What Is Pharmacogenomics (Pharmacogenetics)?

What Is Pharmacogenetic Testing?

Pharmacogenomics (pharmacogenetics) hopes to remove the guesswork from prescribing and taking medications. Pharmacogenomics testing uses individual genetic characteristics to determine the likelihood of pharmaceutical success, allowing doctors to customize prescriptions according to each patient.

Pharmacogenomics research aims to understand how DNA influences responses to a medication. Ideally, pharmacogenetic testing can predict which drug will likely produce the desired results while reducing unwanted side effects. This way, prescribers have more information to recommend an effective treatment plan.

According to Dr. Ron Albucher, advisor for Prairie Health, “Just like the way a difference in one gene can lead one person to have freckles while another person has none, different genetic variations lead to different forms of the same enzyme. Different enzyme variations process the same drug in different ways.

Pharmacogenetic tests can give doctors insight into how their patients might process certain medications and allow them to customize prescriptions as a result. For example, results might show that one person has a type of enzyme that breaks down a medication very quickly. This means that this medication at its standard dosage might not stick around in the body long enough to work. As a result, the doctor might increase the dosage they give to their patient.”

Why Is Genetic Testing for Medication Important?

People exploring new medications and prescription drugs recommended by their mental health providers face a challenging journey of uncertainty. At best, these medicines work to produce the wanted changes.

However, starting new or increasing the dose of medications can trigger dangerous and deadly reactions and side effects. Pharmacogenetic testing hopes to negate these possibilities by establishing safety and confidence when prescribing medications.

Pharmacogenomics & DNA

Pharmacogenetic testing stems from the notion that DNA can predict and explain how individuals will react to specific drugs. DNA testing for medication examines drug receptors, uptake, and breakdown in the body, offering insight into potential side effects and accurate doses.

The role of DNA in pharmacogenomics include:

• Drug receptors: Medications need to attach to cell receptors to be effective, and DNA controls what kind and how many receptors are available. People with fewer receptors will need higher doses of a medication to see benefits.
• Drug uptake: Drug uptake involves the rate and efficiency of absorption in the body. For example, a medication will not produce the desired results and build up in the body if uptake is too low, leading to an increased risk of harmful side effects.
• Drug breakdown: Breakdown refers to how the body processes a drug. High breakdown rates require more medication, while low breakdowns could indicate lower dosages.

How Does Pharmacogenetics Work In Psychiatry?

In psychiatry, pharmacogenetics gives the prescriber and patient more information about the best medication and dosage without needing multiple trials. Pharmacogenetic testing could result in fewer side effects and quicker symptom relief.

Numerous medications are available to address mental health symptoms, meaning a prescriber must choose between these options when recommending a drug. Because everyone responds to medications differently, having a solid understanding of how effectively a drug will work can be impossible. For instance, ten people could take the same dose of the same prescription and have different outcomes.¹

How Do Providers Utilize Pharmacogenetic Testing?

Providers may utilize pharmacogenetic testing preventatively or reactively. Some have patients complete testing before treatment, while others recommend testing after several unsuccessful medication trials.

Who Should Get Pharmacogenetic Testing?

People who have had little success with previous medications should consider pharmacogenetic testing. Their results could provide insight into how to avoid repeat situations in the future.

In some situations, people may become so irritated by ongoing issues they consider giving up on using medications. A round of pharmacogenetic testing could offer new hope and direction for medication treatment.

Ethnic minorities and women should also practice more active curiosity about testing options. Before the 1993 NIH Revitalization Act, pharmaceutical companies were not required to include people assigned female at birth or people of color in their trials. Many current drugs were initially developed or tested before 1993. As a result, previous prescription guidelines cater to white men.²

Dr. Albucher states, “Scientists know that some genetic variations occur more (or less) frequently in white males than in other demographics. Therefore, if you’re not a cisgender white male, pharmacogenetic testing can help your doctor create a medication regimen that is more customized to you.”

Where to Find Pharmacogenetic Testing

Pharmacogenetic testing is a relatively new procedure, meaning the process varies. Generally, a doctor or other practitioner prescribes a test. The individual then presents to a lab location where they provide a sample of saliva, blood, or buccal tissue, but blood is the preferred method.³

Testers receive the sample for analysis, but the turnaround time could be 14 days or longer.³ The laboratory will send results to the prescriber or an electronic database where the individual can review their record.

What Do the Results of a Pharmacogenetic Test Mean?

Pharmacogenetic test results may not provide a definitive path for people interested in modifying their medication treatment. However, they can show how quickly and effectively a person will process a medication. For many, this information will significantly influence their medication decisions.⁴

Tests also indicate whether a specific medication may cause adverse side effects and identify patients who are rapid or slow metabolizers. With this, doctors know what to eliminate from their options and can quickly settle on better alternatives at more effective doses.

New data paired with earlier information gained from medication trials can significantly direct the next step in treatment. In other situations, the findings could offer little additional information, so the treatment team will continue using some degree of guesswork in determining medications.

What Are the Limitations of Pharmacogenetic Testing?

Pharmacogenetic testing will likely yield more helpful and detailed information with time. However, for now, the limitations are significant. Anyone interested in testing options should have an honest and open conversation with their treatment team to explore the potential risks and benefits of the procedure.

Because pharmacogenomics is so new, current tests cannot determine the best treatment for everyone. Fortunately, the only risk comes when an individual or a prescriber relies too heavily on the results. Despite potential, pharmacogenetic testing provides few answers.

Another limitation of pharmacogenetic testing is its validity for children and adolescents. Most researchers in this field work with adult populations, meaning information about pharmacogenetics does not transfer to younger individuals. Therefore, doctors and families should not seek pharmacogenomic testing for children when selecting medications.⁵

Dr. Albucher adds, “Because pharmacogenetic tests look at very specific genes related to treatment, they aren’t useful for answering other commonly asked questions about family history or likelihood of developing a certain disease. They are more likely to tell someone how their enzymes work and how they might respond to medications.”

How Much Does Pharmacogenetic Testing Cost?

The exact cost of pharmacogenetic testing depends on insurance coverage, specific testing policies, and location. Some reports say many tests cost $300 or more when paying out of pocket. However, insurance may cover the costs in some situations.

The cost of testing may seem high, but the process may help people save time, lower symptoms, and avoid adverse medication effects. Also, copays for unhelpful medications and trips to the psychiatrist can quickly add up, which further reduces the overall cost of pharmacogenetic tests.

Does Insurance Cover Pharmacogenetic Testing?

Whether insurance covers the price of a genetic test depends on the insurer and the plan. For example, Medicare and UnitedHealth specifically cover some pharmacogenetic tests. Another major healthcare insurer, Aetna, covers several pharmacogenetic and pharmacodynamic testing options, but these services will likely encounter increased scrutiny.⁶

Anyone interested in such testing should contact their prescriber, the lab, and the insurance company to gather information before deciding. Companies may have extra criteria needed for testing due to its expense. They could require people to have multiple failed medication trials or a history of adverse side effects before agreeing to pay for such services.

Final Thoughts

Anyone struggling with intense, debilitating, or concerning mental health symptoms wants medication to quickly and effectively alleviate their concerns. However, starting a medication can often be frustrating and fruitless. If you are planning to start a medication or change your current regimen, you may want to talk to your prescriber about pharmacogenetic testing.