An Open Study to Evaluate the Sustained Effect in Patients Showing Virological Responses With Muscle-related Symptom of Chronic Hepatitis B Patients Who Received Clevudine

Inclusion Criteria: 1. Patients is currently clevudine treatment. 2. Patients with HBV DNA \< 300 cpoies/mL and ALT normal Showing Muscle-related Symptom Who received Clevudine 3. Patient who is able to give written informed consent prior to study start and to comply with the study requirements. Exclusion Criteria: 1. Patient is currently receiving antiviral, immunomodulatory, cytotoxic or corticosteroid therapy. 2. Patient is pregnant or breast-feeding. 3. Patient has a significant gastrointestinal, renal, decompensated liver, bronchopulmonary, neurological, cardiac, oncologic(except HCC)or allergic disease. 4. Patient, in the opinion of the investigator, unsuitable for the study. 5. Showing Muscle-related Symptom who any other evidence.