Preliminary evidence of the cardiovascular effects of polysubstance misuse in nightclubs

Deconstructing alcohol use on a night out in England: promotions, preloading and consumption

INTRODUCTION AND AIMS

To examine alcohol consumed during a drinking event (a single drinking occasion) by those attending public house/on-trade establishments on nights with standard pricing and nights with promotional prices.

DESIGN AND METHODS

Data (n = 425) were collected in an ecological momentary assessment over eight nights in two locations (Midlands and London) on both promotional and standard (Saturday) nights. Multiple regression was used to predict event alcohol consumption by sex, age, type of night, alcohol preloading behaviour, marital and employment status, education, Alcohol Use Disorders Identification Test alcohol consumption questions separately or total AUDIT-C and social group size.

RESULTS

Mean (UK) units consumed were 11.8 (London) and 14.4 (Midlands). In London, consumption was similar on promotional and standard nights, but in the Midlands, standard night consumption was three units higher. Preloading was reported by 30%; more common on standard nights. Regression analyses revealed being male, preloading and past-year total AUDIT-C were associated with higher event consumption. However, when AUDIT-C questions were added separately, being a standard night was associated with increased event consumption and different AUDIT-C questions were significantly associated with event consumption in each location.

DISCUSSION AND CONCLUSIONS

Event consumption reflected heavy episodic drinking and was influenced by price. Promotional night consumption either matched standard Saturday night consumption or was slightly lower. In London, there was a significant preference for drinking at least one promotional beverage on promotional nights. On standard nights, consumption was over a wider range of venues, and preloading with off-trade alcohol was more likely.

Clinical pharmacology of 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy"): the influence of gender and genetics (CYP2D6, COMT, 5-HTT)

The synthetic psychostimulant MDMA (±3,4-methylenedioxymethamphetamine, ecstasy) acts as an indirect serotonin, dopamine, and norepinephrine agonist and as a mechanism-based inhibitor of the cytochrome P-450 2D6 (CYP2D6). It has been suggested that women are more sensitive to MDMA effects than men but no clinical experimental studies have satisfactorily evaluated the factors contributing to such observations. There are no studies evaluating the influence of genetic polymorphism on the pharmacokinetics (CYP2D6; catechol-O-methyltransferase, COMT) and pharmacological effects of MDMA (serotonin transporter, 5-HTT; COMT). This clinical study was designed to evaluate the pharmacokinetics and physiological and subjective effects of MDMA considering gender and the genetic polymorphisms of CYP2D6, COMT, and 5-HTT. A total of 27 (12 women) healthy, recreational users of ecstasy were included (all extensive metabolizers for CYP2D6). A single oral weight-adjusted dose of MDMA was administered (1.4 mg/kg, range 75–100 mg) which was similar to recreational doses. None of the women were taking oral contraceptives and the experimental session was performed during the early follicular phase of their menstrual cycle. Principal findings show that subjects reached similar MDMA plasma concentrations, and experienced similar positive effects, irrespective of gender or CYP2D6 (not taking into consideration poor or ultra-rapid metabolizers) or COMT genotypes. However, HMMA plasma concentrations were linked to CYP2D6 genotype (higher with two functional alleles). Female subjects displayed more intense physiological (heart rate, and oral temperature) and negative effects (dizziness, sedation, depression, and psychotic symptoms). Genotypes of COMT val158met or 5-HTTLPR with high functionality (val/val or l/*) determined greater cardiovascular effects, and with low functionality (met/* or s/s) negative subjective effects (dizziness, anxiety, sedation). In conclusion, the contribution of MDMA pharmacokinetics following 1.4 mg/kg MDMA to the gender differences observed in drug effects appears to be negligible or even null. In contrast, 5-HTTLPR and COMT val158met genotypes play a major role.

