title: Effect of Body Weight on Dose of Vitamin K Antagonists.
abstract: OBJECTIVE
  Numerous factors are well documented to affect the response to vitamin K antagonists (VKA), including dietary vitamin K, other drugs, age, pharmacogenetics, and disease states. Body weight is perhaps not as well known as a variable affecting VKA dose. Our aim was to review the literature regarding body weight and VKA dose requirements.
  
  
  METHODS
  We reviewed the English-language literature via PubMed and Scopus using the search terms VKA, warfarin, acenocoumarol, phenprocoumon, fluindione, AND body weight.
  
  
  RESULTS
  Among 32 studies conducted since the widespread use of the international normalized ratio, 29 found a correlation with body weight or body surface area and VKA dose requirement. Warfarin was evaluated in 27 studies and acenocoumarol, phenprocoumon, or fluindione were assessed in 5 investigations.
  
  
  CONCLUSIONS
  Because of varying study methodologies, further study is warranted. Based on current evidence, clinicians should include body weight, along with other established variables when dosing VKA. Most important, obese and morbidly obese patients may require a 30% to 50% increase with the initial dosing of VKA.
authors.affiliation: From the University of Tennessee Health Science Center and Methodist University Hospital, Memphis, Lipscomb University and Veterans Affairs Tennessee Valley Healthcare System, Nashville, and Methodist University Hospital, Memphis, Tennessee.
authors.forename: Timothy H
authors.initials: TH
authors.lastname: Self
authors.affiliation: From the University of Tennessee Health Science Center and Methodist University Hospital, Memphis, Lipscomb University and Veterans Affairs Tennessee Valley Healthcare System, Nashville, and Methodist University Hospital, Memphis, Tennessee.
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Wallace
authors.affiliation: From the University of Tennessee Health Science Center and Methodist University Hospital, Memphis, Lipscomb University and Veterans Affairs Tennessee Valley Healthcare System, Nashville, and Methodist University Hospital, Memphis, Tennessee.
authors.forename: Sami
authors.initials: S
authors.lastname: Sakaan
authors.affiliation: From the University of Tennessee Health Science Center and Methodist University Hospital, Memphis, Lipscomb University and Veterans Affairs Tennessee Valley Healthcare System, Nashville, and Methodist University Hospital, Memphis, Tennessee.
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Sands
mesh_terms: D000074:Acenocoumarol / Q000008:administration & dosage*; D000925:Anticoagulants / Q000008:administration & dosage*; D001835:Body Weight; D015897:Comorbidity; D054796:Drug Dosage Calculations; D006801:Humans; D009765:Obesity; D009767:Obesity, Morbid; D010630:Phenindione / Q000008:administration & dosage / Q000031:analogs & derivatives*; D010644:Phenprocoumon / Q000008:administration & dosage*; D014812:Vitamin K / Q000037:antagonists & inhibitors*; D014859:Warfarin / Q000008:administration & dosage*
chemical_list: D000925:Anticoagulants; D014812:Vitamin K; D010630:Phenindione; D014859:Warfarin; C017673:fluindione; D000074:Acenocoumarol; D010644:Phenprocoumon