Opioids were not superior to nonopioid drugs for improving function related to severe chronic back pain or hip or knee osteoarthritis pain, a study found.
To compare opioid and nonopioid drugs for pain-related function, pain intensity, and adverse effects, researchers conducted a pragmatic, 12-month, randomized trial with masked outcome assessment at Veterans Affairs primary care clinics. Eligible patients had moderate to severe chronic back pain or hip or knee osteoarthritis pain despite using analgesics. Of 265 patients enrolled, 25 withdrew before randomization and 240 were randomized, with 234 completing the trial.
Both opioid and nonopioid medication interventions followed a treat-to-target strategy aiming for improved pain and function. In the opioid group, the first step was immediate-release morphine, oxycodone, or hydrocodone/acetaminophen. For the nonopioid group, the first step was acetaminophen (paracetamol) or an NSAID. Patient response dictated when medications were changed, added, or adjusted.
The primary outcome was pain-related function measured by the Brief Pain Inventory (BPI) interference scale over 12 months. The main secondary outcome was pain intensity on the BPI severity scale. BPI scales ranged from 0 to 10, with higher scores signaling worse function or pain intensity. A 1-point improvement was clinically important. The primary adverse outcome was medication-related symptoms measured by a patient-reported checklist ranging from 0 to 19. Results were published in the March 6 JAMA.
There was no significant difference between groups in pain-related function over 12 months (overall P=0.58), with a mean 12-month BPI interference score of 3.4 for the opioid group and 3.3 for the nonopioid group (difference, 0.1; 95% CI, −0.5 to 0.7). Pain intensity was significantly better in the nonopioid group over 12 months (overall P=0.03), with a mean 12-month BPI severity score of 4.0 for the opioid group and 3.5 for the nonopioid group (difference, 0.5; 95% CI, 0.0 to 1.0). The researchers noted that this was less than the minimal clinically important difference of 1. Adverse medication-related symptoms were significantly more common in the opioid group over 12 months (overall P=0.03). Mean medication-related symptoms at 12 months were 1.8 in the opioid group and 0.9 in the nonopioid group (difference, 0.9; 95% CI, 0.3 to 1.5).
The results do not support initiation of opioid therapy for moderate to severe chronic back pain or hip or knee osteoarthritis pain, the authors noted. “Opioids caused significantly more medication-related adverse symptoms than nonopioid medications,” the authors wrote. “Overall, opioids did not demonstrate any advantage over nonopioid medications that could potentially outweigh their greater risk of harms.”