Our doctors note that “with the exception of specific warfarin testing,” pharmacogenetic testing in their patient population has improved clinical decision making and patient outcomes. In one case treating a young woman with chronic pain and “NSAID (non-steroidal anti-inflammatory drug) intolerance” in whom pharmacogenetic testing showed to be a poor metabolizer of almost all NSAIDs, was suggested she could be treated with Naproxen, which is metabolized by a different pathway. Doctors conclude that waiting for the results of future, well-designed, adequately powered studies needlessly condemns countless patients to experience avoidable adverse reactions and treatment failures.
DNA testing can also be used to identify variants that influence drug metabolism or interaction of a drug with its cellular target, allowing customization of choice of drug and dosage.
Annual health care expenditures currently exceed $2.7 trillion in the United States, a cost burden equivalent to more than $8,500 per person per year. Treatment strategies designed to optimize efficacy, ie, avoiding therapeutic failure while minimizing toxicity, hold the potential to reduce this cost burden. For many drugs, variability in outcome is influenced by 1 or more genetic factors. Because many of these genetic factors have only recently been challenged with modern pharmaceuticals, variants of strong clinical relevance are often found at a fairly high frequency within the general population.
More information on Warfarin is available at http://www.coumadin.com/html/index.htm