Chronic non-cancer pain affects 15% to 30% of Canadians. It persists for longer than three months and is frequently related to back pain, osteoarthritis, fibromyalgia, and headaches. Opioids are commonly used to manage pain, but are also associated with harms such as overdose, addiction, and misuse. In addition, many patients are unable to tolerate opioid-related side effects such as dizziness, drowsiness, nausea, and constipation. The 2010 Canadian Guideline for Safe and Effective Use of Opioids for Chronic Non-Cancer Pain provides guidance on how to initiate an opioid trial once alternatives to manage pain have proved unsuccessful.
Opioid pain medications available in Canada include codeine (e.g., Tylenol No. 3), tramadol, buprenorphine, morphine, hydromorphone (e.g., Dilaudid), oxycodone (e.g., OxyContin, OxyNEO, or Percocet), fentanyl, and methadone.
There is uncertainty as to how best to initiate and manage a trial of opioids for patients with chronic non-cancer pain. In fact, both Canadian and American guidelines report being constrained in making recommendations due to the lack of evidence. For example, chronic pain continues for months, yet many trials end after six weeks. A review of the evidence will help inform decisions about the length of trial periods in chronic non-cancer pain.
A limited literature search of key resources was conducted, and titles and abstracts of the retrieved publications were reviewed. Full-text publications were evaluated for final article selection according to predetermined selection criteria (population, intervention, comparator, outcomes, and study designs).
For the treatment of patients in the general community who are experiencing acute or chronic pain:If using opioids to manage chronic non-cancer pain:
- Start with a low dosage, increase dosage gradually, monitor effectiveness (improved function or greater than 30% reduction in pain intensity), and follow up frequently (every 2 to 4 weeks).
- Titration ends when:
- optimal dose is reached
- insufficient relief after a 2- or 3-dose increase
- unacceptable adverse events
- indication of misuse.
- If adverse events are unacceptable or opioid effectiveness is insufficient, stop or switch opioid therapy.
Based on expert consensus opinion.
The literature search produced 653 citations, with1 additional study identified from the grey literature.Of these, 11 articles were deemed potentially relevant, with 3 meeting the criteria for inclusion in this review:1 non-randomized study and 2 evidence-based guidelines.