Explore the list of words commonly used in connection with medical cannabis and read their explanations.
2-arachidonoylglycerol (2-AG) is a cannabinoid produced in the body (hence referred to as an ‘endocannabinoid’). 2-AG binds and activates both of the main cannabinoid receptors (CB1 and CB2), facilitating various responses in the body.
Adverse reactions are all undesired effects of a medical treatment. The adverse reactions observed for medical cannabis are usually mild or moderate and subside within a few hours. In most cases, they can be controlled with dosage reduction and will decline with repeat usage. For more details, see FAQ1.
Anandamide (AEA) is a cannabinoid produced in the body (hence referred to as an ‘endocannabinoid’). AEA binds and activates both of the main cannabinoid receptors (CB1 and CB2) with the highest effect at CB1, facilitating various responses in the body. The pharmacological response to AEA resembles that to THC.
The Active Pharmaceutical Ingredient (API) in a drug product is the substance that produces its therapeutic effect. Medical cannabis contains several APIs, the main ones being THC and CBD, but other compounds in the cannabis plant (such as terpenes and other cannabinoids) are also thought to have therapeutic effects. Medical cannabis thus consists of a complex of many potential APIs that may interact to orchestrate the effects.
Bioavailability is the amount of ingested drug that reaches the systemic blood circulation. Many factors can influence the bioavailability of medical cannabis – one of the most important being the route of administration (oral, inhalation, under the tongue). Other factors include drug design, gender, health status, etc.
Cannabinoids are a group of chemical compounds that interact with the endocannabinoid system (ECS) in the body. Cannabinoids are produced in the body when needed (endocannabinoids) but are also present in the cannabis plant (phytocannabinoids) and responsible for most of the effects obtained from medical cannabis. The major endocannabinoids are Anandamide (AEA) and 2-arachidonoylglycerol (2-AG), whereas the major phytocannabinoids are THC and CBD.
Cannabis sativa L.
The taxonomic naming of plants is a hierarchical way of grouping plants into ranked categories such as families, genera, species, and subspecies. Cannabis sativa L. is the name of the single species belonging to the Cannabis genus, which belongs to the Cannabaceae family that also contains hops plants. It is debatable whether Cannabis sativa L. should be divided into further subspecies, but commonly named subspecies are Sativa and Indica.
Cannabinoid receptor type 1 (CB1) is part of the endocannabinoid system in the body and interacts with cannabinoids produced in the cannabis plant (phytocannabinoids) or in the body (endocannabinoids). CB1 is found in various cells and tissues in the body and is highly expressed in the central nervous system.
Cannabinoid receptor type 2 (CB2) is part of the endocannabinoid system in the body and interacts with cannabinoids produced in the cannabis plant (phytocannabinoids) or in the body (endocannabinoids). CB2 is found in various cells and tissues in the body, but its density is especially high in cells and tissues involved in immune responses.
CBD (cannabidiol) is one of the main cannabinoids in the cannabis plant; it does not create a euphoric ‘high’ in patients but is used medically for anti-inflammatory, anticonvulsant, muscle-relaxant, anxiolytic, neuroprotective, antioxidant and anti-psychotic effects1,2. CBD products (which in Germany contain <0.2% THC) can be bought without a prescription outside of pharmacies, but consumers can rely on the compliance with pharmaceutical standards with regard to the quality, potency and safety of CBD products only with pharmaceutically produced products prescribed by a doctor3.
Chemotypes are plants grouped into a few categories defined by the most abundant cannabinoid (e.g. THC dominant, THC:CBD balanced, CBD dominant) without considering actual concentrations or the presence of other cannabinoids and terpenes. Plants can thus be of the same chemotype but have different strengths and chemical compositions – and hence different effects.
Chemovars are plants defined according to their chemical profile by considering the actual content of several of the main cannabinoids and the dominant terpenes.
Cultivar is short for ‘cultivated variety’ and is used to group plants cultivated by humans to have common distinct, uniform, and stable characteristics that are retainable during propagation.
THC in cannabis has the potential to produce a state of dependence, and it is suggested that higher THC intake increases the risk of this dependence. Most scientific studies on cannabis dependence have been performed on recreational users, however, and there is very little research into the relationship between medical cannabis and dependence. Lack of data means that the risk of dependence caused by medical cannabis cannot be ruled out, with the risk increasing upon higher doses and more frequent use of THC. This risk needs to be evaluated by a doctor against the potential benefits of the treatment. However, The American Psychiatric Association has merged cannabis dependence together with cannabis abuse under the common term ‘cannabis use disorder’ (F12.- in the ICD 10 coding system).
