Warfarin therapy: in need of improvement after all these years.
BACKGROUND
Warfarin therapy has been used clinically for over 60 years, yet continues to be problematic because of its narrow therapeutic index and large inter-individual variability in patient response. As a result, warfarin is a leading cause of serious medication-related adverse events, and its efficacy is also suboptimal.


OBJECTIVE
To review factors that are responsible for variable response to warfarin, including clinical, environmental, and genetic factors, and to explore some possible approaches to improving warfarin therapy.


RESULTS
Recent efforts have focused on developing dosing algorithms that included genetic information to try to improve warfarin dosing. These dosing algorithms hold promise, but have not been fully validated or tested in rigorous clinical trials. Perhaps equally importantly, adherence to warfarin is a major problem that should be addressed with innovative and cost-effective interventions.


CONCLUSIONS
Additional research is needed to further test whether interventions can be used to improve warfarin dosing and outcomes.
Kimmel
Stephen E
SE
University of Pennsylvania School of Medicine, Center for Clinical Epidemiology and Biostatistics, Department of Biostatistics and Epidemiology, 717 Blockley Hall, 423 Guardian Drive, Philadelphia, PA 19104-6021, USA. stevek@mail.med.upenn.edu
D000465:Algorithms; D000925:Anticoagulants / Q000008:administration & dosage* / Q000009:adverse effects; D004305:Dose-Response Relationship, Drug; D006801:Humans; D010349:Patient Compliance; D013923:Thromboembolism / Q000517:prevention & control*; D016896:Treatment Outcome; D014859:Warfarin / Q000008:administration & dosage* / Q000009:adverse effects
D000925:Anticoagulants; D014859:Warfarin