1. Introduction

Treatment of hepatitis B virus (HBV) infection aims to:

• suppress HBV replication

• prevent progression of liver fibrosis

• prevent cirrhosis

• prevent hepatic decompensation

• reduce hepatocellular carcinoma (HCC) risk

• reduce liver-related mortality

• prevent mother-to-child transmission where indicated

• control HBV-related extrahepatic disease

• achieve durable immune control

• ideally achieve HBsAg loss, the closest currently available endpoint to a functional cure

The central principle is:

2. Who Requires Treatment?

Not every person with chronic HBV infection requires immediate antiviral therapy.

Treatment decisions integrate:

1. HBV DNA

2. ALT

3. Liver fibrosis

4. Cirrhosis

5. HBeAg status

6. Age and duration of infection

7. Family history of HCC/cirrhosis

8. Coinfections

9. Extrahepatic manifestations

10. Pregnancy/MTCT considerations

11. Immunosuppression/reactivation risk

3. Major Treatment Categories

HBV treatment can broadly be divided into:

A. Nucleos(t)ide analogue therapy

and

B. Pegylated interferon therapy

The majority of patients requiring long-term antiviral suppression are treated with:

• tenofovir disoproxil fumarate (TDF)

• tenofovir alafenamide (TAF)

• entecavir

Pegylated interferon is used selectively.

4. Goals of Treatment

Short-term goal

Suppress HBV DNA.

↓

Reduce viral replication.

↓

Reduce hepatic inflammation.

Long-term goal

Prevent:

• fibrosis

• cirrhosis

• hepatic failure

• HCC

• liver-related death

Ideal virological goal

HBsAg loss

with or without:

anti-HBs development.

This is often referred to as:

Functional cure

5. Functional Cure

Functional cure generally means:

Sustained HBsAg loss

with:

undetectable serum HBV DNA

after completion or during treatment, depending on the definition used.

It does not necessarily mean complete eradication of HBV from the liver.

Why?

Because:

cccDNA

may persist in hepatocytes.

6. Treatment Does Not Usually Eradicate HBV

Current nucleos(t)ide analogues strongly suppress:

HBV DNA replication

but do not directly eliminate:

nuclear cccDNA.

Therefore:

7. First-Line Nucleos(t)ide Analogues

The principal high-barrier agents are:

Tenofovir disoproxil fumarate

TDF

Tenofovir alafenamide

TAF

Entecavir

ETV

These agents have:

• high antiviral potency

• high genetic barriers to resistance

• excellent long-term HBV DNA suppression

8. Tenofovir Disoproxil Fumarate

TDF

TDF is a nucleotide analogue of adenosine monophosphate.

It undergoes intracellular activation to:

tenofovir diphosphate

which inhibits HBV reverse transcription.

9. Mechanism of TDF

Simplified:

TDF
 ↓
Intracellular conversion
 ↓
Tenofovir diphosphate
 ↓
HBV polymerase/reverse transcriptase inhibition
 ↓
DNA chain termination
 ↓
↓ HBV replication

10. Advantages of TDF

• potent HBV suppression

• high genetic barrier

• excellent long-term efficacy

• effective against many resistant HBV variants

• extensive pregnancy experience

• generally accessible

• relatively inexpensive in many settings

11. Important TDF Adverse Effects

The major long-term concerns include:

Renal toxicity

and:

Reduction in bone mineral density

Potential effects include:

• proximal tubular dysfunction

• phosphate wasting

• decline in renal function

• osteopenia/osteoporosis in susceptible individuals

Therefore renal and bone risk should be considered when selecting therapy.

12. Tenofovir Alafenamide

TAF

TAF is a prodrug of tenofovir designed to deliver active drug more efficiently into hepatocytes.

It generally produces:

lower circulating tenofovir exposure

than TDF.

13. Advantages of TAF

TAF provides:

• potent HBV suppression

• high resistance barrier

• similar antiviral efficacy to TDF

• less renal toxicity in many patients

• less reduction in bone mineral density than TDF

14. Important Considerations With TAF

TAF may be preferred when there are:

• renal concerns

• bone disease

• increased risk of osteoporosis

However, TAF may be less suitable or restricted in some settings depending on:

• renal function

• age

• pregnancy

• availability

• cost

• local regulatory guidance

15. Entecavir

Entecavir is a:

guanosine nucleoside analogue.

It inhibits multiple steps of HBV polymerase function.

It has:

high genetic barrier

in treatment-naïve patients without pre-existing lamivudine resistance.

