Toxicological risk assessment of various emerging drugsNathan Bijl

National Dutch Information Centre for Poisoning, University Medical Center Utrecht, The Netherlands

Writing assignment Toxicology and Environmental Health

Supervisor: Laura Hondebrink1, Annette Nugteren- van Lonkhuyzen2

1. Toxicologist (ERT) / Postdoctoral Researcher, University Medical Centre Utrecht, National Poisons Information Centre

2. Junior Researcher, University Medical Centre Utrecht, National Poisons Information Center

May 21, 2014 Utrecht

Abstract

0.6 per cent of the global adult population is a problem drug of abuse user. Yearly, there are more than a million of emergency department visits worldwide due drug-induced toxicity and 1 per cent of the deaths among adults are attributed to illicit drug use. There are many types of drugs available on the Dutch market which are prohibited but also new legal drugs appears on the market which are manufactured to circumvent the law: designer drugs.

Several emerging (designer) drugs are entering the Dutch market but information about the drugs is lacking: mephedrone, 4-fluoroamphetamine (4-FA), 4-methylethcathinone (4-MEC), para-methoxy-N-methylamphetamine (PMMA), methoxetamine, 4-bromo-2,5-dimethoxyphenethylamine (2C-B) and 25I-NBOMe. These drugs of abuse belong to the group of hallucinogenic drugs or stimulant drugs. We gathered information about these emerging drugs which is necessary to perform a toxicological risk assessment.

Each drug has a specific profile of desired and adverse effects, although both stimulant and hallucinogenic drugs also have many similarities. The effect of the drugs depends on various factors: appearances of the drug, route of administration, dosage, multiple drug use and sensitivity (tolerance). For each drug these factors differ per person which can lead to different desired/adverse effects.

For some drugs it was difficult to gather sufficient information but we can conclude that not all drugs are equally toxic and lethal. The designer drugs are labeled as not for human consumption but the drugs are taken in recreational settings and intoxications occur when taken in excess. Especially for mephedrone, PMMA and 25I-NBOMe which has a high potency to induce toxicity, especially in the presence of other psychoactive drug. The adverse side effects have been associated with many hospitalizations and fatalities worldwide, compared with other emerging drugs. In the Netherlands mephedrone, 2C-B and PMMA are illegal but 25I-NBOMe, 4-MEC, 4-FA and methoxetamine have a legal status. However, no guidelines are available after purchasing the drug so there is no data available about the appropriate dose.

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Table of contents

1 Introduction…………………………………………………………………………………………..….……………………4

2 Stimulants

2.1.1 Mephedrone...……………………………………………………………………………………………….........6

2.1.2 4-Fluoroamphetamine.…………………………………………………………...........………………………12

2.1.3 4-Methylethcathinone……………….……..........................................................................14

2.1.4 Para-methoxy-N-methylamphetamine.…………..……………………………………………………....16

2.2 Discussion………………………...……………………………………………………..…..…....…………..................19

3 Psychedelics

3.1.1 Methoxetamine………………………………………………………………………..…..……………………......20

3.1.2 4-bromo-2,5-dimethoxyphenethylamine…………………………………………………………………23

3.1.3 2-(4-iodo-2,5-dimethoxyphenyl)-N-[(2-methoxyphenyl)methyl]ethanamine.…………..26

3.2 Discussion………………………………………………………………………..…..………………………..……………….29

4 General discussion………………………………………………………………………………………….…….…………30

5 References………………………………………………………………………..…..………………………………………..32

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Introduction

Humans have been using drugs of all kinds and sorts for more than thousands of years. At first, newly discovered substances were unregulated and drugs were freely prescribed by doctors and physicians. Sometimes the drugs were used as medicine but the drugs were often taken for nonmedical reasons. When drugs are taken for nonmedical reasons it is called a drug of abuse. They include legal drugs/medicines as well as illicit drugs5. Until the 19th century, drugs originated from two sources: plants and animals1. In the 20th century, a third source became available via chemical development and the number of drugs increased2. As a result, more people started using drugs and the problems of addiction were quickly noticed. When abuse of these compounds reached concerning levels, their distribution, production and use were more controlled1.

The United Nations Office on Drugs and Crime (UNODC) estimated that around 230 million people, 1 in every 20 adult people, took an illicit drug at least once in 201064. About 27 million people in the global adult population, 1 in every 200 adult people, are problem drug users which is 0.6 per cent of the total adult population64. Approximately 1 in every 100 deaths among adults is attributed to illicit drug use64 of which 80% is male3. However, in the Netherlands the number of fatalities due to a drug overdose of psychoactive drugs is relative low compared to other countries (fig. 1)4.

Psychoactive drugs are substances that acts upon the central nervous system resulting in temporary change of mood, behavior, consciousness and thoughts5. There are many types of psychoactive drugs but the most used worldwide are alcohol, caffeine tobacco, cannabis, cocaine, MDMA, amphetamine, heroin (opiates) and gamma-hydroxybutyrate (GHB)4. In 2009 the life-time prevalence in Dutch adults was 84% for alcohol, 28% for tobacco, 26% for cannabis, 6% for ecstasy, 5% for cocaine, 3% for amphetamine, 1% for GHB and 0.5% for heroin4. Although there is no exact data: caffeine is the most widely used drug. In the Dutch adult population the use of GHB, cannabis, cocaine, amphetamines and MDMA has increased in popularity in the recent years. In addition, the use of opium has declined and the percentage of people using tobacco or alcohol is stable in the last few years4.

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Figure 1. Deaths by overdose of drugs in the Netherlands, from 19964

Illicit drugs are regulated by law on a global level. The same applies in the Netherlands, where regulations on drugs are laid down in the Opium Act: a law that prohibits production, possession, sale, trade, transport, export and import of drugs listed in it. The Opium Act distinguishes category I and category II drugs. List I drugs are classified as hard drugs which can seriously cause health effects of the user (e.g. cocaine, MDMA, amphetamine, heroin) and list II are classified as soft drugs which cause fewer health problems (e.g. cannabis, GHB)82. However, prevention of drug use by listing them on the Opium Act is counteracted by new legal derivatives that appear on the market when existing drugs are prohibited. This occurs especially with ‘designer drugs’, which are manufactured in order to circumvent the law3.

Designer drugs were created in the 1960s and refer to chemicals that are created for recreational use. This is commonly done by modification of the molecular structures of existing illegal drugs with the objective to produce similar effects from recreational drugs7. Creating new substances, which are not regulated yet, hampers control on the sale and possession of these drugs. Mostly, when the popularity of the drug increase, the drug becomes regulated14. Because most designer drugs are relatively new, little or no information on the effects they can induce, are available. Therefore many designer drugs of abuse are being labeled as "not for human consumption" to avoid regulation8.

Drugs are divided into several groups based on their effect: cannabinoids, stimulants, hallucinogens, opioids, club drugs and dissociative drugs6. In this study, we have focused on stimulants and psychedelics.

Stimulants enhance the activity of the peripheral and central nervous systems inducing temporary improvement of physical or mental functions, e.g., enhanced wakefulness, alertness and locomotion28. However, the use of stimulants can also result in adverse effects e.g., feelings of paranoia, depression, feelings of paranoia, panic attacks, sleep and appetite disturbances29. Cocaine, MDMA and amphetamine are the most widely used stimulants. These drugs are closely associated with nightlife but also have a history of being used to enhance performance in the working area64.

