Nucleoside Reverse Transcriptase Inhibitors (NRTIs) are a class of antiretroviral drugs used primarily to treat HIV infections. 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 often used in combination with other antiretroviral medications to enhance their effectiveness and reduce the risk of drug resistance. Common examples of NRTIs include Zidovudine, Lamivudine, and Tenofovir. These medications help manage HIV and improve the quality of life for those living with the virus.