Cannabis use common among people using prescribed opioids for chronic pain

One in six people using prescribed opioids for chronic pain also use cannabis, a study of 1,500 Australians led by researchers at the National Drug and Alcohol Research Centre at UNSW has found. The researchers also found that those who used cannabis in addition to opioids reported greater pain relief than those using opioids alone.
Use of cannabis among chronic pain patients using opioids was common. Past-year cannabis use was more than three times higher than in the general population – 13 per cent of the sample had used cannabis in the past year, compared with only 4.7 per cent of the general population aged over 40 years. One in six had ever used cannabis for pain relief (16%), and a quarter (23%) reported that they would use cannabis for pain with they had access to it.
The analysis of prescription opioid users’ cannabis use was conducted as part of Australia’s largest ever study of chronic pain suffers using pharmaceutical opioids, the POINT study, which is following more than 1,500 Australians over two years.
Those in the cohort who had used cannabis for pain were younger than those who used prescription opioids only (average age of 49 compared with 59 for non-users), were more likely to report more severe pain, had been living with pain for longer and reported that their pain interfered with their lives to a greater extent. They were also more likely to have a history of substance use disorders and mental health problems.
Chief Investigator of the study Professor Louisa Degenhardt said that there was currently limited research evidence on the effectiveness of cannabis use for chronic pain, either on its own or in conjunction with opioids.
Yet despite this, and the fact that cannabis use is illegal in Australia, use of cannabis among this group was high, she said. “Despite scientific uncertainty about the benefits of cannabis use for medical purposes there is a significant sub-population of people living with chronic pain who report that they experience real benefits in terms of pain relief,” said Professor Degenhardt.
Associate Professor Nicholas Lintzeris, an Addiction Medicine specialist from Sydney University and co-author on the study noted: “We need to know much more about the potential role of cannabinoids for chronic pain conditions.
“We have documented that a small but significant population of chronic pain sufferers reported pain relief from their cannabis use. This group of individuals generally reported more complex and debilitating pain
conditions than non-cannabis users, and less satisfactory symptom relief with conventional pain treatments such as opioid medication. It may be that cannabis use provides some additional therapeutic benefits for those not benefiting from usual treatment approaches. However, there is often a complex relationship between pain and other health issues – such as mental health, sleep and substance use, and much more research is required to disentangle the effects of cannabis use in chronic pain sufferers”
Professor Degenhardt added: “This is a group of individuals with complex clinical histories. The potential risks of long term cannabis use, particularly for people with a range of existing health problems, need to be considered and carefully managed.”
The study has been published in the international journal Drug and Alcohol Dependence.
Degenhardt L.et al. Experience of adjunctive cannabis use for chronic non-cancer pain: Findings from the Pain and Opioids IN Treatment (POINT) study. Drug and Alcohol Dependence (2015) 147, 144-150.
Media contacts, National Drug and Alcohol Research Centre:
Marion Downey
Communications Manager, National Drug and Alcohol Research Centre
P: (02) 9385 0180 / 0401 713 850 / m.downey@unsw.edu.au
The Pain and Cannabis In Treatment Study (POINT) is funded by the Australian National Health and Medical Research Council. It is the first Australian study to examine the patterns of prescribing for individual patients, and the outcomes for these patients in the longer term. The National Drug and Alcohol Research Centre at the University of New South Wales is supported by funding from the Australian Government under the Substance Misuse Prevention and Service Improvements Grants Fund