Pharmacogenomic (PGx) testing can bring a wealth of benefits to patient care. Having PGx data can help inform prescribing decisions like medication selection and dosing to support medication efficacy and avoid potential adverse drug reactions.

Some patients, however, will see more actionable information from PGx testing than others. A patient undergoing chemotherapy or struggling to find the right antidepressant will likely have more immediately actionable results than a patient not currently taking medications. Additionally, factors such as drug-drug interactions, patient health, and age play a role in drug metabolism and efficacy.

While testing every single patient would certainly enable you to help those who could see the most utility from a PGx test, that is, at best, impractical. So, how can you determine which patients to test?

Evaluating patients for pharmacogenomic testing

Every patient can gain insight from PGx testing, but providers want to focus their energy where it will produce the most meaningful results. There are two key ways to identify which patients may see the most actionable information from their PGx test: based on existing conditions and through patient-specific evaluation.

Condition-specific testing

At one end of the spectrum are patients with specific, known conditions. Cancer patients on chemotherapy, for example, often see benefit from PGx testing — not just for their chemotherapy drugs, but for ancillary medications like those for pain and nausea.

Other patients who see a great deal of benefit from pharmacogenomic testing are those managing cardiovascular conditions like blood clots or hypertension, patients with depression or anxiety, and patients in need of pain medication. For all these conditions, you can use PGx test results either retrospectively (to determine why a medication didn’t work or caused an adverse reaction) or prior to issuing a prescription to help make prescribing decisions. For more information on PGx testing for specific conditions, download our info sheet.

But, what if a patient doesn’t have one of these conditions or needs? They may still be a good candidate to benefit from PGx, but how do you identify which patients will see actionable results?

Questions to ask your patients

Identifying patients who may be good candidates for pharmacogenomic testing takes just a few strategic questions.

  1. How many prescription medications are you currently taking?
    According to a study by the Mayo Clinic, 70% of people in the U.S. are taking at least 1 prescription medication, and 20% are taking 5 or more. Polypharmacy is a strong indicator that patients will derive value from a PGx test, as the more medications a person is taking, the greater the likelihood one or more could have an actionable gene variant interaction.

  2. Have you ever had a medication not work at it is supposed to?
    Previous experience with medication failure is a flag that a patient may have genetic variants impacting their medication response. Determining what condition the patient had or which medication(s) did not work can help validate whether a PGx test is likely to uncover a genetic cause.

  3. Are you currently or have you ever experienced side-effects from taking a prescription medication? If so, how severe were they?
    Similar to previous experience with medications not working, previous experience with side-effects or adverse drug reactions may indicate genetic variants impacting medication response.

These, of course, are not the only indicators that you will get immediately actionable PGx data for a given patient, and they may not be the only questions worth asking. Other factors like which medications a patient is taking (the RightMed® test, for example, covers more than 300 medications), age, gender, comorbidities, and more can be factors.

Preemptive pharmacogenomic testing

One thing to remember is that there is no “use-by” date on pharmacogenomic test results because people’s DNA doesn’t change. Even if a patient’s test results don’t inform their care plan today, that doesn’t mean they won’t benefit from having this information available down the line. And having PGx data on hand prior to a patient being diagnosed with cancer or developing hypertension can be invaluable.

Imagine having the ability to look at a patient’s PGx report at the point of prescription, rather than after a medication has already failed or produced an adverse reaction. Actionable information, doesn’t necessarily mean actionable today.

While more than 90% of patients have actionable genetic variants that may affect medication response,1,2 you may occasionally have a patient with few or without any known drug-gene interactions. This is not only great news for the patient, but it is still useful for you, since you will be able to focus your attention on other factors, like drug-drug interactions, if a medication doesn’t work as expected or produces side-effects.

How to get started

If you have patients you believe may benefit from PGx testing, you can get started by downloading our provider toolkit. This resource gives you the information you need to add PGx testing to your practice and patient care.

References

1Van Driest, SL, et. al., Clin Pharmacol Ther. 2014; 95(4): 423–431.
2Yuan, J. et. al., Jmol Diag. 2016; 18(3): 438-445.
Julie England
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