Endocannabinoid system (ECS)
Cannabinoids in the cannabis plant were found to interact with a very essential physiological system in the body, which was henceforth called the ‘endocannabinoid system’ (ECS). The ECS consists of the signalling molecules produced in the body (endocannabinoids), the enzymes responsible for endocannabinoid biosynthesis and degradation, and the receptors with binding sites for the endocannabinoids. The ECS is involved in maintaining a steady state for the regulation of appetite, energy balance, pain perception, mood, memory, immune responses, and other factors4.
The combined and interactive therapeutic effect of various compounds in the cannabis plant (e.g. cannabinoids combined with terpenes) is referred to as the ‘entourage effect’
Some products are available as liquids (oils or tinctures) which are extracted from plant material using solvents such ethanol, liquid carbon dioxide, etc. Liquid drug products are typically swallowed or placed under the tongue using a dropper. The extracts can also be filled into capsules for oral administration or made into suppositories or topical products for application via the skin.
When medical cannabis is taken orally, the compounds are transported to the intestines, where they are absorbed and transported directly via the hepatic portal vein to the liver. In the liver, a fraction is transformed into active or inactive metabolites in a process known as ‘first-pass metabolism’. The compounds, including metabolites, are then distributed systemically throughout the body. Due to first-pass metabolism, the amount of orally ingested cannabinoids that reach the systemic blood circulation can be as low as 6%, whereas this is estimated to be 10-35% for inhalation, as cannabinoids are absorbed directly into the systemic blood circulation when administered via this route5.
Flavonoids are a type of compounds found in plants, including the cannabis plant, with various functions. The flavonoids help with important processes, such as development and growth. They also provide the plants with taste, smell and colour, and they function as a defence mechanism against environmental threats such as microorganisms, insects, and UV light from the sun6. The flavonoids are also suggested to add to the therapeutic effect in combination with other compounds of the cannabis plant, referred to as the entourage effect, but further research is required to confirm this.
Flos is the Latin word for ‘flowers’; and when medical cannabis is described as ‘cannabis flos’, it refers to dried cannabis flowers. Flos can be granulated into smaller pieces, that are easier for the patient to dose.
Growing medicinal plants in a reproducible manner requires an adequate quality assurance system. To ensure medical cannabis of high and consistent quality, the plants are grown according to GACP (Good Agricultural and Collection Practice) guidelines.
Cannabis products produced for medical use are produced under GMP (Good Manufacturing Practice) regulations. This ensures that manufacturers control and document all production steps that can influence product quality. The result is consistent production of high-quality products and elimination of the risk of contamination, mix-up, and errors. To ensure patient safety, GMP guidelines are followed in the manufacture of all medicine.
All cannabis products for medical purposes bought without a prescription in Germany are illegal. The majority of patients (up to 90% in a Danish questionnaire7) using cannabis for medical purposes obtain the products from illegal sources. As a result, potency and safety from contaminants are not strictly controlled and vary significantly. This results in large variations in the observed effects between products and a lack of medical advice for patients3.
Indica is sometimes referred to as a subspecies of the overall species Cannabis sativa L. and was originally grown in Southwestern Asia as small, bushy plants with broad leaves. Cannabis plants grown today are mostly hybrid cultivars of plants with different content and characteristics, and it is difficult to truly separate Cannabis sativa L. into subspecies.
A magistral preparation is a cannabis-based product produced by the pharmacy for a specific patient as prescribed by a doctor. In this way, the doctor can prescribe medication customised to the individual patient.
The term ‘medical cannabis’ covers manufactured cannabis products containing the full spectrum of active substances from the cannabis plant, including cannabinoids, terpenes, flavonoids and more. The products are grown and manufactured under strict regulations but do not hold a marketing authorisation the way conventional drugs do.
Opioids, such as Morphine, Fentanyl, Oxycodone, and Hydromorphone, are widely prescribed as painkillers. The usage of opioids carries a high risk of abuse and dependence.
‘Pharmaceutical cannabis’ refers to cannabis-based products that have undergone full medical trials for a certain indication and have obtained a marketing approval in one or more geographical areas like other conventional drugs.
