cannabis

Posted on Pain Management

CBD products don’t ease pain and are potentially harmful – new study finds

There is no evidence that CBD products reduce chronic pain, and taking them is a waste of money and potentially harmful to health, new research finds
There is no evidence that CBD products reduce chronic pain, and taking them is a waste of money and potentially harmful to health, new research finds

There is no evidence that CBD products reduce chronic pain, and taking them is a waste of money and potentially harmful to health, according to new research led by the University of Bath in the UK.

CBD (short for cannabidiol) is one of many chemicals found naturally in the cannabis plant. It’s a popular alternative medicine to treat pain and is readily available in shops and online in the form of oils, tinctures, vapes, topical creams, edibles (such as gummy bears) and soft drinks.

However, consumers would do well to steer clear of these products, according to the new study.

“CBD presents consumers with a big problem,” said Professor Chris Eccleston, who led the research from the Centre for Pain Research at Bath. “It’s touted as a cure for all pain but there’s a complete lack of quality evidence that it has any positive effects.”

He added: “It’s almost as if chronic pain patients don’t matter, and that we’re happy for people to trade on hope and despair.”

For their study, published this week in The Journal of Pain, the team – which included researchers from the Universities of Bath, Oxford and Alberta in Canada – examined research relevant to using CBD to treat pain and published in scientific journals up to late 2023.

They found:

  • CBD products sold direct to consumers contain varying amounts of CBD, from none to much more than advertised.
  • CBD products sold direct to consumers may contain chemicals other than CBD, some of which may be harmful and some illegal in some jurisdictions. Such chemicals include THC (tetrahydrocannabinol), the main psychoactive component of the cannabis plant.
  • Of the 16 randomised controlled trials that have explored the link between pain and pharmaceutical-grade CBD, 15 have shown no positive results, with CBD being no better than placebo at relieving pain.
  • A meta-analysis (which combines data from multiple studies and plays a fundamental role in evidence-based healthcare) links CBD to increased rates of serious adverse events, including liver toxicity.

Medical vs non-medical CBD

In the UK, medical cannabis is the only CBD product that is subject to regulatory approval. It’s occasionally prescribed for people with severe forms of epilepsy, adults with chemotherapy-related nausea and people with multiple sclerosis.

Non-medical CBD is freely available in the UK (as well as in the US and many European countries) so long as it contains negligible quantities of THC or none at all. However, CBD products sold on the retail market are not covered by trade standards, meaning there is no requirement for them to be consistent in content or quality.

Most CBD products bought online – including popular CBD oils – are known to contain very small amounts of CBD. Moreover, any given product may be illegal to possess or supply, as there’s a good chance it will contain forbidden quantities of THC.

Chronic pain

An estimated 20% of the adult population lives with chronic pain, and sufferers are often desperate for help to alleviate their symptoms. It’s no surprise then that many people reach for CBD products, despite their high price tag and the lack of evidence of their effectiveness or safety.

Dr Andrew Moore, study co-author and former senior pain researcher in the Nuffield Division of Anaesthetics at the University of Oxford, said: “For too many people with chronic pain, there’s no medicine that manages their pain. Chronic pain can be awful, so people are very motivated to find pain relief by any means. This makes them vulnerable to the wild promises made about CBD.”

He added that healthcare regulators appear reluctant to act against the spurious claims made by some manufacturers of CBD products, possibly because they don’t want to interfere in a booming market (the global CBD product market was estimated at US$3 billion in 2021 or £2.4 billion and is anticipated to reach US$60 billion by 2030 or £48 billion) especially when the product on sale is widely regarded as harmless.

“What this means is that there are no consumer protections,” said Dr Moore. “And without a countervailing body to keep the CBD sellers in check, it’s unlikely that the false promises being made about the analgesic effects of CBD will slow down in the years ahead.”

The study’s authors are calling for chronic pain to be taken more seriously, with consumer protection becoming a priority.

“Untreated chronic pain is known to seriously damage quality of life, and many people live with pain every day and for the rest of their lives,” said Professor Eccleston. “Pain deserves investment in serious science to find serious solutions.”

