Pharmacogenomics Testing for Drug Metabolism: 7 Things to Know about Pharmacogenomics

So, you have received a prescription from your physician for a drug. You’ve visited your local pharmacy, filled out a form, and now you are reading the long list of side effects. You may even be wondering if the good outweighs the bad.If so, you’re not alone.

The long list of possible side effects is daunting for several reasons. For one, you’re not really sure whether you’ll experience some of them or all of them or simply if you’ll experience any at all. That state of uncertainty is unsettling, especially if it is piled on top of another ailment. Wouldn’t it be convenient to know exactly how effective the drug or drug therapy will be specifically in your body? How can I look into personalized medicine? Wouldn’t it be amazing to also know what types of side effects that you can expect as well as which dose is perfect for you? Well, there is a way to find out, thanks to the medical field of pharmacogenomics that focuses on predicting all of the above based on your genome.

You may have heard of the discipline of pharmacogenetic testing but, in case you have not, it is helpful to begin with remembering that genes code for characteristics such as hair color, eye color, and certain disease predispositions. As it turns out, genes and genetic testing can also predict how a patient will respond to certain medications such as adverse drug reactions. More specifically, pharmacogenomics is all about looking for cues in your genes that could help predict your relationship with a drug and the drug response. And,as no one science is an island, these days, pharmacogenomics is the fusion of two sciences: one dealing with drugs and interactions and one dealing with the genome. (More on that below.) Even more specifically, pharmacogenomics focuses on changes, mutations, and variations in one or more genes that could affect the way your body responds to a specific drug. As you have guessed it, this does provide some sense of relief. So, what exactly is ‘pharmacogenomics testing for drug metabolism’? You’re about to find out!

  1. The word “pharmacogenomics” is inherently made up of two parts, namely pharmacology and genomics. Pharmacology is the area of medicine that focuses on the actions of drugs—applications, effects, and types of actions. Genomics is the analysis of the genome typically using bioinformatics techniques to find genetic variations that cause disease. So, taken together pharmacogenomics an interdisciplinary area of science that revolves around how one’s genes influence one’s response to a specific drug.
  2. Pharmacogenomics testing is performed if you are curious about your relationship with a drug based on what type of information you carry within your genome. Testing will tell you if the drug is an effective treatment solution for you, what the optimal dose would be as well as if there will be any side effects.
  3. Once your sample is submitted to the laboratory, testing is based on looking for changes in your DNA—or variations—in one or several genes that drive your response to the medication or that drive the effect of the medication on your body. Either way, it is essentially looking for changes in your DNA that can predict your relationship with the drug. Pretty nifty, eh?
  4. In terms of metabolism, specifically with drugs, the term itself means the body’s ability to facilitate the drugs excretion or clearance through the system by increasing its solubility. So, in terms of pharmacogenomics testing for drug metabolism, it is essentially testing for genetic mutations, changes, and variations that may offer an idea about how deficiently your body will clear a certain drug through the system.
  5. By virtue of your genome not really changing over time, you’ll only ever do one pharmacogenomics test per one drug to establish a relationship. However, you’ll have to do a pharmacogenomics test for each new drug that you take. This makes sense given that different drugs affect different processes and pathways in the body.
  6. Pharmacogenomics testing is not available for all drugs. This includes aspirin, for example, along with several other over the counter medications.
  7. Not all pharmacogenomics testing results are positive. If your test results indicate that your response to a certain drug may not be favorable, you and your doctor will have to find alternatives. Furthermore, it would also be beneficial to notify your family members of any unfavorable results that indicate a non-match with a drug as they are likely to have the same mutations and, therefore, the same results. Your results may save them the hassle of doing tests themselves.

Pharmacogenomics Testing for Drug Metabolism

It should also be noted that looking for genetic cues as to how you will respond to drugs is inherently a curated approach to therapy, pharmacogenomics has been considered part of the umbrella terms ‘individualized’ and/or ‘personalized’ medicine. Under that umbrella, health care is curated specifically to the patients’ needs. The aim of personalized medicine is to enhance the way diseases are predicted, prevented, diagnosed as well as treated in order to help patients live longer and have better and healthier lives.

So, while there is an immediate sense of relief along with the knowledge gained through pharmacogenomics testing, it is not without limits. For one, the testing is not available for all drugs both prescribed as well as over the counter. Furthermore, while the specificity is attractive, one drug-one test, it is also cumbersome to have to go through testing for every single drug that is prescribed.

Overall, however, pharmacogenomics has helped hundreds of thousands of patients live better and longer lives, as well as reduce the chances of adverse drug reactions. Prior to the efforts of the discipline, patients who did not respond well to drugs were either over-drugged (drugs were piled on to take care of all the inefficiencies of the prior drugs) or they simply did not win the battle against the disease they were suffering from. By having insight into whether and how a drug will respond, therapeutic approaches are both more effective as well as quicker, all of which culminates into better disease management which ultimately means longer and healthier lives.

Laura Day