Cannabis sativa has a long history of use both as a textile and as an intoxicant used for medicinal, spiritual, and recreational purposes. California voted to regulate cannabis for medical use in 1996, and in recent years there has been a wave of US states and other countries passing legislation for legal medical or recreational cannabis.[1] This has also been accompanied by shifting public attitudes toward the drug.[2]

In 2018, the US government introduced the Hemp Farming Act, which now means that hemp can be grown legally on US soil, as long as it meets regulatory requirements. What are the implications of this new era of C. sativa use from an analytic and legal perspective?

They create an imperative for effective testing of plants, products, and people who have consumed the substance. They require evidence to support and inform the medical use of this substance. And they raise important issues around public health and safety that may need to be met with novel testing approaches or regulation.

Cannabis and Hemp

Cannabis and hemp are sometimes thought of separately, but they are simply varieties of the same plant, C. sativa. Hemp, however, is almost devoid of tetrahydrocannabinol (THC), the primary psychoactive component of cannabis, and from a legal perspective must contain 0.3% or less of this compound by dry weight.

The potency is usually determined by liquid chromatography or gas chromatography.[3] Both substances may be subjected to similar types of testing, such as for pesticides, terpene content, or heavy metal contamination. However, hemp may require other testing modalities due to its alternate uses, such as for textiles, biofuel, or as a foodstuff.

Medical Cannabis

It is thought that the psychotropic and medicinal properties of C. sativa have been known for at least 5000 years.[4] However some of the mechanisms underlying these effects have only been uncovered in recent decades. THC was isolated and synthesized for the first time in the 1960s, and the endocannabinoid system, which contains target receptors for cannabinoids, was only discovered in the 1980s and 1990s.

The greatest attention has been paid to THC and cannabidiol (CBD) which are two cannabinoids in cannabis with opposing actions. While THC has psychoactive effects, CBD has anti­ inflammatory, anti­psychotic, and anti­ anxiety properties. Cannabis plants contain varying levels of cannabinoids and other compounds like terpenes, and the thousands of different types are known as chemovars.[5]

Several licensed medical products based on cannabinoids, and one (Epidiolex) derived from cannabis are now approved and regulated by the US Food and Drug Administration (FDA), which are available for specific conditions including multiple sclerosis and chemotherapy­induced nausea and vomiting. [4] However, cannabis remains illegal at the federal level in the USA and so medical cannabis receives no oversight from the FDA.[6]

Public Health Consequences

Although both the law and public attitudes toward cannabis have shifted favorably, there are risks associated with taking the drug. Cannabis can cause acute adverse effects that can lead individuals to the emergency room. These include anxiety, depression, psychotic symptoms, cardiovascular and gastrointestinal symptoms.

Cannabis is also the most common addictive substance for which Americans seek counseling for dependency. If consumed during pregnancy, components of cannabis can easily cross the placenta where they can negatively affect fetal development.

Cannabis legalization has also been linked to an increase in the potency of cannabis on the market, increased consumption among users, and increased cannabis­related hospitalizations and emergency department visits.

Driving Under the Influence

One specific public health concern raised by the legalization of cannabis is the effect of driving under the influence. Cannabis negatively affects cognition and psychomotor function and is known to impair driving performance and increase the risk of road accidents. But in contrast to ethanol, cannabis impairment is more challenging to test for and quantify.[7]

A complicating factor is the lack of a noninvasive roadside test which, given that cannabinoids rapidly decrease in the blood in the hours after consumption, can lead to delays in testing that may not reflect blood levels at the time of an accident. It is difficult for experts to agree where, for example, a legal driving limit for THC should be set given that blood levels do not always correlate with impairment. For example, impairment may be greater when cannabis is taken alongside other substances like alcohol and prescription drug, or less when someone is a heavy user with a level of tolerance.

Courtesy The Cannabis Program at Pittcon

Saved from URL: https://www.news-medical.net/whitepaper/20210209/An-Analytical-and-Legal-Spotlight-on-Cannabis.aspx

  1. National Conference of State Legislatures. State Medical Marijuana Laws. Available at: https://www.ncsl.org/research/health/state­medical­ marijuana­laws.aspx (Accessed Jan 2021).
  2. Hasin DS. US Epidemiology of Cannabis Use and Associated Problems. Neuropsychopharmacology 2018; 43:195­212.
  3. US Department of Agriculture (2021) Laboratory Testing Guidelines U.S. Domestic Hemp Production Program. Available at: https://ww w.ams.usda.gov/sites/default/files/media/TestingGuidelinesforHemp.pdf (Accessed Jan 2021).
  4. Bonini SA, Premoli M, Tambaro S, et al. Cannabis sativa: a comprehensive ethnopharmacological review of a medicinal plant with a long history. J Ethnopharmacol 2018; 227:300­315.
  5. MacCallum CA & Russo EB. Practical considerations in medical cannabis administration and dosing. Eur J Intern Med 2018; 49:12­19.
  6. Liccardo Pacula R (2020) States need to wake up to public health risks