title: Hypophosphatemic osteomalacia and renal Fanconi syndrome induced by low-dose adefovir dipivoxil: a case report and literature review suggesting ethnic predisposition.
abstract: OBJECTIVE
  Adefovir dipivoxil (ADV) is one of the commonly used antiviral agents in the treatment of chronic hepatitis B (CHB) infection. Safety of a daily dose of 10 mg ADV is advocated by the registration trials. We report a case of severe hypophosphatemic osteomalacia and renal Fanconi syndrome induced by low-dose ADV in a CHB-related cirrhosis patient, and discuss the case through a thorough review of other cases reported in the literature.
  
  
  METHODS
  A 48-yr-old Chinese man with CHB-related cirrhosis developed severe progressive generalized bone pain and muscle weakness after receiving ADV 10 mg daily for 54 months. The laboratory results showed severe hypophosphatemia and features of proximal renal tubule dysfunction. Imaging studies were consistent with osteomalacia. After discontinuation of ADV, his symptoms resolved, laboratory abnormalities normalized and imaging studies showed improvement. In addition to our case, 12 other patients have been reported to have developed hypophosphatemic osteomalacia induced by low-dose ADV. Most of the reported cases were of subjects of East-Asian ethnicity. After discontinuation or reduction of ADV, serum phosphate level increased and clinical symptoms significantly improved in all cases.
  
  
  CONCLUSIONS
  Hypophosphatemic osteomalacia and renal Fanconi syndrome can be associated with low-dose ADV. Clinicians treating CHB patients with ADV 10 mg daily over long periods of time should be aware of this infrequent but serious complication.
authors.affiliation: Department of Endocrinology, The Second Affiliated Hospital of Wenzhou Medical College, Wenzhou.
authors.forename: C
authors.initials: C
authors.lastname: Wu
authors.forename: H
authors.initials: H
authors.lastname: Zhang
authors.forename: Y
authors.initials: Y
authors.lastname: Qian
authors.forename: L
authors.initials: L
authors.lastname: Wang
authors.forename: X
authors.initials: X
authors.lastname: Gu
authors.forename: Z
authors.initials: Z
authors.lastname: Dai
mesh_terms: D000225:Adenine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*; D000998:Antiviral Agents / Q000008:administration & dosage / Q000009:adverse effects*; D004305:Dose-Response Relationship, Drug; D005198:Fanconi Syndrome / Q000139:chemically induced*; D006801:Humans; D017674:Hypophosphatemia / Q000139:chemically induced*; D008297:Male; D008875:Middle Aged; D063065:Organophosphonates / Q000008:administration & dosage / Q000009:adverse effects*; D010018:Osteomalacia / Q000139:chemically induced*
chemical_list: D000998:Antiviral Agents; D063065:Organophosphonates; D000225:Adenine; C106812:adefovir dipivoxil
keywords: adefovir dipivoxil; hypophosphatemic osteomalacia; renal Fanconi syndrome; review