Prevalence and Correlates of Serotonin Syndrome in Real-World Inpatients

BACKGROUND

Serotonin syndrome (SS) is a potentially life-threatening adverse drug reaction due to an increased central and peripheral serotonin activity, which usually presents as a triad of behavioral changes, neuromuscular excitability, and autonomic instability. Probably SS is often misdiagnosed, and its symptoms are mistaken for psychiatric symptoms or general medical issues: the true incidence of SS is not clear, and literature concerning potential risk factors is scarce. Our aims were to examine the prevalence of SS in a naturalistic sample of hospitalized patients and to evaluate potential factors related to the risk of developing the condition.

METHODS

The sample included 133 patients being treated with serotonergic medications admitted to the psychiatric inpatient unit of the San Luigi Gonzaga Hospital. All patients received a medical examination (including a neurological examination) within 24 hours of admission. Serotonin syndrome was diagnosed according to Hunter Criteria.

RESULTS

Sixteen patients (12%) were diagnosed with SS. In the subgroup of subjects with SS, we found a higher rate of male patients when compared with subjects with no SS (62.5% vs 33.3%, P = 0.023).

CONCLUSIONS

SS probably is an underestimated condition, which should be carefully assessed in patients on serotonergic medications. Male gender was the only factor found to be significantly related to a higher risk of developing SS. Further studies on larger samples are needed, to gain more information on possible risk factors and to identify subjects more prone to developing SS, given the potential risk for patients' health.

Case Report: Possible Serotonin Syndrome in a Patient Taking Kratom and Multiple Serotonergic Agents

INTRODUCTION

Kratom, an unregulated herbal supplement, has emerged as self-treatment for anxiety/depression. Kratom exhibits inhibition at multiple cytochrome P450 isozymes involved in metabolism of prescription medications, including serotonergic agents. We report a case of possible serotonin syndrome induced by kratom use in combination with prescription psychotropic medications.

CASE

A 63-year-old male presented with diaphoresis, flushing, aphasia, confusion, dysarthria, right facial droop, and oral temperature of 39.6oC (103.2oF), lactate 2.7 mmol/L, and creatine phosphokinase of 1507 IU/L. Initial differential diagnoses included acute ischemic stroke and bacterial meningitis. Despite partial treatment with alteplase and broad-spectrum antibiotics, symptoms persisted, and subsequent physical exam noted hyperreflexia, clonus, tremors, and temperature of 41.1oC (106oF). Home medications included a chronic regimen for anxiety/depression with bupropion, buspirone, desvenlafaxine, trazodone, and ziprasidone, in addition to kratom. Clinical suspicion for serotonin syndrome led to initiation of cyproheptadine, lorazepam, and cooling blankets. Aphasia, facial droop, and confusion improved after administration of cyproheptadine. Bupropion was restarted during hospitalization; remaining medications restarted at the discretion of the primary care provider.

DISCUSSION

Risk of serotonin syndrome with multiple serotonergic agents is well-known. Kratom is metabolized by cytochrome P40 isozymes 3A4, 2C9, and 2D6, and exhibits inhibition at those enzymes, in addition to 1A2. Pharmacokinetic interactions of kratom with prescription serotonergic agents metabolized through these isozymes has the potential to increase systemic exposure of serotonin, potentially leading to serotonin syndrome.

CONCLUSION

Because substances contained in kratom can inhibit metabolism of prescription serotonergic medications, clinicians must be aware of potential development of serotonin syndrome.

Fentanyl-Induced Serotonin Syndrome 5 Days After Cessation of Serotonergic Agents: A Case Report

A 21-year-old patient with intellectual disability was admitted for gastroenteritis due to serotonergic medication overdose, and subsequently developed serotonin syndrome. Her symptoms initially improved after the cessation of serotonergic medications, but worsened 5 days later after fentanyl administration during general anesthesia. On emergence, she had convulsions and was nonresponsive. Subsequent imaging and electroencephalography did not demonstrate intracranial pathology or seizure activity. We suspect she had an exacerbation of her serotonin syndrome. She recovered successfully after supportive care. This case demonstrates that common medications used during anesthesia such as fentanyl can provoke serotonin syndrome, even several days after serotonergic drug discontinuation.

[The serotonin syndrome: why should cardiologists be aware and scared of it]

The serotonin syndrome (SS) represents a life-threatening adverse drug reaction, caused by serotonin overload in the central and peripheral nervous system, producing autonomic instability, neuromuscular and cardiovascular abnormalities, and cognitive alterations. The incidence of SS has been growing over the last few years, as a consequence of population aging and the steadily increasing use of pro-serotoninergic agents in clinical practice, in the presence of various comorbidities, mainly cardiovascular. Cardiologists often use combination therapies including serotoninergic agents, and should therefore consider the risk of serotoninergic adverse events caused by inappropriate drug interactions. SS is often difficult to diagnose and may be life-threatening if not adequately managed. Considering the several published case reports of overdose or not recommended associations, a greater awareness by clinicians about the potential risks associated with inappropriate use of these drugs is needed, as well as better information on the clinical features and therapeutic approaches to SS.

Incidence of serotonin syndrome in patients treated with fentanyl on serotonergic agents

BACKGROUND

There has been a recent surge in the literature highlighting the association of fentanyl as precipitating serotonin syndrome in patients on a serotonergic agent.

OBJECTIVE

The purpose of our study was to understand the incidence of serotonin syndrome in patients who receive fentanyl while on serotonergic agents.

STUDY DESIGN

This retrospective analysis was conducted from 2012 to 2013 after approval from the Institutional Review Board. We searched for all patients that had received a serotonergic agent and were admitted to the hospital during the study period. Next, we split these patients into 2 groups by placing all patients who had received fentanyl and a serotonergic agent into one group. We then searched for any of the Hunter Serotonin Toxicity Criteria in the records of patients that had received both fentanyl and a serotonergic agent. Further, we searched for all patients with serotonin syndrome mentioned in their records.

SETTING

This study was conducted at a 900 bed tertiary care academic center.

RESULTS

Over the 2 year study period, 112,045 patients were on a serotonergic agent, and 4,538 of these patients were treated with both fentanyl and a serotonergic agent. A search for Hunter's Criteria through the records of the patients receiving both fentanyl and a serotonergic agent revealed 23 patients had been documented with some of these symptoms. On detailed chart review, only 4 [95% CI 1 - 10] of these patients truly met Hunter's Criteria for serotonin syndrome. We then searched all admissions for a diagnosis code of serotonin syndrome during the study period. Five additional cases of serotonin syndrome were found, but none of these patients were treated with fentanyl.

