Hepatitis B medical therapy
Hepatitis B |
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Chetan Lokhande, M.B.B.S [2]; João André Alves Silva, M.D. [3]
Overview
The hepatitis B infection does not usually require treatment because most adults clear the infection spontaneously. Early antiviral treatment may be required in fewer than 1% of people, whose infection takes a very aggressive course (fulminant hepatitis) or who are immunocompromised. On the other hand, treatment of chronic infection may be necessary to reduce the risk of cirrhosis and liver cancer. Chronically infected individuals with persistently elevated serum alanine aminotransferase, a marker of liver damage, and HBV DNA levels are candidates for therapy. Treatment lasts from six months to a year, depending on medication and genotype.
Although none of the available drugs can clear the infection, they can stop the virus from replicating, thus minimizing liver damage. As of 2008, there are seven medications licensed for treatment of hepatitis B infection in the United States. These include antiviral drugs lamivudine (Epivir), adefovir (Hepsera), tenofovir (Viread), telbivudine (Tyzeka) and entecavir (Baraclude), and the two immune system modulators interferon alpha-2a and Pegylated interferon-alpha-2a (Pegasys). The use of interferon, which requires injections daily or thrice weekly, has been supplanted by long-acting PEGylated interferon, which is injected only once weekly. However, some individuals are much more likely to respond than others, and this might be because of the genotype of the infecting virus or the person's heredity. The treatment reduces viral replication in the liver, thereby reducing the viral load (the amount of virus particles as measured in the blood). Response to treatment differs between the genotypes. Interferon treatment may produce an e antigen seroconversion rate of 37% in genotype A but only a 6% seroconversion in type D. Genotype B has similar seroconversion rates to type A while type C seroconverts only in 15% of cases. Sustained e antigen loss after treatment is ~45% in types A and B but only 25–30% in types C and D.
Medical Therapy
After infection with the hepatitis B virus, up to 95% of adults are able to eliminate the virus without treatment. Currently, there is no treatment available for acute hepatitis B. Symptomatic treatment of nausea, anorexia, vomiting, and other symptoms may be indicated.
Early antiviral treatment may only be required in fewer than 1% of patients, whose hepatitis B takes a very aggressive course, such as in cases of fulminant hepatitis.
In general, each treatment works by reducing the viral load by several orders of magnitude. In some patients, chronic hepatitis B takes a mild course and does not require immediate treatment. Treatment strategies should be individualized. Considerations include:
- Person's risk for developing complications of persistent infection
- Person's likelihood of adhering and responding to treatment
- Risks of side effects or development of viral resistance
Acute Hepatitis B
- There is no effective treatment for acute hepatitis B. Children are often treated with supportive care alone.
- Nucleoside/nucleotide analog treatment may be considered in severe cases of acute hepatitis, despite trials in adults have not shown benefit.
- Liver transplant may be required for cases of fulminant hepatitis
- Unlike chronic hepatitis, liver transplant in cases of acute hepatitis have a low risk of reinfection.[1][2][3][4]
Chronic Hepatitis B
Treatment of chronic hepatitis B aims to halt the progression of liver disease, eliminate infectivity, and prevent the development of HCC. Virological changes are usually accompanied by normalization of ALT activity, resolution of hepatic inflammation and improvement of the patients’ symptoms.
Two treatment classes are available for chronic hepatitis B: antivirals: aimed at suppressing or destroying HBV by interfering with viral replication; immune modulators: aimed at helping the human immune system to mount a defense against the virus. There are currently several treatments for chronic hepatitis B. While none of the available drugs usually clears the infection, they can stop the virus from replicating, and prevent liver damage such as cirrhosis and/or liver cancer.
Chronic carriers are encouraged to avoid consuming alcohol as it increases their risk for cirrhosis and hepatocellular carcinoma.
Infants born to mothers known to carry hepatitis B can be treated with antibodies to the hepatitis B virus (hepatitis B immune globulin or HBIg). When given with the vaccine within twelve hours of birth, the risk of acquiring hepatitis B is reduced 95%. This treatment also allows a mother to safely breastfeed her child.
