SEARCH · PubMed Health

Results for “Methamphetamine”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,117 records · Page 62Linked to original sources

PubMed2002

Precursor medications as a source of methamphetamine and/or amphetamine positive drug testing results.

Medical Review Officer interpretation of laboratory results is an important component of drug testing programs. The clinical evaluation of laboratory results to assess the possibility of appropriate medical use of a drug is a task with many different facets, depending on the drug class considered. This intercession prevents the reporting of positive results unless it is apparent that drugs were used illicitly. In addition to the commonly encountered prescribed drugs that yield positive drug testing results, other sources of positive results must be considered. This review describes a series of compounds referred to as "precursor" drugs that are metabolized by the body to amphetamine and/or methamphetamine. These compounds lead to positive results for amphetamines even though neither amphetamine nor methamphetamine were used, a possibility that must be considered in the review of laboratory results. Description of the drugs, their clinical indications, and results seen following administration are provided. This information allows for the informed evaluation of results with regard to the potential involvement of these drugs.

Amphetamine↗

PubMed1997

Methamphetamine toxicity: treatment with a benzodiazepine versus a butyrophenone.

Patients with methamphetamine toxicity often present to the emergency department (ED) agitated, violent and psychotic. To determine the efficacy of a benzodiazepine versus a butyrophenone for chemical restraint we conducted a prospective, randomized study at a large urban university ED between January 1995 and January 1997. Patients were randomized to receive either lorazepam or droperidol intravenously. A 6-point sedation scale was devised, with 6 representing extreme agitation and 1 deep sleep. Sedation scores were recorded at time 0, 5, 10, 15, 30 and 60 min. Vital signs were recorded at time 0 and at 60 min. If sedation was inadequate, repeat dosages of each drug could be repeated at 30 min. Toxicology screen, ethanol and creatinine phosphokinase levels were obtained. A total of 146 patients were evaluated. Seventy-four patients received lorazepam and 72 received droperidol. Both drugs had similar sedation profiles at 5 min. Patients receiving droperidol had significantly improved sedation scores at times 10, 15, 30 and 60 min than lorazepam (p < 0.001). More repeat doses of lorazepam were given (26) than droperidol (6) at 30 min. Both drugs produced significant reduction in pulse, systolic blood pressure, respiratory rate, and temperature over 60 min. We conclude droperidol produces a more rapid and profound sedation than lorazepam for methamphetamine toxicity. Lorazepam is more likely to require repeat dosing than droperidol.

Adult↗

PubMed2005

The effects of hepatitis C, HIV, and methamphetamine dependence on neuropsychological performance: biological correlates of disease.

OBJECTIVE: To determine the effects of hepatitis C virus (HCV) infection on neuropsychological (NP) performance. DESIGN: Cross-sectional analysis of a prospectively enrolled cohort. METHODS: A total of 239 HIV-seropositive and 287 HIV-seronegative subjects enrolled in prospective cohort studies at a single center. Subjects underwent standardized assessments, including comprehensive neuropsychological testing, substance use inventory neuromedical examination, venipuncture, and lumbar puncture. HCV antibody was measured in serum. In seropositive individuals, HCV RNA was measured in plasma and cerebrospinal fluid (CSF). RESULTS: HCV-seropositive subjects performed worse on neuropsychological testing and were almost twice as likely to be diagnosed as globally impaired, compared with those who were HCV seronegative. In a multivariate analysis, HCV, HIV, and methamphetamine dependence were independently associated with worse performance, even after adjusting for Centers for Disease Control stage and antiretroviral use. HCV-RNA levels in plasma were higher in those with memory, but not global, impairment. In cerebrospinal fluid, HCV RNA was below 100 copies/ml in all specimens. In HIV-infected subjects, HCV was associated with higher levels of HIV RNA in CSF, but not in plasma. HCV was also associated with higher levels of monocyte chemotactic protein 1, TNF-alpha, and soluble TNF receptor II. HCV-seropositive subjects did not appear to have advanced liver disease. CONCLUSIONS: HIV, HCV, and methamphetamine independently injure the central nervous system, leading to global neuropsychological impairment. HCV may injure the brain by viral or immune-mediated mechanisms. HCV-associated brain injury may be preventable or reversible because HCV infection is potentially curable.

