Introduction
More than 131 million Americans take at least one prescription medication daily, many taking four or more. The greater the number of medications a person takes the greater the risk of having an adverse reaction or event. Unfortunately, adverse reactions to a medication lead to over 1.3 million emergency department visits each year. Adverse drug events are seven times more likely to occur in older adults. Blood thinners to protect from heart attacks or stroke, diabetes medications to control blood sugar levels, psychoactive medications to treat mental illnesses, and heart medications that help with blood pressure or heart rate are just some of the common reasons people go to the emergency room.
How a person takes their medicine, such as mixing two drugs together or taking medication at the wrong time intervals, can lead to adverse drug reactions. Frequently, however, adverse effects are the result of genetics. Genetics affects our physical appearance, our health, and our medications. While we may not control what genes we have, we can control the decisions we make by gaining essential knowledge about our bodies. Genetic testing may help you and your doctor learn more about your body and discover the treatment most likely to work.
How Do Genes Affect Drug Metabolism?
There is a connection between our genes and our metabolism of medicines. Researchers have been able to pinpoint genetic variations that impact how we may respond to certain drugs.
For example:
- Slow-acting N-acetyltransferase: between 50% and 70% of Americans, depending on ethnicity, are slow acetylators, meaning their N-acetyltransferase (a liver enzyme) metabolizes drugs slowly. When the body is unable to remove a medication in an appropriate manner, that medication or a toxic relative of that medicine can cause damage. This can make it dangerous to take drugs such as isoniazid, which treats tuberculosis; and can put patients who use Tylenol regularly at increased risk of liver damage.
- Pseudocholinesterase deficiency: The liver releases pseudocholinesterase into the bloodstream. Anesthesiologists rely on the presence of this enzyme to inactivate common muscle-relaxing drugs given during medical procedures, such as succinylcholine. Normal levels of this enzyme lead to the inactivation of succinylcholine in less than 10 minutes, while those with the deficiency may take over 2 hours to inactivate it. Without timely inactivation, patients may experience trouble breathing and require breathing support until the succinylcholine is completely removed by the body.
- Glucose-6-phosphate dehydrogenase (G6PD) deficiency: G6PD is an important enzyme that protects red blood cells from damage. Those deficient in G6PD may experience hemolytic anemia when the body experiences stress which is more common in people of African, Mediterranean, or Asian descent. Certain drugs, such as chloroquine (which treats malaria) may destroy their red blood cells. Many medicines and over-the-counter drugs should be avoided in those who have this deficiency including acetaminophen (Tylenol), aspirin, and multiple other medications.
In the past, patients had no way of knowing if a medication would be harmful until they experienced an adverse reaction afterward. Fortunately, pharmacogenetic testing is changing how we prescribe medicines.
What Is Pharmacogenetic Testing?
The metabolism of medications is a precise science. Medications either enter the body active or must become active after entering. If an already active medicine is metabolized too quickly, the result could be an ineffective medication. If the medication requires activating and is activated too quickly then toxicity can occur. On the contrary, if the active medicine is not metabolized appropriately it could remain in the system too long and lead to side effects. If the inactive medicine is not activated quickly enough, then the body may never have the benefits expected of that medicine. The good news is many of the genetic variations that affect drug metabolism can be identified early.
Pharmacogenetic testing, or drug-gene testing, examines the genetic differences that affect how people metabolize drugs. It can be done with a simple DNA sample retrieved from a cheek swab. A special Q-Tip is rubbed along the inside of both cheeks to collect cells from your cheeks and saliva. Then the swab is placed into a solution and sent to the laboratory to be evaluated.
The goal of pharmacogenetics is to personalize treatments by determining which drugs may help a patient and which drugs may need to be avoided. Through this type of testing, people can optimize treatment options and determine the best possible medication choices for their health. Pharmacogenetics applies to conditions with established treatments as well as creating individualized therapies.
Pharmacogenetic Test Details
Selecting the right medication is difficult. A medication might work well in 90% of people but cause severe side effects in the remaining 10%. However, you may be one of that 10%. The last thing anyone wants is to take a drug to help battle a medical condition, only for the medication to cause more harm than the actual condition. Trying to decide between medications can be overwhelming. ClarityX can help you make well-informed choices about your medications through pharmacogenetic (PGx) testing. This information helps both you and your prescriber know whether a dosage adjustment or a new drug entirely would be better.
The MaxRx test from ClarityX provides a seamless in-home testing experience. Simply visit the website ClarityX, select the MaxRx test option from the drop-down menu, and complete the checkout process. Once the kit is received follow the package instructions, perform a simple cheek swab, then mail the sample back using the prepaid envelope. The sample is then sent to the lab for processing and the results are posted and available in your patient portal. The results will be available to you or your provider within about 7 to 10 days.
One important fact about pharmacogenetic (PGx) testing is the results can be reevaluated for future medication changes because the test does not need to be repeated for the specific genes evaluated. Over 265 FDA-approved medications can be evaluated to see how an individual’s genetic makeup can affect those drugs. Pharmacogenetic (PGx) testing can provide a lifetime of knowledgeable decisions about medication selection.
References:
https://hpi.georgetown.edu/rxdrugs/
https://www.cdc.gov/diabetes/data/statistics-report/index.html
https://www.cdc.gov/learnmorefeelbetter/programs/chronic-pain.htm
https://www.cdc.gov/medicationsafety/adult_adversedrugevents.html
https://www.cdc.gov/nchs/fastats/drug-use-therapeutic.htm
https://www.healthline.com/health/heart-disease/statistics
https://www.ncbi.nlm.nih.gov/books/NBK470315/
https://www.ncbi.nlm.nih.gov/books/NBK541032/
https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/n-acetyltransferase
