The effect of 3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy') and its metabolites on neurohypophysial hormone release from the isolated rat hypothalamus

The entactogen 3,4-methylenedioxymethamphetamine (MDMA; ecstasy) as a treatment aid in psychotherapy and its safety concerns

The phenylethylamine, 3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy'), is the prototypical example of an entactogen. Its original placement in highly restrictive drug usage categories in the US and UK, led to an inevitable restriction on MDMA neuroscience research and treatment. The dominant pharmacological effects of MDMA are its properties of release and inhibition of reuptake of amine neurotransmitter transporters for dopamine, norepinephrine, and serotonin. MDMA is an agonist of a wide range of receptors; its mood-altering effects are mediated via 5-HT2A receptors; this receptor may also mediate its effects on body temperature, analgesia, and anxiolytic properties. The mechanisms underlying MDMA's entactogenic properties of sociability and interpersonal closeness are not known but release and involvement of oxytocin, a peptide thought by some to be involved in social bonding, has been suggested. Adverse effects of MDMA are mostly transient; acute multiorgan adverse effects occurring during raves or crowded dance gatherings include dehydration, hyperthermia, seizures, rhabdomyolysis, disseminated intravascular coagulation, and acute renal failure. Deaths following MDMA taken by itself are rare compared to fatalities following coadministration with other drugs. A recent FDA-approved phase 3 clinical trial of MDMA for post-traumatic stress disorder (PTSD) led to the conclusion that MDMA-assisted therapy represents a potential breakthrough treatment meriting expedited clinical evaluation. Despite the ongoing deliberations by the FDA and EMA for approval of MDMA treatment of PTSD, the Australian Therapeutic Goods Administration (TGA) recently announced that after an evaluation of the therapeutic value, benefits, and risks of MDMA, it will permit its prescribing for the treatment of PTSD. Further examples of regulatory relaxation toward MDMA-assisted psychotherapy are underway. These include the FDA's recently approved clinical trial to assess MDMA's efficacy in the treatment of "asociality" in patients with schizophrenia and an open trial of MDMA treatment for alcohol-use disorder which showed decreased alcohol consumption. There are also ongoing studies on the little understood startle response, anxiety associated with life-threatening illness, and social anxiety in autistic adults.

Contribution of analog signaling to neurotransmitter interactions and behavior: Role of transporter-mediated nonquantal dopamine release

Neuronal networks cause changes in behaviorally important information processing through the vesicular release of neurotransmitters governed by the rate and timing of action potentials (APs). Herein, we provide evidence that dopamine (DA), nonquantally released from the cytoplasm, may exert similar effects in vivo. In mouse slice preparations, (+/-)-3,4-methylenedioxy-methamphetamine (MDMA, or ecstasy) and β-phenylethylamine (β-PEA)-induced DA release in the striatum and nucleus accumbens (NAc), two regions of the brain involved in reward-driven and social behavior and inhibited the axonal stimulation-induced release of tritiated acetylcholine ([3 H]ACh) in the striatum. The DA transporter (DAT) inhibitor (GBR-12909) prevented MDMA and β-PEA from causing DA release. GBR-12909 could also restore some of the stimulated acetylcholine release reduced by MDMA or β-PEA in the striatum confirming the fundamental role of DAT. In addition, hypothermia could prevent the β-PEA-induced release in the striatum and in the NAc. Sulpiride, a D2 receptor antagonist, also prevented the inhibitory effects of MDMA or β-PEA on stimulated ACh release, suggesting they act indirectly via binding of DA. Reflecting the neurochemical interactions in brain slices at higher system level, MDMA altered the social behavior of rats by preferentially enhancing passive social behavior. Similar to the in vitro effects, GBR-12909 treatment reversed specific elements of the MDMA-induced changes in behavior, such as passive social behavior, while left others including social play unchanged. The changes in behavior by the high level of extracellular DA-- a significant amount originating from cytoplasmic release--suggest that in addition to digital computation through synapses, the brain also uses analog communication, such as DA signaling, to mediate some elements of complex behaviors, but in a much longer time scale.

Hyperacute hyponatremia mimicking acute ischemic stroke: A case report

We present a case of hyperacute hyponatremia with stroke like symptoms on presentation. Symptoms included confusion, left-sided facial droop, right-sided hemiparesis, dysarthria and aphasia, with an NIH stroke score of 5. Sodium level at the time of presentation was 119 mmol/L which dropped acutely from 138 mmol/L seven hours prior. Symptoms improved after treatment with 3% saline and no evidence of stroke, intracranial hemorrhage or space-occupying lesion was seen on imaging. The most likely cause of the hyponatremia was increased free water consumption and ADH surge. The patient remained symptom free after discharge with resolution of hyponatremia. Acute hyponatremia can cause focal neurological complaints and deficits, mimicking acute ischemic stroke. We advise clinicians to be aware of this entity when considering interventions for possible acute ischemic stroke and evaluating a patient with focal neurological deficits.

Protracted hyperthermia and delayed rhabdomyolysis in ecstasy toxicity: A case report

RATIONALE

Despite toxicity and unpredictable adverse effects, ecstasy use has increased in the United States. Onset of hyperpyrexia, rhabdomyolysis, disseminated intravascular coagulation (DIC), among other symptoms, occurs within hours of ingestion. Moreover, patients who experience hyperpyrexia, altered mental status, DIC, and multiorgan failure, rarely survive. This case presents a chronic ecstasy user whose symptoms would have predicted mortality. The report demonstrates a patient who experiences protracted hyperthermia, with delayed rhabdomyolysis and DIC. In addition, his peak creatine kinase (CK) of 409,440 U/L was far greater than the expected 30,000 to 100,000 U/L, being the second largest CK recorded in a survivor.

PATIENT CONCERNS

This case report presents a 20-year-old man who presented to the emergency department after experiencing a severe reaction to ecstasy. He was a chronic user who took his baseline dosage while performing at a music event. He experienced hyperpyrexia immediately (106.5°F) while becoming stiff and unresponsive. Before emergency medical service arrival, his friends placed cold compresses on the patient and rested him in an ice filled bathtub.

DIAGNOSES

Per history from patient's friends and toxicology results, the patient was diagnosed with ecstasy overdose, which evolved to include protracted hyperthermia and delayed rhabdomyolysis.

INTERVENTIONS

Due to a Glasgow coma scale score of 5, he was intubated and sedated with a propofol maintenance. Hyperpyrexia resolved (temperature dropped to 99.1°F) after start of propofol maintenance. He was extubated after 24 hours, upon which he experienced hyperthermia (101.4°F at 48 hours), delayed rhabdomyolysis, and DIC (onset at 37 hours). He remained in hyperthermia for 120 hours until carvedilol permanently returned his temperature to baseline. His plasma CK reached a peak of 409,440 U/L at 35 hours.

OUTCOMES

After primary management with intravenous fluids, the patient returned to baseline health without any consequences and was discharged after 8 days. A follow-up of 3 months postdischarge revealed no complications or disability.

LESSONS

Clinically, the case highlights how physicians should be aware of the unusual time course adverse effects of ecstasy can have. Lastly, as intensity and duration of hyperpyrexia are predictors of mortality, our case indicates maintenance of sedation with propofol and use of oral carvedilol; both are efficacious for temperature reduction in ecstasy toxicity.

