About My Health Careers Internship MedBlogs Contact us

Dosage of Drug for Anticoagulant to Be Determined by Genetics

by Medindia Content Team on August 22, 2007 at 4:51 PM
Font : A-A+

Dosage of Drug for Anticoagulant to Be Determined by Genetics

A research into how an individual's genetic information can be used to personalize medical care. A new research suggests that dosage of drug warafin for anticoagulant can be determined by genetic testing. Since all individuals metabolize the therapeutic drug differently they need varying dosage of the drug in order to be effective.

Too much warfarin can cause severe bleeding, and too little can cause dangerous blood clots. Presently the physicians do not have an accurate guide as to much dosage of warafin a patient needs. He uses a trial and error method for the administration of the drug and then continually monitor a patient's International Normalized Ratio (INR) value (a measure of how fast the blood clots), during treatment to tweak the dosage. The research is published in the issue of Blood, the journal of the American Society of Hematology.


For the first time, a group of St. Louis researchers combined the standard INR method with genetic testing to predict the therapeutic warfarin dose. Since warfarin is often prescribed after major orthopedic surgery to prevent blood clots in the legs, the study followed 92 adults undergoing either total hip or knee replacement at the Washington University Medical Center, who had never previously taken the anticoagulant.

Prior to warfarin treatment, the researchers collected blood samples and each patient's medical history. The blood tests were used to examine variations in two genes, CYP2C9 and VKORC1, that may affect warfarin dosing. Variants in CYP2C9 impair the body's breakdown of warfarin; variants in VKORC1 cause increased warfarin sensitivity. The patients were assigned initial doses of warfarin based on clinical factors and their genotype. The researchers followed the patients until successful treatment outcomes were achieved several weeks later.

By combining variants in these genes with initial INR response and other clinical factors, the researchers derived a dosing equation that estimated the therapeutic warfarin dose. The researchers found that these two genes were important in predicting the response to warfarin. Additional factors, such as blood loss during surgery and smoking status, also correlated with therapeutic dose.

Using these data, the researchers developed a therapeutic model that could be used by physicians to refine warfarin dosage with greater accuracy than clinical factors alone. The researchers have made this dosing model publicly available on a free Website,www.warfarindosing.org, and are now validating it in orthopedic and non-orthopedic patients beginning warfarin therapy.

If validated, particularly in patients taking warfarin for reasons other than orthopedic surgery, such as to prevent stroke, this gene-based dosing could predict a safe and effective warfarin dose at the start of treatment, thus minimizing the risks of the current trial-and-error approach.

Source: Eurekalert

News A-Z
News Category
What's New on Medindia
Memory Loss - Can it be Recovered?
International Day of Persons with Disabilities 2021 - Fighting for Rights in the Post-COVID Era
Effect of Blood Group Type on COVID-19 Risk and Severity
View all

Medindia Newsletters Subscribe to our Free Newsletters!
Terms & Conditions and Privacy Policy.

More News on:
Drug Toxicity Genetics and Stem Cells Signature Drug Toxicity 

Recommended Reading
Drugs Interaction With Warfarin Could Lead to Gastrointestinal Bleeding.
IN order to better assess their patients' therapeutic risk-benefit profiles the doctors have to be ....
Anticoagulants is Better for Atrial Fibrillation
People with atrial fibrillation (AF) have irregular heart beats and have a tendency to form blood .....
Drug Toxicity
Drug toxicity is an adverse reaction of the body towards a drug that results as a side effect of a d...

Disclaimer - All information and content on this site are for information and educational purposes only. The information should not be used for either diagnosis or treatment or both for any health related problem or disease. Always seek the advice of a qualified physician for medical diagnosis and treatment. Full Disclaimer

© All Rights Reserved 1997 - 2021

This site uses cookies to deliver our services. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Use