Hepatitis B Management
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Direct answer
Tenofovir disoproxil fumarate 300 mg once daily is the first-line antiviral for chronic hepatitis B — potent, high-barrier, safe in pregnancy — with entecavir 0.5 mg daily as the alternative, while lamivudine is relegated by resistance. Treatment is not for every carrier: immune-active disease, meaning alanine aminotransferase more than twice the upper limit plus HBV DNA above 20,000 IU/mL in HBeAg-positive disease (above 2,000 IU/mL when HBeAg-negative), cirrhosis with any detectable DNA, or extrahepatic manifestations earns therapy; inactive carriers are monitored. India carries an estimated 40 million infected people, and prevention is programme-driven: hepatitis B birth-dose vaccine in the universal immunisation schedule, HBIG plus vaccine within 12 hours to infants of HBsAg-positive mothers, and tenofovir in late pregnancy to cut vertical transmission.
What you must remember
- Phase thinking: immune-tolerant (high DNA, normal ALT, young) — monitor; immune-active (high DNA, raised ALT) — treat; inactive carrier (low or undetectable DNA, normal ALT) — monitor annually; reactivation can flip phases.
- Treatment thresholds: ALT >2× upper normal limit AND HBV DNA >20,000 IU/mL (HBeAg-positive) or >2,000 IU/mL (HBeAg-negative); treat all cirrhotics with detectable DNA regardless of ALT.
- Drugs: tenofovir disoproxil 300 mg od (monitor renal function and bone density), entecavir 0.5 mg od (1 mg if lamivudine-experienced); pegylated interferon is a finite-course option for selected young HBeAg-positive patients.
- Monitoring: HBV DNA and ALT every 3-6 months on treatment; HBeAg seroconversion (loss of HBeAg, anti-HBe appearance) is a milestone but rarely a stopping point in Indian practice.
- Serology map: HBsAg — current infection; anti-HBs ≥10 mIU/mL — immunity; IgM anti-HBc — acute infection; anti-HBc IgG with negative HBsAg and positive anti-HBs — past infection cleared.
- Prevention protocol: infant of an HBsAg-positive mother gets HBIG 0.5 mL plus the first vaccine dose within 12 hours of birth, completing the schedule; WHO additionally advises maternal tenfovir from around 28 weeks when DNA is high.
- Programme anchors: the National Viral Hepatitis Control Programme since 2018 offers free testing and treatment including tenofovir at district level, and blood-bank screening for HBsAg is universal under national blood-transfusion standards.
- Complication surveillance: every chronic patient deserves six-monthly ultrasound with or without alpha-fetoprotein for hepatocellular carcinoma, the commonest cancer outcome in Indian cirrhotics.
How to work through a chronic HBV case
A 26-year-old woman, HBsAg-positive since an antenatal screen, arrives with HBV DNA of 10 to the eighth IU/mL, ALT of 45 (upper limit 40) and HBeAg positivity. For now she is close to immune-tolerant: DNA high but ALT normal-ish, and treatment is not yet indicated — she is monitored every six months rather than medicated. Two years later her ALT rises to 160 with the same viral load: immune-active disease has declared itself, and tenofovir 300 mg once daily begins, with renal function checked at baseline and periodically.
The goals are honest ones: suppress DNA to undetectable, normalise ALT, push HBeAg seroconversion — functional cure (HBsAg loss) is uncommon and not promised. When she becomes pregnant, tenofovir continues safely or is started from the third trimester if her DNA exceeds about 2 lakh IU/mL; her newborn receives HBIG plus vaccine within 12 hours. Her brother, screened because of family contact, is an inactive carrier — normal ALT, DNA under 2,000 — so he gets annual review, not drugs, plus a clear warning that reactivation (chemotherapy, steroids, anti-TNF therapy later in life) will need prophylactic tenofovir.
How the FMGE frames it
NBE tests the serology table harder than the antiviral choice: expect a panel — HBsAg positive, IgM anti-HBc positive means acute infection, while IgG anti-HBc with anti-HBs means resolved past infection, and isolated anti-HBc invites the window-period question. The second favourite is the treat-or-monitor decision, built exactly on the ALT and DNA thresholds above, with the immune-tolerant young patient offered as the trap for candidates who treat numbers rather than phases. Vertical transmission questions recur in the paediatric-adjacent stems — the 12-hour HBIG-plus-vaccine window is a classic one-liner. Finally, know which drug is safe in pregnancy (tenofovir) and which is compromised by resistance (lamivudine), and remember the free-treatment hook under the National Viral Hepatitis Control Programme that Indian-option MCQs have begun citing.
Frequently asked questions
When should a chronic hepatitis B patient start treatment?
Immune-active disease — ALT above twice normal with HBV DNA over 20,000 IU/mL (HBeAg-positive) or 2,000 IU/mL (HBeAg-negative) — plus any cirrhosis with detectable DNA or extrahepatic disease.
What is the first-line antiviral and its dose?
Tenofovir disoproxil fumarate 300 mg once daily, chosen for potency, a high resistance barrier and safety in pregnancy.
Which serology pattern indicates acute infection?
HBsAg positive with IgM anti-HBc positive; IgG anti-HBc with anti-HBs and absent HBsAg indicates resolved past infection.
How is vertical transmission prevented in an HBsAg-positive mother?
Tenofovir from about 28 weeks when viral load is high, then HBIG plus the first vaccine dose to the newborn within 12 hours of birth, completing the schedule.
What cancer surveillance does a chronic carrier need?
Abdominal ultrasound with or without serum alpha-fetoprotein every six months for hepatocellular carcinoma, beginning earlier if cirrhosis develops.