduled, usually within four to six weeks of the completion of PEP. If the test is negative, you will be counseled on how to reduce your risk of HIV moving forward.
Once started, you need to complete the entire 28-day course of treatment. If you experience intolerable side effects, call your healthcare provider or clinic immediately; other drugs may be used instead. Whatever you do, don’t stop or miss doses.
Effectiveness of PEP
The effectiveness of PEP has typically been evaluated in healthcare settings, mainly because risk assessment, treatment, and post-treatment protocols are standardized and the results are more easily tracked.
In non-occupational settings, this is not the case. Not only do the routes of exposure vary, but it is often difficult to assess whether treatment was adhered to, whether the details of the incident were accurate, or whether PEP was even necessary.
With respect to PEP in healthcare settings, an early study published in the New England Journal of Medicine concluded that PEP administered after a percutaneous (needle puncture) wound reduced the risk of HIV by 81%. Subsequent studies suggest the results today may be closer to 90% or greater.
Based on the current body of evidence, it can be presumed that PEP can significantly reduce the risk of getting HIV through sex or injecting drug use if started early and taken to completion.
A Word From Get Meds Info
PEP is not a morning-after pill. If you are at high risk of getting HIV, speak with your healthcare provider about a preventive strategy known as pre-exposure prophylaxis (PrEP) in which the daily use of Truvada or Descovy can reduce your risk of getting HIV by up to 99%.
Centers for Disease Control and Prevention. Updated guidelines for antiretroviral postexposure prophylaxis after sexual, injecting drug use, or other nonoccupational exposure to HIV—United States, 2016. 2016.
Cardo D, Culver D, Ciesielski C, et al. A case-control study of HIV seroconversion in health care workers after percutaneous exposure. New Eng J Med. 1997;337:1485-1490. doi:10.1056/NEJM199711203372101
Beymer MR, Weiss RE, Bolan RK. Differentiating nonoccupational postexposure prophylaxis seroconverters and non-seroconverters in a community-based clinic in Los Angeles, California. Open Forum Infect Dis. 2017 Spring;4(2):ofx061. doi:10.1093/ofid/ofx061
McCormack S, Dunn DT, Desai M, et al. Pre-exposure prophylaxis to prevent the acquisition of HIV-1 infection (PROUD): Effectiveness results from the pilot phase of a pragmatic open-label randomised trial.Lancet. 2016;387(10013):53-60. doi:10.1016/S0140-6736(15)00056-2
Truvada (Emtricitabine/Tenofovir Disoproxil Fumarate) Oral: Use, Side Effects, Dosages
HIV and Health Disparities in Latinx Communities
What Is the Real Risk of HIV From Vaginal Sex?
Cause and Risk Factors of HIV
HIV in Black Men: Increased Risk, Facts, Testing, Resources
What Is the HIV Window Period?
Can You Lower Your HIV Risk by Pulling Out Early During Sex?
What Is PEP for HIV?