## First-Line Antiviral Therapy for Chronic Hepatitis B **Key Point:** Tenofovir (TDF or TAF) and entecavir are the preferred first-line nucleos(t)ide analogues for chronic HBV because they have high genetic barrier to resistance, potent viral suppression, and favorable safety profiles. **High-Yield:** Lamivudine monotherapy is NO LONGER recommended as first-line due to high rates of resistance (70% at 5 years). It is reserved for special populations (pregnancy, renal impairment) or as part of combination therapy. ## Comparison of Antiviral Agents for Chronic HBV | Agent | Genetic Barrier | Resistance at 5 yr | Renal Safety | First-Line? | |-------|-----------------|-------------------|--------------|-------------| | **Tenofovir (TDF/TAF)** | **High** | **<1–2%** | **Monitor (TDF)** | **YES** | | **Entecavir** | **High** | **<1%** | **Safe** | **YES** | | Lamivudine | Low | ~70% | Safe | NO (monotherapy) | | Adefovir | Intermediate | ~30% | Nephrotoxic | NO | | Interferon-α | N/A (immunomodulator) | N/A | Variable | Limited use | **Clinical Pearl:** Tenofovir alafenamide (TAF) is preferred over TDF in patients with renal impairment or low bone mineral density because it achieves higher intracellular concentrations with lower systemic exposure, reducing nephrotoxicity and bone loss. **Mnemonic: TREAT** — **T**enofovir, **R**esistance-low agents, **E**ntecavir, **A**void lamivudine monotherapy, **T**herapy individualized ## Indications for Antiviral Therapy in This Patient 1. HBeAg-positive chronic HBV 2. HBV DNA ≥2 × 10^5 IU/mL (meets threshold) 3. ALT ≥2× ULN (meets threshold) 4. No cirrhosis (but treatment still indicated) **Tip:** In exam questions, if you see "chronic HBV + HBeAg+ + high HBV DNA + elevated ALT," think **tenofovir or entecavir** first. Lamivudine is a trap answer. [cite:Harrison 21e Ch 297; AASLD/IDSA HBV Guidance 2018]
Sign up free to access AI-powered MCQ practice with detailed explanations and adaptive learning.