View clinical trials related to Amphetamine-related Disorders.
Filter by:Extended-release naltrexone (XR-NTX, VIVITROL) is an FDA-approved medication with efficacy in treating alcohol dependence and prevention of relapse to opioid dependence. It has shown promise in reducing relapse to amphetamine use among amphetamine-dependent, yet currently amphetamine-abstinent heterosexuals. The investigators will expand upon this promising work to determine whether monthly intramuscular injections of naltrexone will reduce methamphetamine (meth) use among actively using, meth-dependent men who have sex with men (MSM) in this double-blind randomized controlled trial of extended-release naltrexone versus placebo. The investigators will focus on MSM because of the disproportionate and intertwining epidemics of meth use and HIV in this population.
The purpose of this study is to determinate the effect of a pre-treatment with doxazosin, a alpha1-adrenergic receptor blocker, on the pharmacodynamics and pharmacokinetics of 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy"). The investigators hypothesize that doxazosin will attenuate the cardiovascular and subjective response to MDMA.
Illicit use of the psychostimulant "Ecstasy" (3,4-methylenedioxymethamphetamine, MDMA) is considered a major public health issue. In Switzerland, MDMA and congeners are - after cannabis and cocaine - number three in the ranking of the most popular illicit drugs. Worldwide, Ecstasy is estimated to be even the second most popular illicit drug, used by millions of regular users. On the basis of animal data, it is likely that MDMA at high or cumulative doses damages serotonin (5-HT) neurons in the human brain. However, because of a multitude of methodological problems and a limited number of studies conducted in human subjects, no firm conclusions can yet be established whether chronic MDMA exposure produces a long lasting 5-HT deficiency syndrome, with consequent neuropsychiatric risks. To further address the putative neurotoxicity of MDMA in the human brain, we propose that novel functional assays of serotonergic neurotransmission may be useful to clarify this issue. We suggest that a 5-HT challenge study using positron emission tomography (PET) in conjunction with the 5-HT releaser dexfenfluramine [(+)FEN] may test the functional integrity of the 5-HT system in the living human brain. Specifically, in a placebo-controlled study, the 5-HT release capacity of serotonergic neurons shall be investigated by assessing [18F]-altanserin binding to 5-HT2A receptors following (+)FEN challenge in former and continuing MDMA users, and age and sex-matched MDMA-naïve controls. (+)FEN is a potent serotonin releaser without relevant affinity for 5-HT, dopamine (DA) or norepinephrine (NE) receptors, and devoid of acute adverse effects in man. This makes (+)FEN an ideal pharmacological probe to explore functional integrity of serotonin neurotransmission. A second aim of our investigation is to detect possible impairments of cognitive functions and to study their relationship to serotonin neurotransmission as indexed by PET. In the course of the neuroimaging study, the investigators therefore also measure cognitive (e.g. attention, visual and working memory, learning, executive function) and affective functions (e.g. anxiety, impulsivity), suspected to be altered due to chronic MDMA use. Using correlational analyses, the investigators aim to determine if circumscribed regions of altered 5-HT function are associated with specific impairments in cognitive and/or behavioural parameters. We hypothesize that (+)FEN-evoked 5-HT release will discernibly alter availability of 5-HT2A receptors to [18F]-altanserin, with a pattern revealing the spatially heterogeneous vulnerability of 5-HT innervations to MDMA. The investigators predict that [18F]-altanserin volume of distribution (DV) will decline following (+)FEN challenge to a lesser extent in current MDMA users compared to MDMA-naïve control subjects. On the basis of animal data and recent neuroimaging studies in humans, the investigators hypothesize that functional recovery in former MDMA users will be manifest by a normalization or overshoot of the 5-HT release capacity. Our methodology will allow us to quantitatively assess serotonergic functions in the living human brain. The novel combination of (+)FEN-induced release of 5-HT from intracellular storage vesicles and subsequent PET assessment of competitively altered [18F]-altanserin binding at postsynaptic 5-HT2A receptors will provide a more direct biological marker of in vivo serotonin function than has been hitherto available. By applying this new pharmacological challenge/PET neuroimaging approach to groups of current and former users of MDMA, the investigators shall be able to gain important new insight in the debated functional consequences of MDMA use, especially concerning the controversy about the reversibility of 5-HT changes following cessation of MDMA use. Successful completion of this project should have useful implications for public education and harm reduction with respect to MDMA use, and may also facilitate the development of possible treatment options for chronic MDMA users.
The purpose of this study is to determinate the effect of a pre-treatment with carvedilol, a alpha- and beta-adrenergic receptor blocker, on the pharmacodynamics and pharmacokinetics of 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy"). The investigators hypothesize that carvedilol will attenuate the cardiovascular and subjective response to MDMA.
The purpose of this study is to determinate the effect of a pre-treatment with centrally acting alpha2-receptor agonist clonidine on the pharmacodynamics and pharmacokinetics of 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy"). The investigators hypothesize that clonidine will attenuate the subjective and cardiovascular response to MDMA.
Until positive results were found with oral naltrexone, no medication has been effective against amphetamine dependence. The primary aim of this pilot study is to replicate the findings of the Swedish team that showed oral Naltrexone prevented relapse to amphetamine addiction and to extend their results by randomizing treatment-seeking amphetamine addicted patients to a 6 month course of VIVITROL (naltrexone for extended-release injectable suspension) or VIVITROL placebo. Patients in each group will receive drug counseling. VIVITROL is administered monthly and may be a better test of efficacy than tablets that must be taken daily.
The purpose of this study is to determinate the effect of a pre-treatment with the combined serotonin (5-HT) and norepinephrine (NE) transport blocker duloxetine on the pharmacodynamics and pharmacokinetics of 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy"). The investigators hypothesize that duloxetine will attenuate the subjective and cardiovascular response to MDMA.
MDMA (3,4-Methylenedioxymethamphetamine, "Ecstasy") produces tachycardia, hypertension, hyperthermia, and other acute adverse effects. Ecstasy use has also been associated with rare cardio- and cerebrovascular complications. The role of beta-blockers in the treatment of cardiovascular and adverse effects of MDMA is unknown.
MDMA releases dopamine, serotonin, and norepinephrine in the brain. Serotonin uptake inhibitors have been shown to interact with 3,4-Methylenedioxymethamphetamine (MDMA) and to decrease its psychoactive and cardiovascular stimulant effects. This finding indicates that MDMA acts in part by releasing serotonin through the serotonin uptake site. However, in vitro studies show that MDMA binds more potently to the norepinephrine uptake site that to the the serotonin or dopamine uptake transporter. In addition, norepinephrine uptake site blockers such antidepressant drugs attenuate some of the behavioral effects of MDMA in animals. These preclinical data indicate that norepinephrine may also contribute to the response to MDMA in humans. To test this hypothesis this study evaluates the interacting effects of the selective norepinephrine transporter inhibitor reboxetine on the subjective and cardiovascular stimulant effects of MDMA in healthy volunteers.
This study seeks to decrease methamphetamine use and concomitant high-risk sexual behaviors among methamphetamine-using men who have sex with men (MSM) by combining a biomedical intervention with a behavioral intervention. The behavioral intervention will consist of an 8-week course of contingency management (CM) through which participants will be reinforced for testing negative for methamphetamine metabolites during periodic urine analyses. The biomedical intervention involves a 28-day course of an antiretroviral drug (Truvada) to be administered after an unanticipated HIV risk exposure (i.e., engaging in either receptive or insertive anal sex without a condom with someone who is HIV-positive or of unknown status). In combining these two interventions, this study seeks to evaluate the combined intervention's effects on sexual risk behaviors and methamphetamine use.