title: Osteomalacia and Fanconi's syndrome caused by long-term low-dose adefovir dipivoxil.
abstract: OBJECTIVE
  Adefovir dipivoxil (ADV) is recommended for patients infected with lamivudine-refractory hepatitis B virus (HBV). We report a case of low-dose ADV-induced hypophosphatemic osteomalacia that initially presented as diffuse musculoskeletal pain.
  
  
  METHODS
  A 59-year-old Chinese man reported an 18-month history of severe chest wall pain and multiple bone pain during the previous 4 months with no antecedent trauma. There was no clinical evidence of an infectious, inflammatory or malignant process. Medical history showed that the patient had a history of chronic hepatitis B infection, and receiving lamivudine at a daily dose of 100 mg for 70 months. Lamivudine was changed to adefovir (10 mg/day) for the past 42 months. His serum inorganic phosphorus concentration was significantly low (0·4 mmol/l; 0·81-1·5 mmol/L), and the result of a urine routine test was abnormal. Combined with unbearable bone pain, spontaneous fractures, changes in laboratory markers and the result of ECT and other radiographic findings, the diagnosis of Fanconi's syndrome with osteomalacia was established. Dramatic clinical, laboratory and imaging improvement was observed after ADV discontinuation.
  This case indicates that Fanconi's syndrome with osteomalacia can be acquired by a chronic hepatitis B patient taking ADV at a conventional dosage of 10 mg/day. Therefore, patients with HBV treated with long-term ADV should be regularly monitored for renal function, serum calcium and serum phosphate. Urine testing for ion concentration should also be undertaken.
authors.affiliation: Department of Elderly Gastroenterology, the First Affiliated Hospital of China Medical University, Shenyang, China.
authors.forename: B-F
authors.initials: BF
authors.lastname: Wang
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: B-Y
authors.initials: BY
authors.lastname: Wang
authors.forename: F-R
authors.initials: FR
authors.lastname: Sun
authors.forename: D
authors.initials: D
authors.lastname: Zhang
authors.forename: Y-S
authors.initials: YS
authors.lastname: Chen
mesh_terms: D000225:Adenine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*; D000998:Antiviral Agents / Q000008:administration & dosage / Q000009:adverse effects*; D002118:Calcium / Q000097:blood; D004305:Dose-Response Relationship, Drug; D016903:Drug Monitoring / Q000379:methods; D005198:Fanconi Syndrome / Q000139:chemically induced* / Q000175:diagnosis; D019694:Hepatitis B, Chronic / Q000188:drug therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D059352:Musculoskeletal Pain / Q000209:etiology; D063065:Organophosphonates / Q000008:administration & dosage / Q000009:adverse effects*; D010018:Osteomalacia / Q000139:chemically induced* / Q000175:diagnosis; D010710:Phosphates / Q000097:blood; D013997:Time Factors
chemical_list: D000998:Antiviral Agents; D063065:Organophosphonates; D010710:Phosphates; D000225:Adenine; D002118:Calcium; C106812:adefovir dipivoxil
keywords: Fanconi's syndrome; adefovir dipivoxil; hypophosphatemic; osteomalacia