March 6 (UPI) -- Opioid medications were not better than nonopioid treatment to improve chronic back, hip or knee pain, according to medical research conducted at Veterans Affairs clinics in Minnesota.
Participants found that pain still interfered with activities that included walking, work and sleep over a 12-month period, according to research released Tuesday in the Journal of American Medical Association.
"Treatment with opioids was not superior to treatment with nonopioid medications for improving pain-related function over 12 months," the researchers wrote. "Results do not support initiation of opioid therapy for moderate to severe chronic back pain or hip or knee osteoarthritis pain."
Pain intensity was less severe in the nonopioid group and adverse medication-related symptoms were more common in the opioid group, according to the researchers.
A total of 240 patients from 62 Veterans Affairs clinics in Minneapolis, Minn., with moderate to severe chronic back pain or hip or knee osteoarthritis pain were examined from 2013 to 2015 and follow-up ended in 2016. The mean patient age was 58.3 years old and 13 percent of participants were women.
Erin E. Krebs at the Minneapolis Veterans Affairs Health Care System, Minneapolis, was the lead author of the study.
The researchers noted that because this study was conducted in VA clinics, "patient characteristics differ from those of the general population, most notably in sex distribution." In addition, patients with physiological opioid dependence due to ongoing opioid use were excluded.
"Recent systematic reviews have concluded that opioids have small beneficial effects on pain compared with placebo that may be outweighed by common adverse effects," the researchers wrote. "Observational studies have found that treatment with long-term opioid therapy is associated with poor pain outcomes, greater functional impairment, and lower return to work rates."
Patients in the opioid group in Step 1 were given morphine IR, hydrocodone/acetaminophen and oxycodone. Step 2 was morphine sustained-action and oxycodone. Step 3 was transdermal fentanyl.
The control group was administered acetaminophen and nonsteroidal anti-inflammatory drugs in Step 1. Then Step 2 included adjuvant oral medications and topical analgesics. Step 3 included drugs requiring prior authorization from the VA clinic, such as pregabalin, duloxetine and tramadol.