The role of opioids in chronic noncancer pain

There is high-quality evidence that opioids provide little, if any, benefit for chronic noncancer pain and cause significant harm (eg death, abuse, opioid-induced androgen deficiency). In recognition of the harm associated with opioid use, the Therapeutic Goods Administration (TGA) has restricted the use of modified-release opioids for chronic noncancer pain; see their advisory here.

In a 12-month randomised controlled trial, opioids reduced chronic low back pain, hip pain or knee pain less than nonopioids and were associated with more adverse effects¹. A 12-month retrospective study of patients using opioids long term for chronic pain showed that pain intensity did not change, or was slightly reduced, when opioids were discontinued².

Opioids are associated with high rates of adverse effects. Approximately 80% of patients experience at least one adverse effect and more than 50% of patients stop opioids because of adverse effects. In some patients, opioids may be perceived as beneficial because they provide short-term relief from anxiety, but opioids are not a suitable anxiolytic. Long-term use of opioids interferes with a patient’s ability to psychologically resolve negative emotions and reduces their problem-solving skills. Opioids can reduce a patient’s motivation to participate in self-management strategies (eg exercise).

It is difficult to define a cohort of patients with chronic noncancer pain that would consistently respond to opioids. Nervous system sensitisation is often a bigger contributor to pain than underlying structural changes and is not responsive to opioids. Opioids should only be trialled in patients with chronic noncancer pain when all of the parameters outlined in Parameters of an analgesic trial for chronic noncancer pain  are met (see Initiating analgesics for chronic noncancer pain for further advice).

For children and adolescents with chronic noncancer pain, seek specialist advice before considering opioids³.

Response to opioid therapy must be reviewed regularly and opioid use limited to the shortest duration of therapy that enables a patient to establish self-management strategies. Even if effective, opioids should not be prescribed for longer than 12 weeks, unless under specialist advice⁴. Stop the opioid if there is evidence of misuse or abuse, if there is no significant progress towards achieving management goals after 4 weeks, or if the opioid is causing intolerable adverse effects. See here for advice on tapering and stopping opioid therapy. If there is concern that the patient may have a disorder of opioid use, see Chronic pain in substance use and addictive behaviours and Opioids: hazardous, harmful and dependent use.