Drug and alcohol dependence
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Drug Alcohol Depend · Apr 2013
Comparative StudyCorrected QT interval during treatment with methadone and buprenorphine--relation to doses and serum concentrations.
Methadone and buprenorphine are widely used in the treatment of opioid addiction. Some study results suggest that methadone can be associated with QT interval prolongation and torsades de pointes ventricular arrhythmias, whereas no such risk has been observed for buprenorphine. The aim of this study is to determine the risk of corrected QT interval (QTc) increase among patients treated with these medications in an opioid maintenance treatment (OMT) programme, and to study possible associations between QTc changes and serum concentrations of methadone or buprenorphine. ⋯ These results support and extend previous findings that treatment with methadone in modest doses (i.e. below 100mg/d) is not associated with clinically significant QTc increases, and that buprenorphine in commonly used doses is a suitable alternative to methadone with regard to the risk of QTc prolongation.
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Drug Alcohol Depend · Apr 2013
Decreased frontal lobe phosphocreatine levels in methamphetamine users.
Mitochondria-related mechanisms have been suggested to mediate methamphetamine (METH) toxicity. However, changes in brain energetics associated with high-energy phosphate metabolism have not been investigated in METH users. Phosphorus-31 ((31)P) magnetic resonance spectroscopy (MRS) was used to evaluate changes in mitochondrial high energy phosphates, including phosphocreatine (PCr) and β-nucleoside triphosphate (β-NTP, primarily ATP in brain) levels. We hypothesized that METH users would have decreased high-energy PCr levels in the frontal gray matter. ⋯ The present findings suggest that METH compromises frontal lobe high-energy phosphate metabolism in a dose-responsive manner. Our findings also suggest that the abnormality in frontal lobe high-energy phosphate metabolism might be more prominent in female than in male METH users. This is significant as decreased PCr levels have been associated with depressive symptoms, and poor responses to antidepressant treatment have been reported in those with decreased PCr levels.
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Drug Alcohol Depend · Apr 2013
Heavy smokers show abnormal microstructural integrity in the anterior corpus callosum: a diffusion tensor imaging study with tract-based spatial statistics.
Abnormal macrostructural brain abnormalities in both gray matter and white matter have been reported in cigarette smokers. However, less is known about white matter microstructure in heavy cigarette smokers. In this study, we used diffusion tensor imaging (DTI) to investigate the integrity of the white matter microstructure in heavy smokers. ⋯ Our findings suggest that heavy smokers demonstrate abnormal integrity of the white matter microstructure in the anterior corpus callosum, which is related to the duration of regular smoking. In addition, our study may increase the understanding of the neurobiological basis of chronic cigarette smoking.