Treatment for hepatitis B
Treatment for hepatitis B is used to manage the effects of the infection but is not a cure. In general, people who are chronically infected but do not have any signs of current liver damage will not need treatment. However, it is important to closely monitor liver health with regular (6 monthly) liver function tests. When a person has signs of liver damage they should consider having treatment for hepatitis B. The decision on when to start treatment is complex and should be made in consultation with your doctor or a gastroenterologist with an interest in hepatitis B.
The Australian Government through the Pharmaceutical Benefits Scheme (PBS) funds several different medications to treat chronic hepatitis B. The most common are anti-viral medications taken as tablets each day for a year or longer:
Entevavir has potent activity against chronic hepatitis B. There are almost no side effects except for the possibility of developing virus mutations and antiviral drug resistance.
Tenofovir has potent activity against chronic hepatitis B. It is particularly useful in patients who have developed drug resistance to other medications.
There are almost no side effects to Lamivudine, however a significant concern is the possible development of hepatitis B virus mutations and antiviral drug resistance after long term use.
In Australia, Adefovir is only funded for people who have developed a hepatitis B virus mutation after taking Lamivudine. There are almost no side effects except for the possibility of developing virus mutations and antiviral drug resistance.
A less common form of treatment is with interferon.
Pegylated Interferon (Pegasys®)Is given by injection once a week, usually for 6 months to a year. The drug has many potential side effects, such as flu symptoms and depression, but can control the virus in a third of patients without need for long term medication
Hepatitis B treatment is suitable for people who are classified as being in a particular stage of hepatitis B infection, which is characterised by:
- increased virus activity and liver inflammation demonstrated by elevated liver enzymes (ALT)
- inflammation and activity in the liver as seen in the results of a liver biopsy
- high levels of hepatitis B virus (HBV DNA) in the blood.
Access to treatment is dependent on a person meeting these criteria.
Treatment aims are to stop the hepatitis B virus from multiplying, or to reduce the rate of multiplication as much as possible. This decreases the risk of serious liver disease developing later in life and makes it possible for the liver to repair some of the damage and to work better. (Keefe, E.C et.al; 2004) However, it is very rare that any of these medications will cure hepatitis B infection.
The main side effect of the antiviral tablets (Lamivudine, Adefovir and Entecavir) is sometimes the hepatitis B virus mutates (changes) during the course of treatment, which means the antiviral tablets are not as effective against the new form of the virus. This is called antiviral resistance.
During treatment, the patient’s blood tests are monitored very carefully to look for signs of antiviral resistance. If there are signs of resistance such as elevated liver enzymes and high levels of hepatitis B virus in the blood, the antiviral tablets will be changed.
Keefe, E.C., Dieterich, D., Han, S-H. et al. (2004). 'A treatment algorithm for the management of chronic hepatitis B virus infection in the United States'. Clinical Gastroenterology and Hepatology. 2, pp.87–106.