Drinking to death: Hyponatraemia induced by synthetic phenethylamines

Synthetic phenethylamines are widely abused drugs, comprising new psychoactive substances such as synthetic cathinones, but also well-known amphetamines such as methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA, ecstasy). Cathinones and amphetamines share many toxicodynamic mechanisms. One of their potentially life-threatening consequences, particularly of MDMA, is serotonin-mediated hyponatraemia. Herein, we review the state of the art on phenethylamine-induced hyponatremia; discuss the mechanisms involved; and present the preventive and therapeutic measures. Hyponatraemia mediated by phenethylamines results from increased secretion of antidiuretic hormone (ADH) and consequent kidney water reabsorption, additionally involving diaphoresis and polydipsia. Data for MDMA suggest that acute hyponatraemia elicited by cathinones may also be a consequence of metabolic activation. The literature often reveals hyponatraemia-associated complications such as cerebral oedema, cerebellar tonsillar herniation and coma that may evolve to a fatal outcome, particularly in women. Ready availability of fluids and the recommendation to drink copiously at the rave scene to counteract hyperthermia, often precipitate water intoxication. Users should be advised about the importance of controlling fluid intake while using phenethylamines. At early signs of adverse effects, medical assistance should be promptly sought. Severe hyponatraemia (<130 mmol sodium/L plasma) may be corrected with hypertonic saline or suppression of fluid intake. Also, clinicians should be made aware of the hyponatraemic potential of these drugs and encouraged to report future cases of toxicity to increase knowledge on this potentially lethal outcome.

Designer drugs: mechanism of action and adverse effects

Psychoactive substances with chemical structures or pharmacological profiles that are similar to traditional drugs of abuse continue to emerge on the recreational drug market. Internet vendors may at least temporarily sell these so-called designer drugs without adhering to legal statutes or facing legal consequences. Overall, the mechanism of action and adverse effects of designer drugs are similar to traditional drugs of abuse. Stimulants, such as amphetamines and cathinones, primarily interact with monoamine transporters and mostly induce sympathomimetic adverse effects. Agonism at μ-opioid receptors and γ-aminobutyric acid-A (GABA_A) or GABA_B receptors mediates the pharmacological effects of sedatives, which may induce cardiorespiratory depression. Dissociative designer drugs primarily act as N-methyl-d-aspartate receptor antagonists and pose similar health risks as the medically approved dissociative anesthetic ketamine. The cannabinoid type 1 (CB₁) receptor is thought to drive the psychoactive effects of synthetic cannabinoids, which are associated with a less desirable effect profile and more severe adverse effects compared with cannabis. Serotonergic 5-hydroxytryptamine-2A (5-HT_2A) receptors mediate alterations of perception and cognition that are induced by serotonergic psychedelics. Because of their novelty, designer drugs may remain undetected by routine drug screening, thus hampering evaluations of adverse effects. Intoxication reports suggest that several designer drugs are used concurrently, posing a high risk for severe adverse effects and even death.

Metabolites of the ring-substituted stimulants MDMA, methylone and MDPV differentially affect human monoaminergic systems

BACKGROUND

Amphetamine analogs with a 3,4-methylenedioxy ring-substitution are among the most popular illicit drugs of abuse, exerting stimulant and entactogenic effects. Enzymatic N-demethylation or opening of the 3,4-methylenedioxy ring via O-demethylenation gives rise to metabolites that may be pharmacologically active. Indeed, previous studies in rats show that specific metabolites of 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxymethcathinone (methylone) and 3,4-methylenedioxypyrovalerone (MDPV) can interact with monoaminergic systems.

AIM

Interactions of metabolites of MDMA, methylone and MDPV with human monoaminergic systems were assessed.

METHODS

The ability of parent drugs and their metabolites to inhibit uptake of tritiated norepinephrine, dopamine and serotonin (5-HT) was assessed in human embryonic kidney 293 cells transfected with human monoamine transporters. Binding affinities and functional activity at monoamine transporters and various receptor subtypes were also determined.

RESULTS

MDMA and methylone displayed greater potency to inhibit norepinephrine uptake as compared to their effects on dopamine and 5-HT uptake. N-demethylation of MDMA failed to alter uptake inhibition profiles, whereas N-demethylation of methylone decreased overall transporter inhibition potencies. O-demethylenation of MDMA, methylone and MDPV resulted in catechol metabolites that maintained norepinephrine and dopamine uptake inhibition potencies, but markedly reduced activity at 5-HT uptake. O-methylation of the catechol metabolites significantly decreased norepinephrine uptake inhibition, resulting in metabolites lacking significant stimulant properties.

CONCLUSIONS

Several metabolites of MDMA, methylone and MDPV interact with human transporters and receptors at pharmacologically relevant concentrations. In particular, N-demethylated metabolites of MDMA and methylone circulate in unconjugated form and could contribute to the in vivo activity of the parent compounds in human users.

Oxytocin-dependent reopening of a social reward learning critical period with MDMA

A critical period is a developmental epoch during which the nervous system is expressly sensitive to specific environmental stimuli that are required for proper circuit organization and learning. Mechanistic characterization of critical periods has revealed an important role for exuberant brain plasticity during early development, and for constraints that are imposed on these mechanisms as the brain matures¹. In disease states, closure of critical periods limits the ability of the brain to adapt even when optimal conditions are restored. Thus, identification of manipulations that reopen critical periods has been a priority for translational neuroscience². Here we provide evidence that developmental regulation of oxytocin-mediated synaptic plasticity (long-term depression) in the nucleus accumbens establishes a critical period for social reward learning. Furthermore, we show that a single dose of (+/-)-3,4-methylendioxymethamphetamine (MDMA) reopens the critical period for social reward learning and leads to a metaplastic upregulation of oxytocin-dependent long-term depression. MDMA-induced reopening of this critical period requires activation of oxytocin receptors in the nucleus accumbens, and is recapitulated by stimulation of oxytocin terminals in the nucleus accumbens. These findings have important implications for understanding the pathogenesis of neurodevelopmental diseases that are characterized by social impairments and of disorders that respond to social influence or are the result of social injury³.

Dark Classics in Chemical Neuroscience: 3,4-Methylenedioxymethamphetamine

Better known as "ecstasy", 3,4-methylenedioxymethamphetamine (MDMA) is a small molecule that has played a prominent role in defining the ethos of today's teenagers and young adults, much like lysergic acid diethylamide (LSD) did in the 1960s. Though MDMA possesses structural similarities to compounds like amphetamine and mescaline, it produces subjective effects that are unlike any of the classical psychostimulants or hallucinogens and is one of the few compounds capable of reliably producing prosocial behavioral states. As a result, MDMA has captured the attention of recreational users, the media, artists, psychiatrists, and neuropharmacologists alike. Here, we detail the synthesis of MDMA as well as its pharmacology, metabolism, adverse effects, and potential use in medicine. Finally, we discuss its history and why it is perhaps the most important compound for the future of psychedelic science-having the potential to either facilitate new psychedelic research initiatives, or to usher in a second Dark Age for the field.

