A physician’s roadmap to treating pain can be filled with twists and turns and sometimes uncertainty whether the final destination of pain relief is attainable. However, a new UF Health study examining a patient’s DNA may provide necessary direction for successful pain therapy.
Researchers in UF Health’s Personalized Medicine Program studied nearly 500 pain patients over a two-year period and found genotype-guided drug therapy improved pain control amongst poor or intermediate metabolizers of the drug-metabolizing enzyme CYP2D6 when prescribed certain opioids.
“We know pain is a major problem in this country and data show that most of the people persistently using opioids are trying to treat pain,” said Larisa Cavallari, Pharm.D., director of the Center for Pharmacogenomics in the UF College of Pharmacy and associate director of the UF Health Personalized Medicine Program. “This study is a piece of the puzzle that may help us better manage pain and enhance quality of life.”
Pain affects more Americans than diabetes, heart disease and cancer combined. Since the 1990s, a physician’s go-to pain treatment has been to prescribe opioids, such as hydrocodone or tramadol. While the medications help alleviate pain in some patients, others experience no relief, and overprescribing has been a factor contributing to a national epidemic of opioid misuse, overdose and death.
Several primary care physicians at UF Health approached the personalized medicine team in 2015 to initiate CYP2D6 genotype testing to help with opioid prescribing. The request sparked what is believed to be the nation’s first genotype-supported opioid therapy study.
“Unfortunately, we were seeing many patients with chronic pain suffering from negative drug effects, either from the drug itself or interactions with others,” said Siegfried Schmidt, M.D., Ph.D., FAAFP, a professor in the department of community health and family medicine at the UF College of Medicine. “Pharmacogenetic testing has provided us some answers why this is happening and helped us determine the right drugs, in the right dosages, at the right time for our patients. This is the future of medicine, and what I want to become reality for all of my patients.”
Study participants initially provided a DNA sample and completed a pain intensity survey. A pharmacist reviewed genetic test results and the patient’s list of medications to identify any factors that may influence response to opioid therapy. Genetic variations of CYP2D6 and competing medications that treat conditions apart from pain, such as depression and anxiety, can play a role in suppressing the CYP2D6 enzyme — rendering certain pain medications ineffective. The pharmacist then made recommendations to the physician based on genotype and other medications patients were taking.
“Our genotype-guided approached led to a reduction in patient-reported pain over three months in the people who we expected to benefit the most,” Cavallari said. “These findings add to the evidence base that pharmacogenetics testing improves outcomes and justifies broader implementation across health care.”