BLOG: Pharmacogenomics is the study of how DNA differences affect response to medications. This can explain why similar patients have different reactions to the same medication even if they receive the same dosage. The pharmacogenomics clinic at NorthShore is the first step toward a larger implementation.
Pharmacogenomics is the study of how differences in DNA affect response to medications. These differences in DNA can help explain why a couple of otherwise similar patients can receive the same medication at the same dose for the same indication and have different responses. The medication may work well for one patient, while the other patient may receive no benefit or experience side effects.
In 2013, 738 million outpatient prescriptions in the United States were written for pharmacogenetically high-risk drugs.1A pharmacogenetically high-risk drug is a drug for which a patient’s response may be substantially altered by a specific genetic variation. Examples of high-risk drugs include codeine, clopidogrel, and mercaptopurine. If a patient’s genotype is known when a medication is prescribed to that patient, the prescriber is able to make a more informed decision on whether to treat with a conventional dose, a modified dose, or a different medication altogether. Based on an individual’s unique genomic data, these actions will reduce the risk that a negative drug-related outcome will occur, leading to a safer, more effective treatment for each individual.
Currently, patients and providers obtain genetic results through various mechanisms, including direct-to-consumer genetic testing and personal genomics services. This has created a demand, from both patients and providers, for assistance with understanding and using these genetic results in the most responsible and beneficial way to optimize drug therapy. The pharmacogenomics clinic at NorthShore University HealthSystem (NorthShore) was created in response to this demand from the local community.
Patients may be self- or physician-referred to the clinic to determine whether pharmacogenomics testing is right for them and have the testing ordered, interpreted, and placed in their electronic medical record (EMR) or to better understand test results obtained elsewhere. During a clinic visit, patients are able to interact with genetic counselors, pharmacists specially trained in pharmacogenomics, and medical geneticists.
A patient’s medical history (eg, family history, medical conditions, previous medications), current medication list, and genetic test results are all evaluated when providing the final recommendations. Many of these recommendations are structured around the pharmacogenomic guidelines written by the Clinical Pharmacogenetics Implementation Consortium.2 The recommendations are commonly to choose another agent in the same drug class and could be impacted by the formulary list of an institution or insurance. For example, if a patient has a particular variant the recommendation may be to use rosuvastatin as an alternative to simvastatin to reduce the risk of side effects. The data collected and recommendations made during the clinic visit are placed in the EMR, from which providers can access this information. The ultimate goal of the clinic is to improve the management of patients by individualizing and optimizing drug therapy.
The pharmacogenomics clinic at NorthShore is the first step in a larger clinical pharmacogenomics implementation effort. This effort entails creating a system of clinical decision support tools that are fully integrated into the EMR. These types of systems are being developed in institutions throughout the United States and represent the future of clinical pharmacogenomics.3-8As more clinicians are exposed to pharmacogenomics, the amount and type of information they will want and need will change. A clinical decision support system needs to be agile, especially when new programs like NorthShore’s pharmacogenomics clinic are being developed. The implementation of clinical pharmacogenomics is a key piece in the initiative to integrate personalized medicine into routine patient care provided at NorthShore. Already, we’ve learned a lot about initiating personalized medicine and pharmacogenomics system wide.
Mark Dunnenberger, PharmD, is senior clinical specialist, Center for Molecular Medicine, Pharmacogenomics, NorthShore Center for Personalized Medicine.
Disclosure information: The author reports no financial disclosures as related to products discussed in this article.
1. Dunnenberger HM, Crews KR, Hoffman JM, et al. Preemptive clinical pharmacogenetics implementation: current programs in five US medical centers. Annu Rev Pharmacol Toxicol. 2015;55:89–106.
2. Relling MV, Klein TE. CPIC: Clinical Pharmacogenetics Implementation Consortium of the Pharmacogenomics Research Network. Clin Pharmacol Ther. 2011;89(3):464–467.
3. Shuldiner AR, Relling MV, Peterson JF, et al. The Pharmacogenomics Research Network Translational Pharmacogenetics Program: overcoming challenges of real-world implementation. Clin Pharmacol Ther. 2013;94(2):207–210.
4. Johnson JA, Elsey AR, Clare-Salzler MJ, et al. Institutional profile: University of Florida and Shands Hospital Personalized Medicine Program: clinical implementation of pharmacogenetics. Pharmacogenomics. 2013;14(7):723–726.
5. Pulley JM, Denny JC, Peterson JF, et al. Operational implementation of prospective genotyping for personalized medicine: the design of the Vanderbilt PREDICT project. Clin Pharmacol Ther. 2012;92(1):87–95.
6. Gottesman O, Scott SA, Ellis SB, et al. The CLIPMERGE PGx Program: clinical implementation of personalized medicine through electronic health records and genomics-pharmacogenomics. Clin Pharmacol Ther. 2013;94(2):214–217.
7. Bielinski SJ, Olson JE, Pathak J, et al. Preemptive genotyping for personalized medicine: design of the right drug, right dose, right time-using genomic data to individualize treatment protocol. Mayo Clin Proc. 2014;89(1):25–33.
8. Hoffman JM, Haidar CE, Wilkinson MR, et al. PG4KDS: a model for the clinical implementation of pre-emptive pharmacogenetics. Am J Med Genet Part C, Semin Med Genet. 2014;166C(1):45–55.