Pharmacogenomics another opportunity to advance the pharmacy profession
Pharmacogenomics, an emerging field in pharmacy practice, is an area of medicine studying how genetics affect medication response in individuals. Generally, pharmacogenomics has been associated with cytochrome P450 metabolism, though the current scope of testing extends well beyond that. Pharmacogenomic testing is recommended for medicines with wide-ranging indications including proton pump inhibitors (PPIs), nonsteroidal anti-inflammatory drugs, and medicines to treat hyperlipidemia, seizures, or depression.
My practice site, The Christ Hospital Physicians (TCHP) in Cincinnati, OH, implements pharmacist services using a model embedding pharmacists within primary care provider (PCP) offices as well as cardiology, oncology, and musculoskeletal clinics. All ambulatory pharmacists work within clinics with physicians, nurse practitioners, and medical assistants to improve medication selection, use, and safety. Pharmacists complete visits for chronic disease management, comprehensive medication reviews, population health, and pharmacogenomics.
All TCHP pharmacists have completed pharmacogenomics certificate programs through the American College of Clinical Pharmacy or the American Society of Health-systems Pharmacists. Pharmacogenomic results are placed in the labs section of patients’ charts for easy access and integration with software that pulls results into a real-time gene–drug and drug–drug interaction checker. Pharmacists analyze all pharmacogenomic results and provide recommendations to ordering clinicians.
Example of improved patient outcomes
Prospective pharmacogenomic testing was completed for a 74-year-old male with depression, atrial fibrillation, and hyperlipidemia. He was taking citalopram, apixaban, and atorvastatin. Testing revealed mutations in the genes for Factor II and HLA-A*31:01, and altered metabolism for CYP2C19 (rapid), CYP2D6 (poor), and SLCO1B1 (decreased). Citalopram was metabolized so quickly that it was likely ineffective. His results indicated there were few alternatives to citalopram unaffected by his genomic profile. Testing also identified increased risks for blood clotting, an increased risk for myalgias related to statins, and a sensitivity to carbamazepine, though he has no history of seizures. Sertraline was identified as a suitable first-line alternative, given his genomic results.
Genomic testing identified he needed lifelong anticoagulation and that he would be more likely to need a dose reduction in atorvastatin rather changing to a different statin. Additionally, the fact that he should avoid carbamazepine if the need ever arises is now accessible to all care providers in our health system. These recommendations were communicated to the patient’s PCP in person and via the electronic health record. The pharmacist and PCP discussed the medication implications of these results.
Following this discussion, the PCP-approved interventions were communicated to the patient via a phone call. The patient noticed improved depression symptoms with sertraline compared to citalopram at his next follow-up visit. Even more interesting, his results were used a month later to identify the need to increase the dose of a newly prescribed PPI.
Medication regimens selected more precisely
Pharmacogenomics can help select medication regimens more prospectively and precisely compared to typical care models. Utilizing pharmacists in the implementation of pharmacogenomics presents an opportunity for pharmacists to provide valuable input to a patient’s care. This case highlights the need for this important information to be directly integrated and easily accessible in a patient’s chart to help reduce medication-related problems and improve patient care.
Garrett Lambert, PharmD, BCACP, is an ambulatory care pharmacist and the clinical coordinator of the primary care pharmacist team at The Christ Hospital Physicians in Cincinnati, OH. He is interested in providing high quality direct patient care and interventions in innovative practice settings. He loves sports, trivia, movies, cooking, and spending time with his wife, daughter, and dog.