Posted on Pain Management

The availability of recreational cannabis reduced the demand for prescription codeine. Have you used cannabis for pain? Tell us more in the comments!


States that permit the recreational use of cannabis to see a reduction in demand for prescription codeine, an opioid with a high potential for misuse, according to a new multi-institutional study led by University of Pittsburgh and Cornell University scientists.

Published this week in Health Economics, the study finds a significant reduction in pharmacy-based codeine distribution in states that have legalized recreational cannabis use. The finding is promising from a public health policy perspective because misuse of prescription opioids annually contributes to more than 10,000 overdose deaths.

Twenty-one U.S. states have passed recreational cannabis laws, and legislatures in other states are considering similar measures.

“A reduction in the misuse of opioids can save lives,” said lead author Shyam Raman, a doctoral candidate in Cornell’s Jeb E. Brooks School of Public Policy. “Our research indicates that recreational cannabis laws substantially reduce the distribution of codeine to pharmacies, an overlooked potential benefit to legalizing recreational cannabis use.”

The study is among the first to examine the impact of recreational cannabis laws on shipments of opioids to hospitals, pharmacies and other endpoint distributors. Previous studies have focused on medical cannabis laws or the use of opioids by subsets of consumers, such as Medicaid beneficiaries.

The researchers analyzed data from the Drug Enforcement Administration’s Automation of Reports and Consolidation Orders System (ARCOS) which tracks the flow of controlled substances in the U.S. These are their key findings from states that passed recreational cannabis laws:

  • A reduction of 26% in the pharmacy-based distribution of codeine and as much as a 37% reduction after recreational cannabis laws have been in effect for four years.
  • Minimal impact on the distribution of other opioids such as oxycodone, hydrocodone and morphine in any setting.
  • Minimal impact on codeine distribution by hospitals which often have less permissive policies than pharmacies.

“This finding is particularly meaningful,” said senior author Coleman Drake, Ph.D., assistant professor of health policy and management at Pitt’s School of Public Health. “Among prescription opioids, codeine misuse is especially high. Our findings suggest recreational cannabis use may be a substitute for codeine misuse.”

While cannabis and opioids can be used to minimize chronic pain symptoms, they aren’t equivalent in their impact on health.  

“Increasing legal access to cannabis may shift some consumers away from opioids and towards cannabis,” said Johanna Catherine Maclean, Ph.D., of George Mason University. “While all substances have some risks, cannabis use is arguably less harmful to health than the non-medical use of prescription opioids.”

Posted on Pain Management

Positive media coverage of cannabis pain studies, regardless of therapeutic effect


In cannabis trials against pain, people who take placebos report feeling largely the same level of pain relief as those who consume the active cannabinoid substance. Still, these studies receive significant media coverage regardless of the clinical outcome, report researchers from Karolinska Institutet in Sweden in a study published in JAMA Network Open.

“We see that cannabis studies are often described in positive terms in the media regardless of their results,” says the study’s first author Filip Gedin, postdoc researcher at the Department of Clinical Neuroscience, Karolinska Institutet. “This is problematic and can influence expectations when it comes to the effects of cannabis therapy on pain. The greater the benefit a treatment is assumed to have, the more potential harms can be tolerated.”

The study is based on an analysis of published clinical studies in which cannabis has been compared with placebo for the treatment of clinical pain. The change in pain intensity before and after treatment were the study’s primary outcome measurement.

The analysis drew on 20 studies published up to September 2021 involving almost 1,500 individuals.

The results of the study show that pain is rated as being significantly less intense after treatment with placebo, with a moderate to large effect. The researchers also observed no difference in pain reduction between cannabis and placebo, which corroborates results from another recently published meta-analysis. 

“There is a distinct and clinically relevant placebo response in studies of cannabis for pain,” says Dr Gedin.

The researchers also examined a possible connection between the magnitude of the therapeutic effect shown by the cannabis studies and the coverage they receive in the media and in academic journals. Media presence was measured through Altmetric, which is a method of evaluating mentions in the media, in blogs and on social media. Academic impact was measured in terms of citations by other researchers.

