How do nucleoside reverse transcriptase inhibitors (NRTIs) function in HIV treatment?

Nucleoside reverse transcriptase inhibitors (NRTIs) function by mimicking natural nucleosides, which are the building blocks of nucleic acids in the body. In the context of HIV treatment, NRTIs are utilized to inhibit the reverse transcriptase enzyme, which is crucial for the replication of HIV. When these drugs enter the cell, they are phosphorylated to their active triphosphate form, which allows them to be incorporated into the viral DNA during reverse transcription.

As NRTIs resemble natural nucleosides, they effectively compete with them for incorporation into the growing viral DNA strand. Once incorporated, these drugs terminate the DNA chain because they lack a 3’-hydroxyl group, which is necessary for the addition of further nucleotides. This premature termination halts the production of viral DNA, ultimately leading to reduced viral replication and lower viral loads in the host.

By mimicking the structure of natural nucleosides, NRTIs impede the replication process of HIV, making them a cornerstone of antiretroviral therapy in managing HIV infection.