By the Incisor Staff
According to the Centers for Disease Control (CDC), 48.2 million people in the United States used cannabis in 2019. Given this, health professionals should consider cannabis a widely used substance their patients might use for recreational and medicinal purposes.
To provide the highest level of care, dentists must be knowledgeable about their patients' health. When using a healthcare intake form, dentists obtain information about the patient's medical history, including heart disease, medications, diabetes, and substance use. In light of the growing use and legalization of cannabis, dentists should ask patients about the substance, particularly when sedation is involved.
Cannabis – also known as marijuana – is a plant used for recreational and medicinal purposes. Under federal law, cannabis is still classified as a Schedule I drug, but 19 states have approved it for recreational use, with 38 for medicinal purposes. Five more states will vote on recreational marijuana use this month: Arkansas, Maryland, Missouri, North Dakota, and South Dakota.
THC and CBD - What's the Difference?
Cannabis sativa is used to create many products containing tetrahydrocannabinol (THC) and cannabidiol (CBD).
THC is a chemical component that binds to the nervous system and causes euphoria. The human brain consists of millions of nerve cells linked together through neurotransmitters. These are responsible for relaying impulse signals to and from the brain. One such neurotransmitter is called anandamide, which binds to cannabinoid receptors with high affinity and mimics the psychoactive effects of plant-derived cannabinoids. These receptors are responsible for pleasure, memory, concentration, coordination, and other sensory functions. When introduced into the body, THC binds to these same receptors and produces the same effect of euphoria and pleasure.
CBD is a bit different. While its chemical structure is similar to THC, it doesn't actively bind to these receptors. As such, CBD is not psychoactive when compared to THC.
CBD is mainly found in edibles and is usually used for medicinal purposes – particularly pain relief. At the same time, THC is predominantly present in the vapor and smoke form of cannabis, which is more for recreational use. However, medicinal products sold in dispensaries in states that have legalized cannabis often contain mixtures of both THC and CBD at various levels.
What Sedation Dentists Should Know About Cannabis
Cannabis Drug Interactions
- CNS depressants may enhance the CNS depressants of cannabinoids.
- CYP3A4 Inhibitors (e.g., Clarithromycin, Diflucan) may increase the serum concentration of THC.
- Vasoconstrictors may enhance the tachycardia effect of cannabis.
- All interactions are [C] level interactions according to Lexi-Comp.
Cannabis & Sedation – Recommendations
- Ask how long (long-term use effects), how often (N&V and physical dependence level), how much (long-term use effects), and what form (possible respiratory disease).
- Evaluate for respiratory disease (baseline O2 sat, existing diagnosis, or medications).
- If heavy (>2X/day) or long-term (>5yrs.) user, ask about nausea and vomiting, and consider using anti-emetic prophylactically.
Withhold use on the day of sedation
- Whenever possible, keep sedation appointments to three hours or less.
- Monitor heart rate closely when using vasoconstrictors.
- CBD is one of 113 cannabinoids in cannabis plants.
- Not psychoactive compared to THC.
- It may reverse THC intoxication or sedation.
- Same drug interactions as THC.
- Same treatment recommendations with sedation as with THC.
The FDA has not approved the cannabis plant for medical purposes. However, individual cannabinoids have been approved by the FDA for use in medications.
Epidiolex contains a purified form of CBD derived from cannabis and has been approved for treating seizures associated with severe and rare forms of epilepsy called Lennox-Gastaut syndrome and Dravet syndrome.
The FDA has also approved Marinol and Syndros, which contain dronabinol (synthetic THC), and Cesamet, which contains nabilone (a synthetic substance similar to THC). In addition to treating nausea and vomiting caused by chemotherapy, dronabinol is also used to treat loss of appetite and weight loss in HIV/AIDS patients.
Have A Conversation with Your Patients
Identifying cannabis users can be a delicate matter for some patients. Therefore, healthcare practitioners should also realize that some patients may be reluctant to share such information for fear of judgment.
Yes – sedation dentists need to be aware of their patients' cannabis usage, but not by being so forward that they become fearful or hesitant to share such an essential part of their medical history. The most straightforward approach is including a question about cannabis use in the medical history questionnaire and reassuring the patient that these are entirely confidential and only used as a preliminary scan for their health. Additionally, in states where cannabis remains illegal, patients may be more hesitant to disclose the use of "street drugs" and must be assured these disclosures will not be shared with law enforcement.
Another aspect to consider is how cannabis reacts with other medications, mainly analgesics, and sedatives. Dentists must also be aware of the patient's cannabis use so their heart rate can be more closely monitored when using vasoconstrictors.
There's still much to learn about cannabis, including its long-term effects. However, cannabis use – both recreational and medical is rapidly expanding, and that means more patients are likely partaking. Therefore, it's prudent for healthcare practitioners to educate themselves, converse with their patients, and ensure they provide a welcoming environment so patients feel safe sharing their complete medical history.