The analysis of media presence included a total of 136 news items in traditional media and in blogs and was categorised as positive, negative or neutral, depending on how the results were presented concerning the effectiveness of cannabis as a treatment for pain.

The researchers found that the cannabis studies received much greater media attention than other published studies. The coverage was substantial regardless of the magnitude of the placebo response and regardless of the therapeutic effect of cannabis. They also observed no link between the proportion of positively described news about a study and the effect it reported. 

The researchers add the caveat that their study combined trials of varying designs and quality and therefore the results should be interpreted with caution.

This research was financed by Riksbankens Jubileumsfond (Karin Jensen). The researchers report no potential conflicts of interest.

Posted on Patient Talk

A new study shows patient preference for medical cannabis products in the absence of clinical guidelines

Due to a lack of publicly available data, understanding what products medical cannabis patients use for various conditions has mostly come from survey responses. In a new study, USC Schaeffer Center researchers established a clearer picture by analyzing point-of-sale data from nearly 17,000 patients who made more than 80,000 purchases as part of the New York state medical cannabis program.

The researchers found considerable variation in the products chosen for most medical conditions, and high variability in labeled doses of THC.

“While the medical cannabis market is not new, there is still relatively little research on patient purchasing behavior,” says Alexandra Kritikos, a postdoctoral research fellow in the USC Schaeffer Center and the USC Institute for Addiction Science. “Unfortunately, our analysis suggests that patients may not be getting consistent guidance from clinicians and pharmacists and, in many disease areas, there seems to be a lack of clear clinical data on appropriate dosing.”

The results, published in JAMA Network Open, rely on purchases made between 2016 and 2019 when cannabis flower and edibles could not be sold in the medical market. Cannabis card holders could purchase vape cartridges and pens, capsules and tablets, tinctures, lotions and suppositories.

Medical cannabis users purchase a range of products with varying potencies

Since its inception in 2014, New York’s medical cannabis program has grown to 150,000 participants, making it one of the largest in the nation.

Using data from an integrated single system of dispensaries, the researchers found that the top three conditions patients recorded on their medical card were chronic pain (52%), neuropathy (22%) and cancer (13%). In addition to a qualifying condition, patients also needed a qualifying symptom to register. The top qualifying symptoms were severe pain (82%), severe muscle spasms (21%) and severe nausea (8%).

Vaporizers were the most popular product purchased (40%), followed by tinctures (38%) and tablets (22%). In terms of potency, the majority of products purchased (52%) were high-THC, low-CBD products. High- THC products contained between 2 and 10 mg of THC per dose, depending on the product.

Given this variation, when patients chose different products, they presumably favored different dosing. For example, 41% of patients with chronic pain preferred a high-THC vaporizer, which delivered 2 mg of THC/0.1 mg of CBD per dose, while 33% of chronic pain patients chose tinctures and 25% chose tablets, both of which delivered 10 mg of THC per dose. Another quarter of chronic pain patients chose a product containing 5 mg of both THC and CBD.

In contrast, the majority of patients suffering from cancer, HIV/AIDS and epilepsy purchased the same product, suggesting similar dosing.

Physicians need to take a more active role in patients using medical cannabis products

Earlier research found that electronic medical records frequently underreport the number of medical cannabis users. Combined with findings in the new Schaeffer Center study, the researchers suggest improving medical guidance and oversight of dosing.

“We suspect the lack of clinical guidelines on dosing of cannabinoids for particular medical conditions has made medical providers uncomfortable talking to their patients about their medical cannabis use,” says Rosalie Liccardo Pacula, senior author on both studies. “It is imperative that this change, as drug interactions with other prescribed medications are likely but impossible to identify if medical cannabis use is not considered or recorded in the medical record.” Pacula is a senior fellow at the Schaeffer Center and the Elizabeth Garrett Chair in Health Policy, Economics & Law at the USC Price School of Public Policy.

Pacula and Kritikos hope that their study provides a basis for conversations between providers and patients about cannabis use, including dosing levels.

Calls for caps in the recreational market will not limit access for medical cannabis patients

According to the labeled dosing, none of the most popular products analyzed for any of the conditions had dosing of more than 10 mg of THC, something policymakers should consider, say the researchers.