LIMITATIONS

Some of the limitations of our study include that it represents a single institution, although it is a large academic center. An inherent limitation may be the under diagnosis of serotonin syndrome.

CONCLUSION

The incidence of serotonin syndrome in patients who receive both fentanyl and a serotonergic agent is low.

Serotonin and sudden death: differential effects of serotonergic drugs on seizure-induced respiratory arrest in DBA/1 mice

In the DBA/1 mouse model of sudden unexpected death in epilepsy (SUDEP), administration of a selective serotonin (5-HT) reuptake inhibitor (SSRI), fluvoxamine, completely suppressed seizure-induced respiratory arrest (S-IRA) at 30 min after administration (i.p.) in a dose-related manner without blocking audiogenic seizures (AGSz), but another SSRI, paroxetine, reduced S-IRA but with a delayed (24 h) onset and significant toxicity. A serotonin-norepinephrine reuptake inhibitor, venlafaxine, reduced S-IRA incidence, but higher doses were ineffective. A selective 5-HT7 agonist, AS-19, was totally ineffective in reducing S-IRA. In developing DBA/1 mice that had not previously experienced AGSz, administration of a nonselective 5-HT antagonist, cyproheptadine, induced a significantly greater incidence of S-IRA than that of saline. This study confirms that certain drugs that enhance the activation of 5-HT receptors are able to prevent S-IRA, but not all serotonergic drugs are equally effective, which may be relevant to the potential use of these drugs for SUDEP prevention. Serotonergic antagonists may be problematic in patients with epilepsy.

Headache as a presenting feature in patients with serotonin syndrome: a case series

INTRODUCTION

Serotonin syndrome (SS) is a drug-induced constellation of various clinical features that result from excess central serotonergic tone. The clinical features range from barely perceptible to life-threatening conditions.

CASES

We describe four patients with acute headache (four days to three weeks) who were receiving serotonergic drugs for other indications. There was a temporal relation between the administration of the serotonergic drugs and the development of the headaches. All four patients fulfilled the Hunter Serotonin Toxicity Criteria for SS. In parallel, two patients fulfilled the Sternbach's criteria for SS. Discontinuation of the serotonergic drugs and the administration of cyprohepatadine led to complete improvement in three to seven days in all four patients.

DISCUSSION

A review of the literature suggests that some overlaps exist in the pathophysiology between SS and headache disorders, including medication-overuse headache. The overlap is also in the management. The drugs found to be effective in SS (cyproheptadine, chlorpromazine, olanzapine, etc.) are also known to have positive effects on some headache disorders.

CONCLUSION

Physicians should consider the diagnosis of SS in patients with new onset or worsening headache after the addition of serotonergic drugs, especially in the presence of objective signs on examination suggestive of the disorder such as tremor, fever, hyperreflexia, diaphoresis or tachycardia.

Ecstasy use and serotonin syndrome: a neglected danger to adolescents and young adults prescribed selective serotonin reuptake inhibitors

BACKGROUND

At present, there are scarce clinical and basic lab data concerning the risk of acute serotonin toxicity from selective serotonin reuptake inhibitors (SSRIs) and 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) co-administration. The health care community can strongly benefit from efforts to address the high risks associated with serotonin syndrome from this specific drug combination.

OBJECTIVE

The aim of this work is to review the risk of serotonin syndrome in adolescents and young adults prescribed with SSRIs and are concurrently using ecstasy.

DATA SOURCES

An electronic search of the major behavioral science bibliographic databases (Pubmed, PsycINFO, Medline) was conducted to retrieve peer-reviewed articles, which detail the clinical characteristics, biological mechanisms and social implications of SSRIs, MDMA, and their potential synergism in causing serotonin syndrome in the pediatric and young adult population. Search terms included "serotonin syndrome", "ecstasy", "MDMA", "pediatric", and "SSRI". Additional references were incorporated from the bibliographies of these retrieved articles.

RESULTS

MDMA, in combination with the widely-prescribed SSRI antidepressant class, can lead to rapid, synergistic rise of serotonin (5-HT) concentration in the central nervous system, leading to the acute medical emergency known as serotonin syndrome. This review addresses such complication through an exploration of the theoretical mechanisms and clinical manifestations of this life-threatening pharmacological interaction.

CONCLUSION

The increasing incidences of recreational ecstasy use and SSRI pharmacotherapy among multiple psychiatric disorders in the adolescent population have made this an overlooked yet increasingly relevant danger, which poses a threat to public health. This can be curbed through further research, as well as greater health care provision and attention from a regulatory body owing.

Long-term adaptive changes induced by serotonergic antidepressant drugs

The development of conventional antidepressants has been largely based on the hypothesis of monoaminergic dysfunctions and focuses particularly on the serotonin 5-hydroxytryptamine (5-HT) system. Hence, various classes of antidepressant treatments enhance 5-HT neurotransmission with a time course consistent with their delayed therapeutic effect. This delayed onset appears to be associated with the gradual development of specific adaptive changes of functional 5-HT receptors. However, recent theories suggest that major depressive disorders may be associated with impairments of functional plasticity and cellular flexibility. This review discusses several physiological mechanisms by which 5-HT function and hippocampal neuroplasticity are regulated. Knowledge of these long-term adaptations will increase not only our understanding of pathological processes underlying affective disorders, but could also lead to the development of new strategies to treat these devastating illnesses.

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.

[Clinically significant drug-drug interactions between analgesics and psychotopics]

Combining analgesic and psychotropic drugs can lead to pharmacodynamic and pharmacokinetic drug interactions. Under treatment with several serotonergic substances serotonin syndrome can occur, e.g., with certain opioids and antidepressant drugs. Serotonin reuptake inhibitors also affect the serotonin level in platelets, this can raise the risk for gastrointestinal bleeding especially in combination with non-steroidal antirheumatic drugs. Anticholinergic effects and sedation are common side effects of psychotropic but also analgesic drugs with possible additive results. A wide range of interactions between analgesics and psychotropics can occure during metabolism, especially via the cytochrome-P-system. The clinical relevance of warnings on drug interactions from data banks has always to be judged for the individual patient.

