On December 1, AIDS Day, the World Health Organization (WHO) recommended simplified post-exposure prophylaxis (PEP), such as after unprotected sexual contact with an infected person or after an infected person’s blood splashes into the eyes.
Post-exposure prophylaxis (PEP) recommendations developed by the WHO in 2007 focus on post-exposure prophylaxis for adults following, for example, occupational exposure (in healthcare settings), or following sexual assault. The original standard measures included two antiretroviral drugs, with the addition of a third antiretroviral drug if the exposed infected person was resistant or if a resistant strain was locally available.
In its new guidance recommendations, WHO recommends receiving three antiretroviral drugs for prophylaxis regardless of the exposure. This option removes the original step of needing to know if a drug is potentially resistant, which makes it less demanding on the health care professional, an important consideration given that in less developed countries, removing this requirement could speed up the implementation of prophylaxis. The three antiviral drugs used for PEP are the same as the treatment regimen for infected individuals, and this could also further simplify matters.
In adults and adolescents requiring PEP, WHO recommends that tenofovir disoproxil fumarate, plus lamivudine or emtricitabine, be given as the “backbone” drug in the initial regimen. These two drugs are also used as the backbone of antiretroviral therapy (ART) for infected patients. The choice of a third PEP for ARV is less clear at present, and due to the lack of good studies, according to the WHO preference is for lopinavir, ritonavir or atazanavir, ritonavir, as these drugs are currently recommended for ART use and have been more widely used in low- and middle-income countries.
WHO noted that the fact that antiretroviral drugs with less drug toxicity and better tolerability have now been developed makes the three-drug PEP intermittently feasible. “Although the addition of a third drug may have increased drug-related toxicity, completion rates were reported to be similar with two- and three-drug PEP.