Thursday, July 31, 2014
Like PCP all over again.
Synthetic cannabis-like “Spice” drugs were first introduced in early 2004, and quickly created a global marketplace. But the drugs responsible for the psychoactive effects of Spice products weren’t widely characterized until late 2008. And only recently have researchers made significant progress toward understanding why these drugs cause so many problems, compared to organic marijuana.
Synthetic cannabinoids (SC), as a class of drugs, are generally more potent at cannabinoid receptors than marijuana itself. As full agonists, synthetic cannabinoids show binding affinities between 5 and 10,000 times higher than THC at these receptors.
A recent literature study by Duccio Papanti at the University of Trieste and coworkers sheds additional light on the problematic nature of these drugs. In an article for Advances in Dual Diagnosis titled “’Noids in a nutshell: everything you (don’t) want to know about synthetic cannabimimetics,” the researchers note that “Spice products’ effects have been anecdotally described by users as intense and ‘trippy’ marijuana-like, with hallucinatory experiences being associated with higher levels of intake. In comparison with cannabis, SC compounds may be associated with quicker ‘kick off’ effects; significantly shorter duration of action; larger levels of hangover effects; and more frequent paranoid feelings.”
The study also points out a trouble spot: “Super-concentrations of synthetic cannabinoids (e.g. ‘hot-spots’) in herbal blends, originating from a non-optimal homogenization between synthetic cannabinoids and the vegetal substrate, can result in overdoses/intoxications and ‘bad trips’ in users.” In other words, the chemical powder is often so poorly mixed with the vegetable matter that potencies in the batch can be way too high, depending upon the luck of the draw, and are bound to vary from batch to batch in any event.
Nonetheless, there is a cluster of specific health effects that brings users to the emergency room. The typical set of symptoms—bearing in mind that polydrug use always complicates the picture—include elevated heart rate, elevated blood pressure, visual and auditory hallucinations, agitation, anxiety, nausea, vomiting, and seizures.
The authors note that “nausea and seizures are very uncommon in marijuana use, due to the suggested anticonvulsant/antiemetic properties of cannabis.” In fact, misusers who present doctors with vomiting as a symptom are often assumed to be free of cannabis-type drugs. Not so with synthetic cannabinoids. In an email interview, lead author Duccio Papanti told me that “many users describe the occurrence of vomiting, even with a non-recurrent and low use of these compounds. My idea is that this may be due to the smoking of hot-spotted blends, and that at high concentrations these compounds can work more on 5-HT receptors (in fact, vomit and seizures are signs of a serotonin syndrome).”
Less common, luckily, are other medical issues like heart attack, kidney injuries, and stroke. Of primary concern, the authors warn, are the reported incidents of “transient psychotic episodes,” “relapse of a primary psychosis,” and “‘ex novo’ psychosis in previous psychosis-free subjects.”
As for the mechanism behind the reported hallucinogenic effects: “A number of synthetic cannabinoids contain an indole moiety, either in their basic structure or in their substituents.” Indoles are molecular groups structurally similar to serotonin, and are active in drugs like LSD and DMT.
“According to this finding,” Papanti says, “their use could interfere with serotonin 5-HT neurotransmission more than THC. It is possible that the indole moieties incorporated in the molecules of synthetic cannabinoids can bind 5-HT2 receptors, acting as an hallucinogenic drug (in fact visual hallucinations are not uncommon in SC use).”
One of the main problems, of course, is that physicians know almost nothing about detecting and treating acute overdoses of synthetic cannabinoid products. And even if an OD victim was lucky enough to wash up at a health facility that had access to instant chromatography detection testing, “[due to] the lack of appropriate reference samples, SC compounds are difficult to identify.”
The risk here is not evenly distributed, obviously. Young people, and anybody subject to marijuana urine testing, are the clear market for these products. This includes students, athletes, members of the Armed Forces, transportation workers, mining workers, and many others. Spice users are overwhelmingly male.
How many people are taking the risk? An estimate of student use comes from the U.S. 2013 “Monitoring the Future” survey, which shows that about 8% of 17-18 year-olds have tried Spice products. For 12th graders, Spice products are second only to marijuana itself in many districts. And yet there is a dearth of longitudinal studies in humans to evaluate the long-term impact of using synthetic cannabinoids.
Papanti and colleagues call for the creation of an international agency dedicated to “toxicovigilance” based on a “non-biased ‘real-time’ database,” including adverse drug effects, as a way of clarifying and promoting appropriate clinical guidelines for Spice drugs. “These substances are dangerous, and they have been associated with a number of deaths,” Papanti says. He would like to see a “network in which users report their adverse effects. Such an online system already exists in the Pharmacovigilance program at the Lareb Centre in the Netherlands. They collect reports of medications’ adverse effects from both patients and doctors and it works very well.”
Tolerance, dependence, and withdrawal have all been documented in several categories of Spice products. Spice withdrawal effects can be severe, the authors say, and may include craving, tremor, profuse sweating, insomnia, anxiety, irritability and depression.
