About one of every four patients in the United States were prescribed medications with PGx information in the label of the drug in 2006. These medications include antidepressants, analgesics, cancer treatments, cardiovascular drugs and gastrointestinal medicines. For example, one enzyme - CYP2D6 (part of the cytochrome p450 system of liver enzymes) - may be involved in the metabolism of 30 percent of all drugs used today. In a case showing a genetic connection to drug metabolism, a test is recommended for patients using the blood thinner warfarin since they can experience serious bleeds or blood clots if given the wrong dose; a genetic test can help determine the accurate dosage based on the patient's genetic profile and prevent these potentially life-threatening incidents. Genetic testing is also important for breast cancer patients on tamoxifen since about 10 percent of those women won't respond well to the medication because of their genetic make-up. Provided with this information, physicians can find the appropriate treatment that will be effective for individual breast cancer patients. Variations in numerous other genes beyond those regulating liver enzymes have also been found to be important in determining the safe and effective use of drugs.

In the future, even more drugs may be linked to genetic tests. From the second half of 2009 through the first half of 2010, seven drugs paired with genetic tests are expected to be up for FDA approval, as well as approximately 10 to 20 percent of new drugs being labeled with PGx-related information over the next five-to-ten years. In particular, the field of oncology will see many more of these drugs in the coming years, with roughly 50 percent of cancer drugs in the pipeline expected to be orally administered by 2013 and 85 percent of those will rely on a genetic biomarker.

SOURCE Medco Health Solutions, Inc.