[Extensive mesenteric ischemia related to naratriptan overuse associated with grapefruit juice absorption]

We reported the case of a 61-year-old woman, who has been hospitalized in ICU because of an extensive mesenteric ischaemia, involving the small bowel, secondary to a naratriptan overuse. This mesenteric ischaemia was complicated by multiple organ failure and was responsible for extensive small bowel resection and left colectomy. A concomitant abundant absorption of grapefruit juice, a well-known P450 inhibitor, may have enhanced this naratriptan toxicity. This case underscore that an abdominal pain occurring in the context of headache treatment may be related to a mesenteric ischaemia.

Evaluation of harm in the pharmacotherapy of irritable bowel syndrome

OBJECTIVE

Current treatment options for irritable bowel syndrome are limited and often poorly studied. A select few drugs have been studied in irritable bowel syndrome, and the number needed to treat is frequently used to assess the relative efficacy of these treatments. However, side effects are an important consideration in the clinical decision on which particular treatment to use. This study examines trials of subjects with irritable bowel syndrome with diarrhea and constipation who are receiving a drug intervention deemed of merit by the American College of Gastroenterology task force and compares these therapies to examine the number needed to harm using a systematic review and meta-analysis approach.

METHODS

Potential studies of irritable bowel syndrome treatments were identified through a search of MEDLINE (1950 to April 2011), EMBASE (1980 to April 2011), the Cochrane central register of controlled trials, and the bibliography of recent meta-analyses. Clinical trials of pharmacotherapy for irritable bowel syndrome were eligible for inclusion only if a description of adverse events and the number of patients who discontinued treatment because of adverse events were reported. The relative risk of experiencing an adverse event requiring discontinuation of treatment was used to determine the number needed to harm. In addition, the number and severity of adverse events were summarized.

RESULTS

Twenty-six clinical trials (4 with selective serotonin reuptake inhibitors, 3 with lubiprostone, 6 with tricyclic antidepressants, 8 with alosetron, and 5 with rifaximin) were included. Lubiprostone was safe with insignificant harm in one combined phase III trial. Selective serotonin reuptake inhibitors did not have enough data for a reliable meta-analysis of harm but seemed to be safe. More rigorous data were available for tricyclic antidepressants, alosetron, and rifaximin; the numbers needed to harm were 18.3, 19.4, and 8971, respectively, and the numbers needed to treat were 8, 7.5, and 10.6, respectively. For tricyclic antidepressant and alosetron, an adverse event resulting in discontinuation of the study medication occurred for every 2.3 and 2.6 patients who benefited from a drug, respectively. For rifaximin, this number was 846 patients. In addition, adverse events were more common with tricyclic antidepressants and alosetron.

CONCLUSION

In irritable bowel syndrome with diarrhea, tricyclic antidepressants and alosetron are associated with a significant number needed to harm compared with rifaximin. Apart from lubiprostone, treatment of irritable bowel syndrome with constipation is limited to small studies (with poor descriptions of side effects), although lubiprostone and selective serotonin reuptake inhibitors appear safe.

Human Ecstasy use is associated with increased cortical excitability: an fMRI study

The serotonergic neurotoxin, 3,4-methylenedioxymethamphetamine (MDMA/Ecstasy), is a highly popular recreational drug. Human recreational MDMA users have neurocognitive and neuropsychiatric impairments, and human neuroimaging data are consistent with animal reports of serotonin neurotoxicity. However, functional neuroimaging studies have not found consistent effects of MDMA on brain neurophysiology in human users. Several lines of evidence suggest that studying MDMA effects in visual system might reveal the general cortical and subcortical neurophysiological consequences of MDMA use. We used 3 T functional magnetic resonance imaging during visual stimulation to compare visual system lateral geniculate nucleus (LGN) and Brodmann Area (BA) 17 and BA 18 activation in 20 long abstinent (479.95±580.65 days) MDMA users and 20 non-MDMA user controls. Lifetime quantity of MDMA use was strongly positively correlated with blood oxygenation level-dependent (BOLD) signal intensity in bilateral LGN (r(s)=0.59; p=0.007), BA 17 (r(s)=0.50; p=0.027), and BA 18 (r(s)=0.48; p=0.031), and with the spatial extent of activation in BA 17 (r(s)=0.059; p=0.007) and BA 18 (r(s)=0.55; p=0.013). There were no between-group differences in brain activation in any region, but the heaviest MDMA users showed a significantly greater spatial extent of activation than controls in BA 17 (p=0.031) and BA 18 (p=0.049). These results suggest that human recreational MDMA use may be associated with a long-lasting increase in cortical excitability, possibly through loss of serotonin input to cortical and subcortical regions. When considered in the context of previous results, cortical hyper-excitability may be a biomarker for MDMA-induced serotonin neurotoxicity.

Prolonged serotonin toxicity with proserotonergic drugs in the intensive care unit

Serotonin toxicity secondary to drug therapy, interaction or overdose is an increasing phenomenon worldwide. A proportion of patients require admission to an intensive care unit, but the treatment needed is usually supportive and of short duration. Prolonged ICU admission to control ongoing or long-lasting serotonin toxicity has not been reported previously. We describe three patients with prolonged serotonin toxicity, lasting 12-18 days. Symptoms of toxicity were easily demonstrable in each and were refractory to currently recommended therapies. We review the pharmacological mechanisms that led to prolonged serotonin toxicity in these patients. Predictors for prolonged serotonin toxicity include involvement of irreversible monoamine oxidase inhibitors (MAOIs) or slow-release preparations resistant to the effects of activated charcoal (eg, lithium). We also discuss the implications of prolonged toxicity for critical care management, to maintain optimal patient outcomes.

Drug-induced fibrotic valvular heart disease

The initial association between the development of valvular heart disease and drugs stems from observations made during the use of methysergide and ergotamine for migraine prophylaxis in the 1960s. Since then, the appetite suppressants fenfluramine and dexfenfluramine, the dopamine agonists pergolide and cabergoline, and more recently, the recreational drug ecstasy (3,4 methylenedioxymethamphetamine; MDMA) have been implicated. Results from clinical trials show that drug dose and treatment duration affect both the risk of developing the disease and its severity. The natural history of the disease remains unclear, although regression of valvular lesions after the end of treatment has been reported. Interference with serotonin metabolism and its associated receptors and transporter gene seems a likely mechanism for development of the drug-induced valvular heart disease. Physicians need to balance the benefits of continued therapy with these drugs against possible risks. Further investigation is needed to assist with treatment decisions. Continued vigilance is necessary because several commonly prescribed treatments interact with serotonergic pathways.