Psychedelics are hallucinogens that are mainly used in closed groups but also as party drug65. Psychedelics primarily alter thought processes in the brain causing primarily illusions and hallucinations3, although mechanisms of action are not known. Psychedelics have a long history of use in medicine, religion or recreational purposes. Psychedelics tend to affect the mind in different ways such as a trance, spirituality, meditation and even near-death experiences65.

We aimed to gather information about various stimulant and psychedelic emerging drug that is necessary to perform a toxicological risk assessment. Included drugs are relative new on the Dutch market so limited data is available about these substances. The following stimulant drugs are included: mephedrone, 4-fluoroamphetamine, 4-methylethcathinone and para-methoxy-N-methylamphetamine. The following psychedelic drugs are included: methoxetamine, 4-bromo-2,5-dimethoxyphenethylamine and 25I-NBOMe.

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Mephedrone

- Chemical name: 2-methylamino-1-(4-methylphenyl)propan-1-one

- Street names: 4 methylmethcathinone, ‐ 4-methylephedrone, MMCat, Drone, 4-MMC, meow meow, Miaow, Ronzio, MMC hammer, Meph, Fiskrens, Bubbles, Ronzio, Tornado Spice E, Krabba, top cat, Charge, Diablo XXX, Crab, Rush and Blow

- Molecular formula: C11H15NO

- Molecular weight: 177.24

Cathinone is an active alkaloid that can be found in the leaves of the Catha edulis (khat plant). Synthetic derivatives of cathinone are entering the recreational drug market, including mephedrone (4-MMC) which is a synthetic stimulant with entactogenic effects: it increases the feelings of empathy. Despite its first synthesis in 1929, it has a short history of consumption14. Until 2010, it was one of the most popular drug in European countries but reports indicate that the popularity of mephedrone is declining12. This is mainly because mephedrone has become illegal, increased pricing, some users have a negative experiences and the availability of a good quality cocaine and MDMA 12. The increase in popularity and its toxicity resulted in taking it under control as a class II drug and prohibit its use in most European countries, including the Netherlands14.

Mephedrone (fig. 2) is also known as bath salts, plant food or plant feeders. In the United States the name bath salts is mainly used but in Europe the term plant feeders and plant food are more common13. Mephedrone can be taken as part of polydrug combinations (e.g. alcohol, cannabis, ketamine)66 but it is also sold as a substitute for ecstasy or cocaine14. In Europe the prices range between €18 and €25 for one gram12.

AppearanceMephedrone is usually sold as an odorless, white crystalline powder with a light yellow hue and less frequently as capsules or tablets10. It is often sold in small plastic sealed bags with the labels ‘research chemical’, ‘not for human consumption’ or ‘not tested for hazards or toxicity’ 14. The quantity of mephedrone in tablets sold to users in the Netherlands was found to be between 96 and 155 mg per tablet15.

Route of administrationCommon modalities of intake are through snorting (nasal insufflation), by ingestion through swallowing capsules/tablets or wrapping mephedrone powder in cigarette papers and swallowing it (bombing)14. Nasal insufflation can lead to significant nasal irritation, so some users switch to ingestion14. Less common methods include rectal administration (plugging or dissolved in an enema), smoking or intravenous use67. Mephedrone powder is readily soluble in water and can be dissolved for rectal/oral use or for injection67.

PharmacokineticsAbsorptionOnset of the desired effects is typically seen within 15 to 45 minutes after ingestion. For nasal insufflation or intravenous injection the desired effects occur within a few minutes 14. Users

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Figure 2. Molecular structure of mephedrone12

recommend to take mephedrone on an empty stomach because a delay of the onset of effects can occur after ingestion on a full stomach14.

MetabolismMephedrone is metabolized by cytochrome P450 2D6 in the liver with the contribution from other NAPDH-dependent enzymes and has five phase I active metabolites12. The following metabolites can be detected in urine after usage: hydroxytolyl mephedrone, nor-hydroxyl mephedrone, normephedrone, nor-dihydro mephedrone and 4-carboxy-dihydro mephedrone11. Mephedrone is metabolized by three phase I pathways. The metabolic pathway of mephedrone starts with the N-demethylation to the primary amine (nor-mephedrone, nor-dihyro mephedrone and nor-hydroxytolyl mephedrone metabolites), the reduction of the keto moiety to the respective alcohols (nor-dihydromephedrone and 4-carboxy-dihydro mephedrone metabolites) and oxidation of the tolyl moiety to the corresponding alcohols (hydroxytolyl mephedrone and nor-hydroxytolyl mephedrone metabolites)10. The nor-hydroxytolyl mephedrone and hydroxytolyl mephedrone metabolites are partly excreted in the urine as sulfate and glucuronide conjugates14.

In rats the maximum concentration (Cmax) was achieved rapidly after oral dosing. The time that Cmax was reached (Tmax) was 25 minutes to 1 hour and plasma concentrations declined to undetectable levels after 9 hours18.

Duration of effectIngested mephedrone effects last for 2 to 5 hours10 but according to different users a typical session can also last for 10 hours12. Several consumers first snort and then ingest the drug in order to achieve both fast and long lasting effects13.

Half-lifeHuman elimination half-life (t1/2) of mephedrone is not known, but t1/2 in rats after oral administration of 30 mg/kg and 60 mg/kg is 30 minutes18.

Mechanism of actionIn vitro studies of mephedrone confirm that the mechanism of action is similar to that of amphetamine. It is being characterized by a predominant action on plasma membrane catecholamine transporters. Mephedrone display potency as non-selective substrates for noradrenalin, serotonin and dopamine transporters, differing from each other by its relative binding potency. Mephedrone evoke transporter mediated release of monoamines through reversal of normal transporter flux83. Repeated mephedrone injections in rats showed an IC50 to inhibit dopamine uptake of 467 nM, whereas the IC50 value for serotonin uptake was 558 nM. There is no data for the IC50 value of norepinephrine72.

In rats, researcher found that mephedrone produce elevations in extracellular dopamine and serotonin with preferential effects on serotonin. A 950% increase in serotonin concentration and a 500% increase in dopamine concentration was observed in nucleus accumbens68.

Due the presence of the beta group in mephedrone, they show a reduced ability to cross the blood brain barrier when compared with amphetamine analogs. The beta group is responsible for increased solubility and it hinders crossing the blood-brain barrier. Because of these properties a higher doses is required to achieve similar effects12.

DoseMephedrone is used in single use doses between 15 and 250 mg when ingested and between 5 and

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125 mg for nasal insufflation. Use by other routes is less common: there is no data available about these routes of administration14.

Mephedrone users commonly start with low amounts for nasal insufflation (50-75 mg), although due to short-lived effects the total doses used per session rapidly increase to hundreds of milligrams per dose14. To achieve an effect of 10 hours an average amount of 0.91 gram was used, divided into several doses66.

Clinical effectsMephedrone shares psychoactive properties of MDMA, amphetamines and cocaine. Users suggest that the acute toxicity associated with mephedrone use is similar to that of MDMA, amphetamines and cocaine9.

