Pharmacists Can Improve Access to Pharmacogenomics

In an interview with Pharmacy Times, Adrijana Kekic, PharmD, a pharmacogenomics clinical specialist with Mayo Clinic in Phoenix, Arizona, discussed current guidelines for pharmacogenomics. She also reviewed pharmacists’ roles and current barriers to wider pharmacogenomics utilization.

Q: What do current guidelines recommend when selecting drugs and doses based on pharmacogenomics?

Adrijana Kekic, PharmD: I would maybe bucket [current guidelines] into buckets. First of all, the current guideline that we use in United States is primarily CPIC—Clinical Pharmacogenomic Implementation Consortium—guideline. We sometimes can leverage DPWG, which is our Dutch colleagues’ or European colleagues’, they also have their own guidelines. Sometimes there is a difference between the 2, so we tend to defer to CPIC typically. Now, how we leverage them, as I said, there are 2 buckets. The way that I see them is that one would be really identifying anything where a drug should not be prescribed. For example, with the genetic testing, we can identify if somebody may not be a good candidate for carbamazepine, and that has nothing to do with how the medication is metabolized. It has to do with so-called HLA genes, human leukocyte antigen genes. And if you're not familiar with these, it's okay. You can think of them simply as genes or proteins, in other words, that help you distinguish self from non-self. We know that there are people who will have mutations or genetic variants on these genes, that if they took carbamazepine, they can have an increased risk of hypersensitivity reactions. So, we actually have some really nice SEPA guidelines that will tell us, well, if this mutation is present, we recommend essentially avoiding the therapy, or maybe going with an alternative therapy. Or if the therapy is really, really, really needed, let's monitor early on for these specific things. So, that's one bucket, I would call that a red bucket. Let's be very careful with that drug if we're prescribing it, but it would be best that we don't.

The second bucket is going to be more of the clinical guidance in terms of the dosing, which is really to do with your question. And that is, we simply can identify which patient will be at increased risk of toxicity, in which case CPIC will give us sometimes specific recommendations, like let's say go with 25% to 50% of the dose of paroxetine if you have somebody who is a poor CYP2D6 metabolizer, something along that line. Or the opposite spectrum of that would be if you have somebody who's an ultra-rapid metabolizer…the current evidence shows that those individuals may not get the full clinical benefit from those medications simply because of greatly altered pharmacokinetics, meaning they metabolize those medications faster. So those are 2 big buckets, meaning the drugs to avoid and the drugs that we can be smart in how we use them, and what would be the most effective dosing strategy based on the patient's genetics.

Q: How are pharmacists involved in pharmacogenomics?

Adrijana Kekic, PharmD: Pharmacists, I hope, are not only going to play important role in terms of interpreting these test results and making sense of what to do with drugs and doses and whatnot. I hope that the trend that we have seen in the past few years continues, and that is on the clinical end. Pharmacists tend to be used in this capacity as, I am hesitant to use the word ‘drug expert,’ but really drug guides, if you will. How do we best personalize therapy once those results are back? This means that a lot of pharmacist will have to do some additional training and education, maybe certification classes in pharmacogenetics, maybe some hands-on training at the institution or places they're at, because overall in the health care community our genetic literacy remains slow, including us as pharmacists. I think where most pharmacists are leveraged now, clinically speaking, is in a way that we understand pharmacology. We’re really trained on pharmacology the most of all of the health care professionals, and I jokingly always say that pharmacogenomics right now is pharmacology on steroids. It really gives you this very detailed insight look at the person's body in terms of their ability to process medication, but also what the medication does to the body. So, clinically, we're used to screening patients, interpreting test results, implementing the CPIC guidelines that I mentioned, layer the genetics on top of other pharmacology considerations when it comes to therapy, and then obviously give some sort of a personalized drug selection and dosing to health care teams.

And the other thing that I'm not going to go into great detail with, but pharmacists are heavily involved in implementation efforts across community settings, institutional settings, and so on. They’re essential integral members of the interdisciplinary teams that are bringing the pharmacogenomics as a tool of precision medicine into their practices. And the reason is exactly what I mentioned. But also, a lot of pharmacists maybe wear a couple of hats, like maybe being not only a clinical pharmacist, but also an IT specialist. And the reason is there is a close communication between labs, clinical decision support, or essentially integrating all of this into either electronic health records or a place where this data will be housed.

Q: What are some barriers to implementing pharmacogenomics more proactively?

Adrijana Kekic, PharmD: This is a great question, because the first thought that comes to mind based on the experiences that I have and what I have seen, is exactly what I mentioned prior. And that is that the health care, health literacy, genetic literacy in the health care is really low. So, one of the first things that we can address if this is a barrier or an opportunity—I like to think of it more as an opportunity—is to increase our genetic literacy. So, how can you do it as a pharmacist? A bunch of certifications are available nowadays. If I reflect back on few years ago, there was not really much available. So, please, my advice to my colleagues, residents, fellows, seasoned pharmacists, is to seek those opportunities and really just further expand your pharmacology knowledge. It's a beautiful thing to be able to get more detailed insight into what's going on in a person's body, so we can help them more appropriately.

The second thing has to do with operability. You know, it's great that we're talking with rose-colored glasses, looking at how pharmacogenetics and pharmacogenomics—those 2 are a little distinct—but how they can improve clinical outcomes in patients’ lives. But there are a lot of logistical barriers that have to be overcome. And my suggestion, our recommendation to pharmacist colleagues, would be get involved with associations that are already helping others implement this in their clinical practice. For example, there are a lot of resources that are available. There are even clinical decision support templates and clinical note templates available, but also pathways and strategies and tactics that you can use on your teams as you're advocating for this, as you're seeking physician champions, for example, which is another opportunity. Or as you're looking for either internal and external vendors, or labs in other words, that will be able to provide genetic testing. Or perhaps, you know, how do you build a clinical decision support? And I think there are 2 distinct buckets here, and that is clinical outcomes and operational outcomes. And the big thing with all of this would be capture it in a way that can tell a story of success and opportunities as they move along. So, genetic literacy, number one, and then operational hurdles. Obviously we already have some resources available that pharmacists can now leverage in their places of practice.

Q: Is there anything you’d like to add?

Adrijana Kekic, PharmD: I would say this is a prime time to get involved. Don't be discouraged, you know, if you read an article, and there is a lot in terms of terminology that you may not be familiar with. All of this is a language, pharmacology and genetics is also a language. Once you get proficient in just basic words, you can start to put pieces together. So do get engaged, share your clinical stories, maybe connect with those colleagues who have been doing this for a while, who maybe can hold your hand in the beginning. But then you can start to really say, I'm getting some clinical insights here and I want to answer these questions, you know, for the patients that maybe we did not tackle before. So, I’m a huge supporter of pharmacogenomics, bringing pharmacogenomics to clinical practice, because this is the future and the future is now and pharmacists are leading the charge.