Qualitative review of serotonin syndrome, ecstasy (MDMA) and the use of other serotonergic substances: hierarchy of risk

Growth of the antidepressant market and widespread use of the illicit drug ecstasy (methylenedioxymethamphetamine; MDMA) creates a need to delineate the potential harms associated with the concomitant use of ecstasy and serotonergic pharmaceutical drugs. One such harm is serotonin syndrome. The study aimed to synthesize the risk of serotonin syndrome associated with the concomitant use of ecstasy and other serotonergic substances in a clinically relevant hierarchy for psychiatrists and other medical practitioners. An extensive online database search was carried out of the literature on serotonin syndrome, in relation to illicit drugs and simultaneous use of other substances. Numerous licit and illicit substances implicated in serotonin syndrome, when used with ecstasy, have potential for increased toxicity and are presented in a resulting hierarchy of risk. Substances that inhibit serotonin re-uptake are less likely to lead to life-threatening elevations in serotonin when used with ecstasy. High doses or repeated use of stimulants such as methamphetamine and cocaine with ecstasy increase the risk of serotonin syndrome; as does the use of pharmaceutical amphetamine and ecstasy. Serotonin precursors also influence the course of serotonin syndrome when used with ecstasy. Substances that inhibit monoamine oxidase are most likely to lead to serious increases in serotonin when used with ecstasy. Findings highlight the importance of screening for the use of ecstasy and other serotonergic substances when prescribing antidepressant drugs.

Is recreational ecstasy (MDMA) use associated with higher levels of depressive symptoms?

Due to potential serotonergic deficits, 3,4-methylenedioxymethamphetamine (MDMA or Ecstasy) may cause long-term mood disruptions in recreational Ecstasy users. The purpose of this review is to evaluate the evidence for a relationship between recreational Ecstasy use and higher levels of depressive symptoms. Eleven out of 22 studies initially have reported significantly higher depression scores in Ecstasy users in comparison to control participants. However, only three studies ultimately have revealed significantly higher depression scores in comparison to cannabis or polydrug controls. Furthermore, most studies have suffered from methodological weaknesses, and the levels of depressive symptoms that have been found in Ecstasy users have not been shown to be much higher than those found in normative groups. The evidence for an association specifically between Ecstasy use and higher levels of depressive symptoms is currently unconvincing, but the frequent concomitant use of Ecstasy and other illicit drugs has been shown to be associated with higher levels of depressive symptoms. Possible causes include polydrug use in general, MDMA-induced serotonergic deficits, individual effects of illicit drugs besides Ecstasy, combined effects of MDMA and other illicit drugs, and preexisting differences in the levels of depressive symptoms in Ecstasy users.

Valvular Heart Disease Associated With Fenfluramine Detected 7 Years After Discontinuation of Treatment

We report the case of a patient referred to us for mitral and aortic valvular disease with a rheumatic appearance. The unusual macroscopic appearance on valve resection was not compatible with a rheumatic cause. A detailed review of this patient's clinical history (ie, a history of treatment with fenfluramine) suggested an iatrogenic cause, which was confirmed by histology. For the first time, a case of valvular heart disease that deteriorated was discovered 7 years after treatment with fenfluramine, whereas this iatrogenic disease classically resolves after discontinuation of treatment. This case illustrates the need for continuing heart valve surveillance of patients who have used these anorectics.

The psychotherapeutic potential of MDMA (3,4-methylenedioxymethamphetamine): an evidence-based review

AIMS AND RATIONALE: The purpose of this study was to review whether methylenedioxymethamphetamine (MDMA) has the appropriate pharmacodynamic profile to be a therapeutic agent.

MATERIALS AND METHODS

Empirical descriptions of MDMA's subjective effects in humans will be reviewed to evaluate the proposal that MDMA has psychotherapeutic properties. The focus will be published evidence on its functional effects in therapeutic, medical, and other situations.

RESULTS

MDMA is a powerful central nervous system (CNS) stimulant which affects several neurotransmitter systems and intensifies a range of psychobiological functions. Its acute mood effects can be very positive and life enhancing, and the affirmative cognitions engendered during MDMA therapy may well endure afterwards. However, MDMA also has a number of potential anti-therapeutic characteristics. Acutely, it can also intensify negative cognitions, and these may similarly endure over time. Psychotherapists have found that setting, intention, and expectancy are crucial for a positive outcome, but these factors cannot be guaranteed. Post-MDMA, there is a period of neurotransmitter recovery when low moods predominate, and these may exacerbate psychiatric distress. The explanations proposed for MDMA-assisted therapy are all psychodynamic, and a neurochemical model needs to be outlined. It has been suggested that enduring therapeutic gains can follow a single session, but again, this lacks a clear psychopharmacological rationale. Finally, diathesis-stress models suggest that psychiatric individuals are more prone to acute and chronic abreactions to CNS stimulants such as MDMA.

CONCLUSIONS

There are a number of issues which need to be addressed before it can be argued that MDMA might be clinically useful for psychotherapy.

Improvement or worsening of psychotic symptoms after treatment with low doses of aripiprazole

Aripiprazole, an antipsychotic recently introduced for clinical use, may worsen psychotic symptoms, even at low dose. In other cases, aripiprazole may exercise an antipsychotic action and induce extrapyramidal side-effects, even at low dose. There are no clear-cut criteria to differentiate the patients whose psychotic symptoms will or will not respond to aripiprazole favourably. Conversely, the effectiveness on negative symptoms seem consistent both in patients with or without antipsychotic response. A low dose may be indicated at the beginning of treatment to assess the kind of response.

[Visual cortes--is it a concern?]

The visual cortex may be involved in adverse drug reactions, leading to three different clinical presentations: cortical blindness, visual hallucinations and visual aura without headache. The drugs with potential visual cortex toxicity are described.

Neuroimaging research in human MDMA users: a review

RATIONALE

Determining whether, under what circumstances, and to what extent 3,4-methylenedioxymethamphetamine (MDMA) exposure produces chronic changes in human brain function is a critical public health issue. MDMA is a widely used recreational drug commonly sold as "Ecstasy". Because findings from the animal literature have indicated that specific dosage regimens of MDMA can produce long-lasting alterations in serotonergic function, existing studies of MDMA effects in humans have examined brain serotonin (5-HT) transporters (5-HTT) and receptors or have examined brain structures or functions potentially affected by MDMA.

