Nucleotide Reverse Transcriptase Inhibitors (NRTIs) are a class of antiviral medications used primarily to treat infections caused by the HIV virus. They work by blocking the action of reverse transcriptase, an enzyme that converts viral RNA into DNA, preventing the virus from replicating within the host's cells. NRTIs are essential in antiretroviral therapy (ART) for managing HIV/AIDS. Common examples include zidovudine, lamivudine, and tenofovir. By inhibiting reverse transcriptase, these drugs help reduce the viral load in the body, improving the immune system's function and overall health of individuals living with HIV.