The study, published in BMJ Supportive & Palliative Care, was a multicenter registry study of 358 cancer patients with pain who were treated with medicinal cannabis at 11 clinics in Canada and the United States. The study was observational, meaning that the researchers did not intervene in the patients’ treatment. Instead, they collected data on the patients’ pain levels, medication use, and side effects before and after they started using medicinal cannabis.

The patients were followed for an average of 12 months. During that time, they were asked to complete questionnaires every three months about their pain levels, how much pain medication they were taking, and any side effects they were experiencing.

The researchers found that the patients’ pain levels decreased significantly after they started using medicinal cannabis. The average pain score decreased from 6.2 at baseline to 4.5 at 12 months. The patients also reported using less pain medication after they started using medicinal cannabis. The average number of pain medications used per day decreased from 3.1 at baseline to 2.4 at 12 months.

The most common side effects reported by the patients were dizziness and fatigue. However, these side effects were generally mild and well-tolerated.

Overall, the study found that medicinal cannabis was a safe and effective treatment for cancer pain. The patients experienced a significant reduction in pain levels and a decrease in pain medication use after they started using medicinal cannabis. The side effects were generally mild and well-tolerated.

Additional details:

• The patients in the study were a diverse group, representing a wide range of cancer types and pain severity.
• The patients were treated with a variety of medicinal cannabis products, including oral capsules, sublingual sprays, and vaporizer cartridges.
• The researchers found that the patients who used products with an equal balance of THC and CBD were the ones who experienced the greatest reduction in pain.
• The researchers also found that the patients who used medicinal cannabis for longer periods of time were more likely to experience a reduction in pain.

Limitations of the study:

• The study was observational, meaning that the researchers did not intervene in the patients’ treatment. This means that it is possible that other factors, such as the patients’ overall health or other treatments they were receiving, may have contributed to their improvement in pain.
• The study did not have a control group, meaning that the researchers could not directly compare the effects of medicinal cannabis to a placebo.
• The study was relatively small, with only 358 participants.

Despite these limitations, the study provides valuable evidence that medicinal cannabis may be a safe and effective treatment for cancer pain. More research is needed to confirm these findings and to identify the optimal dose and formulation of medicinal cannabis for each patient.

The study, published in BMJ Supportive & Palliative Care, researchers found medicinal cannabis to be “a safe and effective complementary treatment for pain relief in patients with cancer”.

Products with an equal balance of the active ingredients tetrahydrocannabinol (THC) and cannabidiol (CBD) seemed to be the most effective.

Cannabis plants contain both – but while THC produces a “high”, CBD does not.

Of the patients studied:

about a quarter took THC-dominant products

38% THC-CBD-balanced drugs

17% CBD-dominant products

The most common side-effects were:

dizziness

fatigue

The researchers, from McGill University, in Montreal, Harvard Medical School, in Boston and the Royal College of Surgeons in Dublin, among others, say about a third of all cancer patients and two-thirds of those who are terminally ill experience moderate to severe pain.

Painkillers are the standard treatment – but a third of cancer patients are still thought to experience pain.

Every three months for a year, the patients were asked:

how much pain they felt

how many drugs they took

After taking the cannabis medicines, they felt much less pain and noticed it interfering less with their daily life.

But more rigorous trials using a control group to compare the effects of cannabis medicines with a dummy drug are needed to confirm the findings, the researchers say.

It is very rare but since 2018 UK law has allowed the prescription of unlicensed cannabis-based medicines in very specific circumstances:

for children and adults with rare, severe forms of epilepsy

for adults with vomiting or nausea caused by chemotherapy

for people with muscle stiffness and spasms caused by multiple sclerosis (MS)

Official guidance says:

medicinal cannabis is not recommended for treating pain, or for most types of epilepsy.

more research is needed, “particularly to understand any benefits and risks of these medicines for children and young people”

A Department of Health and Social Care official said: “Licensed cannabis-based medicines are funded routinely by the NHS where there is clear evidence of their quality, safety and effectiveness.

“Like any other medicine, unlicensed cannabis-based products for medicinal use must be proved safe and effective before they can be considered for routine NHS funding.

“We are working closely with partners to establish clinical trials to test the safety and efficacy of more cannabis-based products for medicinal use to inform future NHS funding decisions.”

Medicinal cannabis can safely relieve cancer pain and curb total meds use

Products with equal balance of THC+ CBD seem to be particularly effective, data indicate

Medicinal cannabis can safely relieve cancer pain, while curbing the total number of meds and opioids taken, suggest the results of a multicentre registry study, published online in BMJ Supportive & Palliative Care.

Products with an equal balance of the active ingredients tetrahydrocannabinol (THC) and cannabidiol (CBD), rather than a dominance of either one, seem to be particularly effective, the data indicate. 

The findings prompt the researchers to conclude that medicinal cannabis is a safe and complementary treatment when conventional drugs fail to touch cancer pain.

Over half of patients undergoing anticancer treatment and two thirds of those with advanced or terminal disease experience pain, say the researchers.

Powerful opioids along with other meds, such as anti-inflammatory and anticonvulsant drugs, are usually prescribed for pain relief. 