Ecstasy (MDMA)-induced hyponatraemia is associated with genetic variants in CYP2D6 and COMT

We hypothesised that genetically determined poor metabolism of 3,4-methylene dioxymetamphetamine (MDMA) due either to the presence of CYP2D6 genotypes giving absent or low CYP2D6 enzyme activity, or a COMT genotype predicting low COMT enzyme activity would be associated with a greater degree of MDMA-induced reduction in plasma sodium and osmolality than other genotypes at these genes following consumption of 'ecstasy' tablets by clubbers. Of the 48 subjects who returned to the test site post-clubbing, 30 provided samples for measurement of vasopressin (AVP), plasma sodium, urea and plasma and urine osmolality. Genotyping was performed for functional variants in CYP2D6 (n = 29) and COMT (Val158Met, n = 30). In subjects with urinary MDMA detected post-clubbing, there was a significant association between change in plasma osmolality (p = 0.009) and in plasma sodium (p = 0.012) and CYP2D6 genotypic category. Individuals with the low-activity but readily inhibitable CYP2D6 extensive metaboliser/intermediate metaboliser (EM/IM) genotype showed greater reductions in these measures than all other CYP2D6 genotypic categories. COMT low-activity genotypes (Met/Met and Val/Met) were also significantly associated with reductions in plasma osmolality (p = 0.028) and in plasma sodium (p = 0.003). On conservative Bonferroni correction for two independent genes, the CYP2D6 and COMT plasma sodium findings remain significant. The relatively high frequency of the low-activity CYP2D6 and COMT genotypes in the population warrants further attention, since consumption of free water following ingestion of MDMA in these individuals may trigger dilutational hyponatraemia and increased risk of syndrome of inappropriate antidiuretic hormone secretion.

Pharmacogenetic studies of change in cortisol on ecstasy (MDMA) consumption

In this study we investigate the association of cytochrome P450 enzyme CYP2D6, catechol-O-methyl transferase (COMT, Val158Met) and serotonin transporter promoter (5-HTTLPR) genotypes on change in cortisol concentration following 3, 4-methylenedioxy-methamphetamine (MDMA, 'ecstasy') consumption. Forty-eight subjects (30 males, mean age 23 years), self-nominating regular clubbers provided 'in the field' pre- and post-clubbing biological samples and associated information. Of the 39 subjects who provided a post-clubbing urine sample, 21 were positive for MDMA. Plasma cortisol concentrations increased in subjects (n = 48) tested for cortisol, with changes being significantly greater in the MDMA-positive group (736.9 ± 83.2 vs. 350.9 ± 34.5 mmol/l, p = 0.001). We found a positive association between the low activity COMT genotype (Met/Met) and MDMA-induced change in cortisol and also between this and change in cortisol in the whole sample (p = 0.039, Bonferroni corrected). For CYP2D6, there was an association between genotype and change in cortisol, confined to subjects with MDMA-positive urine post-clubbing (p = 0.003, Bonferroni corrected). There was no association with 5-HTTLPR genotype. These associations suggest that chronic use of MDMA may lead to HPA axis dysregulation and that the magnitude of this may be moderated by genetic polymorphism, and warrant further investigation in a larger sample of those who consume the drug on a regular basis.

Ethanol co-administration moderates 3,4-methylenedioxymethamphetamine effects on human physiology

Alcohol is frequently used in combination with 3,4-methylenedioxymethamphetamine (MDMA). Both drugs affect cardiovascular function, hydration and temperature regulation, but may have partly opposing effects. The present study aims to assess the acute physiologic effects of (co-) administration of MDMA and ethanol over time. A four-way, double blind, randomized, crossover, placebo-controlled study in 16 healthy volunteers (9 male and 7 female) between the ages of 18 and 29. MDMA (100 mg) was given orally and blood ethanol concentration was maintained at pseudo-steady state levels of 0.6 per thousand by a three-hour 10% intravenous ethanol clamp. Cardiovascular function, temperature and hydration measures were recorded throughout the study days. Ethanol did not significantly affect physiologic function, with the exception of a short lasting increase in heart rate. MDMA potently increased heart rate and blood pressure and induced fluid retention as well as an increase in temperature. Co-administration of ethanol with MDMA did not affect cardiovascular function compared to the MDMA alone condition, but attenuated the effects of MDMA on fluid retention and showed a trend for attenuation of MDMA-induced temperature increase. In conclusion, co-administration of ethanol and MDMA did not exacerbate physiologic effects compared to all other drug conditions, and moderated some effects of MDMA alone.

Cortisol and 3,4-methylenedioxymethamphetamine: neurohormonal aspects of bioenergetic stress in ecstasy users

AIMS

3,4-Methylenedioxymethamphetamine (MDMA) can affect both neurotransmitter and neurohormonal activity. This review will debate the role of the metabolic activation hormone cortisol for the psychobiological effects of ecstasy/MDMA.

METHODS

The empirical literature on cortisol release following acute MDMA administration and cortisol functioning in drug-free recreational ecstasy/MDMA users will be reviewed. This will be followed by an overview of cortisol as a bioenergetic stress neurohormone, and a debate on how it could be modulating the acute and chronic psychobiological effects of MDMA.

