NRTIs, or nucleoside reverse transcriptase inhibitors, are a class of antiviral medications primarily used to treat HIV infection. They work by blocking the action of reverse transcriptase, an enzyme that HIV needs to replicate its genetic material. By inhibiting this enzyme, NRTIs help reduce the viral load in the body, allowing the immune system to recover and function more effectively. Common examples of NRTIs include zidovudine, lamivudine, and tenofovir. These drugs are often used in combination with other antiretroviral medications to enhance their effectiveness and prevent the development of drug resistance. Regular monitoring and adherence to treatment are essential for optimal outcomes.