INTRODUCTION

The use of Cannabis sativa for medical purposes has undergone significant change in Canada over the past two decades, culminating in legalization in October 17^th 2018.¹,² Despite its prevalence of use across the medical system, leading up to and post cannabis legalization, the role of the pharmacist is largely absent.³,⁴ This is due to laws and regulations established by the federal government, that have resulted in the circumvention of cannabis from traditional drug approval processes, and establishing a non-traditional supply and distribution chain.⁵

Beginning in 2001, the Canadian government established regulations that permitted patients to grow cannabis for medical purposes, by the endorsement of a specialist physician.⁶ Over the next two decades, further revisions to these regulations established a distribution chain away from the individual patient, to government regulated, private licensed producers of medical cannabis.²,⁶,⁷ To access medical cannabis from a licensed producer, a patient required either a non-specialist physician or nurse practitioner to prescribe cannabis for patients pursuant to a medical document.⁷-⁹ The medical document serves the same role as a medical prescription, in that it assigns the use of a drug product (in this case cannabis), in a prescribed amount per day (grams) to a select patient for a specified time frame.¹⁰ However, the medical document's format is devoid strict detail as compared to a prescription for a pharmaceutical drug. The medical practitioner is unable to assign the strengths and composition of cannabinoids, as well as the route, frequency and form of administration of cannabis (Online appendix). The medical document is submitted directly to the licensed producer, who then serves as the dispenser of medical cannabis either to the patient or to the prescriber (who then may re-distribute the product to the patient).⁷ Given the open nature of the document, the patient has the opportunity to select the route, composition, frequency and dosage form of cannabis for consumption.

In contrast, a medical prescription for a pharmaceutical product specifies drug product, dose, route, frequency, and duration to be dispensed by a pharmacist with appropriate counselling on safe use and storage (Online appendix). In the absence of pharmacist oversight of medical cannabis, a patchwork system of authorization, counselling and monitoring has taken hold and may be conducted by physicians or nurses, but equally involves other non-healthcare providers that serve as “counselors,” involved in the education of patients regarding usage and therapeutics.¹¹ The lack of strict oversight by prescribers, piecemeal counselling and education of patients, coupled with open access to product selection, dosage and route of delivery cannabis, has resulted in an increase in medical misadventures and treatment failures.¹²-¹⁴

METHODS

RESULTS

A total of 260 participants attended education sessions from September 2018-August 2019, with 203 completing surveys. Briefly, individuals who attended class were predominantly disabled or retired, suffered from musculoskeletal or neuropathic pain, and reported a high degree of mental health comorbidities (Table 2). Additionally, a family history of addiction, ADD/ADHD, bipolar or schizophrenia would be a relative contradiction to the use of cannabis and although individuals with these conditions would be less likely to be referred for the education session, a substantial number did report having a family history of one of these conditions (Table 2). Furthermore, despite being an absolute contradiction to referral to the education session, a small group of participants reported current illicit drug use (other than cannabis) (Table 3).

In terms of cannabis use, a majority of individuals referred to the education session were currently using cannabis, reported using at least weekly or daily, and used amounts under 2 g per day by dried weight, or under 3-4 mL by volume if using an extract (Table 4). Participants were also more likely to report not knowing the amount of THC or CBD in the products they used, and sourcing cannabis from illicit sources (e.g. dispensaries, friends, street supply) (Table 4).

After the pharmacist-led education session on the appropriate medical use of cannabis, a significant number of current users reported they would use less cannabis overall, would favor using using either a low or medium THC concentration strength, and either use a medium or high CBD concentration strength (Table 5). In contrast to product selection, a majority of current users reported they would not change the dosage form or route of administration of cannabis, however a sizeable number indicated they would stop inhaling cannabis and start either oral or topical dosage forms (Table 6).

In contrast to current users, after the session, naïve patient and past cannabis users preferentially indicated they would most likely select a low THC concentration strength product and a high CBD concentration strength product (Table 5). Additionally, in comparison to current users, most naïve and past users reported they would use an oral product and route of administration as opposed to an inhaled product and route of administration.

Current, past and naïve cannabis users were asked to report their opinion on the safety and efficacy of cannabis when compared to opioids, addiction potential and potential for harm, pre and post education. A statistically significant increase in the opinion that cannabis has the potential for addiction (chi-square=42.6, p<0.0001) and harm (chi-square=34.0, p<0.0001) was noted after receiving education. However, after receiving education, more participants, felt that cannabis may be a safer option (chi-square=53.0, p<0.0001) and more efficacious (chi-square=42.5, p<0.0001) for their chronic pain condition than opioids

DISCUSSION

The pharmacist-led cannabis patient education session resulted in some notable changes in potential use patterns among patients referred to the program. A main emphasis of the education program was to promote the use of products with lower percentage strengths of THC, as its relative potency in cannabis is predictor of psychoactivity, impairment, anxiety, psychosis, GI intolerance, tachycardia, hypertension/hypotension, potential for dependence as well as addiction.²⁵-²⁹ In contrast, the session emphasized the use of greater percentage strengths of CBD, as the potential benefits and safety profile as compared to THC is purported to be much more favorable.²⁹-³⁶ Among surveyed participants, after receiving formal education by a pharmacist, these objectives were realized among naïve patients in particular, and to a lesser extent among current users (Table 5 & 6).

