Neurological and Psychopathological Sequelae Associated With a Lifetime Intake of 40,000 Ecstasy Tablets

MDMA-Associated Liver Toxicity: Pathophysiology, Management, and Current State of Knowledge

3,4-Methylenedioxymethamphetamine (MDMA, ecstasy) has become a popular recreational drug of abuse among young adults, partly because of the belief that it is relatively safe compared with other drugs with the same stimulant and hallucinogenic effects. However, MDMA use has been associated with a wide spectrum of organ toxicities, with the liver being severely affected by its deleterious effects. This article discusses the essential pharmacology of MDMA and describes the effects MDMA has on various organ systems of the body, with particular focus on the liver. The putative mechanisms by which MDMA can cause liver damage are explored, with emphasis on patient-related factors that explain why some individuals are more susceptible than others to damage from MDMA. The incidence of hepatotoxicity related to MDMA use is presented, and the nursing management of patients who develop acute liver failure due to MDMA overuse is explored in light of current evidence.

High ambient temperature facilitates the acquisition of 3,4-methylenedioxymethamphetamine (MDMA) self-administration

RATIONALE

MDMA alters body temperature in rats with a direction that depends on the ambient temperature (T_A). The thermoregulatory effects of MDMA and T_A may affect intravenous self-administration (IVSA) of MDMA but limited prior reports conflict.

OBJECTIVE

To determine how body temperature responses under high and low T_A influence MDMA IVSA.

METHODS

Male Sprague-Dawley rats were trained to IVSA MDMA (1.0mg/kg/infusion; 2-h sessions; FR5 schedule of reinforcement) under T_A 20°C or 30°C. Radiotelemetry transmitters recorded body temperature and activity during IVSA.

RESULTS

MDMA intake increased under both T_A during acquisition, but to a greater extent in the 30°C group. The magnitude of hypothermia was initially equivalent between groups but diminished over training in the 30°C group. Within-session activity was initially lower in the 30°C group, but by the end of acquisition and maintenance, activity was similar for both groups. When T_A conditions were swapped, the hot-trained group increased MDMA IVSA under 20°C T_A and a modest decrease in drug intake was observed in the cold-trained group under 30°C T_A. Subsequent non-contingent MDMA (1.0-5.0mg/kg, i.v.) found that rats with higher MDMA IVSA rates showed blunted hypothermia compared with rats with lower IVSA levels; however, within-session activity did not differ by group. High T_A increased intracranial self-stimulation thresholds in a different group of rats and MDMA reduced thresholds below baseline at low, but not high, T_A.

CONCLUSIONS

High T_A appears to enhance acquisition of MDMA IVSA through an aversive effect and not via thermoregulatory motivation.

Predicting the Abuse Liability of Entactogen-Class, New and Emerging Psychoactive Substances via Preclinical Models of Drug Self-administration

Animal models of drug self-administration are currently the gold standard for making predictions regarding the relative likelihood that a recreational drug substance will lead to continued use and addiction. Such models have been found to have high predictive accuracy and discriminative validity for a number of drug classes including ethanol, nicotine, opioids, and psychostimulants such as cocaine and methamphetamine. Members of the entactogen class of psychostimulants (drugs that produce an "open mind state" including feelings of interpersonal closeness, intimacy and empathy) have been less frequently studied in self-administration models. The prototypical entactogen 3,4-methylenedioxymethamphetamine (MDMA; "Ecstasy") supports self-administration but not with the same consistency nor with the same efficacy as structurally related drugs amphetamine or methamphetamine. Consistent with these observations, MDMA use is more episodic in the majority of those who use it frequently. Nevertheless, substantial numbers of MDMA users will meet the criteria for substance dependence at some point in their use history. This review examines the currently available evidence from rodent self-administration studies of MDMA and two of the new and emerging psychoactive substances (NPS) that produce entactogen type neuropharmacological responses - mephedrone (4-methylmethcathinone; 4MMC; "meow meow") and methylone (3,4-methylenedioxymethcathinone). Overall, the current evidence predicts that these NPS entactogens have enhanced abuse liability compared with MDMA.

