Synthetic cannabinoids (Spice)
Synthetic cannabinoids, often called ‘synthetic cannabis,’ ‘K2,’ ‘K9,’ or ‘spice,’ are a class of chemical substances known as synthetic cannabinoid receptor agonists (SCRAs). Developed by scientists in the 1970s to explore the cannabinoid system and potential therapeutic applications, such as treating nausea and pain, these substances began appearing outside laboratories in the early 2000s. They were often sold as smoking mixtures combined with dried herbs. These cannabis-like mixtures quickly gained popularity, particularly in regions where cannabis is illegal or where users seek to evade detection through standard drug tests. Today, there are hundreds of known synthetic cannabinoids, and manufacturers continually create new compounds to circumvent legal restrictions.
SCRAs are designed to mimic the effects of THC, the primary psychoactive component of cannabis. While both SCRAs and THC activate cannabinoid receptors, their effects can be significantly different. The term ‘synthetic cannabis’ is frequently used by the public, policymakers, and the media, but it is misleading. This misnomer can lead to dangerous misconceptions about the risks associated with these substances.
Although commonly used terms like ‘synthetic cannabis’ and ‘spice’ often refer to any and all types of synthetic cannabinoids, there is a great variety of substances available. These compounds interact with biological targets in various ways. Some SCRAs bind to brain receptors with significantly greater strength—up to 82 times stronger—than THC, leading to different physiological effects. Moreover, synthetic cannabinoids are known for their higher addiction potential and increased toxicity, which raises the risk of severe side effects.
Synthetic cannabinoids, such as those commonly known as "spice," were initially marketed as ‘safe’ and ‘legal’ alternatives to cannabis. This marketing strategy made them particularly appealing in countries where cannabis use is prohibited. The substances are often sought after for their promise of euphoria, relaxation, and sometimes a more intense high compared to cannabis. Their accessibility and affordability also contribute to their appeal.
While the general use of synthetic cannabinoids has declined—likely due to their severe side effects and health risks—they remain prevalent among certain populations, notably homeless individuals and those incarcerated. For homeless people, the substances are attractive due to their relatively low cost, high availability, and potent effects.
In prisons, synthetic cannabinoids are popular because standard urine toxicology tests often fail to detect them. Additionally, these substances are sometimes found impregnated in blotter paper, which can be smuggled into correctional facilities more easily than other drugs. This combination of factors contributes to their continued use among prisoners.
Synthetic cannabinoids are frequently confused with cannabis, which is dangerous because they differ significantly in their composition, effects, and associated risks. There are similarities between the SCRA-infused herbal (green leafy) material and cannabis in appearance, the predominantly oral route of administration, and some of the psychotropic effects. Besides, synthetic cannabinoids and cannabis bind to the same cannabinoid receptors (CB1 and CB2). Nevertheless, synthetic cannabinoids are structurally different from plant-derived cannabinoids and should not be seen as similar substances.
Whereas cannabis is a natural plant species that contains a variety of cannabinoids, like THC and CBD, synthetic cannabinoids are chemically made substances. These compounds were designed to mimic the effects of THC and do not naturally occur in the plant. Cannabis can produce effects like relaxation, altered perception and euphoria. Although synthetic cannabinoids can produce similar effects, the effects are often more potent and intense. Synthetic cannabinoids produce severe side effects and have a higher addiction potential, and are thus significantly different from cannabis.
Effects of synthetic cannabinoids can arise minutes to hours after the consumption and also last from minutes to several hours. The diversity and extent of effects are determined by the dose, the route of administration and the user’s vulnerability. Adverse effects of synthetic cannabinoids are common and usually happen because a) the body converting them into harmful substances, b) toxic chemicals released through smoking the herbal blends, or c) interactions with frequently used medications.
Positive effects of synthetic cannabinoids include:
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Euphoria;
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Talkativeness;
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Feelings of joy and laughter;
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Relaxation;
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Creativity;
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Perceptual disturbances like geometric patterns and trails.
Negative effects of synthetic cannabinoids include:
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Agitation, confusion, disturbances in consciousness and memory, dizziness, headache, anxiety, panic attacks, paranoia, hallucinations and convulsions;
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Nausea, vomiting, abdominal pain and diarrhea;
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Coughing, hyperventilation and shortness of breath;
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Increased heart rate, palpitations and chest pain.
