PEP, post-exposure prophylaxis


If you know you do not have HIV or do not know your serological status, and in the last 48 hours:

  • you may have been exposed to HIV during sexual contact (e.g. when a condom broke)
  • you shared a syringe when injecting drugs
  • you have been sexually abused

you should immediately see a doctor and consider taking PEP as soon as possible.

What is PEP, and who should use it?
Post-exposure Prophylaxis (PEP) consists of taking antiretroviral drugs following exposure to potentially infectious material, possibly containing HIV. This may happen in situations such as intercourse without a condom, condom rupture, contact with blood, semen, vaginal mucus, pre-ejaculate, after using a needle or cutting yourself with a sharp tool that could have carried particles of HIV-infected blood. Post-exposure prophylaxis aims to block HIV infection. The drugs stop the virus from spreading immediately after they are taken, preventing it from multiplying. Post-exposure prophylaxis protects against HIV infection when taken immediately and correctly. PEP is also used in situations that have occurred out of control and in which HIV transmission may have happened, e.g. intercourse with an accidental partner under the influence of alcohol or psychoactive substances, when it is not possible to determine what the actual course of the event was.

When PEP should be started?
If a patient has been exposed to a potentially HIV containing material, post-exposure prophylaxis should be taken as soon as possible; ideally, the first dose of the medication should be taken within the first 4 hours after the event! Then, efficacy is 100%! It is assumed that the prophylaxis can be taken up to 48 hours after the event, or up to 72 hours in extreme cases when there was a high risk of exposure to the virus. After this time, the drugs are no longer able to effectively stop the virus from multiplying, and the body will be infected. A set of three medications selected by a doctor is taken daily for 28 days or until it is concluded that the source of exposure is not infected with HIV (the partner must perform appropriate tests).

Does PEP have side effects?
PEP is safe but, as with any medication, side effects may occur, e.g. nausea and malaise, diarrhoea. Side effects are rare. Drugs used in PEP are usually well tolerated. It is important to remember that avoiding HIV infection depends on their proper use. When taking PEP, you can always consult the doctor who recommended to receive additional help and explanation.

Tests before start of your PEP
Before starting PEP, on the day of exposure, an HIV test should be performed to rule out whether HIV infection has already taken place. In the case of HIV infection, it does not make sense to use PEP, and the infected person should be treated at a specialised centre.
During unprotected sexual intercourse, you may have been infected with other sexually transmitted diseases, this is why it is advisable to exclude HBV, HCV (mainly anal contact), and syphilis.