16. Entecavir Mechanism

Entecavir interferes with:

1. HBV polymerase priming

2. negative-strand DNA synthesis

3. positive-strand DNA synthesis

Result:

profound inhibition of HBV replication.

17. Important Limitation of Entecavir

Entecavir should not be considered equivalent to tenofovir in patients with:

previous lamivudine resistance.

Why?

Because lamivudine-associated resistance mutations can substantially lower the genetic barrier to entecavir resistance.

18. Entecavir and HIV

Before using entecavir in a patient with HIV infection:

HIV status should be known.

Entecavir has weak anti-HIV activity and should not be used as HBV monotherapy in untreated HIV/HBV coinfection.

HBV/HIV coinfection requires an appropriate fully suppressive antiretroviral regimen active against both viruses.

19. Older Antivirals

Historically used agents include:

• lamivudine

• adefovir

• telbivudine

They are generally not preferred as first-line monotherapy because of:

lower resistance barriers

and/or:

lower potency.

20. Why Lamivudine Is No Longer Preferred

Lamivudine is potent initially but has a:

low genetic barrier.

Resistance may develop through:

rtM204V/I

often with:

rtL180M.

Long-term monotherapy therefore has a high resistance rate.

21. Why Adefovir Is Less Favoured

Adefovir has:

• lower antiviral potency

• slower suppression

• resistance concerns

• renal toxicity concerns

Therefore newer high-barrier agents are generally preferred.

22. Why Telbivudine Is Less Favoured

Telbivudine has:

• relatively low resistance barrier

• resistance with prolonged therapy

• limited role compared with modern agents

It is therefore generally not a preferred first-line drug.

23. Pegylated Interferon

The main immune-modulating therapy used in selected HBV patients is:

Pegylated interferon alfa

usually:

Peg-IFN-α

It is fundamentally different from nucleos(t)ide analogues.

24. Mechanism of Interferon

Pegylated interferon acts through:

antiviral immune modulation

and:

direct antiviral effects.

It stimulates interferon-dependent pathways and enhances antiviral immune responses.

25. Advantages of Peg-IFN

Potential advantages:

• finite treatment duration

• possibility of durable off-treatment response

• higher probability of HBeAg seroconversion in selected patients

• possibility of HBsAg loss in selected patients

26. Disadvantages of Peg-IFN

Treatment is associated with significant adverse effects.

Common problems include:

• flu-like symptoms

• fatigue

• fever

• headache

• myalgia

• depression

• cytopenias

• thyroid dysfunction

Other serious adverse effects can occur.

27. Contraindications/Limitations of Peg-IFN

Peg-IFN is generally avoided or used with extreme caution in situations such as:

• decompensated cirrhosis

• uncontrolled psychiatric disease

• significant autoimmune disease

• severe cytopenias

• certain thyroid disorders

• pregnancy

Patient selection is therefore critical.

28. Nucleos(t)ide Analogues vs Peg-IFN

29. Treatment of Compensated Cirrhosis

Patients with:

compensated cirrhosis

and active HBV infection generally require antiviral suppression.

High-barrier nucleos(t)ide analogues are preferred.

The threshold for treatment is lower because cirrhosis substantially increases the risk of:

• decompensation

• HCC

• mortality

30. Decompensated Cirrhosis

Features include:

• ascites

• variceal bleeding

• hepatic encephalopathy

• jaundice

• impaired synthetic function

These patients require:

urgent specialist management.

Antiviral therapy is generally indicated irrespective of conventional HBV DNA/ALT treatment thresholds.

31. Why Treat Decompensated Cirrhosis?

Suppressing HBV can:

• reduce ongoing hepatic injury

• reduce further decompensation

• improve transplant-free survival

• stabilize liver disease in some patients

However:

32. HBV Treatment in Acute Hepatitis B

Most immunocompetent adults with uncomplicated acute hepatitis B:

do not require routine antiviral therapy.

Management is usually:

• supportive care

• hydration

• monitoring

• avoidance of hepatotoxic substances

• assessment of severity

33. When Treat Acute HBV

Antiviral therapy may be considered in:

• severe acute hepatitis

• protracted severe disease

• acute liver failure

• significant coagulopathy

• severe cholestasis in appropriate circumstances

Tenofovir or entecavir may be used depending on the clinical situation and specialist guidance.

34. Chronic Hepatitis B Treatment

The main candidates include patients with:

Significant hepatic inflammation

and/or:

significant fibrosis

particularly with:

HBV DNA elevation.

Treatment is also strongly indicated in:

cirrhosis with detectable HBV replication.

