Doctors look for clues when trying to determine if a patient might become addicted to opioid painkillers. Clinical risk factors such as medical history, family history, and other environmental or social clues can help.
Addiction is estimated to be about 40% to 60% heritable, meaning genetics likely account for about half of a person’s risk.
Overdose deaths continue to climb with 19,000 deaths related to prescription opioid painkillers
While pharmacogenetics is not the end all be all, it is a tool used by many healthcare professionals across the country to help guide them in proper prescribing. It can help physicians and pharmacist determine if a patient has the ability to metabolize a pain medication, therefore alerting them if a patient says they are not receiving therapy and need more.
“There might actually be something to that,” said Clay Bullard, president of PGx Medical. “We’ve had physicians tell us they had patients who would complain their pain medication wasn’t working and they needed more. After performing a pharmacogenetic test, they realized the patient wasn’t able to metabolize the medication – or they were a ultra-rapid metabolizer of their pain medication so they needed to adjust their dosage accordingly. On the other hand, we’ve had physicians tell us their concern was validated after performing a pharmacogenetic test. The patient did have the ability to metabolize the medication.” Bullard went on to say with opioids, one concern is with a poor metabolizer. The body doesn’t metabolize the medication the way the manufacturer intended so the drug sits in their body and can build up toxins which can be deadly.
Cytochrome P450 2D6 (CYP2D6) is a gene product responsible for the metabolism of many major drug groups, including opioids. “A pharmacogenetic (PGx) test, approved by the FDA, is available, which looks for specific changes in the gene and interprets whether you have a ‘good copy’ or a ‘bad copy. A good copy would be a functional allele, while a bad copy is a non-functional allele. These changes and their combinations help predict how well a person will metabolize a drug.
An individual’s genotype can help predict the CYP450 activity, which classifies them into one of the four metabolizer types. The incidence of poor and ultrarapid metabolizers varies greatly among various populations. For example, approximately 10% of Caucasians are PMs for CYP2D6.
The CYP450 testing is a once-in-a-lifetime test. The result will be part of your medical record and denotes your genetic capability of handling these drugs. This not only applies to pain medications but also to other medications such as anti-convulsive medications, cardiac medications and psychotropic drugs that are used for depression and anxiety control.
Hydrocodone, the most frequently prescribed drug in the U.S., is metabolized differently depending on an individual’s phenotype. An ultra-rapid metabolizer may get some pain control, but their hydromorphone levels are going to increase and they may complain of side effects. Physicians have to be aware of that and they may need to make dosing adjustments accordingly. Poor metabolizers may not get sufficient pain control. If a patient is complaining about a drug not being effective, or about side effects, and the physician is considering a dosing adjustment, genetic testing can guide them.
The potential risks relating to how pain medications are metabolized are exacerbated by drug diversion. Drugs are now one of the leading causes of death in this country. It’s important for physicians to be aware of the impact of genetic variation on metabolizing drugs and try to identify those patients who may be at risk. If someone says they always take a half dose of a drug because of its effect or somebody else says the drug doesn’t really work for them, it’s a warning sign.
Getting the nation’s opioid addiction epidemic under control is a top priority for U.S. public health officials as overdose deaths continue to climb — with nearly 19,000 deaths related to prescription opioid painkillers.
PGx Medical is the trusted and experience resource for the education and implementation of pharmacogenetics.
For more information on pharmacogenetic testing contact:
PGx Medical
info@pgxmed.com
405-509-5112.
source: medpagetoday.com, Dr Leland McClure