Everybody occasionally partakes in behavior that is potentially dangerous, whether this is intentional, such as casual unprotected sex, or unintentional, such as a workplace injury. The consequences of those actions can be scary, but perhaps the scariest of all consequences is transmitting a life-affecting virus such as HIV – and both of the previous examples could have this result. Of course, there are ways in which you can help protect yourself – avoiding risky situations where possible and following safety advice such as using condoms are a good start – but it’s impossible to avoid every potentially dangerous situation in life. Sometimes, risk of exposure to HIV is going to happen. So is there any way that transmission of HIV can be prevented after exposure? Perhaps surprisingly, the answer is yes. PEP, or post-exposure prophylaxis, is a treatment given to those who have been exposed to a high risk of HIV transmission and it’s used as a preventative medication in order to stop the virus in its tracks.

What is PEP?

PEP is essentially an antiretroviral (ARV) therapy made up of a combination of one to three ARV drugs and is actually the same therapy used to treat HIV once transmitted[1]. Originally only given to occupational exposures, such as needlestick injuries in health care workers, the US Department of Health and Human Services (HHS) offered guidelines in 2005 for the use of PEP in non-occupational (nPEP) cases such as exposure through sexual activity or drug use as well[2]. The treatment is given to those who test negatively for HIV and have been exposed to a high risk in a single case (ongoing exposure, such as a person with an HIV positive partner, is not normally treated with PEP, but with an alternative drug, PrEP – pre-exposure prophylaxis). In contrast to occupational PEP, nPEP is generally coupled with risk-reduction counselling and education in order to help patients learn from their damaging behavior. It is also only administered if treatment is sought within 72 hours of the exposure – any longer than that, and the treatment simply isn’t effective and therefore isn’t prescribed[3].