Desired effects14,10: - Short increases in locomotion- Increased energy and motivation, - Increased alertness and awareness- Euphoria - Improved mood- Excitement- Mild empathogenic effects- Reduced hostility - Intensification of sensory experiences - Sociability and talkativeness- Music sensitivity - Reduced appetite- Moderate sexual arousal - Perceptual distortions

Unwanted effects (per system) 12,13,18,10

1) Central nervous system: - Tremors- Trismus- Bruxism- Tense jaws- Mild muscle clenching- Headache- Stiff neck/shoulders- Dizziness- Rhabdomyolysis- Insomnia- Seizures- Tinnitus- Nystagmus blurred vision- Pupil dilation- Numbness of tactile sensitivity

2) Gastrointestinal system: - Loss of appetite- Nausea- Dry mouth

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- Vomiting - Stomach ache

3) Cardiovascular system: - Tachycardia - Respiratory difficulties- Elevated blood pressure- Peripheral vasoconstriction- Chest pain - Cold/blue fingers

4) Central nervous system/psychiatric: - Anxiety- Confusion- Agitation- Dysphoria- Aggression- Irritability- Depression- Anhedonia; time distortions- Lack of motivation- Long-lasting hallucinations- Short-term psychosis- Paranoid- Short-term mania; insomnia and nightmares- Poor concentration- Impaired short-term memory- Mental fatigue- Suicidal thoughts/actions - Developing psychological dependency

5) Miscellaneous: - Changes in body temperature regulation- Hyperthermia- ‘Mephedrone sweat’ with a strong body odour- Nose and throat bleeds with burns and ulcerations- Painful nasal drip - Immunological toxicity

6) Renal/urinary excretory system: - Kidney failure- Difficulties in urination- Anorgasmia - Nephrotoxicity

7) Others: - Decrease in locomotion- Binging- Hyponatremia- Hyperuricemia- Hyperkalemia

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- Increased serum levels of creatinine kinase and creatinine- Weight loss after prolonged use- Metabolic acidosis

Toxicity (concentration)Overdose: Wood et al. describe 15 patients who arrived at the emergency department after self-reported mephedrone use (mean exposure 2.1-2.3 grams). Several symptoms were reported; most commonly were agitation, tachycardia (>100 bpm), seizures and hypertension (>160 mmHg)(table 1). 20% of the patients required treatment predominantly for management of agitation. The patients were discharged without lasting damage70.

Recreational use of mephedrone usually results in blood levels ~0.3 mg/L. However, levels of 0.74 mg/L were also reported and did not result in fatalities16.

Table 1. Percentage of patients with clinical effects that are presented in the hospital after an overdose of mephedrone70

FatalitiesIn 2010, 45 mephedrone-related deaths were reported in England, 12 in Scotland, 1 in Northern Ireland, 1 in Wales, and 1 in Guernsey13. However, generally there are no toxicological findings available at the time of death to conclude if mephedrone use was responsible for the death. Notably, even if mephedrone is detected, that does not necessarily mean that mephedrone was the cause of or has contributed to the death14.

The first mephedrone-related death was an 18 year old female in Sweden in 2008. Despite a successful resuscitation, she was brain dead 36 hours after arrival in the hospital. Initial investigations showed hyponatraemia (120 mmol/L), cerebral oedema and a metabolic acidosis. Toxicological screening of blood and urine revealed that no other drugs, apart from mephedrone, were used. However, the mephedrone concentration was not reported26.

A few cases are reported in which plasma or blood concentrations of mephedrone are defined. A 22 year old male in the USA who was found collapsed, not responsive and was unsuccessfully resuscitated. Urine toxicological screening was positive for different drugs and mephedrone (198 mg/L). Mephedrone was detected at a concentration of 0.5 mg/L in a postmortem blood sample. The cause of death was due accidental multiple drug toxicity and there is no data available about the amount of mephedrone that is consumed84.

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Maskell et al. describe a 49-year-old female who insufflated 0.5 gram of mephedrone. After 2 to 4 hours she had a sore chest and vomited, shortly afterward she collapsed and died. Autopsy revealed myocardial fibrosis within the anterior left ventricular wall (15 mm) and an old atherosclerotic occlusion of the anterior descending coronary artery. Her death was to the adverse effects of mephedrone with myocardial fibrosis and atherosclerotic coronary artery disease being contributing factors. The mephedrone concentration was 0.98 mg/L in femoral venous blood.9 However, generally in fatal cases concentrations of mephedrone are between 1 to 6 mg/L17.

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4-Fluoroamphetamine

- Chemical name: 1-(4-Fluorophenyl)propan-2-amine

- Street names: PFA, 4-FA, 4-FMP, PAL-303, 4-flava, 4floor, 4-fluor, P-FMP, Flux (-cd cleaner), benzeneethanamine, 1-(4-fluorfenyl)propaan-2-amine, para-fluoroamphetamine, 4-Fluoro-α-methylamphetamine and RDJ

- Molecular formula: C9H12FN

- Molecular weight: 153.20 4-Fluoroamphetamine (4-FA) is a designer drug and belongs to the group of stimulants and has entactogenic effects. 4-Fluroamphetamine is an amphetamine-like substance sharing the same psychoactive properties to that of amphetamine (fig. 3)21. In the Netherlands 4-FA is not listed in the Opium Act. Although scientific studies have been conducted with this drug already in 1975, it entered the market in 200721. The drug exists for some years but limited data is available about 4-FA.

Appearance4-FA is usually sold as crystal or powder. It may also occur that 4-FA is dissolved in a liquid or sold as a tablet21.

Route of administrationThe powder form is usually snorted (nasal) and liquids or tablets are usually ingested. When 4-FA is swallowed, the powder is often placed in a capsule or wrapped into a cigarette paper. The drug can also be smoked but this is less common22.

PharmacokineticsAbsorption After nasal insufflation onset of the desired effects occurs after a few minutes. After ingestion the effects occur within 15 to 45 minutes22.

Metabolism4-FA is probably entirely unchanged excreted from the body. Likely, 4-FA is not metabolized in the liver by cytochrome P450 oxidase because the C-F bond at the 4-position on the phenyl ring resists deactivation20.

Duration of effectUsers report that desired effects are seen within an hour of ingestion and the effects last for 5 to 8 hours. When insufflated, the duration of the effects will be shorter22. There are no published data about the duration of the effects of other routes of administration.

Mechanism of action4-FA strongly inhibits the re-uptake and is a releasing agent of dopamine, serotonin, and norepinephrine.19 The IC50 values for inhibiting the re-uptake of dopamine, serotonin and norepinephrine were 0.77, 6.8 and 0.42 µM, respectively. The EC50 values for stimulating the release of dopamine, serotonin, and norepinephrine from synaptosome were 0.2, 0.73, and 0.037 µM, respectively69.

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Figure 3. Molecular structure of 4-fluoroamphetamine21

Dose4-FA is reported to be used in doses of between 75–150 mg for oral administration and 50-75 mg for nasal insufflation22. Data about the doses for other routes of administration is not available.

Clinical effectsThe effects are broadly similar to that of amphetamine and MDMA. Therefore, 4-FA produce mainly sympathomimetic effects and also exhibit entactogenic properties19. Users reported that it is slightly more hallucinogenic21.

Desired effects21: - Euphoria- Increased energy- Excessive talking- Mood elevation- Increased alertness and awareness- Reduced appetite

Unwanted effects22: - Tachycardia- Headache/dizziness- Anxiety or paranoia- Agitation- Clenching of the jaw- Difficulty concentrating- Hyperthermia- Insomnia- Harmful/painful to the nose (when snorted)- Nausea- Vomiting

Toxicity (concentration)There is data available were serum samples were positive for 4-FA. Röchrich et al. describe two individuals that were suspected for driving under the influence and seemed to have been impaired by psychostimulant drugs. First, both individuals had been diagnosed as not having used drugs but further toxicological screening revealed 4-FA serum concentrations of 0.35 mg/L and 0.475 mg/L. 4-FA psychoactive effects are expected at these serum concentrations19.

There are no reports of fatalities or overdoses directly related to 4-FA use.

