Jacqueline Gardner-Nix1 advocates the use of opioids for chronic noncancer pain, but this issue is more controversial than her article indicates.2,3 Both the Ontario Workplace Safety and Insurance Board (WSIB)4 and the College of Physicians and Surgeons of Ontario (CPSO)5 have prepared evidence-based guidelines for the management of chronic noncancer pain. The WSIB4 found only 2 studies of sufficient quality for use in making recommendations for opioids, and the WSIB noted that these drugs were of limited use for up to 6 months. The CPSO5 concluded that there was some evidence of benefit of short-term (up to 9 weeks) opioid use but noted that “long term opioid therapy may or may not improve functional status and there is some evidence that a treatment program that focuses on analgesics can reinforce pain-related behaviour at the expense of functional restoration.”
The single randomized trial6 that both the WSIB4 and the CPSO5 felt was of highest quality reported only modestly lower pain intensity with morphine relative to placebo; in addition, vomiting (39% in the morphine group), dizziness (37%), constipation (41%), poor appetite or nausea (39%) and abdominal pain (22%) were significantly more frequent with morphine use. The study had a 25% drop-out rate (15 of 61) and did not demonstrate any significant improvement in psychological or functional outcome, nor did it find a significant overall patient preference for morphine over placebo.
The role of opioid analgesics in the management of chronic noncancer pain has not been well established. Further research is needed to determine if the benefits exceed the costs.
Jason W. Busse Department of Clinical Epidemiology and Biostatistics McMaster University Hamilton, Ont.
References
- 1.
- 2.
- 3.
- 4.
- 5.
- 6.