House Calls / Dr. Michael Schwartz
The secret as to why some medications work better than others may be buried in your genes. A company named Genomas has created a simple test that can help determine which drugs may be more efficacious for each individual patient.
A patient's DNA can offer predictive information that could prove helpful when considering which medication to administer for treatment of certain diseases and ailments. The test, known as the HILOmet PhyzioType System, examines a patient's DNA and looks for specific enzyme levels. These levels are essential in the metabolism of many commonly used medications. If a patient is deficient in any one of these enzymes, the patient may not be able to breakdown a specific compound resulting in a reduction of the medications efficacy and/or could actually increase the risk for adverse reactions and side effects. Indeed, studies have proven that certain nationalities are statistically deficient in one or more of these enzymes.
The test is administered in a physician's office. The patient simply swabs both cheeks in the inside of his mouth. The swabs are then sent to a lab for analysis. It generally takes about two weeks for the results.
There are about 250 different drugs that are analyzed to assess a functional profile. These include medications for many different indications including hypertension, diabetes, depression, acute and chronic pain, sexual dysfunction, antibiotics and many more. Once a profile is generated, the physician receives the results through a Web portal and meets with the patient to discuss. An evaluation of the results of this "genetic prescription system" will designate which medications are deemed to work well for treating a specific disease or condition for each individual patient. The results are easy to interpret; drug compounds printed in green are determined to work the best while those with mixed results are in yellow and those to avoid (due to low enzyme levels) are in red.
One example of an undesirable outcome due to poor metabolism was a patient who was taking a drug in order to prevent the clotting of their blood. Despite being on an anti-clot medicine, the patient continued to get life-threatening blood clots. A DNA analysis performed on the patient indicated that the drug was likely not effective due to the patient's enzyme profile. The patient was then changed to another medication with better results.
One distinct advantage of this DNA testing is that results are received relatively quickly and therefore may be considered before starting a medication. Dr. Gualberto Ruano, president of Genomas Inc. and medical director of the Laboratory of Personalized Health said: "DNA testing is predictive. It provides information on the patient's response to a medication before the drug is given."
Presumably, the outcome to therapy would be better if your physician knows in advance which drugs may work better for your condition. "With comfort and expertise, physicians then advance to a proactive strategy, where vulnerable populations (the young, the elderly) are tested to improve therapeutic regimens and prevent side effects and therapy failure." As such, this personalized health evaluation can be used to choose the more efficacious medications.
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Once a patient has been tested, the physician will always have the advantage of reviewing the DNA information prior to choosing a new medication to add to a patient's regimen. Having these results in advance may allow for better choices and better outcomes. It is hoped that the commonly used trial-and-error approach when choosing a medication can be avoided with information that identifies the likelihood of success or failure with adding a new medication.
Currently, the test is covered by Medicare, Oxford and United Health Care insurers although many other carriers may soon be covering the test as well. Ruano stated: "We offer a self pay option to patients with high deductibles or no coverage. In Connecticut, the fee is $450 for the complete HILOmet System; outside of Connecticut the fee is $650. I believe genetics in primary care will become a fundamental tool and the use of DNA will improve outcomes and optimize health care resource utilization." Soundview Medical Associates in Norwalk recently began offering this test for its patients. Eileen Smith, executive director of Soundview said, "We have begun to use this test as we believe it is a very valuable tool to help physicians properly prescribe, or if need be, change medication for best results."
No test is perfect, however. Test results and outcomes can be influenced by many additional factors including liver disease, medication allergies and medication interactions. Furthermore, it should be noted that many patients do perfectly well on medications which are listed as those to be avoided. This is because there are other factors which are needed to metabolize medications including other enzymes not measured by this technology. Therefore, medications that are working well for the patient do not necessarily need to be changed if the results contradict its use.
DNA testing offers your doctor another tool in order to best advise you with respect to your health-care needs. While this technology is new and continues to evolve, it indicates that the future of medicine lies in our genes; wear them well.