Safer Warfarin Treatment

Safer Warfarin Treatment - the Influence of CYP2C9 Genotyping, Genotyping of Vitamine K Dependent Proteins and Dietary Vitamine K Status on Dosing, Clinical Effect and Adverse Events With Emphasis on the Initial Phase of Treatment

The study is a national multicenter prospective observational study, including 200 patients. The main purpose of this study is to explore in more detail the influence of genetic variability (CYP enzymes and vitamin K dependent proteins) and dietary vitamin K status on warfarin dosing, clinical effect and adverse events with emphasis on the initial phase of treatment. The hypothesis is that genetic variability concerning CYP enzymes and vitamin K dependent proteins predict dosing and adverse events during warfarin treatment. The main aim is to individualize warfarin therapy and establish a treatment algorithm based on genotype and dietary vitamin K status to make the anticoagulation therapy with warfarin more secure.

Inclusion Criteria:

• Caucasian
• >18 years of age
• included in the study at the onset of warfarin treatment
• target INR (2-3 for atrial fibrillation, vein thrombosis, pulmonary embolism and 2.5-3.5 for prosthetic heart valves)
• standard indications for warfarin treatment

Exclusion Criteria:

• Non-caucasian
• Clinical significant liver affection
• Heart failure, NYHA class III-IV
• Non-compliant - not able to accomplish protocol demands
• Not able to give informed consent
• Long-term antibiotic therapy
• Malabsorption conditions and inflammatory bowel disease