There is clear evidence that opioids are not effective for long term chronic non-cancer pain. In fact, patients are worse of in terms of pain levels with opioid use potentially due to opioid hyperalgesia. Furthermore opioid use has real harm. Chronic opioid use in the community is associated with a number of risks of adverse outcomes. Broadly, indications for opioid use are acute pain, cancer pain, palliative care, and opioid dependency, but not chronic non-cancer pain. For chronic non-cancer pain, discontinuation is recommended where feasible and does not cause any changes in pain intensity.
Evidence for Chronic Pain
- Opioid Initiation
A landmark study was published in 2018 by Krebs et al - the SPACE study. It was a pragmatic randomised controlled trial comparing opioid versus non opioid analgesics for 12 months in primary care. Participants were 240 VA patients with moderate to severe chronic back pain or knee/hip OA, and not on opioids. The mean pain intensity initially was 5.4 in both arms. Pain scores at 1 year was worse in the opioid arm (4.0) than non opioid (3.5) (P=0.034). There was no difference in pain interference, and adverse effects were worse in opioid group (P=0.03).
- Opioid Cessation
McPherson et al studied changes in pain intensity over 12 months after opioid discontinuation in chronic non-cancer pain. Participants were 551 VA patients, with 87% musculoskeletal pain, 11% headaches, and 6% neuropathic pain. Mean estimated pain at the time of opioid discontinuation was 4.9. There was no statistically significant decline in pain intensity over 12 months after discontinuation. Patients were statistically divided into four groups - no pain (average pain 0.37), mild pain (3.9), moderate pain (6.33), severe pain (8.23). Pain trajectories in each category were similar to the overall results. Patients with mild and moderate pain had the greatest pain reductions after discontinuation. On average, pain intensity after discontinuation did not worsen for patients, and many slightly improved.
Adverse Effects of Long Term Opioid Use
- Respiratory depression: Opioid overdose (<1% per year, more common with increasing MED); breathing problems during sleep (25%)
- Falls causing hip & pelvis fractures (1-2% per year)
- Gastrointestinal: constipation (30-40%); bowel obstruction (<1% per year)
- Endocrine: Hypogonadism; impotence; infertility; osteoporosis (25-75%)
- Psychiatric: Sedation (15%); sleep disruption (25%); hyperalgesia; depression, anxiety, deactivation, apathy (30-40%), addiction, misuse & diversion (5-30%)
- Other: dry mouth that may lead to tooth decay (25%); myoclonus
- FPM ANZCA 2015
Opioids cannot be considered a core component of CNCP management Traffic lights 40 & 100mg Given widespread prescription the following principles are offered...
- BPAC NZ
There is no evidence that opioids are effective for treating chronic non-malignant pain Opioids are associated with significant adverse effects, and analgesic efficacy decreases with continuous use due to neuroadaptations that result in dependence, tolerance and opioid-induced hyperalgesia Improving or retaining function should be the goal of treatment for most patients with chronic non-malignant pain; regular use of potent opioids at high doses is contrary to this aim Pain is only one aspect of managing a patient with a chronic pain condition; attention to psychological and social factors is essential, along with acknowledging and empathising with the emotional wellbeing of the patient If long-term use of opioids cannot be avoided, intermittent dosing using the lowest possible potency and dose is preferable
- US Centres for Disease Control & Prevention 2016
Non pharmacological & non opioid treatments preferred Traffic lights 50 and 90mg oMEDD Consider opioids only if expected benefits outweigh risks
- UK National Institute for Health & Care Excellence. Guideline for LBP and sciatica 2016
Do not offer opioids for chronic low back pain
System Approaches to Deprescribing
Some research has been done in Australia looking at this. Brief training to GPs failed to result in any reduction in opioid prescribing. The availability of pain specialists and multidisciplinary health practitioners is not significantly associated with deprescribing decisions. There is low readiness to wean among both general practitioners & patients. Important concepts are feasibility and acceptability. Feasibility means the proportion of eligible patients who engage in and commit to a treatment. Acceptability refers to the patient perspective of the treatment.
In New Zealand the Health Quality and Safety Commission (HQSC) has identified significant differences between District Health Boards (DHB’s) in rates of long term opioid prescriptions, and and association between these rates and access to specialist pain services. Regular opioid usage is high in chronic pain clinic patients, but rates vary significantly between pain services. The costs to society of high opioid use are direct, indirect and intangible.
Explain that opioids are no longer indicated for chronic non-cancer pain. Have a conversation about opioid weaning. Negotiate rate of reduction, faster versus slower. The standard approach is monthly step down by 10-25% of starting dose.
- The evidence does not support the use of long term opioid use in chronic non-malignant pain.[Level 2]
- With long-term use there are neurohumoral effects which include hormonal dysregulation, immunosuppression, increased risk of falls, impairment of sleep quality, and opioid induced hyperalgesia.
- ↑ 1.0 1.1 Krebs et al.. Effect of Opioid vs Nonopioid Medications on Pain-Related Function in Patients With Chronic Back Pain or Hip or Knee Osteoarthritis Pain: The SPACE Randomized Clinical Trial. JAMA 2018. 319:872-882. PMID: 29509867. DOI. Full Text.
- ↑ 2.0 2.1 McPherson et al.. Changes in pain intensity after discontinuation of long-term opioid therapy for chronic noncancer pain. Pain 2018. 159:2097-2104. PMID: 29905648. DOI. Full Text.
- ↑ Understanding the role of opioids in chronic non-malignant pain. https://bpac.org.nz/2018/opioids-chronic.aspx
- ↑ Holliday et al.. Does brief chronic pain management education change opioid prescribing rates? A pragmatic trial in Australian early-career general practitioners. Pain 2017. 158:278-288. PMID: 28092648. DOI.
- ↑ White et al.. Therapeutic alternatives for supporting GPs to deprescribe opioids: a cross-sectional survey. BJGP open 2018. 2:bjgpopen18X101609. PMID: 30723795. DOI. Full Text.
- ↑ White et al.. Integrated Primary Healthcare Opioid Tapering Interventions: A Mixed-Methods Study of Feasibility and Acceptability in Two General Practices in New South Wales, Australia. International journal of integrated care 2020. 20:6. PMID: 33132791. DOI. Full Text.
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