Age as a determinant of sensitivity to warfarin

Br J Clin Pharmacol. 1977 Jun;4(3):315-20. doi: 10.1111/j.1365-2125.1977.tb00719.x.


1 Parallel human and rat studies were carried out to confirm the previous suggestion of an increased sensitivity to warfarin in old age. 2 The anticoagulant response to warfarin was found to be greater in the elderly groups despite, in the case of the patient study, the elderly subjects being given a smaller weight-related dose. 3 At the same plasma warfarin concentrations there was greater inhibition of vitamin K-dependent clotting factor synthesis in the elderly. There was no difference in the rate of clotting factor degradation in the two age groups. 4 There was no appreciable difference in warfarin pharmacokinetics (plasma half-life, apparent volume of distribution, plasma clearance, plasma protein binding or plasma warfarin alcohol levels) in the two age groups. 5 There appeared to be no major age-related differences in warfarin pharmacokinetics and the increased effect of warfarin in the elderly seemed to result from an increased intrinsic sensitivity to warfarin.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Aging*
  • Animals
  • Blood Coagulation / drug effects*
  • Blood Coagulation Factors / metabolism
  • Blood Proteins / metabolism
  • Half-Life
  • Humans
  • Kinetics
  • Male
  • Middle Aged
  • Protein Binding
  • Rats
  • Time Factors
  • Warfarin / blood
  • Warfarin / pharmacology*


  • Blood Coagulation Factors
  • Blood Proteins
  • Warfarin