Other key messages highlighted in the session was the use of oral and topical route of administration as opposed to an inhalational route, as inhaled forms of cannabis, in particular smoked forms, are more likely to result in respiratory complications such as chronic cough, bronchitis, pneumonia and potentially histopathologic changes in lung tissue. ³⁷-⁴⁰ Naïve patients overwhelmingly supported the notion to use oral and topical dosage forms as their future route of administration while using cannabis (Table 6). Despite receiving education on the risks of smoking and vaping cannabis, approximately one half of current users indicated they would not change this route of administration, with a small number indicating they would begin to use this route of administration (Table 6). As the pharmacokinetics of inhaled cannabis, as compared to oral and topical routes, has a considerably quicker onset of action as well as shorter duration, it is probable that this route of administration is preferred amongst current users for this rationale for the treatment of pain or other medical conditions.⁴¹-⁴⁴ It is also possible that as current users may also be using cannabis for recreational purposes, that the subjective levels of euphoria and psychoactivity with THC conferred via the inhalational route is also preferred over the oral route, as such effects are more likely to be pronounced with inhaled dosage forms. In order to promote and influence a change in use characteristics, targeted intervention, such as motivational interviewing and normative feedback might be helpful.⁴⁵,⁴⁶

Although the cannabis education session's content did not encompass a comparison to opioid therapy for pain management, it is rather remarkable that an overwhelming majority of participants perceived that cannabis was a safer and more efficacious drug treatment option than opioids for pain, prior to and to a greater extent post education (p<0.0001). Opioid use among participants was commonplace, with many either currently taking opioids for chronic pain, or had either failed a trial or discontinued such treatment due to adverse effects (Table 3). Therefore, a perception that cannabis was more efficacious and safer than opioid therapy is possibly the result of previous exposure to opioids with negative outcomes. Among naïve users, past and current users, the current climate surrounding opioids is also expected to have contributed to these findings as well, as the looming opioid crisis in North America has resulted in significant morbidity and mortality, weighing in on the public consciousness as well as impacting the political sphere.⁴⁷-⁵⁰

In a similar vein, the perception of cannabis as being non-addictive and its potential for harm is overlooked amongst members of the general public. After receiving information in the cannabis education session on the potential for addiction to cannabis and harm from cannabis, a significant number of individuals changed their perception with pharmacist led education, with more participants indicating that cannabis as potentially addictive and harmful. This finding underscores the importance of the influence of the impact of healthcare professionals, in particular pharmacists in providing evidence-based findings to contextualize the potential incidence of harmful effects and addiction, which can be glossed over by unlicensed cannabis counsellors and the lay media.⁵¹

Although participants were screened by a prescriber prior to referral to the education program for absolute contraindications for cannabis use including a diagnosis of bipolar disorder, as well as problematic alcohol or drug use history, such individuals were referred to the session (Table 2). It is likely that such individuals either may not have disclosed such information, or such information was not obtained from the patient record or by the prescriber upon consultation. As the initial intention of the surveys were meant as a quality improvement initiative, these findings resulted in another role for the pharmacist, in which the program now involves a thorough history taking and screen by a pharmacist prior to referral for education and a cannabis prescription.

With the recent legalization of cannabis at a national level for recreational use in Canada, changes to the medical cannabis program may occur. At the time of this survey, most individuals being referred to this cannabis education session, was just prior to legalization. As observed in several states in the U.S., when both recreational cannabis and medical cannabis are legalized, patients seeking cannabis for medicinal use may find it easier to access cannabis at recreational outlets, thereby reducing the oversight of patient cannabis use by medical professionals.⁵²,⁵³ Therefore, referrals to our specific cannabis education session may decline over time, and thus the impact of this pharmacist led intervention may decrease. To address this issue, a program that allows open and optional access to cannabis education by pharmacists (e.g. virtual or in person workshops, lectures and e-learning modules) funded by pharmacy chains or advocacy groups, may be able to promote safer and more effective medicinal use of cannabis to those acquiring it from a variety of sources.

Several limitations were noted in this study. As demonstrated elsewhere in literature, the positive impact of pharmacist led group education allows for safer and more effective use of medications.⁵⁴,⁵⁵ Unlike our study which focused on a single group session, most of these other programs involved multiple sessions or assessed patients several months after intervention.⁵⁶-⁵⁸ As our program only offered one session, and our survey was administered immediately after the group-based intervention, it is likely that patient's opinions may change days to weeks after taking the course, as knowledge gained from a single education session, as compared to multiple sessions, is lost over time, and other influences may have more impact on the selection of cannabis, including cost, product availability, and counselling from others. Therefore, to demonstrate the long-term predicative value of the pharmacist-led cannabis group education session on safer usage among patients, the survey would need to be administered several months after the intervention. In addition to this limitation, participants demonstrated a lack of clarity as to what the concentration strength of THC and CBD was if they grew cannabis at home or obtained it from illicit sources. Therefore, the self-reporting of concentration strength of products would have a large degree of error contained within the survey. Moreover, the common method of estimating daily usage in grams by Health Canada is vague and impractical, as weighing cannabis prior to use is not a standard practice amongst most users that used dried dosage forms. Additionally, for liquid or topical dosage forms, each product produced in milliliters is equivalent to variable amounts of dried cannabis, in grams, which is determined by the manufacturer. Given this complexity, it is unlikely that patients are able to accurately quantify and report daily use of cannabis in grams. Lastly, it should be noted that the survey was not validated, and therefore the reliability of the survey at predicting the past and future cannabis use characteristics of participants may not be accurate.

CONCLUSIONS

The implementation of a mandatory group-based education session led by a pharmacist, resulted in greater reports among participants of choosing lower potency THC formulations, a lower likelihood of using an inhalation route of administration, and significant increases in the perception that cannabis may cause harm or addiction. As cannabis therapy is becoming a mainstream alternative to conventional therapies, it is imperative for pharmacists to become more knowledgeable on the benefits and risks associated with monotherapy and when combined with other drugs and substances. Patient counselling, in the format of group-based education or more commonly one-on-one counselling, can be used as an influential practice to promote safe and appropriate usage of cannabis for therapeutic purposes.