OBJECTIVES

The objectives of this review are to provide a background for interpreting human MDMA neuroimaging research, to examine existing neuroimaging data regarding the rationale for and limitations to human MDMA research, and to provide suggestions for improving the design and interpretation of future neuroimaging approaches.

RESULTS

Of the existing neuroimaging studies in human MDMA users, few experimental designs have been replicated across different research groups. Only investigations employing nuclear imaging methods to assay brain 5-HTT levels have been replicated across methods and research laboratories. These studies have found reduced levels of the 5-HTT in recently abstinent MDMA users with some evidence for normalization of 5-HTT levels with prolonged abstinence. However, the sensitivity of these methods is unknown.

CONCLUSIONS

The current state of neuroimaging in human MDMA users does not permit conclusions regarding the long-term effects of MDMA exposure. Future study designs might benefit from improved sample homogeneity, increased length of MDMA abstinence, longitudinal study design, test-retest measures, serotonergic specificity, and multimodal approaches.

Neuroleptic malignant syndrome and serotonin syndrome

This chapter is focused on drug-induced hyperthermia with special regard to use of antipsychotics and antidepressants for the treatment of schizophrenia and major depression, respectively. Neuroleptic malignant syndrome (NMS) develops during the use of neuroleptics, whereas serotonin syndrome is caused mainly by serotoninergic antidepressants. Although both syndromes show various symptoms, hyperthermia is the main clinical manifestation. In this review we describe the historical background, clinical manifestations, diagnosis, and differential diagnosis of these two syndromes based on our observations on the experimental and clinical data.

Loss of serotonin transporter protein after MDMA and other ring-substituted amphetamines

We studied in vivo expression of the serotonin transporter (SERT) protein after 3,4-methylenedioxymethamphetamine (MDMA), p-chloroamphetamine (PCA), or fenfluramine (FEN) treatments, and compared the effects of substituted amphetamines to those of 5,7-dihydroxytryptamine (5,7-DHT), an established serotonin (5-HT) neurotoxin. All drug treatments produced lasting reductions in 5-HT, 5-HIAA, and [(3)H]paroxetine binding, but no significant change in the density of a 70 kDa band initially thought to correspond to the SERT protein. Additional Western blot studies, however, showed that the 70 kDa band did not correspond to the SERT protein, and that a diffuse band at 63-68 kDa, one that had the anticipated regional brain distribution of SERT protein (midbrain>striatum>neocortex>cerebellum), was reduced after 5,7-DHT and was absent in SERT-null animals, was decreased after MDMA, PCA, or FEN treatments. In situ immunocytochemical (ICC) studies with the same two SERT antisera used in Western blot studies showed loss of SERT-immunoreactive (IR) axons after 5,7-DHT and MDMA treatments. In the same animals, tryptophan hydroxylase (TPH)-IR axon density was comparably reduced, indicating that serotonergic deficits after substituted amphetamines differ from those in SERT-null animals, which have normal TPH levels but, in the absence of SERT, develop apparent neuroadaptive changes in 5-HT metabolism. Together, these results suggest that lasting serotonergic deficits after MDMA and related drugs are unlikely to represent neuroadaptive metabolic responses to changes in SERT trafficking, and favor the view that substituted amphetamines have the potential to produce a distal axotomy of brain 5-HT neurons.

Persistent cerebrovascular effects of MDMA and acute responses to the drug

Acutely, 3,4,-methylenedioxymethamphetamine (MDMA) induces cerebrovascular dysfunction [Quate et al., (2004)Psychopharmacol., 173, 287-295]. In the longer term the same single dose results in depletion of 5-hydroxytrptamine (5-HT) nerve terminals. In this study we examined the cerebrovascular consequences of this persistent neurodegeneration, and the acute effects of subsequent MDMA exposure, upon the relationship that normally exists between local cerebral blood flow (LCBF) and local cerebral glucose utilization (LCMRglu). Dark agouti (DA) rats were pre-treated with 15 mg/kg i.p. MDMA or saline. Three weeks later, rats from each pre-treatment group were treated with an acute dose of MDMA (15 mg/kg i.p.) or saline. Quantitative autoradiographic imaging was used to measure LCBF or LCMRglu with [(14)C]-iodoantipyrine and [(14)C]-2-deoxyglucose, respectively. Serotonergic terminal depletion was assessed using radioligand binding with [(3)H]-paroxetine and immunohistochemistry. Three weeks after MDMA pre-treatment there were significant reductions in densities of 5-HT transporter (SERT)-positive fibres (-46%) and [(3)H]-paroxetine binding (-47%). In animals pre-treated with MDMA there were widespread significant decreases in LCMRglu, but no change in LCBF indicating a persistent loss of cerebrovascular constrictor tone. In both pre-treatment groups, acute MDMA produced significant increases in LCMRglu, while LCBF was significantly decreased. In 50% of MDMA-pre-treated rats, random areas of focal hyperaemia indicated a loss of autoregulatory capacity in response to MDMA-induced hypertension. These results suggest that cerebrovascular regulatory dysfunction resulting from acute exposure to MDMA is not diminished by previous exposure, despite a significant depletion in 5-HT terminals. However, there may be a sub-population, or individual circumstances, in which this dysfunction develops into a condition that might predispose to stroke.

Recreational ecstasy use and depression

Research in laboratory animals has shown that 3,4-methylenedioxymethamphetamine (MDMA or ecstasy) destroys serotonergic axons in the brain at certain doses. Serotonin is known to take part in the regulation of mood in humans. Many researchers have hypothesized that if recreational ecstasy use destroys serotonergic axons, then a corresponding decline in the mood of ecstasy users should be seen. The purpose of the present study was to look at the relationship between recreational ecstasy use and depression as measured by the Beck Depression Inventory-II. No significant differences were found between Beck Depression Inventory-II scores of heavy ecstasy users and ecstasy-naive college students. No significant relationships were found between Beck Depression Inventory-II scores and any of the measures of ecstasy use. Most ecstasy users who had been diagnosed with a psychiatric disorder reported that being diagnosed preceded their use of ecstasy.

A randomized, double-blind, placebo-controlled trial of the efficacy and tolerability of a 4-mg dose of subcutaneous sumatriptan for the treatment of acute migraine attacks in adults

OBJECTIVE

The aim of this study was to evaluate the efficacy and tolerability of a single 4-mg dose of sumatriptan SC for the acute treatment of adult patients experiencing a migraine attack with moderate to severe pain.

