Kim Gebrosky, B.S., D.C., National Accounts Manager, Castle Medical
Sometimes, drugs just don’t work. Adverse drug reactions can stretch treatment times far beyond their normal scopes, causing sharp increases in costs and sometimes even physical harm to patients. While this was long considered an unavoidable risk, advances in the new field of personalized medicine show great promise for reducing costs while simultaneously providing patients with valuable knowledge that will last them a lifetime.
Doctors have known for decades that people can respond differently – sometimes disastrously so – to the same medication. A normal dose of codeine, which effectively manages pain in most patients, might provide delayed relief in one patient, next to no relief in another, and a euphoric or dangerous overdose in a third. Fortunately, years of clinical research and technological advances are finally making the prediction of these failures and adverse reactions painless and cost-effective.
When a person takes a drug, their body recognizes it as a foreign substance and starts taking steps to remove it. This usually means either chopping it up into pieces or attaching a chemical that will make it easier to pass in urine. As it turns out, according to Castle Medical’s DNA specialist Alex Schmidt, “there are only a handful of enzymes that are responsible for the vast majority of these reactions, and many of them tend to vary from person to person. Some drugs won’t even work before they’re activated by having a piece broken off of them. For example, the popular anti-clotting medication clopidogrel (AKA Plavix) – at one time the second-most-prescribed drug in the world – is activated by an enzyme called CYP2C19. About 14% of patients are deficient in CYP2C19, and so are over three times as likely as their peers to develop serious clotting problems like heart attack and stroke, despite the use of the drug”.
While genetic testing can tell doctors which drugs to avoid completely, its results can also provide more subtle suggestions. Amitriptyline, a common antidepressant, doesn’t need to be activated the way clopidogrel does. The enzymes that act on it, CYP2D6 and CYP2C19, only serve to break it down into less-active chemicals. This means that, in patients with less enzyme activity, the drug sticks around longer. These patients have increased risk of side effects if given a normal dose, but the drug may still be useful to them – they’ll just need up to 50% less of it to get the same effect. Groups like the Clinical Pharmacogenetics Implementation Consortium (CPIC) have put together DNA-based dosage recommendations for a wide variety of medications.
Even the collection of patients’ DNA has greatly improved in recent years. Genetic tests used to require extra staffing, an invasive puncture, and specialized shipping for blood draws. Current protocols take only minutes to complete with very little training, and are accomplished by a quick mouth swab or even just spitting into a tube.
Patients and payers alike stand to benefit from this new wave of personalized medicine. A test as simple as a mouth swab can inform both drug choice and dosage, reducing the chances of treatment failure and costly, unpleasant side effects. Additionally, the patient is left with a record of his or her genetic makeup that will never change, and will in fact grow more valuable as additional research is done.
About Castle Medical
Based in the Atlanta area, Castle Medical is a rapidly growing, CAP-accredited, national reference laboratory. Castle got its start by protecting physicians and patients through drug confirmation testing in urine, serum, and oral fluid, and has since expanded its repertoire to include hormone, vitamin, genetic, and other molecular pathology tests. Dr. Kim Gebrosky, B.S., D.C. is the National Accounts Manager for Castle Medical (firstname.lastname@example.org) sharing this cutting-edge “Utilization Management Program” and cost containment tool with the Work Comp industry.
Source: Castle Medical