35. HBV DNA + ALT Concept

A simplified framework:

HBV DNA
   +
ALT
   +
Fibrosis
   ↓
Determine treatment need

No single value should be interpreted independently.

36. HBeAg-Positive Disease

Treatment may be indicated when there is evidence of:

• active hepatitis

• significant fibrosis

• cirrhosis

• persistent/high HBV replication with relevant clinical risk

Some younger patients with very high HBV DNA and persistently normal ALT may be monitored rather than immediately treated depending on guideline and individual risk.

37. HBeAg-Negative Disease

Treatment is particularly considered when:

HBV DNA is >2,000 IU/mL

and:

ALT is elevated

or:

significant fibrosis is present.

Again:

38. Significant Fibrosis Can Change the Decision

A patient may have:

HBV DNA relatively modest

but:

significant fibrosis.

Such a patient may benefit from antiviral therapy despite apparently low viral replication.

39. Treatment in HCC

Patients with chronic HBV and HCC generally require:

antiviral suppression

in addition to appropriate HCC-directed therapy.

HBV treatment helps:

• reduce ongoing HBV activity

• reduce hepatic complications

• decrease risk of HBV reactivation during cancer therapy

40. HBV/HIV Coinfection

Treatment must address:

both viruses.

The antiretroviral regimen should contain agents active against HBV, commonly:

• tenofovir + an appropriate partner drug

The exact regimen should follow current HIV treatment guidance.

41. HBV/HDV Coinfection

HDV significantly changes management.

HBV nucleos(t)ide analogues:

suppress HBV

but:

do not directly suppress HDV replication.

Patients with chronic hepatitis D require specialized assessment and HDV-directed management where available.

42. HBV/HCV Coinfection

Direct-acting antiviral treatment for HCV can cause:

HBV reactivation.

Therefore:

Patients with active HBV may require HBV antiviral therapy or close monitoring depending on their status.

43. HBV and Immunosuppression

Patients undergoing:

• chemotherapy

• transplantation

• biologic therapy

• high-dose corticosteroids

• hematological treatment

may develop:

HBV reactivation.

Preventive antiviral therapy is indicated for patients at sufficient risk according to:

• HBsAg

• anti-HBc

• treatment regimen

• degree of immunosuppression

44. HBV Treatment in Pregnancy

The goal is:

prevent mother-to-child transmission.

A pregnant person who is:

HBsAg positive

should undergo HBV assessment.

For those with high HBV DNA, maternal antiviral prophylaxis with:

TDF

is widely recommended during the appropriate gestational window according to current guidelines.

45. Why Tenofovir in Pregnancy?

TDF has:

• potent HBV suppression

• high genetic barrier

• extensive pregnancy safety experience

• strong evidence for reduction of MTCT

46. Neonatal Prevention

Maternal antiviral therapy is:

not a replacement

for neonatal immunoprophylaxis.

The newborn should receive appropriate:

hepatitis B vaccine

and:

HBIG when indicated

as soon as possible after birth according to national protocols.

47. Treatment Monitoring

For patients on nucleos(t)ide analogue therapy, monitor:

HBV DNA

ALT/AST

HBeAg/anti-HBe where relevant

HBsAg

renal function where appropriate

fibrosis/liver disease status

48. Renal Monitoring

Particularly important with:

TDF.

Assess:

• serum creatinine

• eGFR

• renal risk factors

• urine abnormalities where appropriate

Consider additional monitoring for:

proximal tubular dysfunction

in patients at risk.

49. Bone Monitoring

Bone health deserves particular attention in patients at increased risk receiving TDF.

Consider:

• osteoporosis risk

• vitamin D/calcium status where clinically appropriate

• fracture history

• bone mineral density testing when indicated

50. Monitoring TAF

TAF generally has:

lower renal and bone toxicity

than TDF.

Nevertheless, renal function should still be monitored according to patient characteristics and prescribing guidance.

51. Monitoring Entecavir

Entecavir is generally well tolerated.

Dose adjustment may be required with:

renal impairment.

Therefore renal function is relevant when selecting and dosing therapy.

52. Virological Response

The main virological endpoint is:

substantial HBV DNA suppression.

The ideal result is:

HBV DNA below the assay's quantification/detection threshold.

53. Biochemical Response

Successful treatment often results in:

ALT normalization.

However:

ALT can remain elevated because of:

• metabolic dysfunction-associated steatotic liver disease

• alcohol

• HCV

• HDV

• autoimmune hepatitis

• drug-induced injury

• other causes

Therefore:

54. HBeAg Seroconversion

In HBeAg-positive patients:

HBeAg loss

followed by:

anti-HBe development

is called:

HBeAg seroconversion.