Effects of alcohol and psychostimulants on the vasopressin system: behavioral implications

Drug addiction is a chronic brain disease characterized by a compulsion to seek drugs, a loss of control with respect to drug consumption, and negative emotional states, including increased anxiety and irritability during withdrawal. Central vasopressin (AVP) and its receptors are involved in controlling social behavior, anxiety and reward, all of which are altered by drugs of abuse. Hypothalamic AVP neurons influence the stress response by modulating the hypothalamic-pituitary-adrenal (HPA) axis. The extrahypothalamic AVP system, however, is commonly associated with social recognition, motivational and anxiety responses. The specific relationship between AVP and drugs of abuse has been rarely reviewed. Here, we provide an overview of the interaction between the brain AVP system and psychostimulants and alcohol. We focus on the effects of alcohol and psychostimulants on AVP regulation of the HPA axis, their effect on the brain AVP system and their behavioral implications, the influence of the AVP system on addictive behaviors, AVP's organizational effects on the brain and consequently on behavior, and we highlight clinical studies on the relation between the AVP system and drug addiction. Finally, we discuss the data to address areas that need further research to support clinical trials and prevent drug-related disorders. This article is protected by copyright. All rights reserved.

(±)-MDMA and its enantiomers: potential therapeutic advantages of R(-)-MDMA

The use of (±)-3,4-methylenedioxymethamphetamine ((±)-MDMA) as an adjunct to psychotherapy in the treatment of psychiatric and behavioral disorders dates back over 50 years. Only in recent years have controlled and peer-reviewed preclinical and clinical studies lent support to (±)-MDMA's hypothesized clinical utility. However, the clinical utility of (±)-MDMA is potentially mitigated by a range of demonstrated adverse effects. One potential solution could lie in the individual S(+) and R(-) enantiomers that comprise (±)-MDMA. Individual enantiomers of racemic compounds have been employed in psychiatry to improve a drug's therapeutic index. Although no research has explored the individual effects of either S(+)-MDMA or R(-)-MDMA in humans in a controlled manner, preclinical research has examined similarities and differences between the two molecules and the racemic compound. This review addresses information related to the pharmacodynamics, neurotoxicity, physiological effects, and behavioral effects of S(+)-MDMA and R(-)-MDMA that might guide preclinical and clinical research. The current preclinical evidence suggests that R(-)-MDMA may provide an improved therapeutic index, maintaining the therapeutic effects of (±)-MDMA with a reduced side effect profile, and that future investigations should investigate the therapeutic potential of R(-)-MDMA.

The Non-Peptide Arginine-Vasopressin v1a Selective Receptor Antagonist, SR49059, Blocks the Rewarding, Prosocial, and Anxiolytic Effects of 3,4-Methylenedioxymethamphetamine and Its Derivatives in Zebra Fish

3,4-Methylenedioxymethamphetamine (MDMA) and its derivatives, 2,5-dimethoxy-4-bromo-amphetamine hydrobromide (DOB) and para-methoxyamphetamine (PMA), are recreational drugs whose pharmacological effects have recently been attributed to serotonin 5HT_2A/C receptors. However, there is growing evidence that the oxytocin (OT)/vasopressin system can modulate some the effects of MDMA. In this study, MDMA (2.5-10 mg/kg), DOB (0.5 mg/kg), or PMA (0.005, 0.1, or 0.25 mg/kg) were administered intramuscularly to adult zebra fish, alone or in combination with the V_1a vasopressin antagonist, SR49059 (0.01-1 ng/kg), before carrying out conditioned place preference (CPP), social preference, novel tank diving, and light-dark tests in order to evaluate subsequent rewarding, social, and emotional-like behavior. The combination of SR49059 and each drug progressively blocked: (1) rewarding behavior as measured by CPP in terms of time spent in drug-paired compartment; (2) prosocial effects measured on the basis of the time spent in the proximity of a nacre fish picture; and (3) anxiolytic effects in terms of the time spent in the upper half of the novel tank and in the white compartment of the tank used for the light-dark test. Antagonism was obtained at SR49059 doses which, when given alone, did not change motor function. In comparison with a control group, receiving vehicle alone, there was a three to five times increase in the brain release of isotocin (the analog of OT in fish) after treatment with the most active doses of MDMA (10 mg/kg), DOB (0.5 mg/kg), and PMA (0.1 mg/kg) as evaluated by means of bioanalytical reversed-phase high-performance liquid chromatography. Taken together, these findings show that the OT/vasopressin system is involved in the rewarding, prosocial, and anxiolytic effects of MDMA, DOB, and PMA in zebra fish and underline the association between this system and the behavioral alterations associated with disorders related to substance abuse.

Ecstasy (MDMA) and its effects on kidneys and their treatment: a review

Ecstasy (MDMA; 3,4-methylenedioxymethylamphetamine) is an illicit drug that has been increasingly abused by young people. Its effects include euphoria, enhanced sociability and heightened mental awareness. These come about via the increase of serotonin in both the central nervous system and the sympathetic nervous system. Despite the drug's prevalent abuse, serious or adverse effects are rare. Due to personal pharmacokinetics, effects from the same dosage vary according to the individual. Fatal instances may include acute hyponatremia, hyperthermia (>42 °C), disseminated intravascular coagulation (DIC) resulting from hyperthermia affecting the kidneys, and non-traumatic rhabdomyolysis. However, it is seldom the case that hyponatremia and hyperthermia co-exist. Hyponatremia is thought to be caused by HMMA - a metabolite of MDMA. Hyponatremia is caused by the inappropriate secretion of arginine vasopressin (AVP) and the excessive intake of hypotonic liquid accompanied by increased hyperthermia. Symptomatic, even deadly hyponatremia is seen more frequently in females, with the effects of oestrogen on arginine vasopressin believed to be the cause. Onset in such cases is acute, and treatment should be given to symptomatic patients as quickly as possible, with 3% saline administered when necessary. Reasons for acute kidney injury may include rhabdomyolysis, malign hypertension, and necrotizing vasculitis.

MDMA Impairs Response to Water Intake in Healthy Volunteers

Hyponatremia is a serious complication of 3,4-methylenedioxymethamphetamine (MDMA) use. We investigated potential mechanisms in two double-blind, placebo-controlled studies. In Study 1, healthy drug-experienced volunteers received MDMA or placebo alone and in combination with the alpha-1 adrenergic inverse agonist prazosin, used as a positive control to release antidiuretic hormone (ADH). In Study 2, volunteers received MDMA or placebo followed by standardized water intake. MDMA lowered serum sodium but did not increase ADH or copeptin, although the control prazosin did increase ADH. Water loading reduced serum sodium more after MDMA than after placebo. There was a trend for women to have lower baseline serum sodium than men, but there were no significant interactions with drug condition. Combining studies, MDMA potentiated the ability of water to lower serum sodium. Thus, hyponatremia appears to be a significant risk when hypotonic fluids are consumed during MDMA use. Clinical trials and events where MDMA use is common should anticipate and mitigate this risk.