Adult↗

PubMed2003

Repetitive self-mutilation among Japanese eating disorder patients with drug use disorder: comparison with patients with methamphetamine use disorder.

Repetitive self-mutilation and drug use disorder are less prevalent in Japan, although the prevalence of eating disorder is comparable with rates in Western countries. However, repetitive self-mutilation has not previously been described in relation to eating disorder and drug use disorder in Japan. Subjects consisted of 19 patients with eating disorders and drug use disorders (ED+DUD) and 12 patients with methamphetamine use disorders (MAP). Subjects were drawn from 180 patients who were referred because of eating disorders and 22 patients who were referred because of methamphetamine-related problems. All subjects underwent a semistructured interview. Repetitive self-mutilation tended to be more prevalent among ED+DUD patients than MAP patients. Conversely, history of oppositional defiant disorder and antisocial personality disorder tended to be more prevalent in MAP patients than in ED+DUD patients. The low prevalence of repetitive self-mutilation appears to be due to low risk factors in Japan, even though the pathogenesis of these behaviors seems to be universal.

Adult↗

PubMed2003

Sequential versus nonsequential measurement of density and affinity of dopamine D2 receptors with [11C]raclopride: effect of methamphetamine.

The multiple ligand concentration assays (MLCRA) method provides researchers with the ability to measure in vivo receptor characteristics in a stable condition. Measurements of the density and affinity of the dopamine D2 receptors with [11C]raclopride, using a sequential method (three scans throughout 1 day) or a nonsequential method (three scans spread over several weeks but at the same time of the day), yield similar values. However, after an acute challenge with drugs that affect dopamine neurotransmission, the concentration of endogenous ligand may vary over the course of the in vivo sequential MLCRA. Combined PET-microdialysis studies after acute amphetamine showed that during the imaging time frame the concentrations of extracellular dopamine vary widely, but that nonetheless the decrease in raclopride binding potential is sustained and nearly constant over time. These observations apparently contradict the simple competitive displacement model if the changes in extracellular concentration are taken to reflect necessarily comparable changes at the binding sites. To understand the effect of the delay between drug administration and start-to-end of data acquisition on the MLCRA results, we compared the outcomes of the sequential and nonsequential methods after methamphetamine. Comparison of the binding potential, density, and affinity of D2 receptors in both experimental conditions revealed good concordance between the data sets, suggesting that methamphetamine produces sustained and stable increases in synaptic dopamine.

Animals↗

PubMed1988

Chemotaxis for methamphetamine in Escherichia coli.

Escherichia coli showed the chemotactic response for methamphetamine, a biogenic stimulative amine. The response was qualitatively detected by using a paper disk filter. The quantitative assay showed that E. coli responded to methamphetamine at 10(-5) M or more.

Chemotaxis↗

PubMed1988

Alterations of accumbens neuronal activity in freely moving rats following methamphetamine.

Multiple unit activity in the nucleus accumbens, locomotor activity, and stereotyped behavior were simultaneously recorded in freely moving rats. An intraperitoneal injection of 1.5 mg/kg methamphetamine produced an increase in the firing rate while a decrease in the discharge rate occurred following an administration of 4.5 mg/kg methamphetamine. In addition, the unit activity was positively correlated with the locomotor activity and negatively correlated with the stereotypy score. These results suggest that accumbens neuronal activation during locomotor hyperactivity may partly depend on the feedback from locomotion.

Animals↗

PubMed1990

Chronic schizophrenia-like states in methamphetamine psychosis.

In order to clarify the characteristic psychopathology of chronic methamphetamine (MAP) psychosis, the clinical symptoms of 11 chronic MAP psychotics were compared with those of the same number of chronic schizophrenics matched for sex and age. The positive symptoms were almost similar in both groups. However, the negative symptoms evaluated by the Scale for the Assessment of Negative Symptoms (SANS) differed considerably. According to the SANS, the scores of avolition-apathy, anhedonia-asociality and attentional impairment were moderately high in both groups. The scores of affective flattening or blunting and alogia were lower in the MAP group than those in the schizophrenia group. The SANS scores of negative symptoms increased in accordance with the age of onset in the MAP group, while such a correlation was not observed in the schizophrenia group. Furthermore, detailed clinical observations of the patients revealed the following differences between the two groups: 1) spontaneous affective expression during the interviews was more vivid in the MAP group compared to the schizophrenia group, and 2) affective expressions or interpersonal behaviors changed immediately depending on the situation in the MAP group. From the viewpoint of clinical psychopathology, a group of MAP psychotics whose hallucinatory-delusional state persisted for a long period of one month or more after cessation of MAP use seemed to differ from either chronic schizophrenics or patients with acute MAP psychosis. The author proposed that this group of patients should be a clinical entity and be called as "residual methamphetamine psychosis."