It represents an important immunological response.

However:

55. HBsAg Loss

The most desirable treatment endpoint is:

HBsAg loss.

If accompanied by:

anti-HBs development

this represents a particularly favourable outcome.

But spontaneous or treatment-associated HBsAg loss remains relatively uncommon with current oral nucleos(t)ide analogues.

56. Treatment Failure

Possible reasons include:

Non-adherence

Drug resistance

Inadequate drug exposure

Incorrect diagnosis

Coinfection

Another liver disease

Advanced liver disease

Laboratory variation

57. Approach to Apparent Treatment Failure

HBV DNA not suppressed/rises
          ↓
Confirm result
          ↓
Check adherence
          ↓
Review medication
          ↓
Review previous antivirals
          ↓
Check renal function/drug exposure
          ↓
Assess resistance if appropriate
          ↓
Check HDV/HCV/HIV and other liver diseases
          ↓
Modify treatment if required

58. Treatment Discontinuation

One of the most important principles:

Stopping nucleos(t)ide analogue therapy can cause:

HBV rebound

followed by:

ALT flare

and potentially:

severe hepatitis or hepatic decompensation.

This is particularly dangerous in patients with cirrhosis.

59. Who May Stop Therapy?

Selected non-cirrhotic patients may be considered for finite therapy under specific guideline criteria.

Decision depends on:

• HBeAg status

• duration of viral suppression

• HBeAg seroconversion

• HBsAg level

• fibrosis

• relapse risk

• ability to monitor closely

Therefore:

60. Treatment in Cirrhosis

In patients with cirrhosis:

antiviral therapy is generally long-term.

Stopping treatment can precipitate:

severe HBV flare

and:

hepatic decompensation.

61. Resistance and Choice of Therapy

Previous treatment history is essential.

Prior lamivudine resistance

Avoid relying on entecavir monotherapy.

Tenofovir resistance

Clinically confirmed resistance is exceptionally uncommon.

Treatment selection should be individualized using current guidance.

62. Adherence

Adherence is critical.

Patients should understand:

• why treatment is necessary

• expected duration

• importance of daily dosing

• risks of stopping

• monitoring requirements

Poor adherence may mimic:

antiviral resistance.

63. HBV Treatment and HCC Surveillance

Antiviral therapy:

reduces

but does not eliminate:

HCC risk.

Therefore patients who meet criteria for HCC surveillance should:

continue surveillance even when HBV DNA is undetectable.

64. Treatment Does Not Eliminate HCC Risk

A patient may have:

undetectable HBV DNA

but still develop:

HCC.

Reasons include:

• previous fibrosis

• cirrhosis

• long-standing HBV infection

• viral integration

• age

• family history

• metabolic risk

• other cofactors

65. Practical First-Line Selection

TDF

Consider when:

• cost/access is important

• pregnancy is relevant

• excellent antiviral potency is desired

• renal/bone risk is acceptable

TAF

Consider when:

• renal/bone toxicity is a concern

• available and appropriate

Entecavir

Consider when:

• no prior lamivudine resistance

• tenofovir is unsuitable

• renal considerations favour another option

The final choice should follow current guidelines and patient-specific factors.

66. Simple Treatment Algorithm

Chronic HBV
     ↓
Assess HBV DNA
     +
ALT
     +
Fibrosis
     ↓
Cirrhosis?
   ↙      ↘
 YES       NO
  ↓         ↓
Treat    Assess treatment
         criteria
             ↓
       Significant fibrosis/
       active hepatitis/
       other indication?
          ↙       ↘
        YES        NO
         ↓          ↓
       Treat      Monitor
         ↓
TDF / TAF / Entecavir
         ↓
Serial HBV DNA + ALT
         ↓
Long-term monitoring

67. Special Groups

Children

Treatment decisions depend on:

• age

• HBV DNA

• ALT

• fibrosis

• disease phase

• guideline-specific criteria

Older adults

Consider:

• renal function

• osteoporosis

• polypharmacy

• comorbidities

Cirrhosis

Lower threshold for treatment.

Pregnancy

TDF is widely used when maternal antiviral prophylaxis is indicated.

HIV coinfection

Use a fully suppressive ART regimen active against HBV.

HDV coinfection

Requires specific HDV evaluation and management.

Immunosuppression

Assess reactivation risk and use prophylaxis when indicated.

68. Treatment and Extrahepatic Manifestations

HBV can cause extrahepatic disease including:

• polyarteritis nodosa

• glomerulonephritis

• cryoglobulinemic manifestations

• dermatological manifestations

Significant HBV-associated extrahepatic disease can be an indication for antiviral therapy.

