According to the “Reporter” Vanderbilt University’s weekly newspaper, word is spreading to providers in pilot clinics that they should perform prospective genetic testing on certain patients. When a drug doesn’t work for a patient, or when a patient experiences side effects but receives little benefit then further genetic testing could possibly find solutions and avoid adverse drug events.
Certain common genetic variants or genotypes have been found to change the odds for certain drug responses especially with the development of personalized medicine. Soon, personalized medicine will require checking genotypes to ensure patients get the right drug at the right dose from the very start. Across the healthcare system when clinical genotyping is done at all, it is typically limited to a single gene-drug interaction. Looking ahead, Vanderbilt is mounting prospective, wide spectrum genotyping.
A single test, known as PREDICT or PDX test, is able to look at 184 common genetic variants collectively implicated in a host of known and suspected gene-drug interactions. For now, the university provides PREDICT/PDX at no cost to patients. Approximately 4,300 patients have been tested and it is expected that another 6,000 will be tested by June.
The gene-drug interactions that are currently listed for testing involve the cholesterol lowering drug simvastatin (Zocor) and the anti-clotting drug clopidogrel (Plavix). Other gene-drug interactions now being considered for testing involve the anticoagulant warfarin, the cancer drug tamoxifen, and two immunosuppressives.
“This isn’t about any one medicine. If we test prospectively, we can avoid a range of therapeutic delays and mishaps”, said Jim Jirjis, MD, Assistant Chief Medical Officer and the physician lead for the implementation of PREDICT.
Personalized medicine conducted at VUMC is possible since PREDICT can scan electronic records to forecast each patient’s risk over a three year horizon after receiving listed drugs. When the risk surpasses a threshold, the patient’s provider receives an automated alert through StarPanel (Vanderbilt’s EMR application) suggesting a PREDICT/PDX order.
The StarPanel patient summary displays the results but only those results that are of concern on listed drugs. The remaining results are stored for later use as more drugs become listed for testing. As test results become available, providers will then be able to write electronic prescriptions. Should there be a problem an alert will be issued if the genotype suggests an alternate dose or drug.