Entecavir is a guanosine nucleoside analogue that is phosphorylated intracellularly to its active triphosphate form, which competitively inhibits all three functional activities of HBV polymerase: base priming, reverse transcription of the negative strand, and synthesis of the positive strand of HBV DNA. Its active triphosphate has an intracellular half-life of 15 hours, enabling once-daily dosing. Entecavir retains activity against lamivudine-resistant HBV strains, though with reduced potency.
Chronic hepatitis B in patients with compensated liver disease (with evidence of viral replication, and histologically documented active liver inflammation or fibrosis) not previously treated with nucleoside analoguesChronic hepatitis B in patients with decompensated liver diseaseChronic HBV infection in adults and children 2 years or older with active viral replication and persistent elevations in serum aminotransferases or histologically active disease (first-line agent)Indefinite treatment for patients with cirrhosis
- Adult
- 500 micrograms once daily by mouth for chronic hepatitis B in patients with compensated liver disease (with evidence of viral replication, and histologically documented active liver inflammation or fibrosis) not previously treated with nucleoside analogues
- Pediatric
- Weight-based dosing up to 30 kg for children older than 2 years
- Renal adjustment
- Reduced for ClCr less than 50 mL/min (typically by extension of dosing interval)
Onset
Peak plasma concentration (CP) occurs in 0.5 to 1.5 h.
Half-life
128–149 h (terminal)
Protein binding
13% bound to serum proteins
- Lamivudine-resistant chronic hepatitis B (due to cross-resistance)
Common
HeadacheFatigueDizzinessNausea
Serious
- Severe acute exacerbations of HBV upon discontinuation
- Lactic acidosis
- Severe hepatomegaly with steatosis (especially in decompensated cirrhosis)
Nucleoside Reverse Transcriptase InhibitorsSevere
Textbook
Development of HIV resistance (M184V variant) if HIV is not fully suppressed.
Entecavir should only be used in combination with fully suppressive antiretroviral therapy in individuals with HIV/HBV coinfection.
Source: G&G 14e · p1231
11 additional low-confidence interactions hidden — those rows lack a documented mechanism or management plan in our sources.