According to the findings of a recent multicenter registry research from Canada published online in BMJ Supportive & Palliative Care, prescription cannabinoids, sometimes known as medicinal cannabis, can effectively alleviate cancer pain while reducing the number of drugs required, including opioids.

Cannabinoid products having an equal mix of the active components tetrahydrocannabinol (THC) and cannabidiol (CBD), rather than a preponderance of either, appear to be particularly helpful, according to researchers.

The findings lead the researchers to conclude that medical cannabis is a safe and complementary treatment for cancer patients whose alleviation from traditional drugs is inadequate.

Opioids have long been considered the gold standard for cancer pain treatment, however other pharmacological types, such as anti-inflammatory and anticonvulsant medications, are also employed.

However, pain management with opioid analgesics is not always ideal, with one-third of cancer patients experiencing insufficient alleviation, according to the research authors. Furthermore, opioids have well-known adverse effects such as nausea, somnolence, and constipation, and respiratory depression is a concern at large dosages.

According to the authors, physicians, including 61.5% of general practitioners, are increasingly accepting patient requests to investigate medicinal cannabis for pain relief and other cancer-related symptoms. Prescription synthetic cannabinoids (such as nabilone, dronabinol, and nabiximols) have been examined for the treatment of cancer-related pain, nausea, vomiting, and anorexia caused by chemotherapy. The authors also mention studies that show cannabis have the potential to lower opiate usage in cancer pain treatment.

As a result, the Canadian research team set out to investigate the efficacy and safety of medical cannabis for cancer pain management, as well as the potential for the treatments to reduce the use of opioid medications, using data from the large, prospective, multicenter Quebec Cannabis Registry (QCR).

For 3.5 years (May 2015-October 2018), 358 patients with cancer had their QCR data collected. Participants were referred by general practitioners or specialists and enrolled by physicians from around Quebec who consented to dispense medical cannabis within the context of the QCR investigation.

THC-dominant (24.5%), THC:CBD-balanced (38%), and CBD-dominant (16.5%) medications were permitted for participant treatment; oral administration was the most often advised mode (59%).

The Brief Pain Inventory), the Revised Edmonton Symptom Assessment System, the Medication Quantification Scale (MQS), and morphine equivalent daily dose (MEDD) were used to assess the outcomes of medical cannabis usage.

Using validated metrics, pain intensity was graded on a 0 to 10 scale, with 0 representing no pain and 10 being the greatest conceivable agony. The level of pain alleviation ranged from 0% to 100%. Over the last 24 hours, two summary measures assessed overall pain intensity and pain interference.

FINDINGS

The average age of the participants was 57, and 48% were men. Genitourinary, breast, and colon cancer were the three most prevalent cancer diagnoses. Pain was the most commonly reported ailment (72.5%) that generated a prescription for medical cannabis.

According to the findings of the study, medical cannabis appeared to be safe and well tolerated, with only 15 moderate to severe adverse effects recorded by 11 patients, 13 of which were considered insignificant. The two most prevalent adverse effects were somnolence (3 individuals) and tiredness (2 patients).

Two significant adverse effects (pneumonia and a cardiovascular incident) were ruled out as being caused by medical cannabis. Only 5 individuals discontinued using medical cannabis due to negative effects.

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

“The particularly good safety profile of [medicinal cannabis] discovered in this study can be attributed in part to the close supervision of healthcare professionals who authorized, directed, and monitored [the] treatment.”
At 3, 6, and 9 months, there were statistically significant improvements in worst and average pain intensity, overall pain severity, and pain interference [with daily living] (P.01 for all).

Overall, THC:CBD balanced medicines provided superior pain alleviation than either THC-only or CBD-only products.

A review of MQS scores revealed reductions in the number of medicines used relative to baseline at all quarterly follow-ups (for 10%, 23.5%, 26.2%, and 31.6% of patients, respectively). MEDD scores decreased compared to baseline in 11.1%, 31.3%, and 14.3% of patients at 3-month, 6-month, and 9-month follow-ups, respectively.

According to the authors, the study’s observational character precludes the identification of cause and effect. Other limitations they cite include a considerable percentage of patients being lost to follow-up over the course of a year, as well as addition or discontinuation being the only information provided on the usage of other drugs.

Nonetheless, they conclude, “Our data suggest a role for [medicinal cannabis] as a safe and complementary treatment option in cancer patients who are unable to achieve adequate pain relief with conventional analgesics, such as opioids.”