What does the 'S' in SOFOSBUVIR stand for?

The 'S' in sofosbuvir stands for "Structure-based nucleotide." Sofosbuvir is a nucleotide analogue that is specifically designed to inhibit the hepatitis C virus (HCV) RNA polymerase. This structural design is crucial because it allows the drug to effectively mimic the natural nucleotides that are incorporated into the viral RNA during replication, thereby disrupting the replication process.

This structural basis supports its function as a direct-acting antiviral agent, targeting specific viral components. Instead of being a broader category like "standard antiviral" or referring to treatment situations such as "salvage therapy," the naming of sofosbuvir emphasizes its molecular design, which is integral to its mechanism of action and effectiveness against HCV. Understanding this structural aspect helps in the appreciation of how sofosbuvir and similar drugs are developed based on targeted interactions with viral biology.