69. Treatment of HBV-Related PAN

In HBV-associated polyarteritis nodosa:

• antiviral therapy is important

• specialist management is required

• immunological therapy may be used depending on severity

The approach differs from treatment of idiopathic PAN.

70. HBV Treatment and Alcohol

Patients with chronic HBV should be advised to:

minimize or avoid alcohol

because alcohol can accelerate liver injury and increase the risk of cirrhosis/HCC.

71. Metabolic Risk Factors

Management should also address:

• obesity

• diabetes

• dyslipidemia

• metabolic dysfunction-associated steatotic liver disease

Because HBV may coexist with other causes of liver injury.

72. Patient Education

Explain:

HBV is controllable but often not immediately curable.

Antiviral therapy may be long-term.

Missing doses can allow viral rebound.

Treatment does not eliminate transmission risk immediately.

Family/sexual contacts should be appropriately tested and vaccinated.

HCC surveillance may still be required.

73. High-Yield Exam Pearls

Pearl 1

Preferred high-barrier oral agents:

TDF, TAF, entecavir.

Pearl 2

TDF is a nucleotide analogue.

Pearl 3

Entecavir is a guanosine nucleoside analogue.

Pearl 4

TDF has extensive pregnancy experience.

Pearl 5

TAF generally has better renal/bone safety than TDF.

Pearl 6

Lamivudine has a low genetic barrier.

Pearl 7

Previous lamivudine resistance is important when considering entecavir.

Pearl 8

HBsAg loss is the ideal treatment endpoint.

Pearl 9

HBV DNA suppression does not equal eradication.

Pearl 10

Cirrhosis generally requires antiviral therapy when HBV is active.

Pearl 11

Stopping therapy can cause severe HBV flares.

Pearl 12

Antiviral therapy reduces but does not eliminate HCC risk.

Pearl 13

HBV/HIV coinfection requires an HBV-active ART regimen.

Pearl 14

HBV reactivation is an important complication of immunosuppression.

Pearl 15

Maternal TDF can reduce MTCT when used in appropriately selected pregnant patients.

74. One-Minute Revision

HBV Treatment

Main goals

Suppress HBV DNA

↓

Prevent fibrosis/cirrhosis

↓

Prevent decompensation

↓

Reduce HCC risk

↓

Achieve HBsAg loss

Preferred oral agents

TDF

TAF

Entecavir

TDF

High potency.

High resistance barrier.

Extensive pregnancy experience.

Main concerns:

renal + bone toxicity

TAF

High potency.

High resistance barrier.

Generally improved renal/bone safety compared with TDF.

Entecavir

High resistance barrier in treatment-naïve patients.

Avoid relying on it when there is established lamivudine resistance.

Peg-IFN

Finite treatment.

Potential for durable response.

More adverse effects.

Careful patient selection.

Most important monitoring

HBV DNA + ALT + liver fibrosis

Best virological endpoint

HBsAg loss

Critical warning

Do not abruptly stop long-term HBV therapy.

75. Final Take-Home Message

Modern HBV treatment has shifted from simply treating hepatitis to:

The therapeutic backbone is:

TDF / TAF / Entecavir

with treatment selection based on:

HBV DNA + ALT + fibrosis + cirrhosis + previous antiviral exposure + renal/bone status + pregnancy + coinfections + patient-specific factors.

The most important conceptual distinction is:

And the most important safety principle is:

76. Standard References

1. World Health Organization. Guidelines for the prevention, diagnosis, care and treatment for people with chronic hepatitis B infection. Geneva: WHO; 2024.

2. European Association for the Study of the Liver. EASL Clinical Practice Guidelines on the management of hepatitis B virus infection. J Hepatol. 2025.

3. AASLD/IDSA. Current clinical guidance for hepatitis B.

4. Terrault NA, et al. Update on prevention, diagnosis, and treatment of chronic hepatitis B. Hepatology.

5. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases.

6. Fields Virology. Hepatitis B virus.

7. Jawetz, Melnick & Adelberg's Medical Microbiology.

8. Murray, Rosenthal & Pfaller. Medical Microbiology.

9. Sherris Medical Microbiology.

10. WHO guidance on prevention of mother-to-child transmission of hepatitis B.

11. Current product prescribing information for tenofovir DF, tenofovir alafenamide, entecavir and pegylated interferon.

12. Major randomized trials and long-term cohort studies evaluating nucleos(t)ide analogue therapy in chronic HBV.