4-Methylethcathinone

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- Chemical name: 2-Ethylamino-1-(4-methylphenyl)propan-1-one

- Street name: 4-MEC, 4-methyl-N-ethylcathinone

- Molecular formula: C12H17NO

- Molecular weight: 191.27

4-Methylethcathinone (4-MEC) is a synthetic stimulant with entactogenic effects derived from cathinone (fig. 4). Its structure is similar to mephedrone and it has been sold as replacement for mephedrone. After the ban of mephedrone, 4-MEC has become available online in 2010 as a legal alternative product. It can be found in different bath salts including NRG-1 and NRG-2. However, 4-MEC has an extremely short history of human use23.

Appearance4-MEC is commonly sold in the form of a white powder or white/yellow crystals but is also available as capsules or tablets. It is usually sold as a research chemical in quantities that vary from 1 gram to 1 kilogram with the labels not for human consumption. Sometimes 4-MEC is sold in mixtures with other psychoactive substances, especially other cathinones. In that case it is mainly mixed with 3,4-methylenedioxypyrrolidin-1-ynvalerone (MDPV) and 3,4-methylenedioxypyrrolidin-1-ynbutiophenone (MDPBP)23.

Dose/route of administrationUsers report that common starting doses are between 50-100 mg when ingested, although average doses are between 100 to 200 mg and higher doses between 150 to 300 mg or more. Some users consume multiple doses during a session to prolong the duration of the effect (1 to 1.5 gram). When snorted, a lower dosage is used (with a common dose between 40 to 100 mg)23,25.

PharmacokineticsAbsorptionSince pharmacokinetic data on 4-MEC is absent and 4-MEC is structurally similar to mephedrone23, we assume that 4-MEC kinetics resembles mephedrone kinetics.

Onset of desired effects of mephedrone occurs within a few minutes after nasal exposure. When mephedrone is ingested, effects are typically seen within 15 to 45 minutes 14. We assume that the absorption rate of mephedrone is equally to 4-MEC

Duration of effectThe strongest effects are observed after 30 to 40 minutes and the effects ends after approximately 2 to 4 hours when ingested. Effects of 4-MEC are similar to mephedrone but shorter, much weaker and without intense euphoric effects23.

Mechanism of action4-MEC is a re-uptake inhibitor: it inhibits the dopamine, norepinephrine and serotonin transporter. The IC50 values for transporter inhibition dopamine, norepinephrine and serotonin are 4.28, 2.23 and

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Figure 4. Molecular structure of 4-Methylethcathinone23

7.93 µM, respectively. 4-MEC is also a monoamine releaser: it induce transporter-mediated release of serotonin but not dopamine and norepinephrine24.

Clinical effectsDesired effects23: - Excitation- Euphoria- Mood elevation- Increased energy- Relaxation- Empathy- Feeling of bliss- Increased tactile and musical appreciation

Unwanted effects23: - Lethargy confusion- Disappointing and weak effects- Anxiety- Nasal pain- Tremor- Tachycardia- Nystagmus- Sweating- Nausea- Vomiting- Some users reported that 4-MEC, compared with mephedrone, does not cause unpleasant

afterwards effects

Toxicity (concentration)Overdose/fatalities: Gil et al. reported three cases were 4-MEC was found in blood samples with concentrations of 0.046, 0.056 and 0.152 mg/L. In the first case, a man was found dead in his car. The man was driving his car after using 4-MEC and alcohol. The blood concentration of 4-MEC was 0.152 mg/L but the alcohol concentration was also high (0.12 g/dL). In a second case, a man was found unconscious after using multiple drugs. Despite resuscitation attempts, the man died in the hospital following brain damage. Blood levels of 4-MEC amounted up to 0.056 mg/L. However, this was not the main substance present in his blood. In both cases there was not a lethal concentration of 4-MEC. In the last case, a 4-MEC blood concentration of 0.046 mg/L was found in a 27-year old arrested man. The concentration of 4-MEC of the deceased (0.056 mg/L) was not much higher than in the case of the arrested man23.

Fatalities One case of fatal poisoning has been reported where an overdose of 4-MEC is clearly the cause of death. However, limited data is available about this case. The only available information is the concentration: 1.27 mg/L85.

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para-Methoxy-N-methylamphetamine

- Chemical name: 1-(4-methoxyphenyl)-N-methyl-propan-2-amine

- Street names: PMMA, death, 4-MMA, Methyl-MA, 4-methoxy-N-methylamphetamine

- Molecular formula: C11H17NO

- Molecular weight: 179.26

para-Methoxy-N-methylamphetamine (PMMA) is a stimulant with entactogenic effects and a psychedelic drug. It is the 4-methoxy analogue of methamphetamine (fig. 5). Its first synthesis was in 1938 but in the 1990s PMMA appeared on the market. Generally, it is found in combination with MDMA59. In most cases the users are unaware that the ecstasy pills are contaminated with PMMA.54 However, PMMA it is used as a substitute for ecstasy causing that it is mistakenly ingested as ecstasy.58 PMMA is cheaper to produce and has, in small amounts, similar effects to amphetamines or ecstasy, although the toxicity of PMMA is substantially higher. Because many intoxications and deaths were reported, PMMA is known as “death”. In the Netherlands PMMA is scheduled as a controlled drug57.

Appearance PMMA is mostly sold in tablets but also in capsules.60 Common logos that are found on tablets containing PMMA are Jumbo, Mitsubishi, or E58.

Route of administrationData about the routes of administration is not available. Generally, just like ecstasy, ingestion will be the most common route of intake.

Pharmacokinetics AbsorptionKinetics regarding time of onset of effects of PMMA is not known but PMMA has, compared to MDMA, a delayed onset of effects54; MDMA starts to work after 20 to 60 minutes61.

MetabolismPMMA is metabolized by CYP2D6 on cytochrome P450 in the liver of rats mainly by O-demethylation of the methoxy moiety to 4-hydroxy methamphetamine. Then catechol-O-methyl transferase (COMT) catalyses methylation to 4'-hydroxy-3'-methoxy methamphetamine occurred. 3'-hydroxy-4'-methoxy methamphetamine was formed to a small extent either by direct hydroxylation of PMMA or COMT methylation of the 4'-position. A second metabolic pathway was the alteration of the side chain. The metabolite 4-hydroxy amphetamine was formed via PMMA N-demethylation to PMA followed by O-demethylation. PMA is an active metabolite of PMMA56.

Duration of effectThere is no exact data available about the duration of the desired effects. However, when desired effects arise, the duration of effects are short62.

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Figure 5. Molecular structure of PMMA56

Half-lifeThe elimination half-life value in rats was approximately 1.0 hour with a plasma clearance of 4.4 L/h59.

Mechanism of actionPMMAs mechanism of action seems to be similar to that of MDMA: It is a potent releaser of serotonin (EC50=41 nM), norepinephrine (EC50=147 nM) and reduced activity as a releaser of dopamine (EC50=1.0 nM) from synaptic terminals86. PMMA is also a strong inhibitor of monoaminoxidase (MAO) type A54.

PMMA produces long-term effects on brain serotonin neurons: it produces reductions in the concentration of 5-HT and its metabolite (5-HIAA) in the brain. In addition, it produces a loss of cortical 5-HT uptake sites55.

DosePMMA tablets contain between 20 and 97 mg58. PMMA has stimulant and hallucinogenic effects with doses of less than 50 mg. Doses over 60 to 80 mg are potentially lethal, especially in the presence of other psychoactive drug like alcohol63.

Clinical effectsDue the poor MDMA-like effects of PMMA, this can be perceived as a failure or weakness of the pill. This may lead to re-dosing of more pills and eventually an overdose. In other, rare cases, users take PMMA together with ecstasy to enhance the effects54.

