Which medication is used to treat Hepatitis C by inhibiting RNA polymerase?

Which medication is used to treat Hepatitis C by inhibiting RNA polymerase?

• A. Zidovudine
• B. Trifluridine
• C. Oseltamivir
• D. Ribavirin

Answer: (D)

Blocking the viral RNA polymerase stops hepatitis C from copying its genome, which is essential for the virus to replicate. For hepatitis C, the key enzyme is the NS5B RNA-dependent RNA polymerase, and drugs that directly inhibit this enzyme prevent viral RNA synthesis. The drug that best fits this mechanism is sofosbuvir, a nucleotide analog prodrug that directly inhibits NS5B polymerase, effectively halting replication. Ribavirin, while used in hepatitis C therapy in the past, works differently: it reduces viral replication through mechanisms like depleting GTP pools and causing mutagenesis, rather than directly inhibiting the HCV polymerase. The other listed medications target viruses or enzymes unrelated to hepatitis C polymerase activity (for example, zidovudine targets HIV reverse transcriptase, oseltamivir targets influenza neuraminidase, and trifluridine is used topically for ocular herpes). So, the concept being tested is direct inhibition of the hepatitis C RNA polymerase; the drug that demonstrates this mechanism is sofosbuvir.

Blocking the viral RNA polymerase stops hepatitis C from copying its genome, which is essential for the virus to replicate. For hepatitis C, the key enzyme is the NS5B RNA-dependent RNA polymerase, and drugs that directly inhibit this enzyme prevent viral RNA synthesis.

The drug that best fits this mechanism is sofosbuvir, a nucleotide analog prodrug that directly inhibits NS5B polymerase, effectively halting replication. Ribavirin, while used in hepatitis C therapy in the past, works differently: it reduces viral replication through mechanisms like depleting GTP pools and causing mutagenesis, rather than directly inhibiting the HCV polymerase. The other listed medications target viruses or enzymes unrelated to hepatitis C polymerase activity (for example, zidovudine targets HIV reverse transcriptase, oseltamivir targets influenza neuraminidase, and trifluridine is used topically for ocular herpes).

So, the concept being tested is direct inhibition of the hepatitis C RNA polymerase; the drug that demonstrates this mechanism is sofosbuvir.