Long-Term Lamivudine Therapy for Chronic Hepatitis B

This study will evaluate the long-term safety and effectiveness of lamivudine therapy and the possibility of stopping therapy in patients whose hepatitis B is chronic, that is, long lasting, and which has responded to treatment. Chronic hepatitis B, caused by a virus, is a common form of liver disease affecting about 1 million Americans and about 5 percent of the world's population. Health effects include a continuous state of being infectious and the risk of transmitting hepatitis to other people, symptoms of liver disease, and development of cirrhosis-that is, severe damage to the liver-and liver cancer. Lamivudine is a medication that blocks hepatitis B effectively but does not make it disappear completely. Scientists believe that the immune system must also be active to rid the body of the last traces of hepatitis B. Patients ages 18 and older who have chronic hepatitis B and are being treated with lamivudine may be eligible to participate in this study. They will undergo a medical history and physical examination and will be given lamivudine in 100 mg tablets to be taken as one tablet, once each day. Patients will be asked to return to the outpatient clinic every 3 months, when they will undergo a brief interview and measurement of vital signs-such as blood pressure, pulse, and body weight. During the visits, they will fill out questionnaires about any symptoms or side effects they have, and they will be seen by a doctor and have a brief medical history and examination. There will be a collection of blood for complete blood counts, liver enzymes, and hepatitis B virus. Extra blood tests may be done to analyze patients' immune reactions to hepatitis B. Patients will also receive refills of their lamivudine tablets. They will continue to be treated with lamivudine as long as it seems to control the hepatitis infection and liver disease. At intervals of about 1 year, patients will have ultrasound examinations, lasting about 1 hour, of the liver and abdomen. Then