Department of Rheumatology, China-Japan Friendship Hospital, Beijing, 100029, China.
Introduction: Entecavir, a nucleoside analogue (NA), is effective for treatment of chronic hepatitis B virus (HBV) infection. Methods: We report a patient we encountered with entecavir-associated myopathy. We also performed a literature review of myopathies associated with nucleoside analogues. Results: A 44-year-old man presented with a 3-month history of myalgia and progressive weakness. He had HBV infection and had received entecavir antiviral treatment for 5 years. Laboratory tests showed that serum creatine kinase levels were significantly elevated. Muscle histopathology showed abundant T lymphocyte infiltration of muscle fibers, and HBV surface antigen and HBV core antigen were not present inmuscle fibers. Entecavir-associated myopathy was subsequently diagnosed. His symptoms eventually resolved, and his serum CK levels decreased rapidly after he stopped receiving entecavir treatments. Conclusion: Patients who receive NA therapy should be closely monitored for myopathic side effects.