Nephrotoxic effects of common and emerging drugs of abuse

The kidneys can be injured in diverse ways by many drugs, both legal and illegal. Novel associations and descriptions of nephrotoxic effects of common and emerging drugs of abuse have appeared over the past several years. Anabolic androgenic steroids, illicitly used by athletes and others for decades to increase muscle mass and decrease body fat, are emerging as podocyte toxins given recent descriptions of severe forms of FSGS in long-term abusers. Synthetic cannabinoids, a new group of compounds with marijuana-like effects, recently became popular as recreational drugs and have been associated with an atypical form of AKI. 3,4-Methylenedioxymethamphetamine, commonly known as ecstasy, is a widely used synthetic recreational drug with mood-enhancing properties and a constellation of toxicities that can result in death. These toxic effects include hyperthermia, hypotonic hyponatremia due to its arginine vasopressin secretagogue-like effects, rhabdomyolysis, and cardiovascular collapse. Cocaine, a serotonin-norepinephrine-dopamine reuptake inhibitor that serves as an illegal stimulant, appetite suppressant, and anesthetic, also causes vasoconstriction and rhabdomyolysis. Recent adulteration of much of the world's supply of cocaine with levamisole, an antihelminthic agent with attributes similar to but distinct from those of cocaine, appears to have spawned a new type of ANCA-associated systemic vasculitis. This review discusses the nephrotoxic effects of these common and emerging drugs of abuse, of which both community and health care providers should become aware given their widespread abuse. Future investigation into pathogenetic mechanisms associated with these drugs is critical and may provide a window into ways to lessen and even prevent the nephrotoxic effects of these drugs of abuse and perhaps allow a deeper understanding of the nephrotoxicities themselves.

Disorders of sodium and water balance

Dysnatremias occur simultaneously with disorders in water balance. The first priority is to correct dehydration; once the patient is euvolemic, the sodium level can be reassessed. In unstable patients with hyponatremia, the clinician should rapidly administer hypertonic saline. In unstable patients with hypernatremia, the clinician should administer isotonic intravenous fluid. In stable patients with either hyponatremia or hypernatremia, the clinician should aim for correction over 24 to 48 hours, with the maximal change in serum sodium between 8 to 12 mEq/L over the first 24 hours. This rate of correction decreases the chances of cerebral edema or osmotic demyelination syndrome.

High incidence of mild hyponatraemia in females using ecstasy at a rave party

BACKGROUND

Globally, millions of subjects regularly use ecstasy, a drug popular due to its empathogenic and entactogenic effects. Dilutional hyponatraemia, mainly caused by direct stimulation of antidiuretic hormone (ADH) secretion by ecstasy, is among the many side effects of the drug (active substance 3, 4-methylenedioxymethamphetamine, MDMA). Severe, symptomatic hyponatraemia related to the use of MDMA has been reported in more than 30 cases. The mortality of this complication is high and mainly females are involved. Dramatic cases that reach the literature probably represent the tip of the iceberg. We decided to study the incidence of hyponatraemia in subjects using MDMA at an indoor rave party.

METHODS

The study was performed at the indoor event 'Awakenings', held in Amsterdam in the fall of 2010. The plasma sodium concentration was measured at the party using a point of care method in 63 subjects using MDMA and 44 controls. The use of MDMA was confirmed by a urine test.

RESULTS

The plasma sodium concentration in subjects using MDMA was significantly lower than in those not using the drug (138 ± 2 mmol/L versus 140 ± 2 mmol/L, respectively, P < 0.001). The overall incidence of hyponatraemia, defined as a plasma sodium concentration <136 mmol/L, was 14.3% in MDMA users (9/63 subjects). Most cases of hyponatraemia occurred in females, in whom the incidence was 26.7% (8 of 30 females), with lowest values of 133 mmol/L. The number of ecstasy pills ingested by the females developing hyponatraemia was not different from that ingested by those who did not develop this complication. Fluid intake in ecstasy users exceeded that of non-users, suggesting a dipsogenic effect of the drug.

CONCLUSIONS

Only 3% of males, but no less than ∼25% of females attending a rave party and using MDMA developed mild hyponatraemia during the event. Especially females are therefore probably also at risk of developing severe symptomatic hyponatraemia. Not using MDMA is obviously the best option to prevent MDMA-induced hyponatraemia. However, accepting the fact that millions use the drug every weekend, strategies should also be developed to prevent hyponatraemia in subjects choosing to take MDMA. This would include matching the electrolyte content of the fluids and food ingested to that of the fluids that are lost during the use of MDMA, mainly by perspiration. Users of MDMA and emergency health care workers should become more aware of the relatively high incidence of MDMA-induced hyponatraemia and of potential strategies to prevent this complication.

A brief history of oxytocin and its role in modulating psychostimulant effects

Over the past century, the polypeptide oxytocin has played an important role in medicine with major highlights including the identification of its involvement in parturition and the milk let-down reflex. Oxytocin is now implicated in an extensive range of psychological phenomena including reward and memory processes and has been investigated as a treatment for several psychiatric disorders including addiction, anxiety, autism, and schizophrenia. In this review, we first provide an historical overview of oxytocin and describe key aspects of its physiological activity. We then outline some pharmacological limitations in this field of research before highlighting the role of oxytocin in a wide range of behavioral and neuronal processes. Finally, we review evidence for a modulatory role of oxytocin with regard to psychostimulant effects. Key findings suggest that oxytocin attenuates a broad number of cocaine and methamphetamine induced behaviors and associated neuronal activity in rodents. Evidence also outlines a role for oxytocin in the prosocial effects of 3,4-methylenedioxymethamphetamine (MDMA, Ecstasy) in both rodents and humans. Clinical trials should now investigate the effectiveness of oxytocin as a novel intervention for psychostimulant addiction and should aim to determine its specific role in the therapeutic properties of MDMA that are currently being investigated.

MDMA enhances "mind reading" of positive emotions and impairs "mind reading" of negative emotions

RATIONALE

3,4-Methylenedioxymethamphetamine (MDMA, ecstasy) increases sociability. The prosocial effects of MDMA may result from the release of the "social hormone" oxytocin and associated alterations in the processing of socioemotional stimuli.

MATERIALS AND METHODS

We investigated the effects of MDMA (125 mg) on the ability to infer the mental states of others from social cues of the eye region in the Reading the Mind in the Eyes Test. The study included 48 healthy volunteers (24 men, 24 women) and used a double-blind, placebo-controlled, within-subjects design. A choice reaction time test was used to exclude impairments in psychomotor function. We also measured circulating oxytocin and cortisol levels and subjective drug effects.

RESULTS

MDMA differentially affected mind reading depending on the emotional valence of the stimuli. MDMA enhanced the accuracy of mental state decoding for positive stimuli (e.g., friendly), impaired mind reading for negative stimuli (e.g., hostile), and had no effect on mind reading for neutral stimuli (e.g., reflective). MDMA did not affect psychomotor performance, increased circulating oxytocin and cortisol levels, and produced subjective prosocial effects, including feelings of being more open, talkative, and closer to others.

CONCLUSIONS

The shift in the ability to correctly read socioemotional information toward stimuli associated with positive emotional valence, together with the prosocial feelings elicited by MDMA, may enhance social approach behavior and sociability when MDMA is used recreationally and facilitate therapeutic relationships in MDMA-assisted psychotherapeutic settings.