Desired effects54: - Euphoria- Psychedelic effects. - Increased energy

Unwanted effects54: - Extreme hyperthermia- Agitation- Rhabdomyolysis- Cardiomyolysis- Hallucinations- Arrhythmias due to hyperkalemia- Dry mouth- Convulsions- Severe coagulopathy- Teeth grinding- Sweating- Nausea- Headache- Weakness- Difficulty speaking- Coma - Death (serotonin syndrome)

Toxicity (concentration)Overdose: Detailed data is available on 22 cases of acute toxicity associated with recreational PMMA use in Norway during a 6 month period which resulted in hospitalizations but no fatalities. The mean

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PMMA blood concentration was 0.10 mg/L with a range of 0.01–0.65mg/L. However, one person had a PMMA concentration of 0.65 mg/L, which is above the reported toxic range and can lead to the death57. Also in Israel there were cases of recreational use of PMMA without fatalities. The clinical manifestations reported several symptoms: coma, seizures, headache, tremor, dilated pupils, diaphoresis, acute respiratory failure, cardiac arrhythmias, hyperthermia and organ failure76.

Fatalities Worldwide many PMMA-related deaths are reported58. Vevelstad et al. indicate that until 2003 more than 90 fatal poisonings are attributed to the ingestion of PMMA in Canada, USA, Australia and Europe57. Also after 2003 PMMA-related deaths were reported (table 2)57,75,76.

In Norway there was during a 6 month period 12 fatal intoxications related to PMMA use. 12 victims were found dead. Initial investigations showed symptoms of hyperthermia, hyperactivity, acute respiratory distress, cardiac arrest, sudden collapse, convulsions and/or multiple organ failure. The mean PMMA concentration in peripheral blood was 2.02 mg/L. In 11 of these fatalities, the PMMA concentrations were above 0.5 mg/L, and in most cases greater than 1.24 mg/L. PMMA blood concentrations above 0.5 mg/L are reported to be associated with toxic and possibly lethal effects57.

In Israel the presence of PMMA in the blood is confirmed in 24 fatal cases. The mean age of these cases was 27 years and 19 were males. 17 patients were pronounced dead at the scene, three died on the route to the hospital while being resuscitated and four died in the hospital. The mean post mortem blood PMMA concentration was 2.72 mg/L. Multiple drugs were taken in 17 fatal cases76.

In Taiwan there were 8 fatalities related to PMMA use75. The post mortem PMMA blood concentrations in these cases are similar to those found in Israel.

Table 2. Number of PMMA-related deaths worldwide. Reported since 201188

Date No. of cases PlaceJanuary 2011 12 NorwayMarch 2011 4 Netherlands (Limburg)April 2011 1 Iceland2011 4 ScotlandJanuary 2012 Ecstasy related deaths which

occurred that year were in fact the result of a PMMA overdose (N=?)

Canada

September 2012 2 Ireland (County Cork)September 2012 1 Australia (Queensland)December 2012 - January 2013 Several deaths (N=?) United KingdomJune 2013 1 Netherlands (s-Hertogenbosch)August 2013 1 Netherlands (Sliedrecht)

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Discussion

Mephedrone, 4-Fluoroamphetamine, 4-Methylethcathinone and para-Methoxy-N-methylamphetamine are synthetic stimulants which affect the dopaminergic, serotonergic and norepinephrine systems: they increase the neurotransmitter levels of these monoamines. Only PMMA has a reduced effect on the dopaminergic system (EC50=1.0 nM) and there is no data of the effect of mephedrone on the norepinephrine system.

4-MEC entered the market in 2010 as a legal alternative product for mephedrone. 4-MEC and mephedrone (4-MMC) share many similarities and have similar sounding (street) names. Similarity in action and structure of 4-MEC and mephedrone can predict some of its toxicity and properties. However, often 4-MEC doses are used that are 40–100% higher than in the case of mephedrone. Therefore, the similarities may cause confusion amongst users which can have consequences with respect to their use.

In some countries mephedrone can be sold as either cocaine or ecstasy. The same applies for PMMA which is sold as a substitute for ecstasy. This is also the case with 4-MEC, although this is mixed with other psychoactive substances such as MDPV and MDPBP. Because the drug can be mixed with other substances, drug users are unaware what substance is being consumed. This suggests that the effects that occur after the drug is used can be falsely assigned to the use of mephedrone, 4-MEC or PMMA. This is likely more of an issue with drugs that is purchased from dealers rather than from the internet.

Most short-term clinical effects of these stimulants have much in common in which there is an entire spectrum of adverse effects. For mephedrone and PMMA there is detailed information available on the acute health and clinical effects but for 4-FA and 4-MEC there is limited data about overdoses or deaths directly related to their use. However, PMMA is closely associated with toxic and possibly lethal effects; many PMMA-related deaths are reported because PMMA is mistakenly ingested as ecstasy. The toxicity of PMMA is substantially higher compared to ecstasy. Dosages over 60 to 80 mg are potentially lethal for PMMA. In other stimulants this is a common dose to induce desired effects. Mephedrone is also associated with fatalities and hospitalizations. However, generally in fatal cases of mephedrone, higher doses are consumed.

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Methoxetamine

- Chemical name: 2-(3-methoxyphenyl)-2-(ethylamino)cyclohexanone

- Street names: MXE, skang, K-max, Bladder friendly ketamine, METH-O, Roflcoptr, m-ket, mexxy, minx, jipper, and special K

- Molecular formula: C15H21NO2

- Molecular weight: 247.33

Methoxetamine belongs to the group of psychedelics and is an N-ethyl ketamine derivative 2-(3-methoxyphenyl)-2-(ethylamine)cyclo-hexanone (fig. 6)30. It is one of a number of novel designer drugs that is available for purchase over the internet. It is synthesized as a close structural analogue of ketamine specifically to avoid regulations but to retain the psychoactive properties of ketamine. Unlike ketamine, methoxetamine is marketed as a legal “bladder safe” drug32. In comparison with ketamine the 2-chlore group on the phenyl ring of ketamine molecule is replaced with a 3-methoxy group and the N-methyl group on the amine ring is replaced with an N-ethyl group36.

AppearanceMethoxetamine is sold through the Internet as a research chemical in the form of a white, odorless powder31 with a price of 7 dollars for 50 mg33.

Routes of administrationInsufflation, ingestion, intramuscular, sub-lingual, intravenous and rectal are potential routes of methoxetamine administration33. The most common route of administration is by insufflating73.

PharmacokineticsAbsorptionWhen snorted, effects begin commonly after 10 to 20 minutes31. Data about the kinetics regarding time of onset of effects is not available for other routes.

MetabolismMethoxetamine is metabolized in the liver mainly by CYP450 enzymes. Three main metabolic steps are observed: Odemethylation (catalyzed by CYP2C19 and CYP2B6), N-demethylation to the primary amine (catalyzed by CYP3A4 and CYP2B6) and/or hydroxylation at the aryl part (catalyzed by CYP2B6). The following phase I metabolites could be identified but it is currently not known whether these metabolites are active: N-deethyl-, O-demethyl-, N,Obis-dealkyl-, O-demethyl-hydroxy-, hydroxy-aryl- and N,O-bis-dealkyl-hydroxy-MXE.

