Which of the following is a first-line hepatitis B antiviral agent?

• A. Pegylated interferon
• B. Entecavir
• C. Tenofovir
• D. Ribavirin

Answer: (C)

In chronic hepatitis B treatment, the goal is durable viral suppression with a medication that has a high barrier to resistance and good tolerability. Tenofovir fits that goal especially well. It is a nucleotide reverse transcriptase inhibitor that directly blocks HBV replication, achieving strong and sustained reductions in HBV DNA. Its resistance rate is very low, meaning the virus is unlikely to escape treatment over time, which is a major advantage for long-term therapy. It works across different disease states, including patients with high viral loads, cirrhosis, or coinfection with HIV, and it is convenient to dose (usually once daily), which helps with adherence.

In contrast, pegylated interferon is an immunomodulatory therapy given for a finite course and is limited by widespread side effects and contraindications, so it isn’t as broadly usable as a first-line option. Ribavirin has limited activity against HBV and is not used as monotherapy for chronic HBV. Entecavir is also a first-line option, but Tenofovir’s potent antiviral effect, low resistance, and broad applicability make it a particularly solid first-line choice in many patients.