METHODS

In this randomized, double-blind, placebo-controlled study, subjects included men and women aged 18 to 60 years who had migraine with or without aura, as defined by the 1988 International Headache Society criteria. Subjects received either sumatriptan 4 mg SC or placebo SC for a migraine attack with headache pain of moderate to severe intensity. The primary efficacy measurement was pain relief at 2 hours. Secondary efficacy measures included the severity of headache pain at 10, 20, 30, 40, 50, 60, and 90 minutes postadministration. Clinical assessments of pain severity and adverse events were made by way of questioning and observation of subjects and were completed at 10, 20, 30, 40, 50, 60, 90, and 120 minutes postadministration.

RESULTS

Five hundred seventy-seven subjects (87% female and 94% white) participated in this study. Three hundred eighty-four received sumatriptan and 193 received placebo. At 120 minutes postadministration, sumatriptan 4 mg SC was associated with greater proportions of patients who experienced pain relief (70% vs 22%; P<0.001) or were pain free (50% vs 11%; P<0.001). In addition, there were statistically significant differences between sumatriptan 4 mg SC and placebo for multiple secondary end points, including pain relief as early as 10 minutes postadministration (11% vs 6%; P=0.039), pain-free status as early as 30 minutes postadministration (10% vs 3%; P<0.001), nausea as early as 30 minutes postadministration (39% vs 49%; P=0.021), and photophobia as early as 10 minutes postadministration (80% vs 87%; P=0.046). The most common adverse events in the sumatriptan 4-mg SC and placebo groups, respectively, were injection-site reactions (43% and 15%), tingling (12% and 3%), dizziness or vertigo (10% and 5%), and warm or hot sensation (8% and 2%). Treatment groups were not statistically compared for adverse events.

CONCLUSIONS

Sumatriptan 4 mg SC was effective for the acute treatment of migraine attacks and was generally well tolerated in these patients.

[Psychiatric and cognitive long-term effects of ecstasy]

BACKGROUND

MDMA (ecstasy) has been a popular recreational drug among young people. MDMA modulates serotonergic activity in the brain and has been shown to be toxic to serotonergic neurons in animals. Disturbances in this neurotransmitter system lead to neuropsychiatric symptoms, hence it has been a concern that use of ecstasy in humans would lead to a higher frequency of psychiatric disease and cognitive impairment. We wanted to review human studies to find evidence for these side effects of ecstasy.

MATERIALS AND METHODS

We investigated 10 studies regarding the connection between use of ecstasy and mental health, as well as 20 studies regarding the connection between use of ecstasy and cognitive impairment. Three of these studies were longitudinal, the others were cross-sectional.

RESULTS AND INTERPRETATION

There is a higher frequency of both psychiatric illness and cognitive impairment among ecstasy users. On the other hand, many methodological factors must be considered before causality is assumed.

Chronic treatment with a serotonin(2) receptor (5-HT(2)R) agonist modulates the behavioral and cellular response to (+)-3,4-methylenedioxymethamphetamine [(+)-MDMA]

3,4-Methylenedioxymethamphetamine [MDMA; ecstasy] evokes a multifaceted subjective experience in human users which includes stimulation, feelings of well-being, mood elevation, empathy towards others as well as distortions in time, sensation and perception. Aspects of this unique psychopharmacology of MDMA are thought to be related to its potent actions to release serotonin (5-HT) and indirectly stimulate the 5-HT(2A) receptor (5-HT(2A)R). In the present studies, we examined the interrelationship between down-regulation of 5-HT(2A)R expression and the behaviorally stimulatory effects generated by acute administration of (+)-MDMA, the most potent enantiomer of (+/-)-MDMA. Male Sprague-Dawley rats were chronically treated with the preferential 5-HT(2A)R agonist 2,5-dimethoxy-4-iodoamphetamine (DOI) which has been shown to down-regulate expression of the 5-HT(2A)R, but not the closely related 5-HT(2C)R. While chronic DOI treatment did not alter the functional sensitivity of either the 5-HT(2A)R or 5-HT(2C)R, this regimen enhanced (+)-MDMA-evoked hyperactivity. Subsequent analysis of c-Fos and 5-HT(2A)R immunoreactivity in brain sections demonstrated that DOI treatment decreased the number of (+)-MDMA-induced c-Fos immunopositive nuclei and 5-HT(2A)R immunostaining in select cortical and striatal areas. These results indicate that chronic DOI exposure results in an enhanced behavioral response to (+)-MDMA and in a pattern of neuronal activation which resembles that seen in psychostimulant sensitization. These data also suggest that expression of the 5-HT(2A)R in the NAc and PFC may play a role in the sensitivity to the locomotor-stimulating effects of (+)-MDMA and in the processes of neural regulation upon repeated psychostimulant administration.

Prevalence and correlates of current depressive symptomatology among a community sample of MDMA users in Ohio

Research suggests that MDMA can cause serotonin depletion as well as serotonergic neurodegradation that may result in depression among users of the drug. Several small-scale studies have used various editions of the Beck Depression Inventory (BDI) to quantify depressive symptomatology among MDMA users. This study represents the largest application of the BDI to date to explore symptoms of current depression among a community sample of young adult MDMA users (n = 402). Internal consistency testing of the BDI-II with this sample revealed Cronbach's alpha = .92. Results show a mean BDI-II score of 9.8, suggesting low levels of depressive symptomatology among study participants. Two-thirds of the sample had scores that placed them in the non-depressed/minimal depression category, while 4.7% had scores indicative of severe depression. Logistic regression analysis revealed that men were significantly less likely than women and people who used opioids were significantly more likely than non-users to have higher levels of depressive symptomatology. Higher lifetime occasions of MDMA use were marginally related to symptoms of serious depression.

Drug withdrawals and the lessons within

Drug withdrawals over recent decades have triggered changes in the way that drug targets and screening programs are researched and designed. In the cases having the greatest impact, the reason for withdrawal was the reversible interaction of a drug or its metabolite with a single receptor, ion channel or enzyme (primary or secondary pharmacology). Once this interaction is identified, screens can be established and validated. When the mechanism is complex (eg, organ toxicity), however, such screens are difficult to implement and usually examine only the initial step, leading to considerable problems in extrapolation and risk definition. This review classifies drugs withdrawn from the US market over the last 25 years by their reasons for withdrawal, and examines how drug discovery programs have been modified in response to these events.