Breaking the loop: oxytocin as a potential treatment for drug addiction

Drug use typically occurs within a social context, and social factors play an important role in the initiation, maintenance and recovery from addictions. There is now accumulating evidence of an interaction between the neural substrates of affiliative behavior and those of drug reward, with a role for brain oxytocin systems in modulating acute and long-term drug effects. Early research in this field indicated that exogenous oxytocin administration can prevent development of tolerance to ethanol and opiates, the induction of stereotyped, hyperactive behavior by stimulants, and the withdrawal symptoms associated with sudden abstinence from drugs and alcohol. Additionally, stimulation of endogenous oxytocin systems is a key neurochemical substrate underlying the prosocial and empathogenic effects of party drugs such as MDMA (Ecstasy) and GHB (Fantasy). Brain oxytocin systems exhibit profound neuroplasticity and undergo major neuroadaptations as a result of drug exposure. Many drugs, including cocaine, opiates, alcohol, cannabis, MDMA and GHB cause long-term changes in markers of oxytocin function and this may be linked to enduring deficits in social behavior that are commonly observed in laboratory animals repeatedly exposed to these drugs. Very recent preclinical studies have illustrated a remarkable ability of exogenously delivered oxytocin to inhibit stimulant and alcohol self-administration, to alter associated drug-induced changes in dopamine, glutamate and Fos expression in cortical and basal ganglia sites, and to prevent stress and priming-induced relapse to drug seeking. Oxytocin therefore has fascinating potential to reverse the corrosive effects of long-term drugs abuse on social behavior and to perhaps inoculate against future vulnerability to addictive disorders. The results of clinical studies examining intranasal oxytocin effects in humans with drug use disorders are eagerly awaited. This article is part of a Special Issue entitled Oxytocin, Vasopressin, and Social Behavior.

Dissociation of corticotropin-releasing factor receptor subtype involvement in sensitivity to locomotor effects of methamphetamine and cocaine

RATIONALE

Enhanced sensitivity to the euphoric and locomotor-activating effects of psychostimulants may influence an individual's predisposition to drug abuse and addiction. While drug-induced behaviors are mediated by the actions of several neurotransmitter systems, past research revealed that the corticotropin-releasing factor (CRF) system is important in driving the acute locomotor response to psychostimulants.

OBJECTIVES

We previously reported that genetic deletion of the CRF type-2 receptor (CRF-R2), but not the CRF type-1 receptor (CRF-R1) dampened the acute locomotor stimulant response to methamphetamine (1 mg/kg). These results contrasted with previous studies implicating CRF-R1 in the locomotor effects of psychostimulants. Since the majority of previous studies focused on cocaine, rather than methamphetamine, we set out to test the hypothesis that these drugs differentially engage CRF-R1 and CRF-R2.

METHODS

We expanded our earlier findings by first replicating our previous experiments at a higher dose of methamphetamine (2 mg/kg), and by assessing the effects of the CRF-R1-selective antagonist CP-376,395 (10 mg/kg) on methamphetamine-induced locomotor activity. Next, we used both genetic and pharmacological tools to examine the specific components of the CRF system underlying the acute locomotor response to cocaine (5-10 mg/kg).

RESULTS

While genetic deletion of CRF-R2 dampened the locomotor response to methamphetamine (but not cocaine), genetic deletion and pharmacological blockade of CRF-R1 dampened the locomotor response to cocaine (but not methamphetamine).

CONCLUSIONS

These findings highlight the differential involvement of CRF receptors in acute sensitivity to two different stimulant drugs of abuse, providing an intriguing basis for the development of more targeted therapeutics for psychostimulant addiction.

Effects of MDMA and related analogs on plasma 5-HT: relevance to 5-HT transporters in blood and brain

(±)-3,4-Methylenedioxymethamphetamine (MDMA) is an illicit drug that evokes transporter-mediated release of serotonin (5-HT) in the brain. 5-HT transporter (SERT) proteins are also expressed in non-neural tissues (e.g., blood), and evidence suggests that MDMA targets platelet SERT to increase plasma 5-HT. Here we tested two hypotheses related to the effects of MDMA on circulating 5-HT. First, to determine if MDMA metabolites might contribute to actions of the drug in vivo, we used in vitro microdialysis in rat blood specimens to examine the effects of MDMA and its metabolites on plasma 5-HT. Second, to determine whether effects of MDMA on plasma 5-HT might be used as an index of central SERT activity, we carried out in vivo microdialysis in blood and brain after intravenous MDMA administration. The in vitro results show that test drugs evoke dose-related increases in plasma 5-HT ranging from two- to sevenfold above baseline, with MDMA and its metabolite, (±)-3,4-methylenedioxyamphetamine (MDA), producing the largest effects. The ability of MDMA and related analogs to elevate plasma 5-HT is correlated with their potency as SERT substrates in rat brain synaptosomes. The in vivo results reveal that MDMA causes concurrent increases in extracellular 5-HT in blood and brain, but there are substantial individual differences in responsiveness to the drug. Collectively, our findings indicate that MDMA and its metabolites increase plasma 5-HT by a SERT-dependent mechanism, and suggest the possibility that measures of evoked 5-HT release in blood may reflect central SERT activity.

Examining the role of oxytocin in the interoceptive effects of 3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy') using a drug discrimination paradigm in the rat

3,4-Methylenedioxymethamphetamine (MDMA, 'ecstasy') use results in distinctive mood changes of a prosocial nature, most likely through its enhancement of serotonin (5HT) neurotransmission. Activation of 5HT-1A postsynaptic receptors has been shown to stimulate the release of oxytocin in the central nervous system where it regulates aspects of mood and behavior. Using a drug discrimination paradigm, we examined whether modulation of oxytocin receptor activity would affect conditioned behavioral responses to MDMA. Male and female Sprague Dawley rats (n=24) were trained to reliably differentiate between MDMA and a related stimulant, amphetamine (AMP), and saline using a three-lever drug discrimination paradigm. The extent to which substitution with carbetocin (an oxytocin analog) or co-administration with atosiban (an oxytocin receptor antagonist) affected drug-appropriate responding was evaluated. The tricyclic antidepressant imipramine was included as a negative control. The results supported the hypotheses that substitution with an oxytocin analog (carbetocin) would partially generalize to the MDMA training cue, whereas blocking oxytocin receptors with atosiban would result in a selective disruption of MDMA--but not AMP-appropriate responding. These findings were specific to the oxytocin receptor ligands as imipramine pre-treatment did not affect drug-appropriate responding. The results of this study implicate oxytocin receptor activation as a key MDMA-specific interoceptive cue in male and female rats and support the conclusion that this is one of the features of MDMA's subjective effects that distinguishes it from AMP.

Residual social, memory and oxytocin-related changes in rats following repeated exposure to γ-hydroxybutyrate (GHB), 3,4-methylenedioxymethamphetamine (MDMA) or their combination

RATIONALE

There has been little investigation of the possible lasting adverse effects of γ-hydroxybutyrate (GHB).

OBJECTIVES

This study aims to study whether GHB produces residual adverse effects on memory and social behaviour in rats and lasting changes in brain monoamines and oxytocin-related gene expression.

METHODS

Rats received daily intraperitoneal injections of GHB (500 mg/kg), methylenedioxymethamphetamine (MDMA; 5 mg/kg) or their combination (GHB/MDMA) over ten consecutive days. Locomotor activity and body weight were assessed during the dosing period and withdrawal-related anxiety was assessed 24 h after drug cessation. After a washout of 4 weeks, rats were tested on the emergence, social interaction, and object recognition tasks over a 2-week period. Monoamine levels in cortex and striatum, and hypothalamic oxytocin and oxytocin receptor mRNA, were then assessed.

