Opioids are very good analgesics for acute pain and for pain at the end of life but there is little evidence that they are helpful for long-term pain.
A small proportion of people may obtain good pain relief with opioids in the long-term if the dose can be kept low and especially if their use is intermittent (however, it is difficult to identify these people at the point of opioid initiation).
The risk of harm increases substantially at doses above an oral morphine equivalent of 120 mg/day, but there is no increased benefit
If a patient is using opioids but is still in pain, the opioids are not effective and should be discontinued, even if no other treatment is available.
Chronic pain is very complex and if patients have refractory and disabling symptoms, particularly if they are on high opioid doses, a very detailed assessment of the many emotional influences on their pain experience is essential.