What are examples of synthetic cannabinoids?

Examples of Synthetic Cannabinoids

Synthetic cannabinoid receptor agonists (SCRAs) like "Spice" and "K2" are the most common examples of synthetic cannabinoids that have sparked international alarm due to their severe toxicity and elusive detection methods. 1

Common Synthetic Cannabinoids

• "Spice" and "K2" are the most well-known brand names for synthetic cannabinoids that entered markets almost twenty years ago and proliferated rapidly, challenging clinicians with severe toxicity cases 1
• AB-CHMINACA and MDMB-CHMICA are specific synthetic cannabinoids that have been associated with deaths in toxicology reports 2
• Third-generation synthetic cannabinoids have been linked to a higher prevalence of neuropsychiatric symptoms compared to earlier versions 2

Characteristics of Synthetic Cannabinoids

• SCRAs are potent full agonists at cannabinoid receptors, making them much more potent than natural cannabis, with greater efficacy and potentially longer half-lives 3
• Unlike natural cannabis, synthetic cannabinoids do not contain tobacco or cannabis plant material but are typically sprayed onto herbal mixtures and sold as "herbal smoking blends" or "herbal incense" 3, 4
• These substances are often labeled as "not for human consumption" to circumvent legislation, despite being explicitly marketed for recreational use 3

Health Risks and Clinical Presentations

• Tachycardia and seizures are the most common toxicity symptoms associated with synthetic cannabinoid use 2
• Patients may present with agitation, psychosis, cardiovascular distress, or other severe symptoms following what they believe to be standard cannabis use but is actually SCRA-induced toxicity 1
• SCRAs have been associated with greater toxicity and higher addiction potential compared to natural cannabis containing Δ9-tetrahydrocannabinol (Δ9-THC) 2
• Acute mental disturbances can develop after regular use of synthetic cannabinoids, as documented in case reports 5
• Severe neurological complications such as Posterior Reversible Encephalopathy Syndrome (PRES) have been reported following synthetic cannabinoid consumption 6

Current Trends and Concerns

• A second wave of synthetic cannabinoids has emerged in recent years, with SCRAs now being found as adulterants in both low Δ9-THC hemp products and high Δ9-THC cannabis products 1
• The adulteration of cannabis products with SCRAs can lead to unpredictable clinical outcomes and exacerbate potential drug interactions with other medications 7
• Unlike the first wave which primarily targeted those seeking potent experiences or "legal highs," the current wave affects a broader population who may be unknowingly exposed through adulterated products 1
• The variable content of THC and other cannabinoids in these products makes drug interactions unpredictable and difficult to standardize 7

Clinical Implications

• Clinicians should broaden their index of suspicion when patients present with symptoms inconsistent with standard cannabis use, as they may be experiencing effects of synthetic cannabinoids 1
• Monitoring for increased side effects is crucial when patients are using cannabis products alongside other medications, particularly in elderly patients and those with hepatic impairment 7
• Patients with epilepsy and schizophrenia may be at particularly high risk when exposed to synthetic cannabinoids due to the increased risk of precipitating psychiatric and neurologic disorders 2