Peeking into your patients’ DNA to gain insight into their treatment might seem like something out of science fiction. But with pharmacogenetic testing, sometimes known as pharmacogenomic testing, looking at genes isn’t just a plot from a Jurassic Park movie. It’s accessible technology you can use to personalize patient care.
Greenwood Pharmacy and Compounding Center, an enhanced services pharmacy located in Waterloo, Iowa, started offering pharmacogenetic testing as a way for patients to learn more about themselves and their medication therapies.
“Since we are practicing as an enhanced services pharmacy, we try to focus on optimizing the medication therapy for each individual patient,” said Rob Nichols, a pharmacist at Greenwood. “This was another tool that would allow us to move closer to precision medication.”
Most pharmacists are familiar with this scenario: a drug that works perfectly for one person doesn’t have the desired effect on another, or one patient suffers from the worst side effects while others don’t have any side effects at all.
The reason for these differences lies in patients’ DNA, which affects how they metabolize drugs. In the past, physicians and pharmacists would have to go through months of trial and error to figure out the right drug and dosage if a medication wasn’t working as expected, but now pharmacogenetic testing offers a shortcut.
Greenwood Pharmacy started offering pharmacogenetic testing in February 2019 after hearing about the service at trade shows. “We were interested in helping people understand how that one piece of themselves—their genetics—can impact how their medications will work for them in the future, in addition to all the other things that can impact how medication therapies are effective or ineffective for people,” Nichols said. “It’s the kind of thing we’d learn about in pharmacy school, but up until that point, we didn’t really have a good means of implementing it.”
Pharmacogenetic testing works by testing a saliva or blood sample from a patient and looking at a set of genes known to influence how drugs are metabolized. By looking at variations within these genes, pharmacists can assess the effectiveness of the patient’s drug regimen. For example, they may find that the patient is metabolizing drugs faster than average and would therefore benefit from a higher dose to achieve the desired outcome. If a patient has a slower metabolism, they could need a lower dose to avoid side effects.
Having a pharmacogenetic test on file can also help prescribers make better decisions from the beginning because they can prescribe the right drug and dose right off the bat.
Metabolism phenotypes
When you perform a pharmacogenetic test, each gene tested will be classified with a metabolism phenotype. These phenotypes indicate the enzyme activity for each gene, which in turn gives providers a clue about how patients will react to their prescribed medications.
The phenotypes are defined by the Clinical Pharmacogenetics Implementation Consortium as:
Normal Metabolizer (formerly Extensive Metabolizer)
These patients will metabolize drugs at a normal rate, meaning they can take the standard dose.
Intermediate Metabolizer
These patients metabolize drugs more slowly, meaning they could experience unwanted side effects at a normal dose and could benefit from a lower dose.
Poor Metabolizer
These patients metabolize drugs even more slowly than intermediate metabolizers. This could cause an accumulation of the medication in the body. Even at a lower dose, poor metabolizers could experience unwanted side effects.
Rapid/Ultrarapid Metabolizer
These patients metabolize drugs more quickly than a normal metabolizer, meaning the drug could metabolize before it achieves the desired effect. They may need a higher dose to attain the desired effect.
Performing the test
At Greenwood, patients who want to receive pharmacogenetic testing services can sign up for an appointment through the pharmacy’s website. At their scheduled appointment, they will fill out a consent form and a mini medication review. Nichols explained, “That’s so we can appropriately evaluate all their current medications with the test and start thinking about potential future medications.”
After collecting the patient’s medication history, health history, and allergy history, they swab the cheek to collect DNA data from saliva and send that sample off to a lab. After about three weeks, the pharmacy receives results from the lab that break down the genetic reactions of the patient. Then the pharmacist goes over the test results with the patient and discusses how it affects their current and future treatments. The pharmacist also discusses the results with the patient’s healthcare providers and makes recommendations.
Certain types of patients are particularly strong candidates for pharmacogenetic testing—those who have been prescribed four or more medications, those experiencing unwanted side effects or adverse medication reactions, and those who are not responding to their current medications as intended. Nichols has established relationships with medical practices in the area that will refer their patients for pharmacogenetic testing, including pediatricians and mental healthcare providers. “Those are the patients we work with most often,” he said. “But realistically, we will work with anyone who is interested in learning more about their genetics.”