But 1 in 3 patients will still experience pain, added to which the side effects of opioids include nausea, sleepiness, constipation, and respiratory depression, point out the researchers.

They therefore wanted to find out if medicinal cannabis could safely and effectively relieve cancer pain, while at the same time reducing the total number of meds and opioids taken.

They studied the treatment responses of 358 adults with cancer whose details were submitted to a multicentre registry—the Quebec Cannabis Registry in Canada—over a period of 3.5 years (May 2015 to October 2018).

The patients’ average age was 57; nearly half (48%) were men; and the 3 most common cancer diagnoses were genitourinary, breast, and bowel. Pain was the most frequently reported (72.5%) symptom that prompted a prescription of medicinal cannabis.

THC-dominant, THC:CBD-balanced, and CBD-dominant products were authorised in 24.5%, 38%, and 16.5% of patients, respectively. Taking the product by mouth was the most frequently recommended route (59%). 

Patients’ pain intensity, symptoms, total number of drugs taken, and daily morphine consumption were monitored quarterly for 1 year.

Pain intensity was rated, using validated measures, on a sliding scale from none (zero) to the worst possible (10), and pain relief from none (0%) to complete (100%), with two summary measures of overall pain severity and pain interference over the preceding 24 hours.

Medicinal cannabis seemed to be safe and well tolerated, with only 15 moderate to severe side effects reported by 11 patients, 13 of which were regarded as minor. The 2 most common side effects were sleepiness, reported by 3 patients, and fatigue, reported by 2. 

Two serious side effects (pneumonia and a cardiovascular event) were deemed unlikely to have been linked to medicinal cannabis. Only 5 patients stopped taking medicinal cannabis because of side effects.

“The particularly good safety profile of [medicinal cannabis] found in this study can be partly attributed to the close supervision by healthcare professionals who authorised, directed, and monitored [the] treatment,” highlight the researchers.

Statistically significant decreases were observed at 3, 6 and 9 months for worst and average pain intensity, overall pain severity, and pain interference [with daily life].

Overall, THC:CBD balanced products were associated with better pain relief than either THC-dominant or CBD-dominant products. 

The total number of drugs taken also fell consistently at all the subsequent quarterly check-ups, while opioid use fell over the first three check-ups.

This is an observational study, and as such, can’t establish cause, caution the researchers. What’s more, a significant number of patients were lost to follow up over the course of the 12 months while information on the use of other prescribed meds was limited to addition or discontinuation, they acknowledge. 

Nevertheless, they conclude: “Our data suggest a role for [medicinal cannabis] as a safe and complementary treatment option in patients with cancer failing to reach adequate pain relief through conventional analgesics, such as opioids.”

Medical cannabis could be “safe and complementary” treatment option

MAY 5, 2023 BRAIN TUMOUR RESEARCH4 min read

Medicinal cannabis helps relieve cancer pain and can cut down how many drugs people need, research suggests.

A new study published in BMJ Supportive & Palliative Care found that products with an equal balance of the active ingredients tetrahydrocannabinol (THC) and cannabidiol (CBD) seemed to be the most effective for pain.

Currently only specialist hospital doctors can prescribe cannabis-based medicines on the NHS, and only for a few limited conditions such as rare and severe epilepsy, vomiting or nausea caused by chemotherapy and muscle stiffness caused by multiple sclerosis (MS).

Researchers studied 358 adults with cancer over a period of three-and-a-half years. Around a quarter of patients took THC-dominant products in the study, 38% took THC:CBD-balanced drugs and 17% took CBD-dominant products. Patient pain intensity, symptoms, total number of drugs taken and daily morphine consumption were then monitored quarterly for a year.

The study found that at three, six and nine months, there were statistically significant drops in worst and average pain intensity, overall pain severity, and pain interference with daily life. Researchers concluded the data suggests a role for medicinal cannabis as “a safe and complementary treatment option in patients with cancer failing to reach adequate pain relief through conventional analgesics, such as opioids.”

It comes as a clinical trial of an oral spray containing cannabinoids to treat glioblastoma (GBM) – the most common type of primary high-grade brain tumour in adults – has opened at Leeds Teaching Hospitals NHS Trust and the Christie NHS Foundation Trust in Manchester.

The trial, funded by The Brain Tumour Charity, will investigate whether combining nabiximols (a cannabis medicine) and chemotherapy can help extend the lives of people diagnosed with recurrent GBM. It will recruit more than 230 GBM patients at 14 NHS hospitals across England, Scotland and Wales in 2023.

Dr Karen Noble, our Director of Research, Policy and Innovation, said: “We are delighted to see this clinical trial launch. Congratulations to The Brain Tumour Charity for funding this much-needed study. As highlighted in the recent All-Party Parliamentary Group on Brain Tumours Inquiry report, Pathway to a Cure – breaking down the barriers, there are a limited number of clinical trials available for brain tumour patients with only 5% of patients accessing them. Very few treatment options exist for GBM patients and we look forward to the results of this trial to see whether cannabinoid-based drugs can treat the most aggressive form of brain tumour.”