RESULTS

MDMA and GHB/MDMA caused modest sensitization of locomotor activity over time, while sedative effects of GHB diminished with repeated exposure. GHB-treated rats showed reduced social interaction 24 h after the final dose, indicating GHB withdrawal-induced anxiety. All drug-treated groups displayed residual deficits in social interaction and object recognition. No changes in monoamine levels were detected 8 weeks post-drug. However, MDMA pre-exposure increased hypothalamic oxytocin mRNA while GHB pre-exposure upregulated oxytocin receptor mRNA. GHB/MDMA pre-exposure caused intermediate changes in both of these measures.

CONCLUSIONS

GHB treatment caused residual impairments in memory and social behaviour and increases in anxiety, paralleling the lasting adverse effects of MDMA. Both drugs caused lasting neuroadaptations in brain oxytocin systems and this may be related to the long-term social interaction deficiencies caused by both drugs.

Neural and cardiac toxicities associated with 3,4-methylenedioxymethamphetamine (MDMA)

(+/-)-3,4-Methylenedioxymethamphetamine (MDMA) is a commonly abused illicit drug which affects multiple organ systems. In animals, high-dose administration of MDMA produces deficits in serotonin (5-HT) neurons (e.g., depletion of forebrain 5-HT) that have been viewed as neurotoxicity. Recent data implicate MDMA in the development of valvular heart disease (VHD). The present paper reviews several issues related to MDMA-associated neural and cardiac toxicities. The hypothesis of MDMA neurotoxicity in rats is evaluated in terms of the effects of MDMA on monoamine neurons, the use of scaling methods to extrapolate MDMA doses across species, and functional consequences of MDMA exposure. A potential treatment regimen (l-5-hydroxytryptophan plus carbidopa) for MDMA-associated neural deficits is discussed. The pathogenesis of MDMA-associated VHD is reviewed with specific reference to the role of valvular 5-HT(2B) receptors. We conclude that pharmacological effects of MDMA occur at the same doses in rats and humans. High doses of MDMA that produce 5-HT depletions in rats are associated with tolerance and impaired 5-HT release. Doses of MDMA that fail to deplete 5-HT in rats can cause persistent behavioral dysfunction, suggesting even moderate doses may pose risks. Finally, the MDMA metabolite, 3,4-methylenedioxyamphetamine (MDA), is a potent 5-HT(2B) agonist which could contribute to the increased risk of VHD observed in heavy MDMA users.

The agony of ecstasy: MDMA (3,4-methylenedioxymethamphetamine) and the kidney

Ecstasy (MDMA, 3,4-methylenedioxymethamphetamine) is commonly used by college-aged individuals. Ecstasy leads to feelings of euphoria, emotional empathy, and increased energy. These effects come at a significant risk for complications. Ecstasy has been associated with acute kidney injury that is most commonly secondary to nontraumatic rhabdomyolysis but also has been reported in the setting of drug-induced liver failure and drug-induced vasculitis. More common, ecstasy has led to serious hyponatremia and hyponatremia-associated deaths. Hyponatremia in these cases is due to a "perfect storm" of ecstasy-induced effects on water balance. Ecstasy leads to secretion of arginine vasopressin as well as polydipsia as a result of its effects on the serotonergic nervous pathways. Compounding these effects are the ready availability of fluids and the recommendation to drink copiously at rave parties where ecstasy is used. The effects of ecstasy on the kidney as well as therapeutic measures for the treatment of ecstasy-induced hyponatremia are presented.

Developmental effects of 3,4-methylenedioxymethamphetamine: a review

+/-3,4-Methylenedioxymethamphetamine (MDMA) is a chemical derivative of amphetamine that has become a popular drug of abuse and has been shown to deplete serotonin in the brains of users and animals exposed to it. To date, most studies have investigated the effects of MDMA on adult animals. With a majority of users of MDMA being young adults, the chances of the users becoming pregnant and exposing the fetuses to MDMA are also a concern. Evidence to date has shown that developmental exposure to MDMA results in learning and memory impairments in the Morris water maze, a task known to be sensitive to hippocampal disruption, when the animals are tested as adults. Developmental MDMA exposure leads to hypoactivity in the offspring as adults but does not affect outcome on tests of anxiety. MDMA administration decreases pup weight, increases corticosterone and brain-derived neurotrophic factor levels during treatment while decreasing brain levels of serotonin; a decrease that initially dissipates and then reappears in adulthood. Neonatal MDMA exposure increases the sensitivity of the serotonin 1A receptor, a possible mechanism underlying the learning and memory deficits seen. Taken together, the evidence shows that MDMA exposure has adverse effects on the developing brain and behavior. The animal and human data on developmental MDMA exposure are reviewed and their public health implications discussed.

Comparative potencies of 3,4-methylenedioxymethamphetamine (MDMA) analogues as inhibitors of [3H]noradrenaline and [3H]5-HT transport in mammalian cell lines

BACKGROUND AND PURPOSE

Illegal 'ecstasy' tablets frequently contain 3,4-methylenedioxymethamphetamine (MDMA)-like compounds of unknown pharmacological activity. Since monoamine transporters are one of the primary targets of MDMA action in the brain, a number of MDMA analogues have been tested for their ability to inhibit [3H]noradrenaline uptake into rat PC12 cells expressing the noradrenaline transporter (NET) and [3H]5-HT uptake into HEK293 cells stably transfected with the 5-HT transporter (SERT).

EXPERIMENTAL APPROACH

Concentration-response curves for the following compounds at both NET and SERT were determined under saturating substrate conditions: 4-hydroxy-3-methoxyamphetamine (HMA), 4-hydroxy-3-methoxymethamphetamine (HMMA), 3,4-methylenedioxy-N-hydroxyamphetamine (MDOH), 2,5-dimethoxy-4-bromophenylethylamine (2CB), 3,4-dimethoxymethamphetamine (DMMA), 3,4-methylenedioxyphenyl-2-butanamine (BDB), 3,4-methylenedioxyphenyl-N-methyl-2-butanamine (MBDB) and 2,3-methylenedioxymethamphetamine (2,3-MDMA).

KEY RESULTS

2,3-MDMA was significantly less potent than MDMA at SERT, but equipotent with MDMA at NET. 2CB and BDB were both significantly less potent than MDMA at NET, but equipotent with MDMA at SERT. MBDB, DMMA, MDOH and the MDMA metabolites HMA and HMMA, were all significantly less potent than MDMA at both NET and SERT.

CONCLUSIONS AND IMPLICATIONS

This study provides an important insight into the structural requirements of MDMA analogue affinity at both NET and SERT. It is anticipated that these results will facilitate understanding of the likely pharmacological actions of structural analogues of MDMA.

A role for oxytocin and 5-HT(1A) receptors in the prosocial effects of 3,4 methylenedioxymethamphetamine ("ecstasy")

The drug 3,4 methylenedioxymethamphetamine (MDMA; ecstasy) has a widely documented ability to increase feelings of love and closeness toward others. The present study investigated whether oxytocin, a neuropeptide involved in affiliative behavior, may play a role in this effect. A moderate (5 mg/kg, i.p.) dose of MDMA increased social interaction in male Wistar rats, primarily by increasing the amount of time rats spent lying adjacent to each other. MDMA (5 mg/kg) activated oxytocin-containing neurons in the supraoptic and paraventricular nuclei of the hypothalamus, as shown by Fos immunohistochemistry. MDMA (5 mg/kg i.p.) also increased plasma oxytocin levels and this effect was prevented by pre-treatment with the 5-HT(1A) antagonist N-[2-[4-(2-methyoxyphenyl)-1-piperazinyl]ethyl]-N-2-pyridinylcyclohexanecarboxamide maleate salt (WAY 100,635; 1 mg/kg i.p.). The oxytocin receptor antagonist tocinoic acid (20 microg, i.c.v.) had no effect on social behavior when given alone but significantly attenuated the facilitation of social interaction produced by MDMA (5 mg/kg). The 5-HT(1A) agonist 8-hydroxy-2-(di-n-propylamino)-tetraline) (8-OH-DPAT, 0.25 mg/kg, i.p.) increased social behavior in a similar way to MDMA and this effect was also significantly attenuated by tocinoic acid. Taken together, these results suggest that oxytocin release, stimulated by MDMA through 5-HT(1A) receptors, may play a key role in the prosocial effects of MDMA and underlie some of the reinforcing effects of the drug.

