There are three medications approved by the United States Food and Drug Administration (FDA) for HIV preexposure prophylaxis (PrEP): oral tenofovir DF-emtricitabine (TDF-FTC), oral tenofovir alafenamide-emtricitabine (TAF-FTC), and long-acting injectable cabotegravir (CAB-LA). These medications have unique characteristics, and clinicians should be familiar with appropriate indications and populations for use of these medications for HIV PrEP. The medications tenofovir disoproxil fumarate (TDF), tenofovir alafenamide (TAF), and emtricitabine (FTC) are nucleoside reverse transcriptase inhibitors (NRTIs). The NRTIs work by blocking the HIV enzyme reverse transcriptase, which plays a critical role in converting HIV RNA into HIV DNA. Cabotegravir is an integrase strand transfer inhibitor (INSTI); this medication inhibits the function of the HIV integrase enzyme, which normally functions to integrate newly formed HIV DNA into human DNA.
Watch the brief video below on HIV PrEP: Mechanism of Action (8 minutes) to better understand how HIV PrEP medications block HIV replication.