Psychobiological correlates of delayed ejaculation in male patients with sexual dysfunctions

The pathogenesis of delayed ejaculation (DE) is rather unknown, though the contribution of various psychological, marital, hormonal, and neurological factors has been advocated. In this study we systematically investigated the relative relevance of the aforementioned factors in 1,632 men who were seeking medical help for sexual dysfunction. The severity of DE was classified according to Kaplan criteria. Mild and moderate forms of DE (MMDE) recognized different risk factors than the most severe ones (anejaculation or severe DE [ASDE]). ASDE was essentially coupled with the presence of neurological diseases or with the use of serotoninergic drugs. Serotoninergic drugs also significantly increase (by at least 10-fold) the risk for MMDE, which, however, was also coupled with other relational factors (eg, partner's impaired climax, patient's hypoactive sexual desire [HSD]) or intrapsychic factors (eg, stress at work). At multiple regression analysis, some organic pathological conditions (such as psychiatric disorders and hypogonadism) were also associated with MMDE. In particular, hypogonadism retained significance for DE even after adjustment for HSD (adjusted odds ratio = 2.08 [1.11-3.89]; P < .05), suggesting other effects of testosterone deficiency on the ejaculatory reflex besides reduced libido. In conclusion, the present study demonstrates that multiple psychobiological determinants are associated with DE, a still obscure condition that substantially impairs psychosexual equilibrium of the couple.

Das Serotoninsyndrom

The serotonin-syndrome is a possible side-effect in the treatment with serotonergic drugs. There are diagnostic criteria for diagnosis of this syndrome. After discontinuation of administering the serotonergic drug is fully reversible.

[3,4-methylenedioxymethamphetamine ('ecstasy'): its long-term emotional and cognitive effects, and serotonin depletion]

AIMS

The main objective of this study is to describe the different neuropsychological deficits associated to the consumption of 3,4-methylenedioxymethamphetamine (MDMA or 'ecstasy'), as well as the growing evidence that attributes these deficits to the selective axonal damage to serotoninergic cells brought about by this substance.

DEVELOPMENT

MDMA is an amphetamine derivative that, like its precursor, has properties as a stimulant. Part of its chemical structure is similar to that of the hallucinogen mescaline with which it shares the capacity to alter perception. Nevertheless, the primary pharmacological effect of this substance, which is what usually leads to its use and abuse, is chiefly linked to an intense positive emotional state. This effect on the individual's mood is also usually accompanied by numerous feelings of empathy, sociability and closeness, which turn this drug into a powerful entactogenic agent (a term used in psychotherapy to describe a state of wellbeing, closeness and emotional self-awareness produced by certain compounds). The antidepressant and entactogenic effects induced by an acute dose of MDMA can be accounted for by the notable increase in serotonin bioavailability triggered by the drug. Repeated consumption of MDMA, however, ends up affecting many functions that have been related to the serotoninergic systems, such as sleep, appetite, attention and memory, or one's emotional state.

CONCLUSIONS

Most of the neuropsychological disorders found in individuals who take ecstasy on a regular basis can be explained by the selective neurodegeneration processes that the drug appears to produce in the serotonin terminals of the brain in the long run.

Serotonin Toxicity Associated with Concomitant Use of Linezolid

OBJECTIVE:

To report 2 cases of serotonin toxicity (ST) associated with concomitant use of linezolid and serotonergic drugs and review previously published case reports.

CASE SUMMARIES:

Case 1. A 38-year-old white female with cystic fibrosis treated with venlafaxine 300 mg/day for one year was prescribed linezolid 600 mg intravenously every 12 hours for treatment of methicillin-resistant Staphylococcus aureus (MRSA) pulmonary infection. She displayed symptoms of ST 8 days after the introduction of linezolid. The venlafaxine dosage was decreased to 150 mg/day, and symptoms gradually abated over 36 hours. Case 2. A 37-year-old male with multiple myeloma received citalopram 40 mg/day and trazodone 150 mg/day for anxiety-related disorders. Linezolid treatment with 600 mg orally twice daily was instituted for MRSA cellulitis. The following day, the patient developed anxiety, panic attacks, tremors, tachycardia, and hypertension that persisted throughout linezolid treatment. Symptoms finally waned 5 days after linezolid treatment was stopped.

DISCUSSION:

The symptoms observed in our patients were consistent with Sternbach's criteria for ST. A review of published case reports showed a short time to onset of symptoms following the introduction of linezolid, generally within 1–3 days. Also of note is the use of relatively high dosages of serotonergic drugs. Use of the Naranjo probability scale indicated a possible relationship between the use of linezolid and the occurrence of ST in both cases.

CONCLUSIONS:

Clinicians should pay special attention to patients treated with serotonergic drugs, especially those receiving dosages in the higher end of the normal range who are prescribed linezolid, and consider tapering or reducing the dosage of serotonergic drugs for the duration of antibiotic therapy.

Serotonergic antidepressant effects on aggressive, self-injurious and destructive/disruptive behaviours in intellectually disabled adults: a retrospective, open-label, naturalistic trial

There is a growing body of evidence that serotonergic antidepressants are useful in the treatment of maladaptive behaviours in the intellectually disabled. However, not all studies have shown positive results due to lack of efficacy, tolerance development, and troublesome side-effects. The current study consisted of a review of the treatment response to a variety of serotonergic antidepressants, consisting of selective serotonin reuptake inhibitors (SSRIs ) (n = 36) and clomipramine (n = 2) in 38 institutionalized intellectually disabled adults (20 males, 18 females; mean age 45.6 yr, age range 18-74 yr). Those studied were treated for aggression, self-injurious behaviours, destructive/disruptive behaviours, depression/dysphoria, or a combination of these or other challenging behaviours. Most were receiving concurrent psychotropic and/or anticonvulsant medications. Effectiveness was determined by a retrospective review of the summaries of multidisciplinary Neuropsychiatric Behavioural Reviews (NBRs) in which global and specific maladaptive behaviours were rated on a 1- to 7-point scale, and by psychologists' ratings of target behaviours. Overall, statistically significant decreases in the ratings of global maladaptive behaviour and aggression, self-injurious behaviour, destruction/disruption and depression/dysphoria and in psychologists' ratings occurred in the subject group after the initiation of antidepressants. The results suggest that serotonergic antidepressants are useful in the treatment of challenging/maladaptive behaviours in the intellectually disabled.