Contrasting effects of d-methamphetamine, 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxypyrovalerone, and 4-methylmethcathinone on wheel activity in rats

BACKGROUND

Reports from U.S., U.K. and European drug policy entities, and ongoing media accounts, show increasing recreational use of 4-methylmethcathinone (4-MMC, mephedrone) and 3,4-methylenedioxypyrovalerone (MDPV). Severe sympathomimetic symptoms, hallucinations, psychoses, and even deaths have been reported, yet little scientific information is available on the effects of these compounds in laboratory models. Available studies on the neurochemistry of these drugs show that 4-MMC and MDPV enhance DA neurotransmission, while 4-MMC additionally enhances 5-HT neurotransmission--a pattern much like that reported for methamphetamine versus 3,4-methylenedioxymethamphetamine (MDMA). As is the case for designer amphetamines, these neurochemical distinctions may predict differential potential for repetitive versus episodic abuse and distinct lasting toxicities.

METHODS

This study determined relative locomotor stimulant effects of 4-MMC (1-10 mg/kg, s.c.) and MDPV (0.5-5.6 mg/kg, s.c.), in comparison with d-methamphetamine (MA; 0.5-5.6 mg/kg, s.c.) and MDMA (1-7.5 mg/kg, s.c.) on a measure of locomotor activity--voluntary wheel running--in male Wistar rats (N=8).

RESULTS

Compared to counts of wheel rotations after saline, a biphasic change in the pattern of counts was observed after injections of MA and MDPV, with relatively higher counts following lower doses and lower counts following the highest dose. However, monophasic, dose-dependent reductions in counts were observed in response to injections of MDMA and 4-MMC.

CONCLUSION

Thus, voluntary wheel running yielded the same categorical distinctions for these drugs as did prior experiments testing the effects of these drugs on monoaminergic neurotransmission. These data indicate that MDPV produces prototypical locomotor stimulant effects whereas 4-MMC is more similar to the entactogen MDMA.

Memory impairment induced by amphetamine derivatives in laboratory animals and in humans: a review

The 20th century brought with it the so-called club drugs (the most notorious being amphetamine derivatives), which are used by young adults at all-night dance parties. Methamphet­amine and 3,4-methylenedioxymethamphetamine (MDMA or ecstasy) are synthetic drugs with stimulant and psychoactive properties that belong to the amphetamine family. Here, we have reviewed the literature about the cognitive impairment induced by these two amphetamine derivatives and the preclinical and clinical outcomes. Although there is controversial evidence about the effect of methamphetamine and MDMA on learning and memory in laboratory animals, results from published papers demonstrate that amphetamines cause long-term impairment of cognitive functions. A large number of pharmacological receptors have been studied and screened as targets of amphetamine-induced cognitive dysfunction, and extensive research efforts have been invested to provide evidence about the molecular mechanisms behind these cognitive deficits. In humans, there is a considerable body of evidence indicating that methamphetamine and MDMA seriously disrupt memory and learning processes. Although an association between the impairments of memory performance and a history of recreational amphetamine ingestion has also been corroborated, a number of methodological difficulties continue to hamper research in this field, the most important being the concomitant use of other illicit drugs.

Rats preexposed to MDMA display attenuated responses to its aversive effects in the absence of persistent monoamine depletions

RATIONALE

The abuse potential of a given drug may be mediated by both its rewarding and aversive effects, the latter of which are often far less characterized.

OBJECTIVES

Using the conditioned taste-aversion (CTA) preparation, the present experiments examined changes in the aversive effects of the commonly used recreational drug MDMA following repeated drug exposures.

METHODS

Experiment 1 used three varying doses of MDMA (1.0, 1.8, and 3.2 mg/kg) to determine a dose that produced taste aversions of intermediate strength. Experiments 2 and 3 characterized the effects of repeated preexposures to MDMA (1.8 or 3.2 mg/kg) on taste aversions induced by MDMA (1.8 mg/kg). Additionally, levels of several monoamines and metabolites were analyzed in frontal cortex and caudate-putamen from subjects in Experiment 3 to assess for persistent monoamine depletions.

