As a pain specialist, patients often ask me if they should try medicinal cannabis. There is a popular belief that this can be an effective way to manage chronic pain.
Two groups of experts recently recommended anti-medical cannabis for people with persistent, non-cancer pain.
The International Association for Pain Research released a statement last week after its President’s Task Force summarized the evidence on the matter.
And yesterday, the Faculty of Pain Medicine of the Australian and New Zealand College of Anesthetists released guidelines for naturopaths in the form of a cautionary recommendation. (The smart choice is an NPS Medicinewise initiative aimed at highlighting inferior healthcare.)
Many in the community would view this recommendation as controversial. So let’s look at some of the common misconceptions about medical cannabis and chronic pain.
Myth # 1: Evidence shows cannabis products are effective for chronic pain
There is a lack of evidence from randomized controlled trials when it comes to cannabis drugs for chronic pain.
While some studies have looked at tetrahydrocannabinol (THC, the main psychoactive component of cannabis) or a combination of THC and cannabidiol (CBD), there is not a single published randomized controlled trial of a CBD-only product for chronic pain of any kind. Australian cannabis medicines are often just CBD products.
This means we cannot even judge whether claims that medical cannabis can relieve pain could be true. One way or another, the results of THC-containing products in clinical trials do not give a reliable picture because they affect too few participants, have major technical flaws in design, or have an unacceptably high risk of biased results.
The International Association for Pain Studies Task Force examined all available research published in peer-reviewed journals on the use of medical cannabis for pain management, from preclinical studies to human studies.
Overall, they came to the conclusion that the “quality, accuracy and transparency of reporting” of studies on benefits and harms needs to be improved across the board. We would need better quality data, such as through randomized controlled trials, to determine the safety and effectiveness of using medical cannabis for pain.
In the polite and low-key world of academic medicine, this is as big a blow as it gets. Essentially, the authors say that most studies have been too poorly conducted with inappropriate methods to provide an answer to the most basic question of whether medicinal cannabis helps with pain.
Myth # 2: Cannabis products should be provided as a “last resort”.
A doctor has the right to prescribe any drug he believes will be effective for an individual patient based only on his or her clinical judgment. We do this quite often, especially with chronic pain.
This is ethical when we have a scientific reason to believe the drug could be helpful. For patients with chronic pain, however, we have little reason to believe that medicinal cannabis will provide lasting benefits.
Another challenge to the ethical provision of cannabis products as a “last resort” is that they are among the most expensive pharmaceutical products available to patients with chronic pain, many of whom have very modest incomes. The only party that can benefit is the manufacturer.
Many people with chronic pain believe that medicinal cannabis could help
Myth # 3: Medical cannabis can help with the opioid crisis
There is consensus that much of the current use of opioid analgesics for the treatment of chronic non-cancer pain in Australia may be of limited value.
Medical cannabis advocates have suggested that it could hold promise as a possible solution to this problem. While this idea has some appeal, the balance of evidence points the other way.
Data collected from Australia and New Zealand show that participating in best-practice multidisciplinary pain management, such as that provided by a specialized pain clinic, results in half of pain sufferers being able to reduce their opioids by at least 50% and improve their quality of life.
People looking for an alternative to opioid treatment for persistent pain are best advised to seek treatment from a professional team of experts rather than substituting cannabis for opioids.
It could be harmful
The International Association for the Study of Pain Taskforce identified well-known risks from cannabis use, for example in recreational settings. However, no studies have characterized the way the body handles prescribed or over-the-counter cannabis medicines.
The TGA guidance document on medical cannabis does not contain any basic research on the interaction of drugs with the body and other drugs – so-called pharmacokinetic and pharmacodynamic studies – are not available. Without this information, we cannot answer important questions about the safety of medical cannabis.
Medical cannabis is not the solution to the opioid crisis
Cannabis medicines can play a role in treating other conditions, such as: B. in relieving chemotherapy-induced nausea or in treating childhood epilepsy. The evidence for these conditions seems to be more convincing than the studies for persistent pain, although I am not an expert in either of these areas.
Despite the lack of evidence of the use of medical cannabis for chronic pain, medical cannabis legislation in Australia continues to become more permissive.
As of June this year, it will be legal to sell low-dose CBD products over the counter if they meet the minimum requirements listed by the Therapeutic Goods Administration (TGA).
Meanwhile, Tasmania will be the last Australian state to allow general practitioners to prescribe medical cannabis from July.
The Faculty of Pain Medicine can look back on many years of experience in the advocacy of pain patients. We led the process that led to the first National Pain Strategy a decade ago and were founding partners of Painaustralia as an ongoing political voice.
If medical cannabis were really as valuable as it is often claimed, we would be the loudest voice for wider access. The weight of the evidence dismisses us from this conclusion.
This article was originally published on The Conversation by Michael Vagg at the Deakin University. Read the original article here.