Which category of antiviral agents does lamivudine belong to?

Lamivudine is classified as a nucleoside reverse transcriptase inhibitor (NRTI). This class of antiviral agents is primarily used to treat infections caused by retroviruses, particularly HIV. NRTIs work by inhibiting the action of reverse transcriptase, an enzyme crucial for the replication of retroviruses. By incorporating themselves into the viral DNA during the replication process, NRTIs like lamivudine prevent the reverse transcriptase enzyme from further elongating the viral DNA, effectively halting the viral life cycle.

The other categories of antiviral agents serve different mechanisms of action. Non-nucleoside reverse transcriptase inhibitors (NNRTIs) also target reverse transcriptase but do so at a different site and do not mimic nucleosides. Protease inhibitors block the protease enzyme, which is essential for the maturation of viral particles. Fusion inhibitors prevent the virus from entering host cells by inhibiting the fusion process between the viral envelope and the host cell membrane. Each of these classes has distinct roles in antiviral therapy, making lamivudine's classification as an NRTI significant in understanding its mechanism and application in treating HIV infections.