Non-opioid analgesics improved pain-related function over 12 months as much as opioids, according to a study of 240 patients with moderate to severe chronic back pain or hip or knee osteoarthritis pain.

The opioid group initially received immediate-release morphine, oxycodone or hydrocodone plus paracetamol. If this was ineffective, they moved to sustained-action morphine or oxycodone. Step 3 was transdermal fentanyl.

In the non-opioid group, the first step was paracetamol or an NSAID. Step 2 was adjuvant oral medications (nortriptyline, amitriptyline, gabapentin) and topical analgesics (capsaicin, lidocaine). Step 3 consisted of pregabalin, duloxetine and tramadol.

Researchers used the Brief Pain Inventory (BPI), an 11-point scale, to assess interference and pain intensity, and considered a one-point improvement to be clinically important. The patients did not significantly differ on painrelated function: BPI scores were 3.4 for opioid users and 3.3 for the non-opioid group.

Pain was significantly less intense in the non-opioid group and adverse events significantly more common among opioid users.

Anxiety symptoms were statistically better in the opioid group, although the difference was small and the clinical importance “uncertain”.

The authors conclude that the results “do not support initiation of opioid therapy for moderate to severe chronic back pain or hip or knee osteoarthritis pain”.