Aging and the anticoagulant response to warfarin therapy

Area of Science:

• Gerontology
• Pharmacology
• Clinical Medicine

Background:

• Warfarin is a widely prescribed anticoagulant.
• Aging is associated with numerous physiological changes that can affect drug response.
• The impact of age on warfarin's anticoagulant effect requires further elucidation.

Purpose of the Study:

• To evaluate the influence of aging on the anticoagulant response to warfarin.
• To determine if older individuals exhibit altered sensitivity to warfarin therapy.

Main Methods:

• Retrospective cohort study of 530 outpatients from an anticoagulation clinic.
• Patients stratified into four age groups (under 50, 50-59, 60-69, 70+).
• Dose-adjusted prothrombin time ratio calculated to assess anticoagulant response.

Main Results:

• Older patients were more likely to be female, have more comorbidities, and use more medications.
• A significantly increased, dose-adjusted prothrombin time ratio was observed in older patients.
• This exaggerated anticoagulant response to warfarin in the elderly persisted after multivariate analysis.

Conclusions:

• Warfarin's anticoagulant effect is potentiated by advancing age.
• Close monitoring of warfarin therapy is crucial for elderly patients.
• Age-related changes necessitate individualized warfarin dosing and management strategies.