Disposition of methylenedioxymethamphetamine and three metabolites in the brains of different rat strains and their possible roles in acute serotonin depletion

Fatal multi-organ failure after suicidal overdose with MDMA, 'ecstasy': case report and review of the literature

A 53-year-old prisoner died of multiorgan failure after a suicidal overdose with 3,4-methylenedeoxymethamphetamine (MDMA, 'Ecstasy'). Twelve hours after ingestion of MDMA, the patient became severely hyperthermic (107.2 degrees F) with evidence of rhabdomyolysis. He subsequently developed acute respiratory distress syndrome (ARDS), disseminated intravascular coagulopathy (DIC) and acute renal failure. At autopsy, plasma concentration of MDMA was 3.05 mg/L. This case shows that MDMA is still abused in our community and clinicians should know the symptoms of MDMA intoxication. In particular, MDMA should be considered when patients have symptoms or signs of increased sympathetic activity. The pathophysiology and treatment of MDMA-induced hyperthermia are discussed.

The effect of MDMA (3,4-methylenedioxymethamphetamine) on the 5-HT synthesis rate in the rat brain: an autoradiographic study

The effect of MDMA (3,4-methylenedioxymethamphetamine), a psychotropic amphetamine derivative, treatment on the rate of serotonin (5-hydroxytryptamine; 5-HT) synthesis in the rat brain was studied by autoradiography using alpha-[14C]-methyl-l-tryptophan method. Three different treatment protocols were compared to the control (saline) treated rats: (1) rats treated twice with 10 mg/kg every 12 h (20 mg/kg total) and injected tracer for the synthesis measurements 15 h later; (2) rats treated with four injections of 5 mg/kg every 12 h (20 mg/kg total) and injected tracer for the synthesis measurement 17 h after the last dose; and (3) rats given eight injections of 5 mg/kg every 12 h for four days (40 mg/kg) and used in the synthesis study 14 days after the last dose. Results showed a significant decrease in the rate of synthesis in the majority of cerebral structures examined in the 10 mg/kg group. In contrast the group receiving the same total amount (20 mg/kg) of MDMA but over two days (4x5 mg/kg) showed a significant increase in 5-HT synthesis in comparison to controls. The 5-HT synthesis rates measured 14 days after the last dose (four days, 8x5 mg/kg) were significantly reduced. The findings suggest that MDMA can produce either an increase or a decrease in the 5-HT synthesis a short time after a total dose of 20 mg/kg depending on the dose fractionation. However, 14 days after total dose of 40 mg/kg given over four days the synthesis rate was significantly reduced in many brain structures. The latter suggests a possible effect of the MDMA neurotoxicity on the serotonergic neurons, in addition to a possible influence on 5-HT synthesis via a feedback mechanism.

The relationship between the degree of neurodegeneration of rat brain 5-HT nerve terminals and the dose and frequency of administration of MDMA ('ecstasy')

The effect of varying the dose and frequency of administration of 3,4-methylenedioxymethamphetamine (MDMA or 'ecstasy') on both the acute hyperthermic response and the long term neurodegeneration of 5-hydroxytryptamine (5-HT) nerve terminals in the brain has been studied in Dark Agouti rats. A single injection (4-15 mg/kg i.p.) of MDMA produced immediate dose-related hyperthermia and a dose-related decrease in 5-HT, 5-hydroxyindoleacetic acid (5-HIAA) and [3H]paroxetine binding in regions of the brain 7 days later, with a dose of 4 mg/kg having no degenerative effect. This dose was also without effect when given once daily for 4 days, but produced a marked loss of [3H]paroxetine binding and indole concentration ( approximately 55%) when given twice daily for 4 days. When a dose of 4 mg/kg was given twice weekly for 8 weeks it had no effect on these serotoninergic markers, despite a clear anorectic effect of the drug being seen. These data demonstrate that MDMA-induced neurodegeneration is related to both the dose and frequency of administration and indicate that damage to 5-HT neurones can occur in the absence of a hyperthermic response to the drug. We suggest that damage occurs when endogenous free radical scavenging mechanisms become overwhelmed or exhausted.

Causes and consequences of the loss of serotonergic presynapses elicited by the consumption of 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") and its congeners

