In addition to well-documented opioid overprescribing, researchers from the Mayo Clinic have found that inappropriate use of high-potency opioids has contributed to the opioid epidemic in the United States.

“In pain management, there is a need to use a variety of treatment options, including—when appropriate—extended-release opioids and very strong immediate-acting opioids like fentanyl,” said study co-author W. Michael Hooten, MD, in a press release. “However, these particular medications can cause a number of serious adverse effects, so extra safeguards are needed when these medications are prescribed.”

The researchers were particularly interested in whether opioid tolerance influenced the prescriptions.

“One of the key factors in determining whether these drugs can be used safely is the presence of opioid tolerance in the patient who was prescribed one of these medications,” Hooten said. “In other words, tolerance to some of the most dangerous adverse effects of opioids, including suppressing breathing and excessive sedation, develops only after a patient takes daily doses of opioids over time.”

The study examined medications including high-dose, extended-release oxycodone; all doses of extended-release hydromorphone; fentanyl patches; and all varieties of transmucosal fentanyl.

To determine whether the medications were inappropriately used, the researchers used de-identified data, including pharmacy and medical claims data, and linked electronic health records from the OptumLabs Data Warehouse.

Between 2007 and 2016, the investigators found nearly 300,000 prescriptions for medications reserved for patients with opioid tolerance. They eliminated records of patients who had been recently hospitalized or who had an opioid poisoning diagnosis within the preceding 6 months, as well as records of those who did not have at least 6 months of continuous insurance claims information at the time of the prescription.

The remaining 153,385 new outpatient prescriptions of reserved medications occurred among 131,756 people. Less than 48% of these prescriptions showed evidence of prior opioid tolerance.

“Our findings are concerning because it appears that many people starting to use these drugs may be at risk for some quite serious outcomes,” said lead author Molly Jeffery, PhD, in a press release.

The authors noted that a key strength of the study was their ability to look for additional evidence of opioid tolerance in the linked electronic health records for approximately 15% of the study group. By analyzing these records, they found that between 0.5% and 4% of episodes of use of the reserved medications had additional information in the patient’s record that showed evidence of tolerance, which was not indicated in the claims data.

“There was no evidence of opioid tolerance in more than half of the patients in our study,” Jeffery said. “Given how common that was, we wanted to use the clinical notes to look for reasons why physicians would have prescribed these drugs in people who were not opioid-tolerant.”

The team’s analysis of clinical notes did not provide any insight into physicians’ reasoning, but the physicians on the research team had some theories. Hooten said fentanyl patches, in particular, may have been prescribed for patients who cannot swallow oral medications.

“I often treat people mired in addiction,” Hooten said in the release. “As physicians, our first charge is to do no harm, and with opioids—especially this group of medications—the risk of harm is very real.”

REFERENCE
Prescribing an overdose: A chapter in the opioid epidemic [news release]. Mayo Clinic; April 15, 2020. https://newsnetwork.mayoclinic.org/discussion/prescribing-an-overdose-a-chapter-in-the-opioid-epidemic/. Accessed April 17, 2020.