How can marijuana affect the symptoms of cancer?
A number of small studies of smoked marijuana found that it can be helpful in treating nausea and vomiting from cancer chemotherapy.
A few studies have found that inhaled (smoked or vaporized). Marijuana can be helpful treatment of neuropathic pain (pain caused by damaged nerves).
Smoked marijuana has also helped improve food intake in HIV patients in studies.
There are no studies on people of the effects of marijuana oil or hemp oil.
Studies have long shown that people who took marijuana extracts in clinical trials tended to need less pain medicine.
More recently, scientists reported THC and other cannabinoids. Such as CBD slows the growth and/or causes death in certain types of cancer cells growing in lab dishes. Some animal studies also suggest certain cannabinoids may slow growth and reduce the spread of some forms of cancer.
There have been some early clinical trials of cannabinoids in treating cancer in humans and more studies are planned. While studies so far have shown that cannabinoids can be safe in treating cancer. They do not show that they help control or cure the disease.
Relying on marijuana alone as treatment while avoiding or delaying conventional medical care for cancer may have serious health consequences.
Possible harmful effects of marijuana
Marijuana can also pose some harm to users. While the most common effect of marijuana is a feeling of euphoria (“high”). It also can lower the user’s control over movement. Cause disorientation, and sometimes cause unpleasant thoughts or feelings of anxiety and paranoia.
Smoked marijuana delivers THC and other cannabinoids to the body. But it also delivers harmful substances to users and those close by. Including many of the same substances found in tobacco smoke.
Because marijuana plants come in different strains with different levels of active compounds. It can make each user’s experience very hard to predict. The effects can also differ based on how deeply and for how long the user inhales. Likewise, the effects of ingesting marijuana orally can vary between people. Also, some chronic users can develop an unhealthy dependence on marijuana.
There are 2 chemically pure drugs based on marijuana compounds that have been approved in the US for medical use.
- Dronabinol (Marinol®) is a gelatin capsule containing delta-9-tetrahydrocannabinol (THC). That’s approved by the US Food and Drug Administration (FDA). To treat nausea and vomiting caused by cancer chemotherapy as well as weight loss and poor appetite in patients with AIDS.
- Nabilone (Cesamet®) is a synthetic cannabinoid that acts much like THC. It can be taken by mouth to treat nausea and vomiting caused by cancer chemotherapy when other drugs have not worked.
Nabiximols is a cannabinoid drug still under study in the US. It’s a mouth spray made up of a whole-plant extract with THC and cannabidiol (CBD) in an almost one-to-one mix. Now it’s available in Canada and parts of Europe to treat pain linked to cancer. As well as muscle spasms and pain from multiple sclerosis (MS). It’s not approved in the US at this time. But it’s being tested in clinical trials to see if it can help a number of conditions.
How can cannabinoid drugs affect symptoms of cancer?
Based on a number of studies, dronabinol can be helpful for reducing nausea and vomiting linked to chemotherapy.
Dronabinol has also been found to help improve food intake and prevent weight loss in patients with HIV. In studies of cancer patients, though, it wasn’t better than a placebo or another drug (megestrol acetate).
Nabiximols have shown promise for helping people with cancer pain that’s unrelieved by strong pain medicines. But it hasn’t been found to be helpful in every study done. Research is still being done on this drug.
Side effects of cannabinoid drugs
Like many other drugs, prescription cannabinoids, dronabinol, and nabilone can cause side effects and complications.
Some people have trouble with increased heart rate, decreased blood pressure (especially when standing up), dizziness or lightheadedness, and fainting. These drugs can cause drowsiness as well as mood changes or a feeling of being “high” that some people find uncomfortable. They can also worsen depression, mania, or other mental illnesses. Some patients taking nabilone in studies reported hallucinations. The drugs may increase some effects of sedatives, sleeping pills, or alcohol, such as sleepiness and poor coordination. Patients have also reported problems with dry mouth and trouble with recent memory.
Older patients may have more problems with side effects and are usually started on lower doses.
People who have had emotional illnesses, paranoia, or hallucinations may find their symptoms are worse when taking cannabinoid drugs.
Talk to your doctor about what you should expect when taking one of these drugs. It’s a good idea to have someone with you when you first start taking one of these drugs and after any dose changes.
What does the American Cancer Society say about the use of marijuana in people with cancer?
The American Cancer Society supports the need for more scientific research. On cannabinoids for cancer patients and recognizes the need for better and more effective therapies. That can overcome the often debilitating side effects of cancer and its treatment. The society also believes that the classification of marijuana as a Schedule I controlled substance by the US Drug Enforcement Administration. Imposes numerous conditions on researchers and deters scientific study of cannabinoids. Federal officials should examine options consistent with federal law for enabling more scientific study on marijuana.
Medical decisions about pain and symptom management. Should be made between the patient and their doctor, balancing evidence of benefit and harm to the patient. The patient’s preferences and values, and any laws and regulations that may apply.
The American Cancer Society Cancer Action Network (ACS CAN). The Society’s advocacy affiliate has not taken a position on the legalization of marijuana. For medical purposes because of the need for more scientific research on marijuana’s potential benefits and harms. However, ACS CAN oppose the smoking or vape of marijuana and other cannabinoids in public places. Because the carcinogens in marijuana smoke pose numerous health hazards to the patient and others in the patient’s presence.
Read more on the Cancer Research UK investigating cannabinoids