Finding the Right Medication with Pharmacogenomics

What is Pharmacogenomics?

Pharmacogenomics explores how a person’s genetic makeup affects their body’s response to different medications. Studies indicate that up to 98% of people may have a genetic difference that affects how they respond to medication (genome.gov). Knowing these differences can help the healthcare team predict how safe and effective a medication may be for an individual. In areas of medicine with high rates of medical trial and error such as in psychiatric disorders, cancer, and pain management, pharmacogenomics can help guide the healthcare team towards the correct type and amount of medication that works best for an individual. 

What is a genetic difference?

A body’s DNA, or genetic information, contains “genes”. Genes provide the instructions for the body’s cells to build proteins called enzymes. Enzymes serve various functions such as influencing how the body absorbs and uses, or metabolizes, medication. A genetic difference in the body’s DNA can change how an enzyme metabolizes some mediations.

Medication Metabolism

Other factors such as age, lifestyle, and activity can also affect how a body metabolizes medication. However, because of genetic differences in metabolism, a healthcare provider may recommend genetic testing to see if the person has a specific gene that metabolizes a medication too fast or too slow. If the body metabolizes the medication too fast it will not work well. On the flip side, if metabolized too slowly the medication may build up and cause an unwanted reaction. Genetic testing in pharmacogenomics looks at more than just metabolism- it can be used in other situations where genetics impacts medication use, such as with

• A new diagnosis

• When medications do not work as intended

• In people taking multiple medications that may interact with each other

• When finding a medication for a specific purpose

• And when taking a medication that is known to be affected by genetics

Genetic testing

If a healthcare provider recommends genetic testing they will explain what they are testing for and provide information about the process before asking the patient for permission to proceed. If the patient gives consent, then a tissue sample will be taken and sent to a lab where a team will study it for specific changes based on what the genetic testing is looking for. It can take a few days to several weeks for test results to come back, and once available the healthcare provider will review them and discuss any need for medication changes with the patient. 

Looking Forward

The field of pharmacogenomics has grown by leaps and bounds as researchers identify new interactions between medications and genetic differences. However, the there is a small number of conditions and medications that are able to be tested for, testing may not be readily accessible, and may not be covered by health insurance. As new information is made available, researchers are hopeful that more people can experience a positive impact from the knowledge that helps guide safer and better medication choices. If you have questions about pharmacogenomic testing or wonder if it is right for you, talk to your health care provider. 

Centers for Disease Control and Prevention. (n.d.). Pharmacogenomics. Centers for Disease Control and Prevention. https://www.cdc.gov/genomics-and-health/pharmacogenomics/index.html

Mayo Foundation for Medical Education and Research. (2021, October 25). Mayo Clinic Q and a: What is Pharmacogenomics? - mayo clinic news network. Mayo Clinic. https://newsnetwork.mayoclinic.org/discussion/mayo-clinic-q-and-a-what-is-pharmacogenomics/

U.S. National Library of Medicine. (n.d.). How is genetic testing done?: Medlineplus Genetics. MedlinePlus. https://medlineplus.gov/genetics/understanding/testing/procedure/

Yolanda Smith, B. Pharm. (2021, May 10). Pharmacogenetics: Past, present and future. News. https://www.news-medical.net/health/Pharmacogenetics-past-present-and-future.aspx

Assessed and Endorsed by the MedReport Medical Review Board