Clinical testing service for safer dosing of warfarin

Machaon Diagnostics, California's only independent laboratory for testing bleeding and clotting disorders has launched a clinical testing service for patients that have been prescribed warfarin.  Warfarin, also known as Coumadin, Jantoven or warfarin sodium, is a potent 'blood thinner' or anticoagulant. Machaon's FDA-approved array-based technology detects genetic variations in 2 key genes involved in the metabolism of warfarin.  40% of the general population has at least one of these genetic variations, which can lead to over 5-fold differences in weekly warfarin dose.  Warfarin is prescribed annually to 30 million Americans.  Over 6% of these patients are expected to experience an adverse bleeding or clotting event.  The Food and Drug Administration (FDA) has recognizes these risks by placing its strongest warning in the form of a Black Box Warning on warfarin package inserts.

Traditional warfarin dosing is largely based on trial and error.  It can take weeks or months to stabilize a patient within a targeted therapeutic range.  Both under-dosing and over-dosing can result in life-ending events, with serious bleeding most likely to occur at the start of warfarin therapy.  Many of these risks can be avoided when genetic information is used to determine an accurate initial dose.  Machaon's testing service provides physicians this valuable genetic information with a 'same-day' test result, thereby limiting the need for trial and error dosing.

Genetically-tuned starting doses have the potential of dramatically improving the safety of warfarin's use by allowing for individualized therapy. Often, however, this precious genetic information is not available or it is only available after 10 days and well past the window where it can reasonably influence the starting dose. "With warfarin being the second most common trigger for emergency room visits, our goal in designing this service was to enable physicians to accurately identify a safe warfarin dose for their patients within a timeframe that was meaningful," says Dr. Brad Lewis, the hematologist, medical director of Machaon Diagnostics. We believe that we are the first clinical laboratory in the US to offer this genetic testing service that provides results the 'same-day' a blood specimen is received.