Cannabis is legal—why are cannabis-based pharmaceuticals still controlled?

Better safe than sorry—is that the rationale behind restricting high-risk prescription medications? Labelling a drug as addictive and then restricting it seems to happen easily at the time of listing, but this is not necessarily built on strong evidence. Once on the market, that label seems to stick, and when the evidence for harm is lacking, it appears to be much harder to remove the label. In 1923, the decision to criminalize cannabis was as much based on fear as evidence of harm and abuse.^1,2 A daunting number of debates and bills followed, and 95 years later, in 2018, that decision was reversed and cannabis became legal in Canada. However, the grounds for that decision were claims that legalization would eliminate the social and monetary costs of prohibition and diminish the illicit market, rather than on evidence deeming cannabis to be nonaddictive.³ Tramadol represents the opposite side of the coin, where it was listed only as a prescription product and, despite evidence of side effects, abuse and harm, it took a long time to restrict it.^4–6 Clearly, an evidence-based approach to policy is needed for such decisions.

While cannabis-based preparations have been used medicinally for thousands of years, pharmaceutical cannabinoid products are more recent, being first made available in Canada in the 1980s. The 2 currently available prescription products are nabilone (Cesamet®), a synthetic cannabinoid, and Sativex®, an extract of the cannabis plant. In Canada, these agents are currently listed under Schedule II of the Controlled Drugs and Substances Act (CDSA), while in the United States, they are listed alongside cocaine and fentanyl in Schedule II of the Controlled Substance Act. Placement on these schedules indicates a “higher-than-average potential for abuse or addiction” and is intended to restrict access to potentially misused drugs. Provincially, there is variability in how pharmacies regulate access to controlled substances. The range of regulations varies from requiring special prescriptions, establishing a monitoring program, which includes cannabinoids in some provinces but exempts them in others, to having no special requirements for controlled drugs (Figure 1).

Figure 1

Pharmaceutical cannabinoids in prescription monitoring program across Canada

However, strong evidence to support a high risk of abuse with prescription cannabinoids is lacking. Ware et al.⁷ assessed the abuse potential of nabilone and found that people perceive these agents to be more expensive and less euphoric options compared to cannabis. Nabilone had no “street value,” and very few incidents of recreational use were found, debunking the concern regarding a potential abuse.⁷

It is not known how these interprovincial differences in regulations affect utilization of cannabinoids, but the scheduling is expected, in fact purposefully implemented, to lead to lower rates. In Manitoba, we assessed the use of pharmaceutical cannabinoids and found that less than 0.14% of the population filled such prescriptions in 2015.⁸ Moreover, when we measured how long patients continued to use these drugs, we found that more than 30% of new patients never filled more than 1 prescription, and over 80% discontinued use within 1 year.⁹ Notably, our results showed that the highest rates of use were among those with chronic pain and painful conditions such as fibromyalgia and osteoarthritis; these patients also continued using these agents for longer periods.^8,9 This indicates that this population, who already has limited therapeutic options, may be deriving benefit from these agents. Despite the limited evidence across this broad range of indications, facilitating access by moving these drugs out of CDSA and prescription monitoring programs would remove unnecessary barriers and could possibly provide patients with better access to standardized prescription products compared to plant-based cannabis, which can now be legally obtained without a prescription. Additionally, a change in scheduling status could encourage physicians and patients with pain to consider these agents as alternative options before considering a more problematic one, such as opioids.

In short, these prescription agents have reversible nonserious side effects, have no evidence of abuse and may offer therapeutic benefit in some populations. Hence, limiting access in the environment of legal accessible medical and recreational cannabis products seems like a policy whose time has passed. Unnecessary restrictions on accessing these agents wastes the time of health care professionals and places barriers in front of patients who have full unrestricted over-the-counter access to cannabis. Removing these agents from the schedule of controlled drugs is not only evidence based and safe but might be in the best interest of some patients. Over the years, views and public perception of cannabis have shifted dramatically in Canada; this was translated into changes in policy and eventually the legal status of the substance. But now that cannabis is legal—why are cannabis-based pharmaceuticals still controlled? ■