Which class of medication acts as a decoy to nucleosides that are missing a component?

Nucleoside reverse transcriptase inhibitors (NRTIs) are designed to mimic the structure of natural nucleosides, which are the building blocks of DNA and RNA. These medications act as competitive inhibitors, effectively acting as decoys for the reverse transcriptase enzyme. When this enzyme attempts to synthesize viral DNA using the viral RNA as a template, the NRTIs get incorporated into the growing viral DNA strand, which lacks critical components that would allow the DNA synthesis to proceed normally. As a result, the incorporation of NRTIs leads to chain termination, preventing the completion of viral DNA and ultimately inhibiting the replication of the virus.

This mechanism is particularly important in the treatment of viral infections such as HIV, where reverse transcriptase plays a crucial role. The effectiveness of NRTIs lies in their structural similarity to natural nucleosides, allowing them to compete for incorporation into the viral DNA synthesis process, thereby obstructing the virus's ability to replicate within the host.