The popularity of smokable drugs containing synthetic cannabinoids (SCs) has been rising sharply during the past few years. SCs are mainly sold online via darknet marketplaces as an alternative to traditional psychoactive drugs such as opiates, cocaine, and MDMA. SCs are sold under various brand names, e.g. K2 in the USA and Spice in Europe. Considerable variations can exist in the types and concentration of SC substances traded on darknet marketplaces, even within the same batch or brand name.
Clinical and psychiatric effects of SCs depend on the individual, dosage, and route of administration of the drug. Most of the psychoactive effects of SCs are similar to those of cannabis. Distinct chemical properties and metabolism of SCs, as compared to cannabis, are responsible for the observed toxicity. Research has shown that adverse clinical and psychiatric effects associated with SC abuse can be more severe and common than those associated with cannabis use.
A recently published paper reviewed available data regarding SCs sold on darknet marketplaces. The paper presented the types, effects, and adverse effects of SCs. Throughout this article, we will review the most important data presented via this paper.
Classification and development of synthetic cannabinoids (SCs):
The endocannabinoid system is a chemical system that has been found to have an effect in regulating mood, appetite, nausea, pain, and inflammation in humans. In 1990, a group of researchers managed to map the anatomical location of the cannabinoid receptors in the human brain (cannabinoid receptor type 1 or CB2R). In 1993, another group of researchers found cannabinoid receptors in the peripheral nervous system (cannabinoid receptor type 2 or CB2R).
Initially developed in the US and Europe as chemical ligands to study the endocannabinoid system, SCs were found to share no structural similarity with tetrahydrocannabinol, which is the chemical substance that imposes the psychoactive effects of cannabis. As shown in table (1), there are six chemical classes of synthetic cannabinoids. The six classes differ in chemical structure, lipid binding affinity, and binding activity to the cannabinoid receptors.
Table (1): Classification of synthetic cannabinoids (SCs)
Users usually obtain SCs by purchasing them from darknet marketplaces using bitcoin as payment. Known as K2 in the US and Spice in Europe, SC products contain non-psychoactive substances of plant origin. SC compounds are often mixed with plant material on an industrial scale using solvents, such as methanol and acetone, to dissolve the chemical powder that imposes psychoactive effects when SCs are smoked. The composition of SCs, in terms of substances and/or synthetic additives, is changing at too rapid of a rate for European control and regulation efforts to be able to respond effectively. SCs can also take the form of capsules, tablets, powders, or liquid forms that can be smoked via electronic cigarettes.
Manufactured in labs in South Asia and China, SCs have been available in multiple European countries, such as the UK, Germany, Switzerland, and others, since 2004. Nevertheless, it was only in 2008 that forensic investigators in Austria and Germany managed to identify the first psychoactive chemical substance in Spice products, the JWH-018 aminoalkylindole. In 2009, the “Spice phenomenon” attracted the attention of mass media, politicians, and researchers in the scientific community.
SCs are mainly sold over darknet marketplaces. A study published in 2017 found 120 vendors on Alpha Bay and 21 vendors on Valhalla selling SCs. Moreover, SCs are sold in some countries via smart shops or head shops selling accessories for smoking cannabis. Less frequently, SCs are sold by street drug dealers and organized crime gangs as inexpensive alternatives to conventional drugs of abuse.
SCs are often shipped to Europe in the form of bulk powder via express mail and courier companies. Larger amounts are usually shipped by air or sea cargo. Each kilogram of SC bulk powder can be used to produce thousands of SC packets. There is also strong evidence of a considerable online retail trade taking place between the US and Europe. SCs play an essential role in the rapidly growing “legal high” market.
When public health is considered, it is quite important to improve present approaches to controlling, monitoring, and responding to SC use. You can find valuable information via the European Union Early Warning System (EU-EWS) reports, the European Monitoring Centre for Drugs and Drug Abuse (EMCDDA), the US Monitoring the Future study, and the Drug Abuse Warning Network.