Which antiviral agent is used as a first-line treatment for chronic Hepatitis C?

Sofosbuvir is the first-line treatment for chronic Hepatitis C due to its mechanism of action as a direct-acting antiviral that inhibits the HCV RNA polymerase, which is essential for viral replication. This agent has demonstrated high efficacy and is part of combination therapy regimens that lead to sustained virologic response (SVR) in a large percentage of patients.

The choice of Sofosbuvir also reflects its favorable safety profile and ability to be used effectively across different HCV genotypes. Other agents, while possibly involved in Hepatitis treatment, do not possess the same targeted efficacy against Hepatitis C. For example, Ribavirin, while historically used for chronic Hepatitis C, is not typically a first-line monotherapy due to its side effects and the need for combination therapy. Acyclovir is primarily used for herpes virus infections and has no role in treating Hepatitis C. Oseltamivir is an antiviral specifically used for influenza and not applicable to Hepatitis C treatment. Thus, Sofosbuvir stands out as the most appropriate and effective choice for managing chronic Hepatitis C.