Mark Elliott, MDPsychiatrist in San Francisco, CADr. Elliott has disclosed that they have no relevant financial or other interests in any commercial companies pertaining to these educational activities.
While the age-old tradition of smoking cannabis remains very common, several other options for preparing the drug are becoming widely available and frequently used. In this article, we’ll update you on the modern preparations and routes of administration.
The main psychoactive component of cannabis is ∆9-tetrahydrocannabinol (THC), which is present to some extent in all preparations and is responsible for most of the “high” from the drug. Cannabis plants produce more than 100 other identified cannabinoids, most of which we know little about. One of these, cannabidiol (CBD), has received a lot of attention recently. While it’s not as markedly psychoactive as THC, CBD is increasingly believed to be a major, if not the major contributor to the therapeutic effects of cannabis. It has been shown to have anxiolytic, antipsychotic, anti-inflammatory, anticonvulsant, and antineoplastic effects. CBD-enriched preparations have become increasingly popular in recent years, and as long as the THC concentrations are less than 0.3%, they are not currently restricted by the DEA (Mead A, Epilepsy Behav 2017 doi:10.1016/j.yebeh.2016.11.021).
Cannabis preparations have exploded in diversity. They can be separated into two categories: inhaled preparations (including both flowers and concentrates) and ingested preparations.
Flowers (or buds) Flowers are what most people call “pot,” “weed,” “trees,” “herb,” “bud,” etc. They are harvested primarily from unpollinated female cannabis plants (pollination creates unwanted seeds) and trimmed away to leave only the buds, which are high in cannabinoid content. The concentration of THC in these preparations can vary widely—from less than 0.3% to 30% or so, with most modern samples in the 4%–20% range. They are generally smoked, either in cigarettes by themselves as a “joint,” with tobacco as a “spliff,” in a cigar as a “blunt,” or as “bowls” smoked with pipes of various sorts, including “bongs” (water pipes). When people smoke flowers, the effect begins within seconds, with peak concentrations around 10 minutes and subjective effects lasting 3–5 hours (Huestis MA, Chem & Biodiversity 2007;4(8):1770–1804). Smoking flowers likely remains the most common route of administration in the US today, especially when used recreationally and abused.
Concentrates Concentrates are more diverse. These include kief, hash, butane hash oil (BHO), CO2 oil, and many more, all of which are derived from cannabis plant material. The cannabinoids are concentrated before consumption by various means; their cannabinoid content is largely dependent on the source material and the means of extraction.
Kief (pronounced “keef”), the simplest of the concentrates, is merely the separated and collected dried resin, or trichomes, of the plant. Its THC concentration is generally around 20%–60%, many times higher than the concentration in flowers. Kief is usually added to flowers or tobacco to enhance cannabinoid content; it can also be smoked by itself in a pipe.
Hash (also known as “hashish” or “water hash”), one of the oldest and best-known concentrates, is comprised of compressed and purified kief. It has a long history in the Middle East and in much of Europe as the primary mode of cannabis use. In modern preparations, hash has been estimated to contain 50%–80% THC. It is generally added to tobacco and smoked as a cigarette (a spliff), added to cannabis flowers, or used in a pipe or bong. This preparation is relatively unusual in the US.
BHO has undergone a dramatic popularity increase in recent years. It can be prepared in several forms that go by different names—“oil,” “wax,” “budder,” and “shatter,” for instance. These are all created by running butane over whole plant material or hash, then collecting and evaporating the excess butane. This leaves a thick substance rich in cannabinoids, with THC concentrations ranging from 60%–90%. Depending on the process, the product may be hard and clear (shatter), sticky and soft (wax), or somewhere in between (budder). The concentrates can be consumed in many ways: through addition to tobacco or other cannabis products, with electronic vaporizers, and through increasingly notorious “dabs.”
Dabbing has gained significant popularity since around 2011 (https://trends.google.com/trends/explore?date=all&q=dab%20weed). It involves using “dab rigs,” which are elaborate bongs created specifically to vaporize concentrates. In a standard bong, the cannabis is packed into a bowl, and the smoke is drawn through a column of water. In dab rigs, in place of the bowl there is a “nail,” a piece of metal that can be heated with a blowtorch or, in the higher-tech versions, charged up and heated electronically with lithium ion batteries. The concentrate is picked up with the dab tool (looks like a dental pick) and then laid directly onto the heated nail. The vapor is then inhaled through the water column.
Formal research has been sparse, but dabs have achieved notoriety for their reportedly intense, short high and elaborate ritual, as well as the potential danger of working with volatile, flammable liquids in the preparation of BHO. Many suspect that dabs have more addictive potential than other routes of administration, and one survey found that users reported more tolerance and withdrawal with dabs than with other means (Loflin M and Earleywine M, Addictive Behav 2014;39(10):1430–1433).
CO2 oil is produced by pressurizing CO2 into its liquid form. A newer process, it requires elaborate machinery and produces a purer concentrate that can be used in different applications compared to BHO. These are currently primarily being distributed as premade cartridges for “vape pens,” which have become very popular in cannabis dispensaries.
Ingested preparations Edibles have been around for a very long time and are relatively simple to prepare. In general, they are created by extracting cannabinoids from plant material with an edible fat, such as butter or cooking oil. This potent fat is then used to prepare a myriad of products, from brownies to lollipops to Rice Krispies® treats. Compared with smoking, oral administration produces a delayed and less intense but much longer effect, with peak blood concentrations at 2 to 6 hours after ingestion and subjective effects lasting as long as 24 hours.
It is important to note that, while peak blood concentrations are lower in an edible preparation compared to smoking the same dose of cannabinoid, it is much more difficult to determine appropriate edible dosing due to the delayed onset, and people are much more liable to take a larger dose than they intend. This may lead to overwhelming experiences that can land a person in the emergency room, including severe anxiety, paranoia, perceptual disturbances, and tachycardia. Edibles can also be accidentally ingested by toddlers or children.
Medicinal tinctures were the primary mode of preparation prior to the criminalization of cannabis in the US in the early 20th century. These days, they are generally prepared as a source of CBD for therapeutic purposes. CCPR Verdict: The medicalization of the cannabis plant has accompanied a rapid increase in the variety of available cannabis preparations. Particularly in states with medical cannabis laws, these preparations are now being used and abused by many patients. It is important for clinicians to be familiar with some of these trends to be able to competently talk with patients about their drug use. Only time will tell how these preparations transform trends in use and abuse, and how they will affect cannabis addiction in our patients.