抗病毒藥品 Chronic hepatitis B

Antihepadnaviral, Nucleoside Reverse Transcriptase Inhibitor (Anti-HBV)
Entecavir is intracellularly phosphorylated to guanosine triphosphate which competes with natural substrates to effectively inhibit hepatitis B viral polymerase; enzyme inhibition blocks reverse transcriptase activity thereby reducing viral DNA synthesis.

Bioavailability: 100%
Vd: extensive tissue distribution
Metabolism: (Hepatic) minimal
Excretion: (Renal) 62% to 73% unchanged
Dialyzable: (hemodialysis) 13%; (peritoneal dialysis) 0.3%
Elimination Half Life: 128 to 149 hours

Hypersensitivity to entecavir or any component of the formulation

Information related to use in pregnancy is limited. Other agents may be preferred for the treatment of chronic hepatitis B in pregnancy.

Infant risk cannot be ruled out

Common: Nausea, Dizziness, Headache, Fatigue
Serious: Lactic acidosis, Severe Hepatomegaly, With steatosis, Recurrent hepatitis

Nucleoside inhibitor treatment-naive:
0.5 mg orally once daily
Decompensated liver disease, History of hepatitis B viremia:
1 mg orally once daily

1. CrCl ≥50 mL/minute: No dosage adjustment necessary.
2. CrCl 30 to <50 mL/minute: Administer 50% of usual indication-specific dose daily OR Administer usual dose every 48 hours
3. CrCl 10 to <30 mL/minute: Administer 30% of usual indication-specific dose daily OR Administer usual dose every 72 hours
4. CrCl <10 mL/minute: Administer 10% of usual indication-specific dose daily OR Administer usual dose every 7 days
5. Hemodialysis, Peritoneal dialysis: Not significantly dialyzed; Administer 10% of usual indication-specific dose daily
6. CRRT, PIRRT: Drug clearance is dependent on the effluent flow rate, filter type, and method of renal replacement.

No dosage adjustment necessary.