Nichols finds that the vast majority of patients who use the pharmacogenetic testing service gain useful information for the future, regardless of why they chose to take the test. “When we are able to gather more information about patients, we can always find something that can be implicated about their current or future therapy,” he said. “It may be something that we can suggest to the provider if they need to go another route with medication choice or dosage. At the very least we’re able to give some education on things they will need to keep in mind about how their future medication therapy choices will be impacted by the pharmacogenomic data.”
Typically, the pharmacy receives about one referral for the service a month, but it’s a service that patients value highly. Nichols said, “The patients we do interact with are very grateful for the breadth of information that we have regarding their genetic profile.”
Working with vendors
Since pharmacogenetic testing is done in a lab, you will have to find a company to partner with. Many labs offer pharmacogenetic testing, but they aren’t all created equal. When choosing a vendor, look beyond the price point and investigate what each testing panel actually tells you. Some testing companies will give you information pertaining to 45 genes, while other companies will only test for 30 genes. Ask vendors to provide you with a sample report so you can get a detailed idea of what kind of information you will be able to share with your patients.
“The feedback we have been getting from our patients is that our panel is more extensive and provided at a lower cost than what they are able to find online,” Nichols said.
When Greenwood Pharmacy decided on Rx Genomix as their vendor, they enrolled with the company as a provider, which means they can send samples to the company’s lab for testing. They pay Rx Genomix for each test rather than paying on a contract basis.
“It’s very simple. We send the tests in and receive the lab reports, and then we get an invoice for the test, which we pay for,” Nichols explained. “It allows for really good cash flow prediction, which made it an easy decision for us to start offering the service.”
On the patient side of the payment equation, some insurance plans cover pharmacogenetic testing, but that coverage is spotty. Greenwood offers their pharmacogenetic testing as a cash service, and the service began turning a profit just a few months after implementing it.
Implementing pharmacogenetics
Like any new service, one of the biggest challenges Greenwood Pharmacy faced was simply getting the word out to the community. “It’s still a relatively new service, but it was nice when we started to have providers reach out to us asking questions about the service, and those referrals really helped us along,” Nichols said. “I would definitely recommend that people reach out to local providers to see who is interested.” Tell them about the test that you offer and the kind of results you can share with patients, because they may see a way to apply that information to their practice.
Another asset Greenwood had when starting its program was an online scheduling program where patients book their appointment online. “It made things a lot easier that we could predict when people were going to be interested in the service and make sure to have it available for them,” Nichols said. “It definitely helped us manage our workflow a little better.”
Training staff on the cheek swabbing was fairly easy, as the skill overlaps with some of the other services the pharmacy offers. “There’s not much of a training barrier,” Nichols said. “We were doing the nasal swab for patients during Covid, and transitioning to a cheek swab for the pharmacogenetic testing meant that training for that collection was really easy.”
Greenwood Pharmacy is one of the University of Iowa’s community-based residency sites, and the residents can easily perform the service. “In pharmacy school, we learn a lot about the main enzymes that pharmacogenetic tests evaluate, so our residents are already trained and knowledgeable about how to evaluate these tests,” he said. Overall, pharmacogenetic testing has required no time-consuming staff training or burdensome workflow disruption.
Who is pharmacogenetic testing for?
Most patients can benefit from learning more about how their genes affect their medical treatment, but certain conditions are more frequently treated with medications that have a pharmacogenetic implication. Patients with these conditions may see an even greater benefit from pharmacogenetic testing:
- Acute or chronic pain
- High blood pressure
- Depression
- Anxiety
- Mental health conditions
- Diabetes
- High cholesterol
- Cancer
- Arthritis
- Acid reflux
- Peptic ulcer
- Migraines
- Thyroid disorders
- Asthma/COPD
- Heart attack
Source: Rx Genomix
From the Magazine
This article was published in our quarterly print magazine, which covers relevant topics in greater depth featuring leading experts in the industry. Subscribe to receive the quarterly print issue in your mailbox. All registered independent pharmacies in the U.S. are eligible to receive a free subscription.
More articles from the December 2021 issue:
- Artificial Intelligence: Will Machine Learning Revolutionize Retail Pharmacy?
- Pharmacy Relief Agencies: How to Get Through Staff Shortages
- Risk Management Strategies for Small Businesses
- This Community Pharmacy Personalizes Patient Care Down to DNA
- National Retail Trend: Creating Your Own Brand of OTC Products
- Best Practices for Front-End Pharmacy Shelving
- Mental Health First Aid: Why Every Pharmacist Should Take the Training
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