Roughly one in 12 bariatric patients who did not take opioid pain medications until their weight loss surgery, or the month before it, reported that they are still using prescription opioids one year postoperatively, a rate of prolonged use that is more than 45% higher than people who underwent other general surgery procedures.
Among all bariatric patients, including those who reported using opioids before their particular procedure, nearly one in four was still taking opioid pain medications one year after surgery.
The study, presented at the American College of Surgeons 2017 Clinical Congress, provides further evidence that bariatric patients are more prone to persistent opioid use than others, said senior investigator Amir A. Ghaferi, MD, associate professor of surgery at the University of Michigan, in Ann Arbor.
“Surgeons must identify patients who may be at higher risk for addiction to opioids so they can adjust prescribing for postoperative pain,” said Dr. Ghaferi, who directs the Ann Arbor–based Michigan Bariatric Surgery Collaborative, a quality improvement program that supplied the study data.
“Patients undergoing bariatric surgery may be particularly vulnerable to opioid dependence, possibly because of chronic knee and back pain associated with morbid obesity,” he said.
Dr. Ghaferi and his co-investigators used the Michigan Bariatric Surgery Collaborative database, which collects data on 95% of bariatric surgeries performed in the state. They identified 14,063 patients undergoing first-time bariatric surgical procedures who completed surveys about their use of prescription painkillers preoperatively and again one year after the procedure. The researchers initially administered the survey by email and, if there was no response after several reminders, by mail or phone. The survey listed commonly prescribed opioid medications, such as hydrocodone and oxycodone.
Patients undergoing weight loss procedures routinely receive an opioid prescription for postoperative pain, and most patients discontinue using opioid medications earlier than two weeks after their operation. The study, however, found a minority who continued taking the medications much longer.
Three-fourths of survey respondents stated they had not taken opioid medications in the one to 12 months before their surgical treatment. Of these opioid-naive patients, 8.8% said they were still using their opioids one year after starting them for postoperative pain.
The rates of newly persistent opioid use were significantly higher than the 6% rate reported among opioid-naive patients in the general surgery population, Dr. Ghaferi said. The general surgery data came from the Michigan Opioid Prescribing Engagement Network, or Michigan-OPEN, an initiative that aims to prevent surgery-related opioid abuse.
Richard M. Peterson, MD, MPH, director of the University of Texas Health San Antonio Weight Loss Center, said the rates of opioid use in the study were far higher than expected. “It’s kind of eye-opening. I don’t believe this is what I’m seeing in my own patients, but if this is truly happening, we need to look at why.”
Drs. Peterson and Ghaferi said the theory of addiction transfer might explain why bariatric patients continue to use opioids long after surgery. Some data support this concept in bariatric surgery patients: Patients who used overeating as a coping mechanism before surgery may resort to other means postoperatively, relying on alcohol, drugs or other maladaptive behaviors.
But the physiologic explanation behind the persistent use of opioids, such as a difference in bioavailability or absorption patterns of medications after weight loss surgery, could result in increased likelihood of addiction, Dr. Ghaferi noted.
Although the cause remains unknown, providers should pay special attention to opioid use during the postsurgical period, he said.
Based on these findings, Dr. Ghaferi and his colleagues have made changes in their bariatric surgery practice that they hope will reduce the risks of long-term opioid use. They moved away from a one-size-fits-all approach to prescribing, and use patients’ pain scores and inpatient opioid requirements to guide prescriptions.
They recommend that surgeons screen patients for substance abuse risk factors, such as excessive alcohol use or a family history of substance use disorder; prescribe fewer opioid pills in the first prescription; and perform local nerve blocks in the operating room to minimize the need for postoperative opioid medications.
In the next year, Dr. Ghaferi and his colleagues hope to publish evidence-based prescribing recommendations for bariatric patients. Researchers from Michigan-OPEN, working with the Michigan Surgical Quality Collaborative, developed the Opioid Prescribing Recommendations for Surgery (https://opioidprescribing.info/ ), which provides guidance for prescriptions following 11 common general surgery procedures. The recommendations were developed using data and surveys from patients across the state.
Several studies from the University of Michigan published over the last year have shown newly persistent opioid use to be a problem after minor and major surgical procedures in U.S. adults. In one study published this summer, opioid use one year after surgery ranged from 5.9% to 6.5%, depending on the procedure. Risk factors independently associated with new persistent opioid use included preoperative tobacco use, alcohol and substance abuse disorders, mood disorders, anxiety and preoperative pain disorders (JAMA Surg2017;152:e170504).