Determination of stimulants using gas chromatography/high-resolution time-of-flight mass spectrometry and a soft ionization source.

Filed under: Methadone Side Effects

Rapid Commun Mass Spectrom. 2012 Dec 15; 26(23): 2714-24
Lopez-Avila V, Cooley J, Urdahl R, Thevis M

The aim of this study was to investigate the mass spectral fragmentation of a small set of stimulants in a high-resolution time-of-flight mass spectrometer equipped with a soft ionization source using vacuum ultraviolet (VUV) photons emitted from different plasma gases. It was postulated that the use of a plasma gas such as Xe, which emits photons at a lower energy than Kr or Ar, would lead to softer ionization of the test compounds, and thus to less fragmentation.A set of nine stimulants: cocaine, codeine, nicotine, methadone, phenmetrazine, pentylenetetrazole, niketamide, fencamfamine, and caffeine, was analyzed by gas chromatography/time-of-flight mass spectrometry (GC/TOFMS) in positive ion mode with this soft ionization source, using either Xe, Kr, or Ar as plasma gases. Working solutions of the test compounds at 0.1 to 100?ng/?L were used to establish instrument sensitivity and linearity.All test compounds, except methadone and pentylenetetrazole, exhibited strong molecular ions and no fragmentation with Xe-microplasma photoionization (MPPI). Methadone exhibited significant fragmentation not only with Xe, but also with Kr and Ar, and pentylenetetrazole could not be ionized with Xe, probably because its ionization energy is above 8.44?eV. The Kr- and Ar-MPPI mass spectra of the test compounds showed that the relative intensity of the molecular ion decreased as the photon energy increased.When coupled to a TOF mass spectrometer this soft ionization source has demonstrated signal-to-noise (S/N) ratios from 7 to 730 at 100?pg per injection (depending on the compound), and a dynamic range of three orders of magnitude (100?pg to 100?ng) for some of the test compounds. Copyright © 2012 John Wiley & Sons, Ltd.
HubMed – Methadone

Do drug treatment variables predict cognitive performance in multidrug-treated opioid-dependent patients? A regression analysis study.

Filed under: Methadone Side Effects

Subst Abuse Treat Prev Policy. 2012 Nov 2; 7(1): 45
Rapeli P, Fabritius C, Kalska H, Alho H

ABSTRACT: BACKGROUND: Cognitive deficits and multiple psychoactive drug regimens are both common in patients treated for opioid-dependence. Therefore, we examined whether the cognitive performance of patients in opioid-substitution treatment (OST) is associated with their drug treatment variables. METHODS: Opioid-dependent patients (N = 104) who were treated either with buprenorphine or methadone (n = 52 in both groups) were given attention, working memory, verbal, and visual memory tests after they had been a minimum of six months in treatment. Group-wise results were analysed by analysis of variance. Predictors of cognitive performance were examined by hierarchical regression analysis. RESULTS: Buprenorphine-treated patients performed statistically significantly better in a simple reaction time test than methadone-treated ones. No other significant differences between groups in cognitive performance were found. In each OST drug group, approximately 10% of the attention performance could be predicted by drug treatment variables. Use of benzodiazepine medication predicted about 10% of performance variance in working memory. Treatment with more than one other psychoactive drug (than opioid or BZD) and frequent substance abuse during the past month predicted about 20% of verbal memory performance. CONCLUSIONS: Although this study does not prove a causal relationship between multiple prescription drug use and poor cognitive functioning, the results are relevant for psychosocial recovery, vocational rehabilitation, and psychological treatment of OST patients. Especially for patients with BZD treatment, other treatment options should be actively sought.
HubMed – Methadone

Factors associated with HCV antiviral treatment uptake among participants of a community-based HCV programme for marginalized patients.

Filed under: Methadone Side Effects

J Viral Hepat. 2012 Dec; 19(12): 836-42
Charlebois A, Lee L, Cooper E, Mason K, Powis J

While the majority of cases of hepatitis C virus (HCV) in developed countries occur among illicit drug users, HCV antiviral treatment uptake is poor in this population. Several studies have shown that patients can successfully be treated for HCV in the context of methadone maintenance programmes, but little evidence exists evaluating HCV treatment models for substance users where methadone maintenance is not indicated. This retrospective cohort study involved 129 persons participating in psycho-educational support groups and integrated, interprofessional, community-based health services focused on the treatment for HCV among marginalized populations with high rates of crack cocaine use and mental health comorbidities. We sought to identify the factors associated with antiviral treatment uptake. Group participation improved access to health care. While 19% had previously seen an HCV specialist prior to group initiation, 59% saw an HCV specialist during the group. Half of the participants were nonimmune to hepatitis A or B at baseline, and 80% of these patients received immunization through the programme. The programme treated 24 patients with pegylated interferon and ribavirin and achieved a sustained virologic response (SVR) rate of 91% for genotype 2 or 3 and 54% for genotype 1. Stable housing was independently associated with initiation of treatment, and there was a nonsignificant trend towards lower rates of treatment initiation among women. SVR rates for those who had used crack or injection drugs in the month prior to joining the programme did not differ significantly from those who had abstained.
HubMed – Methadone

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