Adult↗

PubMed1992

Lack of effect of haloperidol or methamphetamine treatment on the mRNA levels of two dopamine D2 receptor isoforms in rat brain.

In order to investigate whether changes of the two mRNAs encoding the D2 receptor isoforms were induced by chronic haloperidol or methamphetamine treatment in rats, we measured the brain mRNA levels using in situ hybridization histochemistry (ISHH). We used two oligonucleotide probes, an "insert" probe to hybridize with the longer D2 receptor, D2(444), mRNA, and a "spanning" probe to hybridize with the shorter D2 receptor, D2(415), mRNA. Both D2 mRNAs were detected by ISHH in the caudate putamen, nucleus accumbens, substantia nigra, pars compacta and ventral tegmental area. The distributions and the amounts of the mRNAs for the two D2 isoforms did not change after chronic administration of haloperidol (1 mg/kg/day for 14 days, ip) or methamphetamine (4 mg/kg/day for 14 days, ip). These results suggest that the changes of D2 receptor density induced by chronic neuroleptic and psychostimulant treatment are not due primarily to receptor expression.

Animals↗

PubMed2004

Long-term suppression of methamphetamine-induced c-Fos expression in rat striatum by the injection of c-fos antisense oligodeoxynucleotides absorbed in water-absorbent polymer.

The use of water-absorbent polymer (WAP) as a hydrogel carrier for the slow delivery of antisense oligodeoxynucleotides (ODN) in the brain, was recently developed. In this experiment, 15-mer phosphorothioate ODN, complementary to c-fos gene absorbed in WAP, was injected in the rat striatum. The expression of c-Fos-immunoreactivity induced by methamphetamine (6 mg/kg, intraperitoneally) around the injection site was suppressed until 5 days after injection. Using this method, it was observed that unilateral injection with c-fos antisense ODN into the rat striatum caused robust ipsilateral rotations after methamphetamine challenge 4 days post injection. This method is simple, and the biological and behavioral effects of antisense ODN in WAP can be maintained for several days even after a single injection into the brain.

Animals↗

PubMed2005

Relapse antecedents for methamphetamine use and related factors in Taiwanese adolescents.

The purpose of the present study was to identify the relapse antecedents for methamphetamine (MAMP) use in Taiwanese youth, and to examine the relationships between attribution of these antecedents, demographic variables, psychiatric disorders, characteristics of MAMP use, attitudes toward MAMP use, and personality. A total of 60 Taiwanese adolescents who had previously experienced MAMP relapse were studied. Their relapse antecedents for MAMP use were evaluated using the Questionnaire for Relapse Antecedents of Methamphetamine Use. Their psychiatric disorders were also assessed. The relationships among the relapse antecedents of MAMP use, demographic variables, MAMP-use characteristics, psychiatric disorders, attitudes toward MAMP use and personality were analyzed. The results of the analysis reveal that social pressure to use MAMP was the leading antecedent of relapse. Social adaptation, emotional stability, and education level were the factors that influenced adolescents' attributions of relapse antecedents for MAMP use. However, psychiatric disorder status and attitudes toward MAMP use were not related to any of the relapse antecedents. The results indicate that multiple factors influenced adolescents' attributions of relapse antecedents for MAMP use, and may serve as a basis for construction of models for teaching adolescents to manage the antecedents and reduce the risk of relapse of MAMP use.

Adolescent↗

PubMed2006

Phosphodiesterase 1B differentially modulates the effects of methamphetamine on locomotor activity and spatial learning through DARPP32-dependent pathways: evidence from PDE1B-DARPP32 double-knockout mice.

