Antiviral Therapy in Acute Hepatitis B
Antiviral therapy should be initiated in patients with severe acute hepatitis B characterized by coagulopathy (INR >1.5), severe jaundice (total bilirubin >3 mg/dL), or progression to liver failure (encephalopathy or ascites). 1
Indications for Antiviral Therapy
The decision to start antiviral therapy in acute hepatitis B depends on disease severity:
Severe Acute Hepatitis B (Requires Treatment)
- International normalized ratio (INR) >1.5
- Total bilirubin >3 mg/dL
- Presence of hepatic encephalopathy
- Development of ascites
- Protracted course with persistent symptoms
Mild to Moderate Acute Hepatitis B
- Generally does not require antiviral therapy
95% of immunocompetent adults with acute HBV infection clear the virus spontaneously
- Observation is appropriate for these patients
Treatment Considerations
Medication Selection
- Nucleos(t)ide analogues (NAs) with high genetic barriers to resistance are preferred:
- Entecavir
- Tenofovir disoproxil fumarate (TDF)
- Tenofovir alafenamide (TAF)
Timing of Treatment
- Immediate initiation of therapy is crucial in severe cases
- Early administration of potent antivirals may prevent progression to acute liver failure, reduce need for liver transplantation, and improve survival 1
Potential Benefits of Treatment
- Reduction in viral replication
- Improvement in biochemical parameters (coagulopathy, jaundice)
- Decreased mortality rate compared to placebo (7.5% vs. 25%) 1
Potential Concerns with Treatment
- Some studies suggest antiviral therapy may interfere with natural immune response
- May potentially reduce anti-HBs seroconversion rates
- Increased risk of progression to chronic hepatitis B in some studies (OR 1.99; 95% CI 1.05-3.77) 1
Special Considerations
Acute Liver Failure
- Patients developing acute liver failure should be considered for liver transplantation
- Continue antiviral therapy while awaiting transplantation
- Close monitoring in an intensive care setting is essential
Acute Exacerbation of Chronic HBV
- May present similarly to acute hepatitis B
- Requires careful evaluation for underlying chronic liver disease
- High HBV DNA levels (>2 × 10^4 IU/ml) suggest possible chronic infection 2
- Liver biopsy, endoscopy, and/or imaging may be needed to differentiate
Monitoring During Treatment
- Regular assessment of liver function tests
- Coagulation parameters
- HBV DNA levels
- Clinical signs of liver failure
Treatment Duration
- No clear consensus on optimal duration
- Continue treatment until HBsAg clearance or seroconversion
- In severe cases, treatment may need to be continued long-term, especially if there is evidence of progression to chronic infection
Prognosis
- Most patients with acute hepatitis B recover completely
- Mortality is significantly higher once hepatic encephalopathy develops 3
- Patients who survive severe acute exacerbation may recover to near-normal liver function, unlike those with end-stage cirrhosis 3
Remember that while most cases of acute hepatitis B resolve spontaneously, prompt recognition of severe cases requiring antiviral therapy is essential to prevent progression to liver failure and improve survival outcomes.