The massive and prolonged stimulation of serotonin (5-HT)-release and the increased dopaminergic activity are responsible for the acute psychomimetic and psychostimulatory effects of 3,4-methylenedioxy-methamphetamine (MDMA, "ecstasy") and its congeners. In vulnerable subjects, at high doses or repeated use, and under certain unfavorable conditions (crowding, high ambient temperature), severe, in some cases fatal, averse systemic reactions (hyperthermia, serotonin-syndrome) may occur during the first few hours. Animal experiments revealed the existence of similar differences in vulnerability and similar dose- and context-related influences on a similar sequence of acute responses. The severity of these acute systemic responses is closely related to the severity of the long-term damage to 5-HT axon terminals caused by the administration of substituted amphetamines. Attempts to identify the mechanisms involved in this selective degeneration of 5-HT presynapses brought to light a multitude of different factors and conditions which either attenuate or potentiate the loss of 5-HT terminals caused by MDMA and related amphetamine derivatives. These puzzling observations suggest that the degeneration of 5-HT presynapses represents only the final step in a sequence of events which compromise the ability of 5-HT terminals to maintain their functional and structural integrity. Substituted amphetamines selectively tax energy metabolism in 5-HT presynapses through their ability to exchange with 5-HT and to dissipate transmembrane ion gradients. The active carrier systems in the vesicular and presynaptic membrane operate at a permanently activated state. The resulting energy deficit can no longer adequately restored by the 5-HT presynapses when their availability of substrates for ATP production is additionally reduced by the hyperthermic and other energy consuming reactions which are elicited by the systemic administration of substituted amphetamines. The exhaustion of energy in 5-HT nerve terminals compromised all energy-requiring endogenous mechanisms involved in the regulation of transmembrane-ion exchange, internal Ca(++)-homeostasis, prevention of oxidative stress, detoxification, and repair. Above a critical threshold the failure of these self-protective mechanisms will lead to the degeneration of the 5-HT axon terminals. Based on the role of 5-HT as a global modulatory transmitter-system involved in the stabilization and integration of impulse flow between distributed multifocal neuronal networks, the partial loss of 5-HT presynapses must be expected to impair the ability of these networks to maintain the integrity of signal flow pattern, and increase the likelihood of switching to unstable information processing. Behavioral responding may therefore become more dominated by activities generated in individual networks, and hitherto "buffered" personality traits and predisposition may become manifested as defined psychiatric syndromes in certain predisposed subjects.

The effect of the spin trapping agent α-phenyl-n-tert-butyl nitrone on dexfenfluramine-induced serotonin depletion in rat brain

Oxygen-free radical formation from either the parent compound amphetamine, its metabolites or drug-released serotonin (5-HT) has been implicated in the reduction of serotoninergic markers caused by amphetamine derivatives. Therefore, the present study investigated the effects of the spin-trapping agent α-phenyl-tert-butyl nitrone (PBN) on the 5-HT-lowering action of dexfenfluramine (DF) in rats, compared with p-chloroamphetamine (PCA). PBN (150 mg/kg, i.p, divided in two doses) almost totally prevented the reduction of 5-HT in particularly sensitive regions of the rat brain (cortex and striatum) 1 and 7 days after DF (10 mg/kg, i.p.). It also provided complete protection against the acute 5-HT-depleting action of PCA (5 mg/kg, i.p.), reducing it at 7 days in striatum, although with the higher dose (300 mg/kg, divided in two doses) there was a tendency to antagonize the long-term effects in both regions. With DF, however, the antagonistic effect of PBN was associated with a marked reduction of the plasma and brain concentrations of the parent drug, but particularly its active metabolite dexnorfenfluramine (DNF). Thus, reduced brain availability of the total active drug (DF+DNF) may explain why PBN prevents the neurochemical effects of DF (but not PCA), including the long-term one which possibly depends on the extent of the initial 5-HT lowering.

Enantioselective determination of 3,4-methylene-dioxymethamphetamine and two of its metabolites in human urine by cyclodextrin-modified capillary zone electrophoresis

Using capillary zone electrophoresis with a phosphate buffer at pH 2.5 containing 30 mM (2-hydroxypropyl)-beta-cyclodextrin as chiral selector, the simultaneous separation of the enantiomers of 3,4-methylenedioxymethamphetamine (MDMA or Ecstasy) and its two metabolites 4-hydroxy-3-methoxymethamphetamine (HMMA) and 3,4-methylenedioxyamphetamine (MDA) in human urine is reported. The assay described is based upon enzymatic hydrolysis of conjugated HMMA (major urinary metabolite) and solid-phase extraction followed by injection of a few nL of the extract onto a 50 microm internal diameter (ID) fused-silica capillary of 60 cm length. Solutes are detected via on-column absorbance at 195 nm. For 375 ng/mL drug levels, intraday and interday imprecision is < 4%. With 5 mL urine samples, the detection limit is in the 20-50 ng/mL range. Via analysis of the urines of two patients, the metabolism of MDMA is demonstrated to be enantioselective, with significantly higher urinary amounts of R-(-)-MDMA being excreted compared to S-(+)-MDMA. Within 72h after drug administration one patient was determined to excrete 42.28 and 10.16% of the racemic MDMA dose (1.5 mg/kg body weight) as R-(-) and S-(+)-MDMA enantiomers, respectively. Corresponding values for the second subject were found to be 28.63 and 9.34%. The metabolism of the enantiomers of the two metabolites showed interindividual differences. The first and second detected HMMA enantiomers represented 3.79 and 5.42% (first subject) and 8.51 and 4.36% (second), respectively, of the administered MDMA dose. For the MDA enantiomers, corresponding values were 2.44, 1.76, 0.75, and 0.79%, respectively.