title: Identification of a novel human circulating metabolite of tenofovir disoproxil fumarate with LC-MS/MS.
abstract: BACKGROUND
  Tenofovir disoproxil fumarate (TDF) is an antiretroviral drug used for the treatment of Human Immunodeficiency Virus and Hepatitis B infections.
  
  
  RESULTS
  A metabolite that has previously not been observed in the circulation of humans was detected by LC-MS/MS in early time point plasma samples following administration of TDF to healthy volunteers. The metabolite was identified using a range of LC-MS/MS-based techniques as a monoester of TDF, derived from the partially hydrolyzed bis-ester prodrug. TDF, when spiked into plasma, was observed to degrade first to the putative monoester and subsequently to tenofovir.
  
  
  CONCLUSIONS
  The presence of this unstable metabolite in some samples has implications for sample collection, handling and storage in studies of tenofovir where serum concentrations are determined.
authors: Division of Computational & Systems Medicine, Department of Surgery & Cancer, Faculty of Medicine, Imperial College, London, SW7 2AZ, UK.
authors: Leanne C
authors: LC
authors: Nye
authors: Nicola
authors: N
authors: Gray
authors: Myra
authors: M
authors: McClure
authors: Marta
authors: M
authors: Boffit
authors: Elaine
authors: E
authors: Holmes
authors: Robert S
authors: RS
authors: Plumb
authors: Ian D
authors: ID
authors: Wilson
mesh_terms: D053000:Analytic Sample Preparation Methods; D044966:Anti-Retroviral Agents / Q000097:blood* / Q000378:metabolism*; D001774:Blood Chemical Analysis; D002853:Chromatography, Liquid; D064368:Healthy Volunteers; D006801:Humans; D012015:Reference Standards; D053719:Tandem Mass Spectrometry; D000068698:Tenofovir / Q000097:blood* / Q000378:metabolism*
chemical_list: D044966:Anti-Retroviral Agents; D000068698:Tenofovir