As interest grows in the use of cannabinoids for the management of cancer-related pain, a recent study shows that they do not provide a benefit in pain management for patients with advanced cancer using opioids.
For adults with advanced cancer adding cannabinoids to opioids did not reduce their cancer related pain and was associated with short term side effects, according to a study published in BMJ Supportive & Palliative Care.
Cancer-related pain is unfortunately common among all patients — especially those with advanced cancer, and as patients and physicians look for methods to control that pain outside of opioids the interest in cannabinoids and cannabis as means of pain management has grown. The medicinal use of cannabis is now legal in 40 countries and 29 US states, and the use of cannabis is increasing in multiple cancer centers.
“A recent systematic review and metanalysis that assessed the efficacy, tolerability and safety of medical cannabis and cannabis-based medicines for cancer pain reported very low-quality evidence for a non-significant 50% reduction in pain,” the researchers wrote. They set out to determine the beneficial effects and side effects of cannabinoids for the treatment of cancer-related pain in adults and found that adults with advanced cancer not only don’t derive benefit from it for pain management compared to placebo but also have more side effects from cannabinoids.
Cannabinoids are 66 of the 480 different components found within the cannabis plant itself. These include both THC, the component associated with euphoric high typical with cannabis, and CBD, the component associated with the relaxed or tired feeling.
The researchers conducted a systematic review of 2,805 unique records detailing the use of cannabinoids for cancer related pain, including studies that looked at THC and CBD, THC extract, nabiximols, Sativex and medical cannabis compared to placebo or other active agents for cancer related pain treatment. The studies used for this analysis assessed clinically relevant cannabinoids that were given as a treatment for cancer related pain in addition to opioids for advanced cancer treatment.
They found from these studies that there was no difference in the change of pain reported on their numerical rating scale between cannabis and placebo and that any change in pain intensity was not statistically different between the two categories as well. Looking at only phase 3 studies included in the research, they found no benefit from the cannabinoid use.
Cannabinoids are also associated with side effects such as dizziness, nausea, vomiting, somnolence and fatigue and were generally reported to have a higher risk of these side effects compared to placebo. According to the research, patients who used cannabinoids for pain related management had 1.86 times higher risk of non-serious side effects.
“For a medication to be useful, there needs to be a net overall benefit, with the positive effects (analgesia) outweighing adverse effects. None of the included phase III studies show benefit of cannabinoids,” the researchers concluded. “Based on evidence with a low risk of bias, cannabinoids cannot be recommended for the treatment of cancer-related pain.”