Considerations for Pharmacogenomic Testing in the Pediatric Population for Behavioral Health Treatment

Kimberly Erlich, MSN, RN, MPH, CPNP, PMHS, Nurse Practitioner, Pacific Coast Psychiatric Associates & the Healthy Teen Project and Consulting Associate Faculty, Duke University School of Nursing, discusses considerations for pharmacogenomic testing in the pediatric population for behavioral health treatment following her presentation on the subject at the 2020 Virtual Conference on Pediatric Health Care.

Alana Hippensteele: Hi, I'm Alana Hippensteele from Pharmacy Times. Before we get started, one of our top articles today discusses the dangerous cardiovascular complications of COVID-19. There’s more of that on PharmacyTimes.com.

Today, I’m speaking with Kimberly Erlich, Nurse Practitioner at Pacific Coast Psychiatric Associates and the Healthy Teen Project, as well as a consulting associate faculty at the Duke University School of Nursing, on pharmacogenomics and behavioral health following her presentation on the subject at the 2020 Virtual Conference on Pediatric Health Care.

When is it appropriate to consider pharmacogenomic testing for a patient?

Kimberly Erlich: So, we have talked about this a little bit in the talk, right, so in this field, there are two different schools of thought. So, there's a school of thought that considers testing appropriate for patients before a clinician prescribes any medication at all, kind of as a guide to medication prescribing practices, and there's another school of thought that considers this testing appropriate for patients who have been prescribed medications in terms of helping to monitor response. I, myself, use this testing exclusively after prescription of medications after patients have tried at least a couple of different medications. Most typically I have no hard and fast rules, but I myself don't use this testing pre-prescription. I understand that some people are using it like that, but that's not how I use it. I use it as a tool in my toolbox, my sort of virtual tool box, as a medications prescription support tool, sort of a decision support tool, to think about how to help patients through sort of an inadequate response or an unexpected response to medications. We have patients who come and have had 1, 2, 3, or upwards of 3 sort of adequate medication trials, meaning they've been on an appropriate dose for an appropriate amount of time, they've been actually taking the medication, their adherence is appropriate, and they've not had the appropriate response that we as clinicians know to expect in this population, in this age group. In this population of people who has a specific disease entity, specific diagnosis can help because they're not having the anticipated response so this pharmacogenomic testing can help provide a little into why that might be the case.

Alana Hippensteele: Great, great. Why might pharmacogenomic testing potentially be less applicable for the pediatric population?

Kimberly Erlich: So testing could potentially be less applicable for a pediatric population because they might have not had as many drug trials as people who are adults. Also, I wanted to mention that there are, I don't know that this directly affects applicability to the pediatric population, but it certainly could impact applicability. There are ethical questions involved in any sort of genetically based testing, including pharmacogenomic testing for children, adolescents, and something I mentioned in the talk as well was that, you know, there's a place on many testing sheets from these companies who offer this type of testing for parents to provide written consent for their children and adolescents to be tested. There isn't any space on these forms that I've ever seen from any of the companies that I've used for children or adolescents to provide written assent. Of course, I and many other clinicians are documenting in our clinical notes assent for pediatric and adolescent patients for whom we've explained this testing in a developmentally appropriate manner, but some could argue that there's still an ethical issue with parents deciding for their children whether to have genetically based testing.

Alana Hippensteele: Right, right. How can pharmacogenomic testing guide decisions regarding medication dosage?

Kimberly Erlich: Yeah, so this is an interesting question, and this is kind of at the heart of pharmacogenomic testing at this point. So, the most applicable testing relates to what's called cytochrome p450 metabolism, and there are multiple components of that cytochrome p450 metabolism, and those components can actually show how a person metabolizes different medications. For example, it can describe whether patients are normal metabolizers, extensive metabolizers, poor metabolizers, and those metabolizer phenotypes, as they're called, may impact the dosage of medication. That's more appropriate for those patients as compared with the general more homogeneous group of patients receiving any medication, and this really gets at the applicability of pharmacogenomic testing to the idea of personalized medicine being able to provide a more personalized approach to prescribing based on individual genetic polymorphisms.

Alana Hippensteele: Right, right. And why is pharmacogenomic testing potentially less applicable in an inpatient setting?

Kimberly Erlich: So, before, I am sorry, I wanted to mention that, you know, I personally don't have experience working in an inpatient setting. I've never had that experience and that's not currently where I work. But I can provide some thoughts about this. So, in general, as I mentioned in terms of thinking about the use of pharmacogenomic testing as a way to help guide patients through their trajectory of care that requires a lot of monitoring, and an ongoing relationship that clinicians and prescribers have with their patients over time. In an inpatient setting, clinicians are seeing these patients for really a brief snippet of time and don't have the ability to monitor reactions to medications over a longer period of time that you would actually need to determine whether testing is appropriate and kind of the outcome of testing and to really allow the testing to help guide prescription of medication over time.

Alana Hippensteele: Right, right. You mentioned in your lecture that pharmacogenomic testing can show whether a patient's behavioral health would benefit from exercise. Could you explain further how pharmacogenomic testing is able to show this?

Kimberly Erlich: Sure, I can explain a little about this briefly because it's quite complicated, and there are a lot of studies. So in general, research has shown that carriers of variations of several genes, most importantly the brain-derived neurotropic factor BDNF gene, have a significant response in their depressive symptoms when implementing an exercise regimen. If an individual patient knows this about themselves ahead of time, it might help to improve their motivation for exercise. This is really important, especially with patients with major depressive disorder who have a motivation or lack of motivation as one of their depressive symptoms. It may be hard to convince a patient that exercise could actually impact their depressive symptoms.

Alana Hippensteele: Right, right. And what is the future of pharmacogenomics and behavioral health in your opinion?

Kimberly Erlich: So, this is one of my favorite questions, and I'm going to pull this back to the fact that I'm a child adolescent specialist. I think that the future of pharmacogenomic testing and behavioral health is more high quality pediatric focused studies and additional populations even beyond pediatric populations, additional populations that are not research populations, but are more clinical populations, community samples, also racially and ethnically based genetic information to help advance the personalized approach to medication prescribing in the future.

Alana Hippensteele: Fantastic. Alright, thank you so much for taking the time to speak with me today, Kimberly. Now let's hear from some of our other MJH Life Sciences brands on their latest headlines.