[A case of chronic hepatitis B managed with continued adefovir despite treatment-related Fanconi syndrome and osteomalacia].

A 64-year-old woman was prescribed lamivudine and adefovir (ADV) for chronic hepatitis B. Although her serum creatinine level was normal (<1.01 mg/dl), she developed bone pain due to Fanconi syndrome and osteomalacia. Therefore, ADV was discontinued and she was switched to entecavir (ETV); however, she developed an ETV-resistant mutant virus and a small dose of ADV was restarted. Her hepatitis B virus (HBV) -DNA levels and renal function were closely monitored. She has had preserved creatinine levels and tubular function, with almost undetectable HBV-DNA levels for more than a year after treatment.