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Hot flushes, excessive sweating and higher body temperature.
Synthetic cannabinoid intoxication can cause delirium or temporary psychotic states. People can then show aggressive, combative, and / or suicidal behaviour for up to several days.
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Synthetic cannabinoids are much more harmful than natural cannabis. Intake of synthetic cannabinoids is associated with a 30-fold higher risk of seeking the emergency room as compared with traditional cannabis.
Synthetic cannabinoids bind stronger to the cannabinoid receptors than natural cannabis and do not contain any compounds that counteract the effects of THC which are found in natural cannabis. This creates more intense psychoactive effects and a greater severity of undesired effects. It also causes a greater risk of addiction. Although there are similarities between low doses of synthetic cannabinoid products and cannabis intake, there are greater risks to the use of synthetic cannabinoids. Determining the exact dosage of a synthetic cannabinoid is extremely difficult, if not impossible, for the user. The amount of active compounds can vary greatly, even in a single batch, and a great variety of chemical formulations is used. This results in varying substances and doses, increasing the risk of adverse effects.
Due to the diversity in chemical structures and the difficulty with dosing synthetic cannabinoids, the risk of overdosing is high. Severe intoxications involve seizures, severe agitation, stroke, liver and kidney failure and in some cases death. Adverse reactions to natural cannabis usually involve anxiety and panic, which are unpleasant, but not as harmful.
As synthetic cannabinoids have psychoactive properties, they can induce psychotic symptoms or prolonged psychotic episodes in users. These symptoms can occur for users with no history of mental health problems, but pose a specific risk for users with a (family) history of psychosis. Synthetic cannabinoids are known to exacerbate symptoms, trigger relapse, and have negative consequences on the course of the illness.
Also users with a (family) history of seizure disorders like epilepsy are at elevated risk, as synthetic cannabinoids can cause persistent, dangerous seizures.
As research on the working and effects of synthetic cannabinoids is relatively recent, not much is known on the long-term risks of the substances. However, there is growing evidence that synthetic cannabinoids are associated with an increased risk of developing neuropsychiatric disorders, especially when used by adolescents and young adults whose brains are still developing.
Chronic synthetic cannabinoid users have shown impaired cognitive and emotional function. There is an elevated risk of depressive and anxiety symptoms, impairments in working and long-term memories, and response inhibition. Synthetic cannabinoids have also been associated with premature skin aging and early baldness.
Synthetic cannabinoids have a high addiction potential and can cause strong withdrawal symptoms. Both physical and psychological dependence develop quickly after a short period of repeated use. Withdrawal from synthetic cannabinoids causes strong adverse symptoms, including restlessness, headache, irritability, craving, nausea, tremors and nightmares. In severe cases seizures and cardiovascular arrest may also occur.
1) Synthetic cannabinoids are safe because they are legal.
Many people assume that because synthetic cannabinoids were sold legally for a time or are labeled as "herbal" or "natural," they are safe. However, these substances can be far more potent and unpredictable compared to natural cannabis. The chemical structure of these substances is changed constantly to circumvent legal restrictions, making it difficult to restrict them.
2) Synthetic cannabinoids are a synthetic version of natural cannabis.
While synthetic cannabinoids act on the same brain receptors as THC (found in natural cannabis), they often produce much stronger effects that can lead to severe toxicity. These include agitation, hallucinations, seizures, and even psychosis. The effects vary widely between different synthetic compounds, making them highly unpredictable.
3) Synthetic cannabinoids are non-addictive.
Synthetic cannabinoids can be highly addictive and can produce severe withdrawal symptoms. Users can quickly develop a tolerance, dependence, and addiction, which may lead to compulsive use and difficulty stopping. Dependence is developed significantly quicker than natural cannabis.
4) Like natural cannabis, you can’t overdose on synthetic cannabinoids.
Unlike natural cannabis, synthetic cannabinoids have a high risk of overdose. Users have been known to experience severe health issues, including heart attacks, respiratory failure, and death. The unpredictable potency of these substances means that even a small amount can lead to dangerous side effects.
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