Graphics Credit: http://www.caregroupnz.org.nz/drug-prevention-education-campaign/
Saturday, July 26, 2014
I wish I could stop writing blog posts about Spice, as the family of synthetic cannabinoids has become known. I wish young people would stop taking these drugs, and stick to genuine marijuana, which is far safer. I wish that politicians and proponents of the Drug War would lean in a bit and help, by knocking off the testing for marijuana in most circumstances, so the difficulty of detecting Spice products isn’t a significant factor in their favor. I wish synthetic cannabinoids weren’t research chemicals, untested for safety in humans, so that I could avoid having to sound like an alarmist geek on the topic. I wish I didn’t have to discuss the clinical toxicity of more powerful synthetic cannabinoids like JWH-122 and JWH-210. I wish talented chemists didn’t have to spend precious time and lab resources laboriously characterizing the various metabolic pathways of these drugs, in an effort to understand their clinical consequences. I wish Spice drugs didn’t make regular cannabis look so good by comparison, and serve as an argument in favor of more widespread legalization of organic marijuana.
A German study, published in Addiction, seems to demonstrate that “from 2008 to 2011 a shift to the extremely potent synthetic cannabinoids JWH-122 and JWH-210 occurred…. Symptoms were mostly similar to adverse effects after high-dose cannabis. However, agitation, seizures, hypertension, emesis, and hypokalemia [low blood potassium] also occurred—symptoms which are usually not seen even after high doses of cannabis.”
The German patients in the study were located through the Poison Information Center, and toxicological analysis was performed in the Institute of Forensic Medicine at the University Medical Center Freiburg. Only two study subjects had appreciable levels of actual THC in their blood. Alcohol and other confounders were factored out. First-time consumers were at elevated risk for unintended overdose consequences, since tolerance to Spice drug side effects does develop, as it does with marijuana.
Clinically, the common symptom was tachycardia, with hearts rates as high as 170 beats per minute. Blurred vision, hallucinations and agitation were also reported, but this cluster of symptoms is also seen in high-dose THC cases that turn up in emergency rooms. The same with nausea, the most common gastrointestinal complaint logged by the researchers.
But in 29 patients in whom the presence of synthetic cannabinoids was verified, some of the symptoms seem unique to the Spice drugs. The synthetic cannabinoids caused, in at least one case, an epileptic seizure. Hypertension and low potassium were also seen more often with the synthetics. After the introduction of the more potent forms, JWH-122 and JWH-210, the symptom set expanded to include “generalized seizures, myocloni [muscle spasms] and muscle pain, elevation of creatine kinase and hypokalemia.” The researchers note that seizures induced by marijuana are almost unheard of. In fact, studies have shown that marijuana has anticonvulsive properties, one of the reason it is popular with cancer patients being treated with radiation therapy.
And there are literally hundreds of other synthetic cannabinoid chemicals waiting in the wings. What is going on? Two things. First, synthetic cannabinoids, unlike THC itself, are full agonists at CB1 receptors. THC is only a partial agonist. What this means is that, because of the greater affinity for cannabinoid receptors, synthetic cannabinoids are, in general, stronger than marijuana—strong enough, in fact, to be toxic, possibly even lethal. Secondly, CB1 receptors are everywhere in the brain and body. The human cannabinoid type-1 receptor is one of the most abundant receptors in the central nervous system and is found in particularly high density in brain areas involving cognition and memory.
The Addiction paper by Maren Hermanns-Clausen and colleagues at the Freiburg University Medical Center in Germany is titled “Acute toxicity due to the confirmed consumption of synthetic cannabinoids,” and is worth quoting at some length:
The central nervous excitation with the symptoms agitation, panic attack, aggressiveness and seizure in our case series is remarkable, and may be typical for these novel synthetic cannabinoids. It is somewhat unlikely that co-consumption of amphetamine-like drugs was responsible for the excitation, because such co-consumption occurred in only two of our cases. The appearance of myocloni and generalized tonic-clonic seizures is worrying. These effects are also unexpected because phytocannabinoids [marijuana] show anticonvulsive actions in humans and in animal models of epilepsy.
The reason for all this may be related to the fact that low potassium was observed “in about one-third of the patients of our case series.” Low potassium levels in the blood can cause muscle spasms, abnormal heart rhythms, and other unpleasant side effects.
One happier possibility that arises from the research is that the fierce affinity of synthetic cannabinoids for CB1 receptors could be used against them. “A selective CB1 receptor antagonist,” Hermanns-Clausen and colleagues write, “for example rimonabant, would immediately reverse the acute toxic effects of the synthetic cannabinoids.”
The total number of cases in the study was low, and we can’t assume that everyone who smokes a Spice joint will suffer from epileptic seizures. But we can say that synthetic cannabinoids in the recreational drug market are becoming stronger, are appearing in ever more baffling combinations, and have made the matter of not taking too much a central issue, unlike marijuana, where taking too much leads to nausea, overeating, and sleep.
(See my post “Spiceophrenia” for a discussion of the less-compelling evidence for synthetic cannabinoids and psychosis).
Hermanns-Clausen M., Kneisel S., Hutter M., Szabo B. & Auwärter V. (2013). Acute intoxication by synthetic cannabinoids - Four case reports, Drug Testing and Analysis, n/a-n/a. DOI: 10.1002/dta.1483
Graphics Credit: http://www.aacc.org/