Patterns of Ecstasy-Associated Hyponatremia in California

STUDY OBJECTIVE

We describe the clinical characteristics of patients with ecstasy- (3,4-methylenedioxymethamphetamine [MDMA]) associated hyponatremia (serum sodium level <130 mmol/L) reported to the California Poison Control System during a 5-year period and determine whether a sex difference exists among patients with ecstasy-associated hyponatremia and hyponatremia-associated adverse outcomes.

METHODS

We performed a retrospective review of cases involving ecstasy intoxication reported to the California Poison Control System and recorded in its computerized database from January 1, 2000, through October 9, 2005. We excluded cases that did not involve MDMA exposure or in which there were no symptoms or were minimal effects only. Confirmation of exposure to MDMA was based on history of use and, when available, urine toxicology testing results positive for MDMA or amphetamine derivatives. Hyponatremia was defined as a measured serum sodium level less than 130 mmol/L.

RESULTS

A total of 1,436 cases potentially involving ecstasy were reported to the California Poison Control System during the 5-year study period, of which 891 were excluded according to the criteria described above. Of the 545 cases that met inclusion criteria, 296 (54.3%) were women and 249 (45.7%) were men. There were 188 cases (34.5%) with a documented serum sodium level, of which 73 (38.8%) reported hyponatremia (Na <130 mmol/L). Of the 73 subjects with hyponatremia, 55 (75.3%) were women and 18 (24.7%) men; of the 115 nonhyponatremic subjects, 50 (43.5%) were women and 65 (56.5%) were men. Among patients with a documented serum sodium level, female sex was associated with increased odds of hyponatremia (odds ratio [OR] 4.0; 95% confidence interval [CI] 2.1 to 7.6). Among women, those with hyponatremia demonstrated increased odds of coma (OR 3.9; 95% CI 1.2 to 12.9), whereas among men, no increased odds of hyponatremia-associated coma were observed (OR 0.8; 95% CI 0.15 to 4.0).

CONCLUSION

Female sex was associated with increased odds of hyponatremia and increased odds of hyponatremia-associated coma among persons with ecstasy intoxication and a documented serum sodium level reported to the California Poison Control System from 2000 to 2005. Multiple potential confounders, including spectrum bias, incomplete laboratory data, and individual differences in study subject characteristics, prevent determination of causality about sex differences in the incidence of ecstasy-associated hyponatremia and its complications.

CYP2D6 increases toxicity of the designer drug 4-methylthioamphetamine (4-MTA)

4-Methylthioamphetamine (4-MTA) belongs to a group of new amphetamine derivatives that is usually sold as "ecstasy" or "flatliners" on the illicit drug market. Large interindividual differences in 4-MTA mediated toxicity have been reported in humans. Therefore, we tested whether CYP2D6 or its variant alleles as well as CYP3A4 influence the susceptibility to 4-MTA. For this purpose, we used the colony formation assay with Chinese hamster lung fibroblast V79 cells expressing human wild-type CYP2D6 (CYP2D6*1), the low activity alleles CYP2D6*2, CYP2D6*9, as well as human CYP3A4. The obtained results showed that the expression of wild type CYP2D6*1 clearly enhanced the susceptibility to the cytotoxic effects of 4-MTA compared with the parental cells devoid of CYP-dependent enzymatic activity. Toxicity in V79 CYP2D6*1 was also higher compared to the V79 cell lines expressing the low activity alleles CYP2D6*2 and CYP2D6*9. In contrast to CYP2D6, the CYP3A4 isoenzyme did not enhance 4-MTA toxicity. In conclusion, our results suggest that CYP2D6 rapid metabolizers may be more susceptible to 4-MTA toxicity than CYP2D6 poor metabolizers.

3,4-Methylenedioxymethamphetamine (MDMA) neurotoxicity in rats: a reappraisal of past and present findings

RATIONALE

3,4-Methylenedioxymethamphetamine (MDMA) is a widely abused illicit drug. In animals, high-dose administration of MDMA produces deficits in serotonin (5-HT) neurons (e.g., depletion of forebrain 5-HT) that have been interpreted as neurotoxicity. Whether such 5-HT deficits reflect neuronal damage is a matter of ongoing debate.

OBJECTIVE

The present paper reviews four specific issues related to the hypothesis of MDMA neurotoxicity in rats: (1) the effects of MDMA on monoamine neurons, (2) the use of "interspecies scaling" to adjust MDMA doses across species, (3) the effects of MDMA on established markers of neuronal damage, and (4) functional impairments associated with MDMA-induced 5-HT depletions.

RESULTS

MDMA is a substrate for monoamine transporters, and stimulated release of 5-HT, NE, and DA mediates effects of the drug. MDMA produces neurochemical, endocrine, and behavioral actions in rats and humans at equivalent doses (e.g., 1-2 mg/kg), suggesting that there is no reason to adjust doses between these species. Typical doses of MDMA causing long-term 5-HT depletions in rats (e.g., 10-20 mg/kg) do not reliably increase markers of neurotoxic damage such as cell death, silver staining, or reactive gliosis. MDMA-induced 5-HT depletions are accompanied by a number of functional consequences including reductions in evoked 5-HT release and changes in hormone secretion. Perhaps more importantly, administration of MDMA to rats induces persistent anxiety-like behaviors in the absence of measurable 5-HT deficits.

CONCLUSIONS

MDMA-induced 5-HT depletions are not necessarily synonymous with neurotoxic damage. However, doses of MDMA which do not cause long-term 5-HT depletions can have protracted effects on behavior, suggesting even moderate doses of the drug may pose risks.

Influence of CYP2D6 polymorphism on 3,4-methylenedioxymethamphetamine (‘Ecstasy’) cytotoxicity

OBJECTIVES

Remarkable interindividual differences in 3,4-methylenedioxymethamphetamine ('Ecstasy')-mediated toxicity have been reported in humans. Therefore, we tested whether CYP2D6 or its variant alleles as well as CYP3A4 influence the susceptibility to 3,4-methylenedioxymethamphetamine.

METHODS

3,4-Methylenedioxymethamphetamine cytotoxicity was determined in V79 cells expressing human wild-type CYP2D6 (CYP2D6*1), the low-activity alleles CYP2D6*2, *9, *10, and *17, as well as human CYP3A4. Metabolites of 3,4-methylenedioxymethamphetamine formed by the different cell lines were quantified by high-performance liquid chromatography/electrochemical detector.

