Medicinal cannabis found to reduce opiate pain medicine usage

17th October 2022

A survey has found that medicinal cannabis use substantially reduced the use of opiate-based painkillers and improved physical functioning

Medicinal cannabis use appears to be associated with a reduction in patient’s use of opiate-based analgesics and improvements in self-reported physical functioning according to a study by US researchers.

In the US there has been an opiate crisis of epidemic proportions. Data from the CDC indicate that in the year ending in June 2020, 48,006 deaths were attributable to overdosing on synthetic opioids other than methadone. Fortunately, it appears that the level of opiate-related deaths in the US is beginning to fall with a slight decrease in 2019 compared to 2017. Although there may be any number of reasons as to why deaths are falling, one potential explanation for this reduction is greater use of medicinal cannabis (MC) use compared to opiates. In fact, a 2017 study identified how patients reported less use of opiates, antidepressants, alcohol, anti-anxiety, migraine and sleep medications after using MC. Despite this possible rise in use, an overview of the efficacy, tolerability and safety of cannabis-based medicines for chronic pain management concluded that there were inconsistent findings of the efficacy of cannabinoids in neuropathic pain, painful spasms in multiple sclerosis and for any chronic pain. However, many US states have taken steps to legalise and decriminalise the use of MC. As a result, for the present study, the US team sought to characterise the demographics and use patterns of those who had physician-approved medical cannabis access and to examine patient’s perceptions of changes in health functioning and use of opiate-based pain medicines (OBPM) after access to MC. The team developed a 66-item questionnaire that was distributed online, assessing a wide range of factors including demographics, medical conditions, health functioning and changes in pain medication use before and after use of MC.

Medicinal cannabis and changes to opiate-based medicine use

A total of 2,183 responses were included of whom 54.4% were female and nearly two thirds (64.9%) were aged 30 to 59. A third (33%) of respondents reported that they had 6 or more ailments and nearly half (47.9%) reported having pain and mental health issues, whereas pain alone was reported by only 9.1%.

The majority (54.9%) reported using medicinal cannabis regularly throughout the day and 7.8% had been using medicinal cannabis for more than 10 years.

In terms of physical functioning, bodily pain (e.g., the level of pain or interference of pain in normal work) was reportedly improved by 89.6% of respondents after use of MC, as was social functioning (84.3%).

Prior to MC usage, 60.9% of respondents were using OBPM with 36.8% using hydrocodone-acetaminophen (paracetamol) or oxycodone-acetaminophen (26.8%). However, after using MC, 41.7% reported that they had stopped using pain medicines and 37.5% had reduced their pain medicines. Interestingly, 11.5% reported improved functioning after using MC and reducing their OBPM.

The authors concluded that medicinal cannabis may play an important role at both the individual and community level as a viable alternative to opioids for pain management and without negatively affecting health functioning.

Citation
Prtichett CE et al. Medical Cannabis Patients Report Improvements in Health Functioning and Reductions in Opiate Use Subst Use Misuse 2022

Medical cannabis provides only small improvement in chronic pain

21st September 2021

A systematic review found that use of non-inhaled medical cannabis in patients with chronic pain leads to only a small improvement compared with placebo.

In a 2006 European survey of over 46,000 respondents in 15 countries, 19% reported experiencing pain which lasted for at least 6 months. Moreover, a more recent 2019 study in developing countries found a similar incidence (18%) among the general population. However, the impact of chronic pain, i.e., which persists past the normal healing time and lasts or recurs for more than 3 to 6 months, has a much wider impact upon affected individuals, reducing physical functioning, daily activities and mental health. Although opioid drugs have been used for the management of chronic pain, evidence suggests that compared with placebo, there are only small beneficial effects. Consequently, there has been increased interest in the use of alternative pain management strategies, one of which is the use of medical cannabis. In fact, its use as a therapeutic alternative has been recommended in some guidance for chronic pain, especially in cases where other treatments have been ineffective. However, the overall effectiveness of medical cannabis in chronic pain remains unclear with some organisations such as NICE in the UK, advising against the use of cannabis-based medicinal products to manage chronic pain in adults unless as part of a clinical trial.

With uncertainty over the effectiveness of medical cannabis in chronic pain, Canadian researchers led by a team from the Department of Anesthesia, McMaster University, Ontario, Canada, performed a systematic review and meta-analysis to determine the benefits and harms of medical cannabis in patients with chronic pain, including cancer pain. They included randomised controlled trials that enrolled at least 20 patients with chronic pain (defined as lasting longer than 3 months) and who were assigned to any form of medical cannabis and which was compared to placebo with a follow-up period of at least one month. As well as the impact on pain, the team also captured data on physical, emotional and social functioning and sleep quality. They assessment the benefits in terms of change scores from baseline as opposed to end of study results and determined whether use of cannabis achieved the minimally important difference (MID). This represents the smallest amount of improvement in a treatment outcome that patients recognise as important. For example, using a 10 cm visual analogue scale for pain, the MID is approximately 1 cm. The researchers modelled the risk difference (RD) of achieving at least the MID.

Findings
A total of 32 trials with 5174 adults in which 29 compared medical cannabis with placebo were included in the analysis. In terms of pain relief, there was moderate certainty evidence from 27 trials that medical cannabis compared to placebo, resulted in a small increase in the proportion of patients experiencing pain relief at or above the MID. This difference was modelled as 10 % (95% CI 5% to 15%). Data from 10 trials suggested a 7% increase in the proportion of patient experiencing at least a 30% reduction in pain with medical cannabis compared to placebo. Similarly, there was a 4% modelled difference in physical functioning and a 6% modelled risk difference for an improvement in sleep quality. However, there was no apparent improvement in emotional or social functioning. With respect to adverse effects, it appeared that medical cannabis gave rise to a 2% risk of transient cognitive impairment, impaired attention (3%) and nausea (5%).

The authors concluded that there was moderate to high certainty evidence of a small to very small increase in the proportion if people with chronic pain who experience an important improvement in their pain. Their results have been summarised in an accompanying rapid recommendation.

Citation
Wang L et al. Medical cannabis or cannabinoids for chronic non-cancer and cancer related pain: a systematic review and meta-analysis of randomised clinical trials. BMJ 2021