Important Information About the Use of Medical Cannabis
This information is intended for patients and caregivers who have questions about the use of medical cannabis. It provides an overview of cannabis-related concerns for young people, people who are pregnant or breastfeeding, people at risk of dependence or addiction, people with mental health conditions, and people with heart or liver conditions.
What You Should Know Before Starting Medical Cannabis
Cannabis-derived medicines include Epidiolex (cannabidiol), as well as three synthetic cannabis-related medicines: Marinol (dronabinol), Syndros (dronabinol), and Cesamet (nabilone). Other medical cannabis products have not been approved by the FDA.¹
For most medical conditions, further research is needed to understand the appropriate role of medical cannabis as part of comprehensive medical care. Medical cannabis products may or may not provide symptom relief. Existing research on medical cannabis suggests that symptom relief may vary from patient to patient.
Side effects are common. The most common side effects include dizziness, fatigue, dry mouth, lightheadedness, drowsiness, and nausea. Side effects are usually mild or moderate and generally resolve quickly, but serious side effects can occur.
If you experience any side effects, consult a pharmacist at your medical cannabis dispensary.
Consult a Healthcare Professional About Medical Cannabis
Like other medications, medical cannabis may interact with other medicines you are taking. To avoid side effects, it may be necessary to monitor the blood levels of other medications or adjust their dosages.
Medical cannabis may also affect the body in other ways. For example, inhaling medical cannabis (whole-plant products or vaporized products) can cause dry mouth, which may increase the risk of tooth decay and other dental problems.
Start Low, Go Slow, Keep It Low
To avoid unpleasant side effects, it is best to start with a low dose and gradually increase the dose over time until symptoms are relieved or side effects occur. Consult a pharmacist at a medical cannabis dispensary for guidance on following this approach.
Research suggests that the effects of medical cannabis generally have an upper limit. For THC, doses above 20–40 mg per day, and for CBD, doses above 50–100 mg per day, may not provide most patients with additional benefits compared with lower doses.
Tips for new patients:** Until you know how you respond to a specific medical cannabis product, it is recommended that you purchase less than a 30-day supply during your first few visits to a medical cannabis dispensary.
Some People May Have a Higher Risk of Harm from Cannabis Use
People who belong to the groups listed in this section generally should not use medical cannabis because they may have an increased risk of harm. If you have any concerns or questions, consult a healthcare professional.
Children, Adolescents, and Young Adults
The use of medical cannabis in children, adolescents, and young adults requires special consideration. The human brain is actively developing and continues to develop until approximately age 25. Cannabis use during adolescence may affect the developing brain and may lead to problems with attention, motivation, and memory.
There are also risks associated with secondhand cannabis smoke, as it contains many of the same toxic and carcinogenic chemicals found in tobacco smoke.
Evidence Links Recreational Marijuana Use in Children, Adolescents, and Young Adults to
- Delayed or impaired information processing in the brain
- An increased risk of developing cannabis dependence in the future
- The development of mental health conditions such as schizophrenia
Much remains unknown about who is at risk of these outcomes and whether the risks associated with recreational marijuana use also apply to medical cannabis use in children, adolescents, and young adults.
For some people with serious illnesses or debilitating symptoms that cannot be adequately controlled with conventional medical treatments, the potential benefits of medical cannabis may outweigh the potential risks, particularly for medical cannabis products containing only CBD extracts.
For more information, see Dosage and Chemical Composition.
People Who Are Pregnant or Breastfeeding
If you are pregnant, planning to become pregnant, or breastfeeding, avoid using medical cannabis. There is some evidence that cannabis use during pregnancy may be associated with low birth weight and premature birth. However, most studies have difficulty distinguishing harms caused by cannabis use from those caused by tobacco use.
Cannabis use during pregnancy may affect the developing brain of the baby and may be associated with problems with memory, attention, and behavior, such as aggression or impulse control, during childhood and adolescence. Children whose parents used cannabis during pregnancy may also have an increased risk of experiencing psychosis during adolescence.
People at Risk of Dependence or Addiction
Medical cannabis use can lead to cannabis dependence or addiction. People who have experienced other forms of addiction or who use large amounts of products with high levels of THC may have a higher risk of developing an addiction.
People at Risk of Dependence or Addiction
If you have a dependence on tobacco or other substances containing nicotine, do not use medical cannabis, or use it only with extreme caution.
If you regularly use large amounts of medical cannabis, suddenly stopping may cause uncomfortable and severe withdrawal symptoms that can last for several days. Withdrawal symptoms are more likely to occur when using large amounts of products with high THC content.
People with Mental Health Conditions
Recreational marijuana use is known to be associated with psychosis. Psychotic episodes can be distressing and potentially dangerous. The following factors may increase the risk of psychosis:
- Using medical cannabis extracts with a high THC concentration or a high THC-to-CBD ratio.
- Having a family history of schizophrenia or other psychotic disorders. Therefore, medical cannabis should not be used, or should be used only with extreme caution, in patients with a family history of psychotic disorders such as schizophrenia.
People with psychotic disorders such as schizophrenia, or those with a family history of schizophrenia or other psychotic disorders, should not use medical cannabis. In particular, they should avoid medical cannabis products with high concentrations of THC.
For people with schizophrenia or psychotic disorders, psychotic symptoms generally improve after stopping cannabis use.
People with Severe Heart or Liver Disease
People with severe heart or liver disease should not use medical cannabis, or should use it only with extreme caution.
For patients with severe heart disease, there is evidence that medical cannabis use may increase the risk of a heart attack. Severe liver disease may interfere with how cannabis is metabolized in the body.
Warning
Cannabinoid Hyperemesis Syndrome
People who develop cannabinoid hyperemesis syndrome may experience nausea, severe vomiting, and abdominal pain for several days, with episodes recurring weekly or every few weeks.
Several patients enrolled in medical cannabis programs have been hospitalized with cannabinoid hyperemesis syndrome.
If you experience signs or symptoms of this syndrome, consult a healthcare professional or a pharmacist at your medical cannabis dispensary.
Do not drive, operate machinery, or perform tasks that could put others at risk while using medical cannabis.
Do not drive, operate machinery, or perform tasks that could put others at risk while using medical cannabis.
Medical cannabis may slow reflexes and reaction time, make it more difficult to pay attention or make decisions, and alter your perception of your surroundings. For these reasons, driving, operating machinery, engaging in activities that could harm others, or performing activities where professional negligence could occur may be dangerous.
How long these effects last varies from person to person and depends on factors such as the type of medical cannabis product used, the dosage, and other factors. At a minimum, these effects may last for several hours.
#### **The effects of medical cannabis may be greater in the following situations:**
- Using products with high levels of THC.
- Drinking alcohol while using medical cannabis.
Store medication safely and keep it in its original container.
If medication is not kept in its original container, it can be easier to mistake it for another medication. The label on the original container identifies the legal owner of the product.
Like other medications, medical cannabis should be stored in a secure place where children and other people cannot access it.
Talk to Your Doctor About Inflammation