Mice lacking phosphodiesterase 1B (PDE1B) exhibit an exaggerated locomotor response to D-methamphetamine and increased in vitro phosphorylation of DARPP32 (dopamine- and cAMP-regulated phosphoprotein, M r 32 kDa) at Thr34 in striatal brain slices treated with the D1 receptor agonist, SKF81297. These results indicated a possible regulatory role for PDE1B in pathways involving DARPP32. Here, we generated PDE1B x DARPP32 double-knockout (double-KO) mice to test the role of PDE1B in DARPP32-dependent pathways in vivo. Analysis of the response to d-methamphetamine on locomotor activity showed that the hyperactivity experienced by PDE1B mutant mice was blocked in PDE1B-/- x DARPP32-/- double-KO mice, consistent with participation of PDE1B and DARPP32 in the same pathway. Further behavioral testing in the elevated zero-maze revealed that DARPP32-/- mice showed a less anxious phenotype that was nullified in double-mutant mice. In contrast, in the Morris water maze, double-KO mice showed deficits in spatial reversal learning not observed in either single mutant compared with wild-type mice. The data suggest a role for PDE1B in locomotor responses to psychostimulants through modulation of DARPP32-dependent pathways; however, this modulation does not necessarily impact other behaviors, such as anxiety or learning. Instead, the phenotype of double-KOs observed in these latter tasks may be mediated through independent pathways.

Analysis of Variance↗

PubMed2000

Neonatal methamphetamine in the rat: evidence for gender-specific differences upon tyrosine hydroxylase enzyme in the dopaminergic nigrostriatal system.

Methamphetamine (Meth) neurotoxicity upon the mesencephalic dopaminergic systems was demonstrated in the adult, both in humans and in experimental models. In the rat, the development and maturation of the dopaminergic systems is accomplished during the first month of postnatal life, a period of particular vulnerability to environmental influences. In this study, the effect of Meth exposure during the first month of life was assessed in the nigrostriatal dopaminergic system of the rat. For this purpose, Wistar rat litters were culled to 8 pups, retaining preferentially 4 males and 4 females, which, in the day following birth (postnatal day 1, PND1), were randomly attributed to either the Meth or control group. Meth-groups were administered 10 mg of (+)-methamphetamine hydrochloride/kg body weight/day, subcutaneously, twice daily, from PND1 until PND29; control groups received isovolumetric doses of saline. Animals were sacrificed at PND30. Males exposed to Meth during the first month of life had increased tyrosine hydroxylase (TH) activity both in the caudate-putamen and substantia nigra. Males also had increased nigral TH mRNA levels, as assessed by in situ hybridization. These effects did not exist in females. These results support the evidence that Meth exposure during the first month of life in the rat has a gender-specific stimulatory effect upon the maturation of TH, the key enzyme for dopamine biosynthesis in the nigrostriatal dopaminergic system.

Analysis of Variance↗

PubMed2002

Structural and functional cellular alterations underlying the toxicity of methamphetamine in rat retina and prefrontal cortex.

The consumption of illicit drugs is an increasing problem in contemporary societies, and is one of the major causes of death and illness all over the world. Methamphetamine is among the drugs more widely used. Although evidence for a role of reactive species--especially reactive oxygen species (ROS) and apoptotic events--has been shown, the mechanism(s) underlying the cellular toxicity induced by this drug is not yet fully identified. In this context the elucidation of the cytotoxic effects induced by methamphetamine in rat frontal cortex and retina, which compromise cell viability and ultimately result in cell death, can further contribute to the understanding of its mechanism of action. This knowledge may provide new insights into the development of new therapeutic approaches to prevent or ameliorate deleterious alterations of the nervous system. The use of epifluorescence microscopy associated with different fluorescent probes, markers of structural and/or functional cell parameters, can be used as a powerful tool to carry out those studies, in particular, the viability probes propidium iodide (PI) to assess plasma membrane integrity and fluorescein diacetate (FDA), which can monitor intracellular esterase activity and/or pH. In a preliminary study, the kinetic assessment of cellular changes induced by different drug concentrations (0, 1.2, 3, and 6 mM) allowed detection of dose-dependent alterations that are observed earlier in the retina. In fact, in the retina it was possible to monitor alterations (at 4 h of incubation) both in plasma membrane integrity and in esterase activity and/or pH for the lowest drug concentration (1.2 mM). In the prefrontal cortex these changes were only visible for drug concentrations > or = 3 mM. This work is a novel approach to the mechanisms of action of illicit drugs in the central nervous system and will provide the foundations and guidelines for further investigations in the context of tolerance, dependence, and addiction.