An individual exposed to the virus who has never been vaccinated may be treated with HBIg immediately following the exposure. For instance, a health care worker accidentally stuck by a needle used in a hepatitis B carrier would qualify. Treatment must be soon after exposure, however.
Treatments are available in the form of antiviral drugs, such as lamivudine, adefovir, entecavir or telbivudine, and immune system modulators such as interferon alpha (Uniferon) or peg-interferon alpha (PEGASYS). There are several other antivirals under investigation. However, some individuals are much more likely to respond than others.
It does not appear that combination therapy offers any advantages.[5] However, it may help in patients with resistant viruses, or in advanced stages of liver disease.
Goal of therapy
- Eradicate the virus from the body
- Prevent progression of end stage liver disease (ESLD)
- Prevent progression to hepatocellular carcinoma (HCC)
- Clear off HBV DNA
- HBeAg and HBsAg negative
- Normal ALT / AST
- Normal histology
Indications to start antiviral medications
- Following are the curent indications to start treatment for chronic hepatits B:[6]
- Chronic hepatitis B ( HbeAg postive and negative ) with HBV DNA >2000 IU/ml and/or
- Elevated ALT and
- Severe necrosis and fibrosis on biopsy
- Decompensated or compensated cirrhosis with normal ALT or HBV DNA <2000 IU/ml
- Treatment should be continued for at least 6 months after HBeAg loss / conversion.
Antiviral Medications
There are three types of treatment groups:
Drug | Description |
---|---|
Entecavir |
|
Tenofovir |
|
Interferons |
|
Drug | Description |
---|---|
Telbivudine |
|
Adefovir |
|
Lamivudine |
|
Recommended Treatment
HBeAg | ALT | HBV DNA | Treatment Regimen |
---|---|---|---|
+ | ≤2 x Upper Limit of Normal | >20,000 IU/mL |
|
+ | >2 x Upper Limit of Normal | >20,000 IU/mL |
|
- | >2 x Upper Limit of Normal | >20,000 IU/mL† |
|
- | [1; >2] x Upper Limit of Normal | >2,000 IU/mL |
|
- | ≤ Upper Limit of Normal | ≤2,000 IU/mL |
|
+/- | Cirrhosis | Traceable |
|
+/- | Cirrhosis | Untraceable |
|
Management of Drug Resistance
Prevention
To prevent HBV infection antiviral drug-resistance, the following measures should be observed:
- Avoidance of unnecessary treatment
- Treatment should be initiated with a low resistance drug, or with combination therapy
- Alternative treatment should be initiated if patients fail to respond
Monitoring
During treatment the following should be monitored:
- Serum HBV DNA during course of treatment, every 3 to 6 months
- Treatment compliance
Treatment
Recommendations on Whom to Treat and with What Antiviral Agent: AASLD Practice Guidelines 2009[10]
“ |
1. Patients with HBeAg-positive chronic hepatitis B
2. Patients with HBeAg-negative chronic hepatitis B (serum HBV DNA >20,000 IU/mL and elevated ALT >2 times normal) should be considered for treatment. (Grade I)
3. Patients who failed to respond to prior IFN-α (standard or pegylated) therapy may be retreated with nucleoside analogues (NA) if they fulfill the criteria listed above. (Grade I) 4. Patients who failed to achieve primary response as evidenced by <2 log decrease in serum HBV DNA level after at least 6 months of NA therapy should be switched to an alternative treatment or receive additional treatment. (Grade III) 5. Patients who develop breakthrough infection while receiving NA therapy
6. Treatment of patients with lamivudine (or telbivudine)-resistant HBV
should be stopped as continued presence of lamivudine- (or telbivudine-) resistant mutations will increase the risk of entecavir resistance. (Grade II-3 for lamivudine-resistant HBV and Grade III for telbivudine-resistant HBV). Entecavir is not an optimal therapy because of increasing risk of resistance to entecavir over time. (Grade II-2) 7. Treatment of patients with adefovir-resistant HBV
8. Treatment of patients with entecavir-resistant HBV
9. Patients with compensated cirrhosis — Treatment should be considered for patients with ALT >2 times normal, and for patients with normal or minimally elevated ALT if serum HBV DNA levels are high (>2,000 IU/mL). (Grade II-2)
10. Patients with decompensated cirrhosis — Treatment should be promptly initiated with a NA that can produce rapid viral suppression with low risk of drug resistance. (Grade II-1)
11. In patients with inactive HBsAg carrier state antiviral treatment is not indicated, but these patients should be monitored. |
” |
Recommendations for Dose Regimens: AASLD Practice Guidelines 2009[10]
