Commentary on opioid addiction and chronic pain
Prof Nick Bateman
Pain and medicine has been inexorably linked since the beginnings of time. Opioids were used in antiquity. Synthetic opioids [morphine, diacetyl morphine (heroin) and codeine] were amongst the first inventions of the 19th century German synthetic chemists. Each was hailed as non-addictive; all are effective at controlling acute pain. However, they suffer major drawbacks. Many pains are unresponsive, patients develop tolerance and more worryingly addiction. This is because the mu receptor responsible for analgesia also causes addiction. As an article in the BMJ neatly expressed in its title "Expect analgesic failure; pursue analgesic success”.1 The point being that different patients need different drugs, working through different mechanisms; success or failure can be determined within 2 to 4 weeks, opioids do not work in many chronic pains.
Nevertheless the pharmaceutical industry still pursues the mu receptor, and doctors continue to prescribe ever-increasing quantities of opioids. They certainly have a real place in medicine, particularly post-operatively and in control of the severe time-limited pain as in cancer, however many millions of opioid pills prescribed in the UK are not for these indications, and are increasingly to feed an opiate addiction, overt or covert. 2
The latest in this story of ‘false dawns’ has been the approval by the US FDA of another slow-release opioid hydrocodone; this has raised a political and medical debate on the issues of analgesia and addiction in the USA, where abuse of prescription opiates is at least as common as in the UK. 3 Best practice is not being followed, and deaths from overdose have tripled in the USA. We need to think as doctors, if one opioid does not work, why should another? Also many chronic pains are opioid non-responsive. Opioid dependency is a very real problem: stopping is far harder than starting.
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