Ms J decides to start using medical cannabis, including 10-mg CBD tablets twice daily, and a vape pen that contains THC with 2-second inhalations as needed for pain. She experiences improvement in her chronic pain, but she also reports feeling somewhat dizzy and confused, particularly immediately after using vaped THC. Her family members say that she is more active and sleeping better, but ask about the risk of cannabis addiction, whether she can drink any alcohol with cannabis, and whether she is at risk for lung disease related to vaping.
THC and CBD are metabolized in the cytochrome P450 (CYP450) system. Most drug interactions with medical cannabis are drugs that are also metabolized by this system. 79 Cannabis may inhibit the metabolism of strong CYP450 inhibitors, such as warfarin, rifampicin, and omeprazole. 80 Cannabis has additive sedative effects with other sedating agents. 81,82
There is concern that cannabis use will lead to motor vehicle accidents associated with cannabis intoxication. 66 Cannabis use impairs driving in a dose-response manner. 67 However, population level studies have not shown a relationship between medical cannabis laws and an increase in motor vehicle accidents or traffic fatalities. 68,69 Patients should be cautioned regarding driving impairment while using cannabis, and advised to avoid driving if intoxicated.
Cannabis Hyperemesis Syndrome
Declaration of Conflicting Interests: The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Dr Cook receives funding from the National Institutes of Health, including research grant R01DA042069.
Products at the dispensary Ms J visited include a range of options that contain THC alone, CBD alone, and several different THC/CBD ratios, and that can be administered by several different modes of consumption. The potential medical effects and side effects could thus vary by the relative amounts of THC and CBD, and the timing and duration of the effects will vary according to the mode of consumption.
To illustrate these points, this article will describe a case of a patient engaged in primary care who is considering whether to try medical cannabis for chronic pain. The subsequent review gives a description of key information that is important for PCPs to know when caring for patients who choose to use medical cannabis, including a brief review of the pharmacology of medical cannabis, the state of evidence regarding its efficacy, variations in the types of medical cannabis, and safety monitoring considerations for the PCP.
Few valid, succinct, and reliable screening tools are available. The Cannabis Use Disorder Identification Test (CUDIT) is a 10-item screening tool that is 73% sensitive and 95% specific. 85 However, its length makes it difficult to use in a clinical setting. Modifications of the CUDIT, including the CUDIT-R 86 and the CUDIT-Short Form, 87 attempt to make more brief screening tools appropriate for busy clinical settings, but none of these measures have been studied in the primary care setting.
To avoid questions of inappropriate prescription of CBD oil for medical conditions, the FSMB recommends that physicians first make sure they have a documented, existing medical relationship with the patient before recommending products such as CBD oil.
Then there’s the liability of prescribing CBD oil and any product related to cannabis. Does the regulatory environment and the risk of malpractice outweigh the benefits for patients? This article will focus on this third challenge related to CBD oil for medical use.
1. Establish a Preexisting Medical Relationship with the Patient
Currently, prescribing CBD oil still is relatively unexplored territory for physicians in terms of legal liability. But medical boards want clarity.
Second, its status as an illegal substance makes it hard to test and run clinical trials that definitively prove its medical efficacy. This creates a vicious circle where marijuana and CBD are not fully legal because there is no data on its safety and efficacy, and its medical use in not proven because there is not enough testing due to being illegal.
Guidelines for Minimizing Liability Around CBD Oil Recommendation
Cannabidiol oil (CBD), a cannabinoid derived from cannabis that doesn’t create the “high” associated with marijuana since it lacks the cannabinoid THC, is gaining interest among health practitioners for its long list of potential benefits.