RESULTS

Cortisol release is increased by stimulatory factors, including physical activity, thermal stress and stimulant drugs. In laboratory studies MDMA leads to an acute cortisol increase of around 150% in sedentary humans. In MDMA-using dance clubbers, the cortisol levels are increased by around 800%, possibly due to the combined factors of stimulant drug, physical exertion and psychosocial stimulation. Regular ecstasy/MDMA users also demonstrate changes in baseline cortisol levels and cortisol reactivity, with compromised hypothalamic-pituitary-adrenal activity. Nonpharmacological research has shown how cortisol is important for psychological aspects such as memory, cognition, sleep, impulsivity, depression and neuronal damage. These same functions are often impaired in recreational ecstasy/MDMA users, and cortisol may be an important modulatory co-factor.

CONCLUSIONS

The energizing hormone cortisol is involved in the psychobiology of MDMA, probably via its effects on energy metabolism. Acute cortisol release may potentiate the stimulating effects of MDMA in dance clubbers. Chronically, cortisol may contribute to the variance in functional and structural consequences of repeated ecstasy usage.

Interactions between ethanol and cocaine, amphetamine, or MDMA in the rat: thermoregulatory and locomotor effects

RATIONALE

(+/-)-3,4-methylenedioxymethamphetamine (MDMA, ecstasy) is often taken recreationally with ethanol (EtOH). In rats, EtOH may potentiate MDMA-induced hyperactivity, but attenuate hyperthermia.

OBJECTIVE

Experiment 1 compared the interactions between EtOH (1.5 g/kg) and MDMA (6.6 mg/kg) with EtOH + cocaine (COCA; 10 mg/kg) and EtOH + amphetamine (AMPH; 1 mg/kg) on locomotor activity and thermoregulation. Experiment 2 used a weaker dose of MDMA (3.3 mg/kg) and larger doses of COCA (20 mg/kg) and AMPH (2 mg/kg).

MATERIALS AND METHODS

Drug treatments were administered on four occasions (2, 5, and 2 days apart, respectively; experiment 1) or two (2 days apart; experiment 2).

RESULTS

All psychostimulants increased activity, and EtOH markedly increased the effect of MDMA. AMPH alone-related hyperactivity showed modest sensitization across treatment days, while MDMA + EtOH activity showed marked sensitization. AMPH, COCA, and MDMA induced hyperthermia of comparable amplitude (+1 to +1.5 degrees C). Co-treatment with EtOH and AMPH (1 mg/kg) or COCA (10 mg/kg) produced hypothermia greater than that produced by EtOH alone. Conversely, EtOH attenuated MDMA-related hyperthermia, an effect increasing across treatment days. These results demonstrate that the interaction between MDMA and EtOH may be different from the interaction between EtOH and AMPH or COCA.

CONCLUSION

Because of potential health-related consequences of such polydrug misuse, it is worth identifying the mechanisms underlying these interactions, especially between EtOH and MDMA. Given the different affinity profiles of the three drugs for serotonin, dopamine, and norepinephrine transporters, our results appear compatible with the possibility of an important role of serotonin in at least the EtOH-induced potentiation of MDMA-induced hyperlocomotion.

Dance clubbing on MDMA and during abstinence from Ecstasy/MDMA: prospective neuroendocrine and psychobiological changes

BACKGROUND/AIMS

The present study is the first to prospectively compare a group of recreational Ecstasy users when dance clubbing on 3,4-methylenedioxymethamphetamine (MDMA) and when clubbing during abstinence from Ecstasy/MDMA.

METHODS

Twelve normal healthy volunteers (mean age = 23.2 years) were assessed at a Saturday night dance club under self-administered MDMA. On the other weekend they went to the same dance club without taking MDMA (order counterbalanced). Both conditions involved 5 test sessions conducted at similar times: pre-drug baseline, 1 h post-drug clubbing, 2.5 h post-drug clubbing, and 2 and 4 days later. The assessments included body and ambient temperature, physical activity (pedometer), as well as self-ratings for mood state, physical activity, thermal comfort and thirst. Saliva samples were analyzed for MDMA, cortisol and testosterone.

