Hepatitis B
Hepatitis is a general term that means inflammation of the liver. The liver
can become inflamed as a result of infection, a disorder of the immune system,
or exposure to alcohol, certain medications, toxins, or poisons. The most
common serious liver infection in the world, Hepatitis B is caused by infection
with the hepatitis B virus (HBV). This infection has 2 phases, acute and
chronic:
Acute (new, short-term) hepatitis B occurs shortly after exposure to the
virus. A small number of people develop a very severe, life-threatening
form of acute hepatitis called fulminant hepatitis.
Chronic (ongoing, long-term) hepatitis B is an infection with HBV that
lasts longer than 6 months. Once the infection becomes chronic, it may
never go away completely.
About 90-95 percent of people who are infected are able to fight off the virus so their infection never becomes chronic. Only about 5-10 percent of adults infected with HBV go on to develop chronic infection.
HBV infection is one of the most important causes of infectious hepatitis. People with chronic HBV infection are called chronic carriers. About two-thirds of these people do not get sick, but they can transmit it to other people. The remaining one third develop chronic hepatitis B, a disease of the liver that can be very serious.
Liver damage in chronic hepatitis B, if not stopped, continues until the liver becomes hardened with scar tissue. This is called cirrhosis, a condition traditionally associated with alcoholism. When this happens, the liver can no longer carry out its normal functions, a condition called liver failure. The only treatment for liver failure is liver transplant.
Chronic hepatitis B also can lead to a type of liver cancer known as hepatocellular carcinoma. Any of these conditions can be fatal. About 15-25 percent of people with chronic hepatitis B die of liver disease.
Once a person has developed chronic hepatitis B, few treatment options exist. In some cases--especially if one doesn't have signs and symptoms or liver damage--a doctor may suggest monitoring, rather than treating the condition. In other cases, the doctor may recommend treatment with antiviral medications. When liver damage is severe, liver transplantation may be the only option.
Doctors currently use five drugs to treat chronic HBV infection:
Interferon
The body naturally produces interferon to help protect against invading
organisms such as viruses. Taking additional interferon that has been
made in a laboratory may stimulate the body's immune response to HBV and
help prevent the virus from replicating in cells. Not everyone is a candidate
for treatment with interferon. In a few cases, interferon eliminates the
virus completely, although the infection can later return. Interferon
has a number of side effects-- many of which resemble signs and symptoms
of hepatitis B. These include depression, fatigue, muscle pains, body
aches, fever, and nausea. Signs and symptoms are usually worse during
the first two weeks of treatment and in the first four to six hours after
receiving an injection of interferon. A more serious side effect that
may occur over time is a decreased production of red blood cells. Two
interferon medications are available--interferon alfa-2b (Intron A) and
peginterferon alfa-2a (Pegasys). Intron A is given by injection several
times a week. Pegasys is given by injection once a week.
Telbivudine (Tyzeka)
This antiviral medication helps prevent HBV from replicating in the cells.
It is taken in pill form once a day and has almost no side effects for
up to a year. Studies show telbivudine is more effective than are other
common treatments such as lamivudine and adefovir dipivoxil. However,
one can experience a severe worsening of symptoms when s/he stops taking
the drug. Telbivudine can cause a drug-resistant form of HBV, particularly
when taken as a long-term treatment.
Entecavir (Baraclude)
This antiviral medication is taken once a day in pill form. Studies comparing
Baraclude with lamivudine found Baraclude to be more effective. Baraclude
may cause worsening of symptoms when the drug is stopped.
Lamivudine (Epivir-HBV)
This older antiviral medication is similar to telbivudine, though slightly
less strong. It is usually taken in pill form once a day. Side effects
during treatment are generally minimal, but one may experience a severe
worsening of symptoms when s/he stops taking the drug. Lamivudine can
also cause a drug-resistant form of HBV, particularly when taken as a
long-term treatment. Tell the doctor if there are kidney problems or a
history of pancreatitis before starting this medication. If one experiences
worsening jaundice or any unusual bruising, bleeding, or fatigue while
taking lamivudine, call a doctor right away.
Adefovir dipivoxil (Hepsera)
This drug, taken in pill form once daily, also helps prevent HBV from
replicating in the cells. An added benefit is that it is effective in
people who are resistant to lamivudine. Like lamivudine, side effects
during treatment usually are minimal, but symptoms may worsen when you
go off the medication. Hepsera may cause kidney problems.
When your liver has been severely damaged, a liver transplant may be an
option. The encouraging news is
transplants are increasingly successful. Unfortunately, not enough donor
organs are available for every person who needs a transplant.
