Pharmacogenetics in the Community Pharmacy
Knowing the genes can help in choosing the drugs
Pharmacogenetics is moving into the community pharmacy. A patient’s DNA sample is taken in the pharmacy, sent to a lab, and in a couple of weeks, the patient, pharmacist, and health-care provider can learn which medications are the best choice for that patient—the ones most likely to work safely. Pharmacogenetic testing, a form of precision medicine, has a large potential for helping prevent adverse reactions and wasted medications, and it may also become a new revenue stream for pharmacists.
Pharmacogenetics is the study of the genetic factors that affect the drug metabolism, drug transport, or drug receptors in individual people. Genetic variations cause individuals to respond differently to medications; they give some people a lesser or greater sensitivity to certain drugs, which in turn can increase the likelihood that a given drug will be ineffective or produce an adverse reaction.
Many Genes and Dozens of Drugs
An average pharmacogenomics panel contains 10 to 20 genes known to affect how a patient might respond to medications. The number of drugs linked to these genes may number in the dozens or hundreds, depending on the laboratory doing the reporting. For example, the laboratory at NorthShore University HealthSystem in Evanston, IL, tests a sample and gives a report on 60 different drugs, according to Mark Dunnenberger, PharmD, Program Director for Pharmacogenomics at the NorthShore Center for Personalized Medicine.
Rxight, developed by MD Labs of Reno, NV, tests a sample and creates a genetic medication report on more than 200 individual drugs in over 50 different categories, said Chuck Dushman, MBA, Vice President for Marketing and Business Development for MD Labs, which owns Rxight. These classes of drugs include categories such as blood pressure drugs, cholesterol lowering agents, anticoagulants, antidepressants, and anxiolytics among others. Individual drugs that can be affected include Plavix, Adderall, Celexa, codeine, Synthroid, and Xanax.
The difference in the number of drugs for which any two pharmacogenetic laboratories create reports stems from what threshold they use for evidence of how the gene affects the drug, said Dunnenberger. NorthShore, for example, uses a very rigorous evaluation of the literature on pharmacogenetics, he said.
Currently, there is not a lot of regulation in what the results mean or on how patients should be counseled on what they mean, Dunnenberger noted. The Clinical Pharmacogenetics Implementation Consortium (CPIC) creates guidelines on how to use information on specific genes, but different laboratories interpret the results differently. “There is a little bit of a Wild, Wild West feel to some of the things that are happening in pharmacogenomics,” Dunnenberger said. “This is a new thing and it can be done wrong. We need to be responsible in how we do it, otherwise we are going to lose the value of pharmacogenomics.”
However, the spread of pharmacogenetics into the community pharmacy makes sense, Dunnenberger said. “Pharmacogenomics can help patients regardless of their setting as long as it is done responsibly and there is a way to store the data and use it over and over again,” he said. “It can bring a lot of value to the patient.”
In the Pharmacy
Several pharmacogenetics laboratories work with physicians’ offices and medical groups, but there are a few that work directly with pharmacists to offer the testing through pharmacies. Pharmacists can screen for patients who might benefit from the testing, said Edana Holliday, PharmD, a PGY1 Community Pharmacy Resident at RxClinic Pharmacy in Charlotte, NC. This could include those who have been switched from one antidepressant to another more than once, or a patient on several cardiac medications.
Participating pharmacies have displays and product boxes for Rxight that customers might ask about, added Tana N. Kaefer, PharmD, Clinical Coordinator with Bremo Pharmacies in Richmond, VA. In addition, health-care providers can request testing for a patient once they know a local pharmacy is offering testing. Anyone asking about the test is informed that it does not help diagnose or treat any medical conditions, she said. “We are only looking at genes that are implicated for metabolism of medications.”
“We have to have a doctor’s order for it and we do have to collaborate with providers,” Kaefer said.
Holliday said that pharmacists from RxClinic talk with local physicians. “If they are not sure or if they have concerns about the process in general, then we typically provide an in-service education to the provider and practice.”
Once the provider’s prescription for the test is in hand and the patient is counseled on the purpose of the testing, the patient swabs the inside of each cheek—one swab to a side—for 45 seconds. The swabs are then placed in the box along with the prescription, a complete list of the patient’s medications, and forms filled out by the patient. The box is mailed off to the laboratory, Holliday said.
With Rxight, the lab generates a report and a Rxight-certified pharmacist schedules a personalized medication review with the patient. During this review, the pharmacist goes over the results and makes sure that the patient understands what they mean. The patient is instructed that no changes to any medication regimen should be made without the approval of the health-care provider. The provider receives a copy of the report with the pharmacist’s recommendations about changes in medications.
“We go over all their medications and make sure there are no interactions or problems with the regimen they are currently on and then we go a step further,” Holliday said. “We talk about all the genetic implications based on those medications. We ask about the patient’s education and what they currently know about genetics and pharmacogenetics and explain some of the terms.” Part of the counseling session involves educating the patient about nongenetic problems with drugs. The report is posted to a secure website for future use, but the patient cannot access the report before talking with the pharmacist, she said.
All results for pharmacogenetics testing should be available to health-care providers to guide their prescribing in the future, Dunnenberger stressed. If more drug interactions are found in the future for the genes that were tested, the test does not have to be redone.
Although pharmacogenetic test results have been described as unchanging because genes don’t change, this is not entirely true. If new and important gene variants are uncovered in the future, a patient may need additional testing. “What is true is that the test has lifetime value because that test result is accurate the rest of the patient’s life, but we may need to augment that,” he said.
Who Pays? (And Who Pays the Pharmacist?)
As yet, health insurance companies are not always on board with covering pharmacogenetics testing for most drugs, Dushman said. Some insurance providers cover pharmacogenetic testing for patients being prescribed Plavix, and others cover testing for antidepressant medications.
The cost to the patient for Rxight’s testing is $399, according to Kaefer and Dushman. Some patients are willing to pay out-of-pocket because they feel the testing will help them. Total out-of-pocket cost to a NorthShore patient is $450, said Dunnenberger, and the health system facilitates billing insurance companies. “But we’ve had pretty poor response on trying to get insurances to cover this upfront.”
For the community pharmacist, pharmacogenetic testing is reimbursed directly by the laboratory. Rxight reimburses the pharmacist for the time spent in the personalized medication review, Dushman said. However, he declined to give a figure for this reimbursement.
Rxight is working with independent and regional chain pharmacies across the country, Dushman said. “We have hundreds of pharmacists across the country trained and certified to provide the Rxight program to their patients,” he said. “There is this window of opportunity for them to become the leader and expert in pharmacogenetics in their community.”
“This is a great program and a great idea. The people who have struggled with medications or finding the right ones are really seeing the benefit,” said Kaefer.
“I think this is the future of pharmacy,” she said.