“ |
1. IFN-α and pegIFN-α are administered as subcutaneous injections.
2. Lamivudine is administered orally.
3. Adefovir is administered orally.
4. Entecavir is administered orally.
5. Telbivudine is administered orally.
6. Tenofovir is administered orally.
7. Duration of nucleoside analogue treatment
|
” |
Recommendations for Initial Evaluation of Persons with Chronic HBV Infection: AASLD Practice Guidelines 2009[10]
“ |
1. Initial evaluation of persons newly diagnosed with chronic HBV infection should include history, physical examination and laboratory testing. (Grade III) 2. All persons with chronic hepatitis B not immune to hepatitis A should receive 2 doses of hepatitis A vaccine 6 to 18 months apart. (Grade II-3) |
” |
Recommendations for Treatment of Patients with Acute Symptomatic Hepatitis B: AASLD Practice Guidelines 2009[10]
“ |
1. Treatment is only indicated for patients with fulminant hepatitis B and those with protracted, severe acute hepatitis B. (Grade III) 2. Lamivudine or telbivudine may be used when the anticipated duration of treatment is short; otherwise, entecavir is preferred. (Grade II-3)
|
” |
References
- ↑ Vargas HE, Dodson FS, Rakela J (2002). "A concise update on the status of liver transplantation for hepatitis B virus: the challenges in 2002". Liver Transpl. 8 (1): 2–9. doi:10.1053/jlts.2002.29765. PMID 11799479.
- ↑ Omata M (1990). "Significance of extrahepatic replication of hepatitis B virus". Hepatology. 12 (2): 364–6. PMID 2202639.
- ↑ McGory RW, Ishitani MB, Oliveira WM, Stevenson WC, McCullough CS, Dickson RC; et al. (1996). "Improved outcome of orthotopic liver transplantation for chronic hepatitis B cirrhosis with aggressive passive immunization". Transplantation. 61 (9): 1358–64. PMID 8629297.
- ↑ Marzano A, Gaia S, Ghisetti V, Carenzi S, Premoli A, Debernardi-Venon W; et al. (2005). "Viral load at the time of liver transplantation and risk of hepatitis B virus recurrence". Liver Transpl. 11 (4): 402–9. doi:10.1002/lt.20402. PMID 15776431.
- ↑ Lau GKK; et al. (2005). "Peginterferon Alfa-2a, lamivudine, and the combination for HBeAg-positive chronic hepatitis B". N Engl J Med. 352 (26): 2682–95. PMID 15987917.
- ↑ "http://www.easl.eu/assets/application/files/ef520780b91cf4f_file.pdf" (PDF). External link in
|title=
(help) - ↑ 7.0 7.1 "Chronic Hepatitis B: Integrating Long-Term Treatment Data and Strategies to Improve Outcomes in Clinical Practice".
- ↑ Lai, CL.; Shouval, D.; Lok, AS.; Chang, TT.; Cheinquer, H.; Goodman, Z.; DeHertogh, D.; Wilber, R.; Zink, RC. (2006). "Entecavir versus lamivudine for patients with HBeAg-negative chronic hepatitis B.". N Engl J Med. 354 (10): 1011–20. doi:10.1056/NEJMoa051287. PMID 16525138. Unknown parameter
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ignored (help) - ↑ "http://jid.oxfordjournals.org/content/204/3/415.full". External link in
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(help) - ↑ 10.0 10.1 10.2 10.3 Lok AS, McMahon BJ (2004). "[AASLD Practice Guidelines. Chronic hepatitis B: update of therapeutic guidelines]" (PDF). Romanian Journal of Gastroenterology. 13 (2): 150–4. PMID 15229781. Retrieved 2012-02-10. Unknown parameter
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