Pharmacotherapy options for noncancer pain: an efficacy review
Opioids are not more effective than other medications for treating noncancer pain.
Strong opioids are no more effective than acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs) in patients with musculoskeletal disease and other forms of noncancer pain, according to a review published in Joint Bone Spine.1
Strong opioids, including morphine, fentanyl, and oxycodone, have been on the top step (step III) of the World Health Organization (WHO) analgesic ladder for many years. However, it may be time to rethink this model; when it comes to noncancer pain, strong opioids are neither strong nor effective.
"This is a review, so there is nothing here [that] we don't already know — in fact, there is not much evidence for use of any opioids for longer than 3 months," Troy Buck, MD, an assistant professor of anesthesiology and pain management from Loyola University Medical Center in Maywood, Illinois, told Clinical Pain Advisor.
Jahangir Maleki, MD, a pain management specialist at the Cleveland Clinic's Center for Neuro-Restoration, agrees that opioids may be overestimated for pain. However, they have other important benefits, he notes.
"In terms of other good indications, there are many. I would invite the authors of this review to join an anesthesiologist for a day. They would see what opiates are capable of delivering before, during, and after any surgery. Opiates [achieve] more than just analgesia. Sedation, relaxation, and mood elation are great benefits, if used properly in acute conditions," Dr Maleki told Clinical Pain Advisor.
What the Research Shows
The review authors note that there is a "stunning" lack of high-quality studies on the efficacy of step III analgesics, especially given their widespread use and abuse. Among their findings:1
- Several randomized, double-blind, emergency-room trials found that IV acetaminophen was similarly effective or superior to IV morphine in patients with conditions such as renal colic, low back pain, and acute limb pain.
- In a trial of 137 patients with intense and acute limb pain, there was no difference in pain relief between 1 gram of IV acetaminophen and 0.1 mg/kg of IV morphine.
- In 31 studies of chronic neuropathic pain, opioids were only slightly more effective than placebo.
- A meta-analysis of oxycodone used to treat diabetic neuropathy, postherpetic neuralgia, or fibromyalgia concluded there was no proof of efficacy, but there were more side effects.
- A systematic review of opioids for osteoarthritis pain found them no more or less effective than NSAIDs.
All of these studies examined opioid doses below 100 mg/day morphine-equivalents. Although higher opioid doses may achieve greater analgesia, are they worth the cost?