RESULTS

MDMA induced dose-dependent taste aversions. Preexposure to MDMA (at both doses) resulted in an attenuation of MDMA-induced taste aversions. These effects were not likely due to persistent monoamine depletions, as subjects preexposed to the higher MDMA dose did not differ from controls in levels of monoamines or metabolites in either brain region examined.

CONCLUSIONS

Prior MDMA experience weakened the ability of MDMA to induce taste aversions. This attenuation of MDMA's aversive effects may occur with low doses that do not persistently alter monoamine levels.

Involvement of nicotinic receptors in methamphetamine- and MDMA-induced neurotoxicity: pharmacological implications

During the last years, we have focused on the study of the neurotoxic effects of 3,4-methylenedioxymethamphetamine (MDMA) and methamphetamine (METH) on the central nervous system (CNS) and their pharmacological prevention methods. In the process of this research, we have used a semipurified synaptosomal preparation from striatum of mice or rats as a reliable in vitro model to study reactive oxygen species (ROS) production by these amphetamine derivatives, which is well-correlated with their dopaminergic injury in in vivo models. Using this preparation, we have demonstrated that blockade of alpha7 nicotinic receptors with methyllycaconitine (MLA) prevents ROS production induced by MDMA and METH. Consequently, in vivo, MLA significantly prevents MDMA- and METH-induced neurotoxicity at dopaminergic level (mouse striatum), without affecting hyperthermia induced by these amphetamines. Additionally, when neuroprotection was assayed with memantine (MEM), a dual antagonist of NMDA and alpha7 receptors, an effective neuroprotection was obtained also ahead of serotonergic injury induced by MDMA in rats. MEM also prevents MDMA effect on serotonin transporter functionality and METH effect on dopamine transporter (DAT), suggesting that behavioral effects of these psychostimulants can also be modulated by MEM. Finally, we have demonstrated that MEM prevents the impaired memory function induced by MDMA, and also, using binding studies with radioligands, we have characterized the interaction of these substances with nicotinic receptors. Studies at molecular level showed that both MDMA and METH displaced competitively the binding of radioligands with homomeric alpha7 and heteromeric nicotinic acetylcholine receptors (nAChRs), indicating that they can directly interact with them. In all the cases, MDMA displayed higher affinity than METH and it was higher for heteromeric than for alpha7 subtype. Pre-incubation of differentiated PC12 cells with MDMA or METH induces nAChR upregulation in a concentration- and time-dependent manner, as many nicotinic ligands do, supporting their functional interaction with nAChRs. Such interaction expands the pharmacological profile of amphetamines and can account for some of their effects.

(+/-)-3,4-Methylenedioxymethamphetamine treatment in adult rats impairs path integration learning: a comparison of single vs once per week treatment for 5 weeks

3,4-Methlylenedioxymethamphetamine (MDMA) administration (4 x 15 mg/kg) on a single day has been shown to cause path integration deficits in rats. While most animal experiments focus on single binge-type models of MDMA use, many MDMA users take the drug on a recurring basis. The purpose of this study was to compare the effects of repeated single-day treatments with MDMA (4 x 15 mg/kg) once weekly for 5 weeks to animals that only received MDMA on week 5 and saline on weeks 1-4. In animals treated with MDMA for 5 weeks, there was an increase in time spent in the open area of the elevated zero maze suggesting a decrease in anxiety or increase in impulsivity compared to the animals given MDMA for 1 week and saline treated controls. Regardless of dosing regimen, MDMA treatment produced path integration deficits as evidenced by an increase in latency to find the goal in the Cincinnati water maze. Animals treated with MDMA also showed a transient hypoactivity that was not present when the animals were re-tested at the end of cognitive testing. In addition, both MDMA-treated groups showed comparable hyperactive responses to a later methamphetamine challenge. No differences were observed in spatial learning in the Morris water maze during acquisition or reversal but MDMA-related deficits were seen on reduced platform-size trials. Taken together, the data show that a single-day regimen of MDMA induces deficits similar to that of multiple weekly treatments.