RESULTS

Toxicity of 3,4-methylenedioxymethamphetamine was clearly increased in cells expressing CYP2D6*1 compared with the parental cells devoid of CYP-dependent enzymatic activity. Toxicity in V79 CYP2D6*1 cells was also higher than in V79 cell lines expressing the low-activity alleles CYP2D6*2, *9, *10, or *17. In contrast to CYP2D6, the CYP3A4 isoenzyme did not enhance 3,4-methylenedioxymethamphetamine toxicity. Formation of the oxidative 3,4-methylenedioxymethamphetamine metabolite N-methyl-alpha-methyldopamine was greatly enhanced in V79 cell line transfected with CYP2D6*1 compared to all other cell lines. The increase in the cytotoxic effects of 3,4-methylenedioxymethamphetamine observed in this cell line was therefore suspected to be a consequence of the production of this metabolite. This was further investigated by testing the cytotoxicity of N-methyl-alpha-methyldopamine to the control cell line. The results confirmed our hypothesis as the metabolite proved to be more than 100-fold more toxic than the parent compound 3,4-methylenedioxymethamphetamine.

CONCLUSIONS

CYP2D6*1 mediates 3,4-methylenedioxymethamphetamine toxicity via formation of N-methyl-alpha-methyldopamine. Therefore, it will be important to investigate whether CYP2D6 ultrarapid metabolizers are overrepresented in the cases of 3,4-methylenedioxymethamphetamine intoxications.

Synthesis and Cytotoxic Profile of 3,4-Methylenedioxymethamphetamine (“Ecstasy”) and Its Metabolites on Undifferentiated PC12 Cells: A Putative Structure−Toxicity Relationship

The toxicological and redox profiles of MDMA and its major metabolites (MDA, alpha-methyldopamine, N-methyl-alpha-methyldopamine, 6-hydroxy-alpha-methyldopamine, 3-methoxy-alpha-methyldopamine) were studied to establish a structure-toxicity relationship and determine their individual contribution to cell death induction by apoptosis and/or necrosis. The results of the comparative toxicity study, using undifferentiated PC12 cells, strongly suggest that the metabolites possessing a catecholic group are more toxic to the cells than MDMA and metabolites with at least one protected phenolic group. Redox studies reveal that an oxidative mechanism seems to play an important role in metabolite cytotoxicity. Nuclear features of apoptosis and/or necrosis show that most of the metabolites, particularly N-methyl-alpha-methyldopamine, induce cell death by apoptosis, largely accompanied by necrotic features. No significant differences were found between MDMA and the metabolites, concerning overall characteristics of cell death. These results may be useful to ascertain the contribution of metabolism in MDMA neurotoxicity molecular mechanisms.

Ecstasy (MDMA, MDA, MDEA, MBDB) consumption, seizures, related offences, prices, dosage levels and deaths in the UK (1994-2003)

In the last decade, a global trend of escalating ecstasy (MDMA, MDA, MDEA, MBDB) use was observed. Mentions on medical death certificates, last year's ecstasy use, number of drug offenders, seizures, prices and dosage levels figures were used for this descriptive and correlational study. Figures (1994-2003) were taken from the UK General Mortality Registers, from the Home Office Statistical Bulletins, from the British Crime Survey and from those reported to both the National Crime Intelligence and Forensic Science Services. A total of 394 ecstasy deaths mentions were here identified from the UK; in 42% of cases ecstasy was the sole drug mentioned. Overall, number of fatalities showed a year-per-year increase and positively correlated with: prevalence of last year's use (p < 0.01); number of offenders (p < 0.01) and number of seizures (p < 0.01) but negatively correlated with ecstasy price (p < 0.05). Price negatively correlated with: prevalence of last year's use (p < 0.001) and number of seizures (p < 0.01); but positively correlated with average MDMA dosage per tablet (p < 0.01). MDA, MDEA and MBDB accounted for a significant proportion of tablets only up to 1997, but not afterwards. Increasing production with a concomitant decrease in ecstasy price may have facilitated an increase in consumption levels and this, in turn, may have determined an increase in number of ecstasy deaths mentions. Only medical death certificates and not coroners' reports at the end of their inquests were here analysed; no data were available in respect of other drugs use and toxicology results.

Vasopressin and oxytocin secretion in response to the consumption of ecstasy in a clubbing population

Despite the common use of MDMA (ecstasy) in the UK, the mechanism underlying associated potentially fatal cerebral oedema is unclear. We used a new experimental approach working directly with clubbers to perform a study on 30 (17 male) experienced clubbers (mean 6.6 years of clubbing). Pre- and post-clubbing measurements were performed to compare plasma levels of pituitary hormones (vasopressin, oxytocin), plasma and urine osmolality, urinary pH, and plasma sodium and urea. Ecstasy consumption was confirmed by using urinary drug screening pre- and post-clubbing. MDMA was detected in the urine samples of 17 subjects, three of which tested positive during pre-clubbing tests. Mean plasma vasopressin concentration increased in the MDMA group (1.28 +/- 0.29 to 1.43 +/- 0.41 pmol/l), but fell in other participants (1.23 +/- 0.42 to 1.16 +/- 0.0.34 pmol/l). Similarly, mean plasma oxytocin concentrations increased after ingestion of MDMA (2.02 +/- 0.29 to 2.43 +/- 0.24 pmol/l), but fell in the group that did not use MDMA (2.17 +/- 0.36 pmol/l to 1.89 +/- 0.37 pmol/l). There was a significant group by time interaction for plasma osmolality and plasma sodium (p = 0.001 and p = 0.003, respectively) and between change in urinary osmolality (p < 0.001) and MDMA use, with the pattern of change being consistent with the induction of inappropriate vasopressin secretion (also known as SIADH) by MDMA. This report demonstrates SIADH in ecstasy-using "clubbers", which has important clinical implications.

Repeated MDMA ("Ecstasy") exposure in adolescent male rats alters temperature regulation, spontaneous motor activity, attention, and serotonin transporter binding

Previous research in our laboratory found that repeated exposure of adolescent rats to 3,4-methylenedioxymethamphetamine (MDMA) impaired working memory and reduced anxiety. The present experiment extended these findings by investigating the physiological, behavioral, and neurotoxic effects of a modified MDMA treatment regimen. Male Sprague-Dawley rats received 5 mg/kg of MDMA hourly for a period of 4 hr on every fifth day from postnatal day 35-60. Acute effects of the MDMA treatment included hypothermia, serotonin syndrome behavior, and ejaculation. Body weight gain was attenuated by repeated drug administration. The animals completed anxiety and working memory tests beginning 4 days after the final MDMA dose. MDMA altered habituation to the open-field, increased locomotor activity in the elevated plus-maze, decreased attention in the novel object-recognition test, and reduced serotonin transporter binding in the neocortex. These results indicate that repeated exposure to a relatively moderate MDMA dose during adolescence produces later changes in behavior and neurochemistry.

Amphetamine toxicity in the emergency department

XTC and other amphetamines are considered to be safe by the majority of partying young people who are unaware of (or unwilling to know about) the acute and chronic toxicity of these substances, and these drugs are widespread, illicit stimulants. In this article, we describe four cases of severe acute toxicity due to recreational use of amphetamines 3,4-methylene-dioxymethamphetamine, 3,4-methylenedioxyethylamphetamine, 3,4-methylenedioxyamphetamine, 4-methylthioamphetamine or p-methoxyamphetamine, with emphasis on the presenting symptoms and acute treatment in the emergency department.