Deadly drug interactions in emergency medicine

Many life-threatening drug interactions are predictable, avoidable events. Emergency medicine physicians have a responsibility to recognize and prevent drug interactions. Keeping current on the many pharmaceutical therapies,their pharmacology, and potential drug interactions currently represents one of the biggest challenges for emergency medicine practitioners. Using current drug interaction resources and knowing the limited number of medications that are responsible for the most serious drug interactions can ease this seemingly overwhelming burden greatly. Clinicians need to be particularly vigilant when prescribing drugs for patients who are taking medications with potential for drug interactions leading to serious consequences.

Prescription weight loss pill use among Americans: patterns of pill use and lessons learned from the fen-phen market withdrawal

BACKGROUND

Despite the popularity of antiobesity medications, there is a lack of population-based data on their use. In addition, response (termination of pill use and receipt of an echocardiogram) to the fenfluramine and dexfenfluramine market withdrawal among the public has not been described. Lessons learned from this event have implications for future withdrawals.

METHODS

We used data from the Behavioral Risk Factor Surveillance System (BRFSS) a random-digit telephone survey. In 1998, six states included detailed questions about the use of prescription weight loss pills in the previous 2 years, n = 16,460 noninstitutionalized adults aged 18 years or older.

RESULTS

Almost one third of prescription weight loss pills users were not obese before taking pills. Family and friends and other nonphysicians were reported as sources of medication by one in ten users. One third of users also reported taking nonprescription diet products. Among fenfluramine or dexfenfluramine users, one third continued pill use after the market withdrawal and only one quarter received echocardiograms.

CONCLUSIONS

Despite enormous publicity, many persons continued to use fen-phen after the market withdrawal and most did not receive follow-up echocardiograms. Our study raises issues regarding the effectiveness of withdrawal warnings in a small but significant subset. Additional means of communicating risk to individuals are needed for future product withdrawals including special strategies for those lacking healthcare coverage.

Effets aigus et à long terme de l’ecstasy

Side effects in the short term Recreational use of Ecstasy (3,4-methylenedioxymethamphetamine or MDMA), a synthetic drug, has considerably increased over the last decade. Since its appearance it is associated with the rave culture, but its use has spread to other social settings. The drug produces euphoria and empathy, but can lead to side effects, notably acute, potentially lethal, toxicity (malignant hyperthermia and/or hepatitis). Neurotoxicity in the long-term Moreover, MDMA has been shown to induce long-term deleterious effects and provoke neurotoxic affecting the serotoninergic system. However, the psychopathological consequences of such neurotoxicity are still controversial, particularly since many ecstasy consumers are multi-drug users. A complex pharmacological profile The mechanism of action of MDMA involves various neurobiological systems (serotonin, dopamine, noradrenalin), that may all interact.

A voxel-based PET investigation of the long-term effects of "Ecstasy" consumption on brain serotonin transporters

OBJECTIVE

Recent functional imaging studies have reported evidence of alterations in the serotonergic system induced by 3,4-methylenedioxymethamphetamine (MDMA), or "Ecstasy." However, these studies have often been limited by small sample size, lack of tracer selectivity, unreliable assessment of MDMA doses, insufficiently matched comparison groups, or region-of-interest analysis.

METHOD

Positron emission tomography (PET) using the specific serotonin transporter ligand [(11)C](+)McN5652 was performed in 117 subjects: 30 current MDMA users, 29 former MDMA users, 29 drug-naive comparison subjects, and 29 users of drugs other than MDMA (polydrug comparison subjects). Self-assessment of drug history was checked by analyzing hair samples. Local serotonin transporter availability was computed by a regularized reference tissue approach. Voxel-based comparison of serotonin transporter availability was performed using statistical parametric mapping (SPM 99).

RESULTS

Serotonin transporter availability in current MDMA users was significantly reduced in the mesencephalon, thalamus, left caudate, hippocampus, occipital cortex, temporal lobes, and posterior cingulate gyrus compared with all other groups. Reduction was more pronounced in female than in male subjects. There was no significant difference of serotonin transporter availability among former MDMA users and the drug-naive and polydrug comparison subjects. A negative correlation between serotonin transporter availability and mean MDMA dose was found in occipital visual areas and in the left precentral sulcus of current MDMA users. In addition, there was a significant positive correlation between the serotonin transporter availability and the MDMA abstention period in brainstem and in the basal forebrain in all MDMA users.

CONCLUSIONS

These findings support the hypothesis of MDMA-induced protracted alterations of the serotonergic system and indicate that the reduced availability of serotonin transporter, as measured by PET, might be reversible. Women appear to be more susceptible than men to MDMA-induced alterations of the serotonergic system.

Plasticity of the acoustic startle reflex in currently abstinent ecstasy (MDMA) users

RATIONALE

3,4-Methylenedioxymethamphetamine (MDMA, ecstasy) is neurotoxic upon central serotonin systems in experimental animals and probably also in humans. Serotonin is involved in the habituation, sensitization and prepulse inhibition (PPI) of the startle reflex.

OBJECTIVES

To study the plasticity of startle reflex in currently abstinent MDMA users.

METHODS

Electromyographic responses to acoustic startle stimuli (pulse alone and prepulse-pulse trials) were recorded in 23 currently abstinent ecstasy users and 20 matched control subjects. Depending on the extent of their previous drug use ecstasy users were divided into two groups [life-time dose <90 (n=11) and > or =90 pills (n=12), respectively].

RESULTS

There were no significant differences in habituation, sensitization or PPI of the startle reflex between the entire group of ecstasy users and controls. However, sensitization of the startle reflex was stronger in the > or =90 compared with either the <90 MDMA pills or the control group. Correlations between patterns of drug use and startle parameters did not reach the level of significance, although users with a younger age at the onset of MDMA (and other drug) use tended to present with higher sensitization of the startle reflex.

CONCLUSIONS

Heavy users of MDMA (and other recreational drugs) present with strong sensitization of the startle reflex. Nevertheless, it is unclear whether this finding is secondary to the use of MDMA and its well-recognized neurotoxic potential. Alternatively, strong sensitization might reflect a pre-existing trait predisposing to drug use. A clearer picture of the impact of ecstasy on startle plasticity may be obtained from longitudinal investigations.