Medications

All of the following medications described that are used to treat chronic hepatitis B are antiviral medications. They stop or slow replication of the virus in the body. This then gives the liver a chance to heal itself. Although these medications are similar in some ways, they differ in other important ways. Talk to your health care provider about the best medication for you.

Interferon alfa-2b (Intron A) - Interferon was the standard treatment of chronic hepatitis B for several years.

• It both slows the replication of the virus and boosts the body's immune system to fight the infection.
  
  
• This is the first choice of treatment for many people with HBV infection that is likely to progress, as indicated by lab test results.
  
  
• It works best in people who have relatively low levels of HBV DNA but liver function tests and liver biopsy show that the liver is affected.
  
  
• Interferon usually is not given to people whose liver damage has progressed to cirrhosis, because it can make the damage worse.
  
  
• Treatment is shorter than the other medications, but requires regular shots (injections) and is more expensive than the others. The older forms of interferon are given 3 or more times a week. Pegylated interferon A (PEG-Intron), a newer form of interferon, has been slightly altered to last longer in the body, so it can be given only once a week. 
  
  
• Interferon has unpleasant side effects in many people. Many describe the side effects as being like having the flu. For many people, the side effects are so severe that they cannot continue taking the medication.
  
  
• Liver function tests and HBV DNA tests are used to check how well the treatment is working.
  
  
• Interferon stops the infection in about 40% of people. In these people, the infection usually does not return.

Lamivudine (Epivir) - This medication is considered an alternative for people who cannot or do not want to take interferon. It also may be prescribed in people with weakened immune systems.

• Lamivudine slows replication of HBV.
  
  
• Lamivudine is taken as a pill and has almost no side effects. The side effects, when they do occur, are similar to those of interferon but are much milder.
  
  
• Liver function tests and HBV DNA tests are used to check how well the treatment is working.
  
  
• Lamivudine works better than interferon in people who already have severe liver damage (cirrhosis).
  
  
• Lamivudine reduces the amount of HBV in the blood in almost everyone who receives this treatment. In about 40 percent, the amount goes so low that the test cannot detect the virus.
  
  
• In about half of people who take lamivudine as recommended, liver inflammation goes away (on liver biopsy). In as many as two-thirds, liver function test results return to normal.
  
  
• In most people, however, the virus starts to multiply again as soon as the treatment is stopped. Sometimes during the treatment, the virus becomes genetically altered (mutated) and no longer responds as effectively as before to the medication.
  
  
• Ongoing research is looking at combining lamivudine with interferon or with other medications or vaccines to make it work better.

Adefovir dipivoxil (Hepsera) - This antiviral drug was approved by the FDA in 2002.

• Adefovir slows replication of HBV.
  
  
• It is a pill that must be taken every day, like lamivudine.
  
  
• It works well even in people whose disease is resistant to lamivudine.
  
  
• The virus begins to replicate again after stopping the treatment.
  
  
• Adefovir can damage the kidneys. This occurs mostly in people who already had some kidney problems.

Entecavir (Baraclude) - This antiviral is the newest medication approved for chronic hepatitis B.

• Entecavir slows replication of HBV.
  
  
• It is swallowed either as a tablet or an oral solution.
  
  
• Like adefovir, it can be prescribed for people who have become resistant to lamivudine.
  
  
• It must be continued long-term, otherwise the virus begins to replicate again.
  
  
• Dosage adjustment is required for individuals with kidney impairment.