It’s fair to say that my patients were using cannabis long before I knew it was a “thing”.
My first memory of encountering the drug was at the bedside of a dying patient ten years ago. I was about to give a morphine drip when a large man quietly asked me to come outside. Moments later, my concern turned to surprise when the son, with tears streaming down his face, begged me to wait while his brother bought some cannabis from an underground supplier, “just in case it works.”
“Works for what?” I asked in surprise.
“As a cure for cancer,” he stammered.
My heart melted and I told the son that nothing could save his dying father, who deserved to die with dignity. Shortly afterwards the inevitable happened, but I vividly remember the fervor with which the son believed in cannabis as a cure for cancer.
Today, cannabis is no longer a backchannel substance evoked in hushed tones. Cancer patients openly ask for access and expect good help. Oncologists pride themselves on addressing questions about proven and debunked interventions, but when it comes to cannabis, most doctors won’t prescribe it and most hospitals won’t allow it. So the most common attitude patients face is, “We don’t do that here,” leaving them feeling rejected or, worse, judged.
When my elderly patient recently announced that she wanted to try cannabis for pain, I hesitated and preferred that she try conventional painkillers. Nevertheless, when she insisted, I let her find her own way to an online doctor because I didn’t know how to prescribe or monitor the drug. Soon, her family reported that she was even more confused and forgetful before she fell, ending the experiment. I had a nagging feeling of guilt that I hadn’t done better with her.
Up to 40% of cancer patients report using cannabis. For a psychoactive substance that rivals caffeine, alcohol and nicotine for global popularity, ignoring cannabis does a disservice to patients. That’s why I was happy to get the American Society for Clinical Oncology releasing a set of evidence-based guidelines to help oncologists manage their patients.
Here are some key points.
Cannabis is associated with significant side effects
The body absorbs approximately 10% of oral and 30% of inhaled cannabis. The psychoactive effects of inhaled cannabis occur within seconds, while oral cannabis can take up to two hours to work. Acute side effects include sedation, euphoria, lightheadedness, lightheadedness, mood changes, and hallucinations. Long-term toxicity can affect the liver, heart and brain.
There are potential drug interactions, but we don’t yet have evidence-based answers about which ones. In the meantime, every cannabis user and prescriber should be aware of these pitfalls.
It is not a cure for cancer
Cannabis is not a treatment, let alone a cure for cancer. It is not a substitute for chemotherapy and can cause significant fatigue, confusion and mood disturbances.
The advent of immunotherapy has led to patients experiencing unprecedented responses. Despite anecdotal reports that cannabis exhibits anti-inflammatory properties, researchers warn that cannabis consumption may interfere with immunotherapy. This has resulted in a recent recommendation to avoid cannabis while undergoing any form of immunotherapy.
Cannabis can somewhat improve nausea and sleep
For patients who experience severe nausea despite taking the many strong medications now available, oral cannabis can provide relief. However, it should not be used as a first-line drug for the treatment of nausea and vomiting, or as a preventive during chemotherapy or radiotherapy.
When it comes to sleep, cannabis is associated with a very small improvement in adults with cancer pain, but this may come at the expense of other troublesome symptoms, so caution is advised. The bottom line is that for most patients, there are better remedies to curb nausea and promote sleep.
It does not reduce the pain
In four randomized controlled trials focusing on cancer pain, cannabis provided no significant benefit. This is why, outside of a clinical trial, guidelines do not recommend the use of cannabis for the relief of cancer pain.
The effect of cannabis on anxiety and depression is unclear
In a systematic review, no study has robustly addressed psychological symptoms. Therefore, experts do not make recommendations about cannabis and patients should try other ways to control the psychological effects of cancer.
It does not benefit appetite and weight
Loss of appetite and weight is a disturbing fact for many cancer patients. Unfortunately, cannabis does not provide any benefits in either case and should therefore not be used.
Not all products are the same
Synthetic cannabis products are more potent than natural cannabis products and can lead to more increased toxicities. When prescribing, physicians and patients should take a “start low, go slow” approach while continually weighing the risks and benefits.
Chronic users can develop serious problems
Early cannabis use is a predictor of future dependence, and chronic users are at greater risk for psychiatric disorders. Long-term daily cannabis users can experience severe withdrawal symptoms, including irritability, insomnia, anxiety and pain.
Cannabis users should avoid driving
A meta-analysis shows that cannabis users are at significantly greater risk of being involved in car accidents. The rate of car accidents involving cannabis and alcohol has risen sharply, making this a serious issue that oncologists need to discuss with their patients.
There is a lot we don’t know
For a drug that is so ubiquitous, there are many gaps in our knowledge. Are there preparations with meaningful anticancer activity? Can some forms ease the feared side effects of cancer therapy? How can we spare patients the stigma and financial toxicity while helping them reap the benefits? Recognizing what we don’t know is the first step to asking relevant questions in the patient’s best interest.
There was a time when oncologists frowned upon the idea of talking about cannabis, leaving patients with no choice but to seek out unscrupulous suppliers. But when their apex body publishes guidelines on the subject, it signals a new attitude of openness.
Cannabis is not going away and I look forward to learning more about its possible role in cancer. When patients ask, “Doctor, should I use cannabis for my cancer?” the answer is still no. But at least we’re talking.