With the ever-changing landscape of cannabis legislation in recent years, cannabis use has become more accessible and accepted. Currently, 33 states plus the District of Columbia (D.C.) allow cannabis use for medical purposes, and in 11 of those states plus D.C. recreational use is also legal. A law that would legalize cannabis at the federal level (H.R. 3884) – a move that is supported by two-thirds of US adults – is working its way through the House of Representatives. Over 8% of US adults report using cannabis in the last month, and over 2% of adults report using cannabis daily. In short, clinicians will increasingly encounter patients who are using cannabis whether for medical purposes, recreation or both.

In parallel with these trends, the potency of cannabis has increased substantially while the public perception of the potential harmful effects of cannabis has decreased. Most people who are using cannabis get their advice through employees at cannabis dispensaries, also known as “budtenders,” while very few get advice about cannabis from their physicians This creates an extremely important missed opportunity for the health care professionals to be part of an increasingly important health care conversation.

Cannabis and health: More smoke than fire

There is a lot of uncertainty about the health effects of cannabis. One thing is clear: we desperately need more high-quality scientific research about the benefits and harms of cannabis. There are signals that cannabis has the potential to be helpful for certain conditions, though the evidence is not as consistent and long-term as we would like. For example, two recent systematic reviews (read them here and here) found indications that cannabis may offer promise for neuropathic pain in some patient populations, however, the research is not definitive.

Exercise caution

Cannabis is often thought of as a natural remedy and as having few serious adverse effects. However, there are some reasons for caution that healthcare professionals should educate patients about:

1. Overdose risk: Edible cannabis products have a delayed onset, and individuals may unwittingly take too much with additive effects mounting over time. Acute psychosis can occur with excessive THC intake. There is also the risk of accidental ingestion and overdose by children, and individuals who use cannabis for medical or recreational purposes should be advised to properly store all cannabis products out of the reach of children.
2. Cannabis use disorder: Many individuals do not realize that heavy cannabis use carries risk of addiction, and the potential to cause withdrawal symptoms with cessation or reduction of use
3. Higher risk populations: Regular cannabis use – especially in young adults and among those with a genetic predisposition to schizophrenia – is associated with chronic psychosis.
4. Lack of safety information in older, multimorbid populations

First do no harm

Even though there is much to be learned about the health effects of cannabis, and many health care professionals aren’t in a position to directly endorse its use, patients are using – and will continue to use – cannabis. To help decrease the potential harms associated with cannabis, providers should engage in evidence-based discussions with patients.

Start the conversation:

1. Ask patients about their cannabis use in a routine and non-judgmental way.
2. If the patient uses cannabis, ask about the purpose, quantity, frequency, and route of administration.
3. Assess for Cannabis Use Disorder using a tool like the three-item Cannabis Use Disorders-Short Form, followed by assessment with DSM-V criteria in the case of a positive screen.

Communicating risks to patients:

1. Cannabis naïve patients should be cautious with edible products.
2. Individuals should avoid frequent and long-term cannabis smoking, and long, deep breath holds during inhalation.
3. Warn against use of any unregulated product obtained outside of dispensaries, including products advertised as CBD-only, given the existence of dangerous synthetic cannabinoids, labeling inaccuracies, and the risk of severe illness such as vaping-related pulmonary illness.
4. Caution patients who are prescribed other central nervous system (CNS)-acting agents (e.g. , opioids, benzodiazepines, muscle relaxants, and gabapentinoids) of the additive effect of cannabis on psychomotor slowing and other CNS side effects. Decreasing CNS-acting agent polypharmacy (in a safe, patient-centered way) prior to or concomitant with patients initiating cannabis regimens is recommended.
5. Avoid driving while using cannabis.