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Figure 6. Molecular structure of ketamine (1) and methoxetamine (2)31

Also the following phase II metabolites could be identified: O-demethyl-MXE sulfate, O-demethyl-MXE glucuronide, N-deethyl-MXE glucuronide, N,O-bis-dealkyl-MXE sulfate, N,O-bisdealkyl-MXE glucuronide, O-demethyl-hydroxy-MXE glucuronide, hydroxy-MXE glucuronide, O-demethyl-hydroxy-MXE sulfate, and N,Obis-dealkyl-hydroxy-MXE sulfate35.

The main excretion product in urine is the N-deethyl metabolite. Hydroxy-metabolites are also present but are probably of minor relevance35.

Duration of effectMethoxetamine has been marketed as having longer lasting effects than ketamine based on the new N-ethyl group and replacement of 2-chlorine by 3-methoxy moiety35. Users report that the average duration of effect is 2.5 to 4 hours when insufflated, 3 to 5 hours when ingested and 2 to 3 hours when intramuscular73.

Half-lifeKinetics regarding half-life time of methoxetamine are not known34. However, methoxetamine has, compared with ketamine-induced effects, longer lasting effects. Therefore, it is likely that the elimination half-life of methoxetamine last longer than ketamine (which is 2.5 hours)31.

Mechanism of actionIt is believed that methoxetamine affect the dopaminergic system (it is a dopamine D2 receptor agonists) and is an N-methyl D-aspartate (NMDA) antagonist32. NMDA receptors are glycine and glutamate gated ionotropic receptors expressed in the central nervous system. NMDA receptors are activated when glycine and glutamate are bound to it. Methoxetamine primarily acting at the NMDA receptor pore as open channel blockers and deactivate the NMDA receptor32. Disruption of NMDA processes is the common mechanism of anesthetic action89.

Methoxetamine also affect other neurotransmitter systems: it interact with 5-HT2 receptors, σ receptors, μ and κ opioid receptors and muscarinic cholinergic receptors31.

DoseLarge variations in exposure doses have been reported by users. The most common way of application is intranasal with a single dose of 20 to 50 mg. For intramuscular a single dose is between 10 and 50 mg35. A research of Kjellgren et al. collected information from public Internet forums and the amount of methoxetamine ingested varied between 10–200 mg during a single session with an average of 88 mg73. There is no data about the doses of other routes of administration.

Clinical effectsThe effects of methoxetamine are similar to those of ketamine and are dose-dependent. At a very high dose dissociation of the physical body (M-Hole) can occur: there is a complete loss of bodily awareness, a total loss of time perception and profound distortions34. The side effects of ketamine, like bladder pain and ureter obstruction, are lower. Because of the N-ethyl group, chronic use of methoxetamine has been as a bladder safe derivative of ketamine32.

Desired effects31,32,33: - Euphoria- Anti-depressant effects- Anxiolysis- Sociability and talkativeness- Relaxation- Therapeutic self-reflection

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- Increase in clarity of thoughts

Unwanted effects31,32,33: - Insomnia- Depressive thoughts- Intensive hallucinations- Agitation- Disorientation- Sweating- Nausea- Numbness- Anxiety- Vomiting- Tachycardia- AataxiaToxicity (concentration)Overdose: Shields et al. describe three cases of acute methoxetamine overdose. A 19 year old male was brought to the hospital with severe truncal ataxia, incoordination, nystagmus and reduced conscious level after nasal insufflation of methoxetamine. Adverse health effects persisted for 3-4 days before recovery. A serum sample was positive for methoxetamine at a concentration of 0.24 mg/L. Two other patients with the age of 17 and 18 years (with serum methoxetamine concentrations of 0.45 mg/L and 0.16 mg/L, respectively) were presented in the hospital after nasal insufflation of methoxetamine with several symptoms: severe cerebellar ataxia, incoordination, difficulty with speech, imbalance and reduced conscious level. Within 24 hours spontaneous recovery occurred. In the three cases an unknown dose of methoxetamine is insufflated and no other drugs were used30.

Wood et al. also described three cases of acute methoxetamine overdose. The first patient was a 42-year-old man who was found collapsed on the ground. After he had insufflated 0.5 gram of methoxetamine, he was hypertensive (blood pressure 187/83 mm/Hg), tachycardic (heart rate 135 beats/min) and pyrexial. His serum methoxetamine concentration was 0.12 mg/L. The second patient was a 29-year-old man who was found confused with tremor and hallucinations after he had ingested 0.2 gram methoxetamine. He had hypertension (201/104 mm/Hg) and tachycardia (121 beats/min). His serum methoxetamine concentration was 0.09 mg/L. The third patient was a 28-year-old man who collapsed in a nightclub after he had used an unknown amount of methoxetamine. He was significantly agitated and confused. He had hypertension (198/78 mm/Hg) and tachycardia (113 beats/min). His serum methoxetamine concentration was 0.20 mg/L. All recovered after treatment with low dose of benzodiazepines and the methoxetamine was purchases from the internet and smart shop90,32.

Fatalities There are not many methoxetamine-related deaths reported. Wikstro et al. describe a case were a 26-year-old male was found dead on his floor of his apartment. Post-mortem examination revealed pulmonary edema. A concentration of 8.6 mg/L methoxetamine was found in his femoral blood as were three different cannabinoids. According to the circumstances and the high femoral blood concentration of methoxetamine it was concluded that an unintentional acute fatal intoxication with methoxetamine had occurred. However, the presence of the synthetic cannabinoids can have contributed to his death37.

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4-bromo-2,5-dimethoxyphenethylamine

- Chemical name: 2-(4-bromo-2,5-dimethoxyphenyl)ethanamine

- Street names: 2C-B, Nexus, Rusko, Erox, Synergy, Performax, Cyber, Toonies, Bromo, Spectrum and Venus

- Molecular formula: C10H14BrNO2

- Molecular weight: 260.13

4-bromo-2,5-dimethoxyphenethylamine (2C-B) is a psychoactive agent related to both the amphetamine-like stimulants like ecstasy and the mescaline-like psychedelics like LSD (fig. 7). 2C-B is part of the 2C family and was the firstly synthesized of the 2Cs42. 2C-B was synthesized from 2,5-dimethoxybenzaldehyde by Alexander Shulgin in 1974 and was initially intended for psychotherapy use. The drug was used in therapies and allowed patients to bring up repressed memories and suppressed emotions. After becoming popular for medical use, it became popular recreationally38.

It was used as a replacement for MDMA after MDMA became scheduled in 1985. In 1997, 2C-B was listed in the Opium Act to prevent further popularity in the Netherlands. However, after 2C-B get banned in the Netherlands other 2C analogues (e.g. 2C-I) became available by suppliers as legal alternatives but after a while also these 2C analogues got banned38. Nowadays, 2C-B is used as a rave and club drug43.

Appearance 2C-B was first sold as a white powder, although recently it is also present as tablets or capsules 43. In the Netherlands, pure 2C-B tablets are difficult to obtain and 2C-B is probably only available as mixture with MDMA (but sold as 2C-B)39.

Routes of administrationOrally and intranasal exposure are the most common routes of administration although insufflating is painful to the nose43.

PharmacokineticsAbsorptionWhen ingested, onset of the desired effects is delayed compared when 2C-B is insufflated. When orally consumed, effects are seen within 30 to 90 minutes and when insufflated the effects occur within a few minutes (after 5 minutes)44.

Metabolism2C-B is metabolized by liver hepatocytes resulting in demethylation and deamination of 2C-B that produces several metabolites. It is unknown whether these metabolites are active. Six metabolites are identified: BDMPAA, BDMPE, B-2 HMPAA, B-2-HMPE, BDMBA, and B-2-HMPEA41.