Quality of Life (QoL)
Health-related Quality of Life is a patient-reported end point (measurable goal of a treatment) often measured in clinical trials with medical cannabis. QoL outcomes are especially important during medical treatments in which the therapeutic goal is not to cure the disease but to relieve symptoms. QoL measurements show the patient satisfaction and perceived benefits obtained through the treatment and might go overlooked in other medical measurements of end point. The QoL assessment includes evaluation of the patient’s physical, social, emotional, and mental health.
Ruderalis is sometimes recognised as a subspecies of the overall species Cannabis sativa L. and is a smaller plant originating from Central Russia. The cannabis plants grown today are mostly hybrid cultivars of plants with different characteristics, and it is difficult to truly separate Cannabis sativa L. into subspecies.
Sativa is sometimes referred to as a subspecies of the overall species Cannabis sativa L. and was originally grown in Southern Asia. It is characterised by its tall height and describes fibrous plants with long, thin leaves. The cannabis plants grown today are mostly hybrid cultivars of plants with different characteristics, and it is difficult to truly separate Cannabis sativa L. into subspecies.
Strains are commonly used when referring to different types of cannabis plants grouped by name (likely similar lineage) but without standardised cannabinoid or terpene content. Hence, the same strain may vary from batch to batch and is not a precise indicator of the strength or expected effects. Strains are used in microbiology to group bacteria, fungus, and virus, but not in botany science to rank plants, so the notion of strains is a more informal and popular grouping of cannabis plants.
Terpenes are a group of chemical compounds present in the cannabis plant (and other plants). As the main compounds of essential oils, terpenes give the plants fragrance and flavour, and different combinations of terpenes in plants give them unique characteristics. It has been suggested that the terpenes also add to the therapeutic effect of cannabis in humans, but this is not well defined and established scientifically, and further research is needed6.
THC (Δ9 – tetrahydrocannabinol) is one of the main cannabinoids in the cannabis plant and is mostly known for psychoactive effects such as the euphoria experienced by some patients, which is also the most well-known adverse reaction when cannabis is used as medicine. THC is used medically for its analgesic, muscle-relaxant, antiemetic and appetite-stimulating effects1.
The term ‘therapeutic window’ describes the range between the lowest effective dose and the dose generating undesirable and/or intolerable adverse reactions. Patients with little or no experience with medical cannabis typically have a very narrow therapeutic window, while regular users develop a broader therapeutic window.
Upon repeat usage of medical cannabis, a decrease in one or more of the effects and/or adverse reactions experienced is observed for some patients. This is referred to as ‘tolerance’. In order to avoid severe adverse reactions, it is thus always recommended to start with a low dosage of medical cannabis, to permit the patient to observe any physical and psychological reactions and slowly build up tolerance.
Medical cannabis products in 'flos' or 'flower' form can be administered by inhalation using a vaporiser. It is recommended to use vaporisers, which are licensed as medical devices. Your doctor will guide you to the right choice of vaporiser. Smoking of cannabis is not recommended, as the products of combustion are carcinogenic and can be harmful for the lungs1.
1. MacCallum, C. A. & Russo, E. B. Practical considerations in medical cannabis administration and dosing. European Journal of Internal Medicine vol. 49 12–19 (2018).
2. Health Canada. Information for Health Care Professionals. Cannabis (marihuana, marijuana) and the cannabinoids. (2018).
3. Hazekamp, A. The Trouble with CBD Oil. Medical Cannabis and Cannabinoids 1, 65–72 (2018).
4. Lowe, H., Toyang, N., Steele, B., Bryant, J. & Ngwa, W. The endocannabinoid system: A potential target for the treatment of various diseases. International Journal of Molecular Sciences vol. 22 (2021).
5. Lucas, C. J., Galettis, P. & Schneider, J. The pharmacokinetics and the pharmacodynamics of cannabinoids. British Journal of Clinical Pharmacology vol. 84 2477–2482 (2018).
6. Lowe, H., Steele, B., Bryant, J., Toyang, N. & Ngwa, W. Non-Cannabinoid Metabolites of Cannabis sativa L. with Therapeutic Potential. Plants 10, 1–17 (2021).
7. Kvamme, S. L., Pedersen, M. M., Alagem-Iversen, S. & Thylstrup, B. Beyond the high: Mapping patterns of use and motives for use of cannabis as medicine. Nordic Studies on Alcohol and Drugs 38, 270–292 (2021).