“We’ve seen the industry and media make the claim that putting caps on potency would limit access to necessary medicine,” Pacula says. “But our research in New York state suggests that medical cannabis users are consuming products that are less potent than what recreational users take.”

Posted on Pain Management

Cannabis-related products demonstrate a short-term reduction in chronic pain


The evidence behind the effectiveness of cannabis-related products to treat chronic pain is surprisingly thin, according to a new systematic evidence review by researchers at Oregon Health & Science University.

The federally funded review, which will be updated on an ongoing basis, was published today in the Annals of Internal Medicine.

Researchers did find evidence to support a short-term benefit in treating neuropathic pain – caused by damage to peripheral nerves, such as diabetic neuropathy resulting in pain described as burning and tingling, involving two FDA-approved synthetic products with 100% tetrahydrocannabinol, or THC: dronabinol (under the trade name Marinol) and nabilone (Cesamet). Both products also lead to notable side effects including sedation and dizziness, according to the review.

Another product, a sublingual spray of equal parts THC and cannabidiol, or CBD, extracted from the cannabis plant, known as nabiximols, also showed evidence of some clinical benefit for neuropathic pain, although that product is not available in the U.S. This product also led to side effects, such as nausea, sedation and dizziness.

“In general, the limited amount of evidence surprised all of us,” said lead author Marian S. McDonagh, Pharm.D., emeritus professor of medical informatics and clinical epidemiology in the OHSU School of Medicine. “With so much buzz around cannabis-related products, and the easy availability of recreational and medical marijuana in many states, consumers and patients might assume there would be more evidence about the benefits and side effects.

“Unfortunately, there is very little scientifically valid research into most of these products,” she said. “We saw only a small group of observational cohort studies on cannabis products that would be easily available in states that allow it, and these were not designed to answer the important questions on treating chronic pain.”

Voters in Oregon, Washington and 20 other states have legalized medical and recreational marijuana, however, the researchers found many of the products now available at U.S. dispensaries have not been well studied.

“For some cannabis products, such as whole-plant products, the data are sparse with imprecise estimates of effect and studies had methodological limitations,” the authors write.

This situation makes it difficult to guide patients.

“Cannabis products vary quite a bit in terms of their chemical composition, and this could have important effects in terms of benefits and harm to patients,” said co-author Roger Chou, M.D., director of OHSU’s Pacific Northwest Evidence-based Practice Center. “That makes it tough for patients and clinicians since the evidence for one cannabis-based product may not be the same for another.”

The living review, including a visual abstract summary of the findings, will also be shared on a new web-based tool launched by OHSU and VA Portland Health Care System early this year to help clinicians and researchers evaluate the latest evidence around the health effects of cannabis. Known as Systematically Testing the Evidence on Marijuana, or STEM, the project includes “clinician briefs” to help health care workers translate the clinical implications.

“This new living evidence review is exactly the type of resource clinicians need to clarify for patients the areas of potential promise, the cannabis formulations that have been studied and, importantly, the major gaps in knowledge,” said co-author Devan Kansagara, M.D., M.C.R., professor of medicine in the OHSU School of Medicine and a staff physician at the VA Portland.

Reviewers searched more than 3,000 studies in the scientific literature as of January of this year and landed on a total of 25 with scientifically valid evidence – 18 randomized controlled studies and seven observational studies of at least four weeks.

The effects of cannabis and related products are based on their ability to mimic the body’s own endocannabinoid system. The system is comprised of receptors and enzymes in the nervous system that regulate bodily functions and can affect the sensation of pain.  In the evidence review, researchers sorted the types of product into high, comparable and low ratios of THC to CBD and compared their reported benefits and side effects.

Dronabinol and nabilone fit into the high THC to CBD ratio category, with 100% THC (no CBD), showing   the most benefit among the products studied, with meta-analysis of the six randomized controlled studies demonstrating statistically valid benefits for easing neuropathic pain compared to a placebo.

“Honestly, the best advice is to talk to your primary care physician about possible treatments for chronic pain,” McDonagh said. “If you want to consider cannabis, you need to talk to your doctor.”