4-bromo-2,5-dimethoxybenzoic acid (BDMBA) is produced by oxidative deamination of 2C-B. It is expected that this reaction is catalyzed by monoamine oxidase. Oxidative deamination also results in 4-bromo-2,5-dimethoxyphenylacetic acid (BDMPAA) and 2-(4-bromo-2,5-dimethoxyphenyl)-ethanol (BDMPE) metabolites. B-2-HMPE and B-2-HMPAA can arise due further metabolism of BDMPE and BDMPAA by demethylation which is catalyzed by a cytochrome P450 dependent reaction although

23

Figure 7. Molecular structure of 2C-B40

which isoforms are involved is not identified. These metabolites can also be generated by demethylation of 2C-B to B-2-HMPEA followed by oxidative deamination41.

Duration of effectUsers report that the effects last for 4 to 8 hours when taken orally. When insufflated, the duration of the effects will be shorter but more intense: 2 to 4 hours42.

Half-lifeThe elimination half-life value in rats was 1.1 hours42.

Mechanism of action2C-B has an affinity towards various central adrenergic and serotonergic receptors. 2C-B shows affinity at the 5-HT2 receptor. It also shows agonist and antagonist activity at specific sub-receptor sites. 2C-B also demonstrates affinity to 5-HT1C, 5-HT1B and 5-HT1A.91 Activation of the serotonin system by an agonist ligand has been associated with hallucinogenic effects, although activation of 5-HT2A –coupled phospholipase D pathway or functional antagonism may also play a role42.

Researchers also found that 2C-B has inhibitory effects on monoamine oxidase (MAO): it increases dopamine levels in the brains of rats which explain its stimulatory effects. However, the underlying mechanism remains unclear78.

DoseUsers report that the most common doses are between 4–30 mg when ingested. Doses of 2C-B exceeding 30 mg may cause health effects (like agitation and hyperthermia). Insufflated doses are a little lower. When consumed orally, lower doses (4–10 mg) induce entactogenic-stimulating effects (like euphoria) while higher doses (10–20 mg) induce psychedelic effects (like an increase in receptiveness of the visual, auditory, tactile and olfactory sensations)42.

Clinical effects Desired effects42,43,44: - Euphoria- Increased energy- Increased receptiveness of the visual, auditory, tactile and olfactory sensations- Increased laughing- Increased access to spiritual ideation - Hallucinations

Unwanted effects42,43,44:

- Frightening hallucinations- Tachycardia- Diarrhea- Hyperthermia- Hypertension- Paranoia- Insomnia- Headache- Sweating- Confusion - Difficulty concentrating

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Toxicity (concentration)Because of its very low cross-reactivity, it is hardly detectable in urine in immunoassays and no human data on concentrations of 2C-B is available40.

In rats orally exposed to 50 mg/kg, the maximum 2C-B serum concentration amounted up to 23.3 mg/ml, attained within 30 minutes42.

No intoxication or deaths involving 2C-B are reported in literature. Limited data is available about its involvement in mortality40.

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2-(4-iodo-2,5-dimethoxyphenyl)-N-[(2-methoxyphenyl)methyl]ethanamine

- Chemical name: 2-(4-iodo-2,5-dimethoxyphenyl)-N-[(2-methoxyphenyl)methyl]ethanamine

- Street names: 25I-NBOMe, 25I, INB-MeO, NBOMe-2C-I, N-bomb, Smiles, 25I-NBOMe Solaris and Cimbi-5

- Molecular formula: C18H22INO3

- Molecular weight: 427.28

NBOMe compounds have become popular psychedelics and the best known NBOMe compound is 25I-NBOMe (fig. 8)46. 2-(4-iodo-2,5-dimethoxyphenyl)-N-[(2-methoxyphenyl)methyl]ethanamine (25I-NBOMe) is a derivative of the substituted phenethylamine psychedelic 2C-I. This substitution of the structure significantly increases the effectiveness of the drug to induce hallucinogenic effects 47. In 2003 Ralf Heim synthesized 25I-NBOMe at the Free University of Berlin. It was made as a pharmacological tool to study the 5-HT2A receptor45. It has similar effects as LSD but 25I-NBOMe is active at a lower dose and the synthesis is relatively easy46.

Although 25I-NBOMe was discovered in 2003, it was not used as a common recreational drug until 201046. In the Netherlands this drug has a legal status and can easily be obtained over the internet45.

Appearance25I-NBOMe was first sold as powder. After a while it became available in the form of pre-loaded paper doses (blotter), as a spray50, as liquid and as a powder enclosed in purple capsules47.

Routes of administration Modalities of intake are usually by holding 25I-NBOMe (in blotter form) in the mouth and not swallowing it (buccal or sublingual administration). Some users take the drug through nasal insufflation in liquid (spray) or powder form50. Administration by means of intravenous injection or ingesting the capsules occurs but is rare47.

PharmacokineticsAbsorptionAccording to user reports the liquid or blotter must be held in the mouth for 10 minutes for total absorption51. Data about kinetics regarding time of onset of effects for other routes is not available. MetabolismThere is reduced information available about the metabolism of 25I-NBOMe. However, generally 25I-NBOMe undergoes N-acetylation or O-demethylation of the aromatic ring followed by sulfation

26

Figure 8. Molecular structure of (1) 2C-I and (2) 25I-NBOMe47

or glucuronidation. Another metabolic pathway is the deamination to the corresponding aldehyde followed by reduction to the corresponding alcohol or by oxidation to the corresponding acid. These Phase II metabolites can be detected in the urine. It is unknown whether these metabolites are active53.

Duration of effectAfter insufflation, the duration ranging from 4 to 6 hours and to 8 to 10 hours when taken buccal or sublingual51.

Mechanism of action 25I-NBOMe acts as a full potent 5-HT2A receptor agonists (with Ki =0.044nM): it increases serotonin levels and stimulation of the 5-HT2A receptors appears to be essential for the hallucinogenic effects48. Other psychedelics (like LSD) are partial 5-HT2A receptor agonists79. This difference in receptor affinity makes 25I-NBOMe a strong psychedelic.

Dose25I-NBOMe can be active at low doses ranging from 50 to 250 μg when the administration is buccal, oral or sublingual. The common dose range from 500 to 800 μg. However, doses above 700 μg can cause a strong psychedelic experience46.

Clinical effectsTo improve their bioavailability some internet suppliers offer the materials with hydroxypropyl-beta-cyclodextrin. The inside surface of hydroxypropyl-beta-cyclodextrin is hydrophobic and the exterior surface is hydrophilic so they form complexes with hydrophobic compounds 87. This improves the poor water solubility of 25I-NBOMe and increase buccal or sublingual absorption50.

Desired effects45,50: - Euphoria- Feelings of love/empathy- Open and closed eye visual - Mental and physical stimulation- Hallucinations- Increased awareness- A change in consciousness - Unusual body sensations

Unwanted effects45,50: - Confusion- Difficulty communicating- Hypertension- Frightening hallucinations- Chest pain- Agitation- Tachycardia- Nausea- Insomnia- Paranoia- Aggression - Unwanted feelings (depression)

27

Toxicity (concentration)Overdose: In 2013, seven patients were presented to hospitals in England after an acute overdose. 25I-NBOMe was the main active substance in both plasma and urine samples but data about the concentrations is not available. 25I-NBOMe was used at a house party in almost all patients. All recovered after treatment and several days in the hospital. However, one patient recovered from his symptoms after 43 days. The clinical manifestations reported were tachycardia (n=7), agitation (n=6), hypertension (n=4), aggression and hallucinations (n=6), seizures (n=3), hyperpyrexia (n=3), elevated white cell count (n=2), clonus (n=2), rhabdomyolysis with acute renal failure (n=1), elevated creatine kinase (n=7), metabolic acidosis (n=3) and acute kidney injury (n=1)47.In another case an 18 year old male was presented to the emergency department in the USA after he jumped out of a moving car. The patient admitted that he used 25I-NBOMe. He had hallucinations, was tachycardiac, hypertensive and required physical restraints and treatment. His symptoms gradually improved and returned to normal after 48 hours. A serum sample was positive for 25I-NBOMe at a concentration of 7.6x10-4 mg/L80.

