Pharmacogenetics uses a patient’s genetic information to aid prescribers in selecting the right drug at the right dose for that patient.
WHAT is Pharmacogenetics?
Researchers have identified some 200 drug–gene pairs in which a particular gene mutation has implications for how a patient will respond to a given drug. The National Institutes of Health (NIH)–funded Clinical Pharmacogenetics Implementation Consortium (CPIC) has compiled these pairs into a list along with clinical guidelines. FDA offers a list of drugs for which pharmacogenomic markers are included in the labeling.
In addition to cancer drugs, medications for HIV, heart disease, depression, and chronic pain, among many other conditions, are associated with genes that can modulate the drugs’ effects or the adverse effects they bring.
Take codeine, for example. The cytochrome P450 (CYP) 2D6 gene produces a protein that converts codeine into morphine in the body. The morphine then has its pain-relieving effect. Some people have a mutation in CYP2D6, however, that causes the body to convert codeine too slowly or not at all, rendering the drug ineffective. Another possible mutation in the gene can cause dangerously high levels of morphine to accumulate in the body after a standard dose of codeine.
“There’s been cases where children have died from having too much morphine because the conversion by that gene is ramped up,” said James Hoffman, PharmD.
Just as a patient’s age, lifestyle, existing comorbidities, and other medications figure into a prescriber’s selection of a drug, genetic predisposition to do well or poorly on that drug is a crucial clinical factor that health care providers can now consider.
“If you’re a patient newly diagnosed with depression, we have 10 or 15 drugs that we know will work in the population, but we need to know which one to pick for you,” said Mark Dunnenberger, PharmD, director of the pharmacogenomics program at NorthShore University HealthSystem in Evanston, IL. “Up until today we might ask the patient, ‘Has somebody in your family had this problem before? What medications worked for them?’ That really is a genetic question.”
Physicians sometimes do the “trial and error” process of trying numerous drugs before finding one that works. Each drug can bring new potential risks, and the time it takes to find the right drug is time that the condition goes untreated. Genotyping can increase the odds that prescribers try the right drug first.
“We believe it will lead to safer, more effective medication therapy by reducing the probability that patients accumulate side effects and by increasing the probability that the patient receives the benefit we expect from the medication,” said Dunnenberger.
Pharmacists and other health care providers should not see pharmacogenomics as an esoteric bench science, Hoffman added, but as a tool for optimizing medication safety.
Rather than removing codeine from formularies, for example, in response to mortalities associated with the drug, “it allows us to still use codeine safely in our patient population,” Hoffman said. “[Codeine] is a good application for pharmacogenomics because it leaves this therapeutic option that can be used safely. More therapeutic options are usually better.” ~American Pharmacists Association
Pharmacogenetics has many applications in todays medicine. PGx Medical is the trusted and experienced resource for the implementation of pharmacogenetics in the field of aging services.
Our team of educators/consultants travel around the country working with healthcare professionals to help implement this program into senior communities, pharmacies and provider organizations. Pharmacogenetics addresses key clinical concerns such as falls, dementia, sleep, pain, med management and overall staff efficiencies.
For more information on pharmacogenetics, contact: PGx Medical, firstname.lastname@example.org or 405-509-5112.