PEP is short for post-exposure prophylaxis. The word "prophylaxis" means the prevention of or protective treatment against disease or infection. The term post-exposure prophylaxis implying treatment after exposure.
PEP is a temporary antiretroviral (ARV) treatment administered to reduce the chances of HIV infection after possible exposure which could have happened through healthcare work or outside of a healthcare environment, through unprotected sex or rape. It should be offered as early as possible to anyone who has been potentially exposed within 72 hours.
Who should take PEP?
PEP is administered to HIV negative individuals who have, in the last 72 hours (3 days), been accidentally exposed to HIV whether as healthcare workers or outside the healthcare environment, for instance, through unprotected sex, shared a needle or sexual assault.
PEP is intended for emergency situations like those mentioned above. It is not intended for constant use by people who may be frequently exposed to HIV, for instance, MSM (men who have sex with men), PSID (people who Inject drugs), sex workers. PEP isn't a replacement for regular use of other HIV prevention methods, such as steady condom-use during sex or pre-exposure prophylaxis (PrEP). PrEP is the prophylaxis taken daily for the prevention of HIV infection.
When should PEP be taken?
For it to be effective, PEP has to be started within 72 hours (3 days) of possible exposure. The earlier it's started, the better. If started immediately after exposure, PEP can reduce the risk of HIV infection by more than 80%. The treatment takes a full 28-day course and adherence to it is instrumental to the effectiveness of the intervention.
How effective is PEP?
Corroborating evidence on the effectiveness of PEP has been difficult. However, PEP is most effective in preventing HIV infection when it’s taken immediately after exposure and correctly: This is when those potentially exposed to the virus do not miss doses and complete the full 28-day course. Effectiveness also relies on the time when treatment started, while it should be started within 72 hours, it's better if it's started early enough.
It's also been found that the most common cause of HIV infection in people who take PEP is on-going risk behaviour. It's important that while taking PEP, potentially-exposed people should keep using other HIV-preventive methods such as using only new, sterile needles when injecting drugs, and using condoms with their sexual partner(s) as unprotected sex could further expose them to HIV while using PEP.
What medicines are used for PEP?
PEP is usually made up of three anti-HIV drugs. WHO recommendations are, for adults: Tenofovir mixed with either lamivudine (3TC) or emtricitabine (FTC) as preferred backbone drugs. The recommended third drug is ritonavir-boosted lopinavir (LPV/r).
The alternative drugs for kids are, Zidovudine (AZT) and lamivudine (3TC) backbone drugs for children below the age of 10, and for the third drug choice, ritonavir-boosted lopinavir (LPV/r) is recommended.
There are also recommendations for other specific groups such as adolescents, pregnant women or people with kidney problems. Your health care provider should be able to determine which medicines to take for PEP.
What are the side effects?
HIV treatment may cause side effects in some people which tend to be worse at the start of the treatment. However, the side effects are not life-threatening and can be treated. The side effects include feelings such as dizziness, diarrhoea and fatigue. It's advised to speak to a healthcare provider if you are uncomfortable with the side effects and if they have persisted over time.