Fatalities It is believed that 25I-NBOMe use have been responsible for several deaths. There are many reports in the media of people who die as a result of 25I-NBOMe intoxication. However, there is a lack of scientific background information in these cases such as the confirmation that 25I-NBOMe was used or the 25I-NBOMe concentration. An example of such a 25I-NBOMe-related death is an 18 year old man from Scottsdale. This man died in 2013 after ingesting an unknown amount of 25I-NBOMe that was sold as LSD. A toxicology screen revealed that the cause of death was due acute 25I-NBOMe poisoning. No other drugs or alcohol were found in his blood but there is no data about the 25I-NBOMe concentration50.

Poklis et al. describe a fatality of a 19 year old man who had ingested blotter paper of 25I-NBOMe. After ingestion his friends found him unresponsive on the floor near his apartment. He was pronounced dead at the scene and the police concluded that the man had either jumped or fallen from his apartment balcony. The peripheral blood concentration of 25I-NBOMe was 0.405 mg/L and the urine was determined to contain 2.8 x10-3 mg/L. However, the man was suffering from hallucinations and the fall has probably led to his death81.

Discussion

Methoxetamine, 2C-B and 25I-NBOMe are psychedelics which belong to the group of hallucinogens. However, 2C-B has both psychedelic and stimulant effects. In general, lower doses of 2C-B induce

28

stimulating effects while higher doses induce psychedelic effects42. Most short-term clinical effects of these hallucinogens have much in common. However, the most common routes of administration differ for each drug: buccal or sublingual for 25I-NBOMe, ingestion for 2C-B and insufflating for methoxetamine.

Methoxetamine and 25I-NBOMe are novel designer drugs which are legal in the Netherlands. More designer drugs become available on the Dutch market and the designer drugs can simply be ordered over the internet. However, most designer drugs disappear after a while. Only when the drug is increasing in popularity and the product appears to be harmful to human health, the drug is listed in the Opium Act. This was also the case with 2C-B, which in 1997 was included in the Opium Act to prevent further increase in popularity. However, 2C-B is still a popular drug. An explanation could be that despite the offer of many designer drugs, people still choose for the ‘old familiar’, illegal drugs. Cocaine, MDMA, ampthetamines and heroin are worldwide still the most popular drugs despite the fact that they are listed in the Opium Act. This may be because users rather choose for the drugs which they are familiar with the effects and risks than for new substances for which the effects are unknown. Although the availability, quality and price also play a role in what kind of drugs is consumed.

In comparison with 2C-B and (especially) 25I-NBOMe, a large dose of methoxetamine is needed to induce psychedelic effects. For methoxetamine the average amount used during a session is 88mg. For 2C-B a dose of 10-20 mg is enough to induce psychedelic effects and for 25I-NBOMe a dose of 700 μg causes strong psychedelic effects. Therefore, only a small amount of 25I-NBOMe is needed for a strong psychedelic experience. Because only a small dose is needed, intoxications occur quickly if too high doses are consumed.

The reason why a higher dose is needed for methoxetamine is because it differs in mechanism of action. Most psychedelic/hallucinogenic drug (2C-B and 25I-NBOMe) increase the serotonin levels and stimulate the 5-HT2A receptors which is essential for the hallucinogenic effects. However, this is not the case for methoxetamine: it affects the dopaminergic system and it is a NMDA antagonist which is the common mechanism of anesthetic action. As a result, methoxetamine does not belong to the group of hallucinogens but is it rather a dissociative drug. 2C-B also affects the dopaminergic system which explains its stimulatory effects.

General discussion

Based on these risk assessments, psychedelics are potentially more lethal than stimulants. This is partly because hallucinogens have a high potency to induce toxicity in small doses. Aside from

29

PMMA, hallucinogens are active at smaller doses so intoxications occur quicker when taken in excess. Hallucinogens can also cause frightening hallucinations which frequently caused severe or fatal accidents. PMMA is an exception: this stimulant is associated with many hospitalizations and fatalities but this is more due the fact that PMMA is confused with ecstasy . In most toxicities the data suggest that the user have used multiple drugs. It is likely that combined drug consumption will increase the risk of toxicity. However, the data on potential drug-related fatalities needs to be interpreted carefully. Detection of a drug in a sample does not necessarily mean that this drug is responsible for, or has contributed to, death.

Stimulants and hallucinogens differ in their mechanism of action. Stimulants may affect multiple monoamine mechanisms but for hallucinogens this is usually not the case. Mephedrone, 4-FA, 4-MEC and PMMA are stimulants with entactogenic effects and exert their effects through affecting the norepinephrine, serotonin and/or dopamine systems. The hallucinogens have mainly one working mechanism: affecting the serotonin system. However, methoxetamine and 2C-B also affect the dopaminergic system and methoxetamine is a NMDA antagonist.

Because most designer drugs are new on the market, limited research has been conducted to the drug. The absence of information and research finding is a general problem for risk assessments. Therefore, the risk assessment conclusions are based on partial knowledge and are tentative. For some emerging drugs there is detailed information available on the acute health effects associated with drug toxicity from clinical case series. However, data about the chronic effects related to the consumption of designer drug remain unknown. In order to still gather information, occasionally information is obtained from user self-reports on Internet forum (e.g. Erowid). This may have the effect that the information is not entirely reliable, although Internet forums also have positive aspects. It can ensure that the use of designer drugs is less risky. Users interact extensively on Internet forums about their experiences per dose. This means that users pay attention to what they do and take an appropriate dose. The dose that is consumed determines together with the way of administration and with the sensitivity of the user, to what extent and duration effects occur. This means that for each person different effects can arise.

Mephedrone, PMMA and 2C-B have a longer history of human use compared to 4-MEC, 4-FA, methoxetamine and 25I-NBOMe. Because mephedrone, PMMA and 2C-B have increased in popularity and are associated with adverse effects, they are listed in the Opium Act. More data is available about the adverse effects and toxicity of drugs that are listed in the Opium Act. The legal status of the drug makes the drug easy to obtain. Either from internet suppliers, smart shops or from street drug dealers. Individuals are often able to purchase unlimited amount of drugs. Controlling a drug has the potential to bring with it both positive and negative consequences. Positive consequences may include reduced availability and use of the drug. However, control measures could create an illegal market with criminal activity and reduced quality of the drug.

All drugs are toxic to humans but mephedrone, PMMA and 25I-NBOMe have a high potency to induce toxicity. The adverse side effects have been associated with many hospitalizations and fatalities. Mephedrone and PMMA are listed in the Opium Act but this does not apply for 25I-NBOMe. The designer drugs of abuse are labeled as not for human consumption but it is taken for recreational use. 25I-NBOMe, 4-MEC, 4-FA and methoxetamine are designer drugs which are legal in the Netherlands but no guidelines are available so there is no data available about the appropriate dose or on the effects they can induce. A proper dose of the drug must be consumed and not as part of a polydrug combination to avoid intoxication. Further research is needed, especially with respect to potential toxicity.

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