The neuropsychology of ecstasy (MDMA) use: a quantitative review

A growing number of empirical studies have found varying neuropsychological impairments associated with use of 3,4-methylenedioxymethamphetamine (MDMA) use. We set out to determine to what extent neuropsychological abilities are impaired in MDMA users. To do so, meta-analytical methods were used to determine the magnitude of neuropsychological impairment in MDMA users across pre-specified cognitive domains. We found that cognitive impairment secondary to recreational drug use may result in what might be described as small-to-medium effects across all cognitive domains with learning and memory being most impaired. We also found that total lifetime ingestion of MDMA appears to be negatively associated with performance on tasks ranging from attention and concentration to learning and memory. Implications and limitations of these findings are discussed.

Alterations in body temperature, corticosterone, and behavior following the administration of 5-methoxy-diisopropyltryptamine ('foxy') to adult rats: a new drug of abuse

Many drugs are used or abused in social contexts without understanding the ramifications of their use. In this study, we examined the effects of a newly popular drug, 5-methoxy-diisopropyltryptamine (5-MEO-DIPT; 'foxy' or 'foxy-methoxy'). Two experiments were performed. In the first, 5-MEO-DIPT (0, 10, or 20 mg/kg) was administered to rats four times on a single day and animals were examined 3 days later. The animals that received 5-MEO-DIPT demonstrated hypothermia during the period of drug administration and delayed mild hyperthermic rebound for at least 48 h. Corticosterone levels in plasma were elevated in a dose-dependent manner compared to saline-treated animals with minor changes in 5-HT turnover and no changes in monoamine levels. In experiment 2, rats were examined in behavioral tasks following either 0 or 20 mg/kg of 5-MEO-DIPT. The animals treated with 5-MEO-DIPT showed hypoactivity and an attenuated response to (+)-methamphetamine-induced stimulation (1 mg/kg). In a test of path integration (Cincinnati water maze), 5-MEO-DIPT-treated animals displayed deficits in performance compared to the saline-treated animals. No differences were noted in the ability of the animals to perform in the Morris water maze or on tests of novel object or place recognition. The data demonstrate that 5-MEO-DIPT alters the ability of an animal to perform certain cognitive tasks, while leaving others intact and disrupts the endocrine system. 5-MEO-DIPT may have the potential to induce untoward effects in humans.

Treatment with MDMA from P11-20 disrupts spatial learning and path integration learning in adolescent rats but only spatial learning in older rats

RATIONALE

Previous studies in rats showed that postnatal day (P)11-20 exposure to +/-3,4-methylenedioxymethamphetamine (MDMA, ecstasy) causes learning and memory deficits in adulthood. The emergence and permanence of these learning deficits are currently unknown.

OBJECTIVE

This study was designed to investigate learning and memory deficits in adolescent (P30 or P40) and older (P180 or P360) rats exposed to MDMA from P11-20.

MATERIALS AND METHODS

Within each litter half the animals were exposed to MDMA (20 mg/kg) and half to saline (SAL) twice a day (8 h apart) from P11-20. In experiment (exp) 1, behavioral testing began on either P30 or P40, whereas in exp 2, testing began on either P180 or P360. Offspring were tested in the Cincinnati water maze (CWM), a test of path integration learning (2 trials/day for 5 days), and the Morris water maze (MWM) (three phases, with 5 days of 4 trials/day and a probe trial on the sixth day per phase).

RESULTS

MDMA-treated rats took longer to find the platform and traveled a greater distance to find the platform at all ages tested in all phases of the MWM. MDMA-treated animals also spent less time in the target quadrant during probe trials. In the CWM, P30 and P40 animals took longer to find the goal and committed more errors in locating the goal, while P180 and P360 MDMA-treated animals performed similarly to SAL-treated animals.

CONCLUSION

The data suggest that the spatial learning and memory deficits induced by MDMA are long lasting, while the path integration deficits recover over time.