RESULTS

The cortisol levels increased significantly by 800% when dance clubbing on MDMA, while testosterone increased significantly by 75%; neither neuroendocrine measure was altered during abstinence. Saliva analyses confirmed the presence of MDMA when dancing on Ecstasy and its absence when dancing off Ecstasy. The pedometer values and self-rated levels of dancing were similar at both weekends. Hot and cold flushes and feeling hot increased significantly under MDMA. The mean body temperature did not change significantly, although there was a borderline trend for increased values after MDMA. Feelings of happiness and excitement increased under MDMA, although they were not significantly greater than when clubbing during abstinence.

CONCLUSIONS

Neurohormonal release may be an important part of the acute MDMA experience. The large cortisol increase provides further data on the bioenergetic stress model of recreational Ecstasy/MDMA.

Poly-club-drug use among gay and bisexual men: a longitudinal analysis

OBJECTIVE

We sought to delineate patterns of poly-club-drug use among gay and bisexual men. Data were drawn from a large-scale 12-month longitudinal investigation of club drug use and sexual behavior among 450 racially, ethnically, and geographically diverse sample of gay and bisexual men in New York City.

METHODS

Using community-based sampling, we recruited the sample from numerous venues and assessed the self-reported use of five drugs and their relation to one another: cocaine, ecstasy, GHB, ketamine, and methamphetamine. Multivariate hierarchical linear modeling (HLM) was utilized to examine associations of usage over the 12-month data collection period.

RESULTS

Use of the five club drugs was highly related as noted by both parametric and non-parametric analyses of the cross-sectional data. Patterns of use over time also indicated significant longitudinal associations. Specifically, the use of methamphetamine over time was related to both the use of ecstasy and GHB.

CONCLUSIONS

The analyses suggest that usage patterns of individual club drugs such as methamphetamine, ecstasy, and GHB among gay and bisexual men are highly related across time. These findings hold implications for the treatment approaches that are utilized to address substance abuse in this segment of the population, and suggest that practitioners focus on the totality of the substance abuse behaviors and not necessarily individual drugs which are administered.

Dancing hot on Ecstasy: physical activity and thermal comfort ratings are associated with the memory and other psychobiological problems reported by recreational MDMA users

BACKGROUND

Non-drug factors such as ambient temperature can heighten the adverse effects of MDMA (3,4-methylendioxymethamphetamine) in animals. We assessed whether dancing and feeling hot on Ecstasy would be associated with more psychobiological problems in recreational users.

METHODS

In an internet study, 206 unpaid participants (modal age 16-24) reported that they had used recreational Ecstasy/MDMA. They completed a drug use questionnaire, the Prospective Memory Questionnaire (PMQ), questions about dancing and feeling hot when on Ecstasy, and psychobiological problems afterwards.

RESULTS

Those who danced 'all the time' when on Ecstasy, reported significantly more PMQ memory problems than the less intensive dancers. Prolonged dancing was also associated with more complaints of depression, memory problems, concentration and organizational difficulties afterwards. Feeling hot when on Ecstasy was associated with poor concentration in the comedown period, and with mood fluctuation and impulsivity off-drug. PMQ long-term problems demonstrated a significant curvilinear relationship with thermal self-ratings; more memory problems were noted by those who felt very hot, and by those who did not feel hot when on Ecstasy.

CONCLUSIONS

Non-drug factors such as dancing and feeling hot are associated with the incidence of psychobiological problems reported by recreational Ecstasy/MDMA users.

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.

Ecstasy: are animal data consistent between species and can they translate to humans?

The number of 3,4-methylenedioxymethamphetamine (ecstasy or MDMA) animal research articles is rapidly increasing and yet studies which place emphasis on the clinical significance are limited due to a lack of reliable human data. MDMA produces an acute, rapid release of brain serotonin and dopamine in experimental animals and in the rat this is associated with increased locomotor activity and the serotonin behavioural syndrome in rats. MDMA causes dose-dependent hyperthermia, which is potentially fatal, in humans, primates and rodents. Subsequent serotonergic neurotoxicity has been demonstrated by biochemical and histological studies and is reported to last for months in rats and years in non-human primates. Relating human data to findings in animals is complicated by reports that MDMA exposure in mice produces selective long-term dopaminergic impairment with no effect on serotonin. This review compares data obtained from animal and human studies and examines the acute physiological, behavioural and biochemical effects of MDMA as well as the long-term behavioural effects together with serotonergic and dopaminergic impairments. Consideration is also given to the role of neurotoxic metabolites and the influence of age, sex and user groups on the long-term actions of MDMA.