Animals↗

PubMed2004

Drug discrimination in methamphetamine-trained monkeys: effects of monoamine transporter inhibitors.

The involvement of brain monoamine systems in the discriminative stimulus effects of methamphetamine (MA) was studied in squirrel monkeys by evaluating the effects of differentially selective monoamine uptake inhibitors alone and in combination. In monkeys discriminating i.m. injections of 0.3 mg/kg MA from saline, methamphetamine (0.01-0.3 mg/kg), and dopamine transporter (DAT) inhibitors, including 1-[2-(bis(4-fluorophenyl)-methoxy)ethyl]-4-(3-phenylpropyl)piperazine (GBR 12909; 1.0-17.8 mg/kg) and its analogs AM2502 (1.0-17.8 mg/kg), AM2506 (1.0-30.0 mg/kg), AM2515 (1.0-17.8 mg/kg), and AM2517 (1.0-5.6 mg/kg), produced dose-related increases in responding on the MA-associated lever and, at the highest doses, full substitution. The time course of MA-like effects was similar for equivalent (3.0 mg/kg) doses of GBR 12909 and its most potent analog, AM2517. Unlike the DAT blockers, the selective 5-hydroxytryptamine (serotonin) uptake inhibitor clomipramine (1.0-10.0 mg/kg) and the selective norepinepherine (NE) uptake inhibitor desipramine (1.0-10 mg/kg) produced responding primarily on the saline lever. The selective NE uptake inhibitor nisoxetine partially substituted at the highest dose tested (10.0 mg/kg). Pretreatment with GBR 12909 or AM2517 enhanced the discriminative stimulus effects of MA, shifting the dose-effect curve leftward. The NE uptake inhibitors desipramine or nisoxetine also enhanced the discriminative stimulus effects of MA, whereas clomipramine only attenuated them. These results support the view that dopaminergic mechanisms play a prominent role in the discriminative stimulus effects of MA in monkeys, whereas involvement of serotonergic and noradrenergic systems may be limited to a modulatory role.

Animals↗

PubMed1971

Methamphetamine-induced insulin release.

Administration of methamphetamine or amphetamine to rats and mice produces a rapid increase in the level of immunoassayable plasma insulin not attributable to hyperglycemia. While in the mouse this release of insulin is followed consistently by a profound hypoglycemia, in the rat this response is variable. Studies in vitro demonstrate that insulin is released by a direct effect of methamphetamine on the pancreas.

Animals↗

PubMed1994

Stroke associated with methamphetamine inhalation.

Seven patients (all men, mean age 32 years, range 17-47) with stroke following methamphetamine inhalation were collected during the last 2 years. Like oral or intravenous abusers, our patients had more hemorrhagic (n = 5) than ischemic strokes (n = 2). Cases of intracerebral hemorrhage (ICH) were lobar (n = 3), caudate (n = 1) or putaminal (n = 1), whereas the infarctions were both in the middle cerebral artery region. Each stroke event occurred within 3 days after drug use. Three patients had hypertension on admission. Though young in age, most patients had multiple stroke risk factors. In 3 patients with ICH, we also found small, low attenuated lesions on the brain computed tomography, however, without clinical correlations. Except for arteriovenous malformation in 1 patient, all angiograms failed to show vasculopathy or vasospasm. Contrary to what one might surmise from previously published reports, methamphetamine inhalation is at least as likely to produce ICH as it is to produce brain infarction.

Administration, Inhalation↗

PubMed1986

Effects of methamphetamine on arterioles of rat caudate nucleus and midbrain.

No differences in arteriolar metabolic profiles from rat caudate nucleus, ventral tegmental area or substantia nigra were observed between saline-control and methamphetamine HCl-treated (20 mg/kg, i.p. twice daily for 10 consecutive days) animals. Arterioles from the above regions of forebrain and midbrain are metabolically active vessels with a capacity for aerobic and anaerobic metabolism. These results suggest that a high dose of methamphetamine does not alter cerebral arteriolar metabolism in the areas examined.

Animals↗