Long-term Use of Z-Hypnotics and Co-medication with Benzodiazepines and Opioids.

Benzodiazepine-like drugs (z-hypnotics) are the most commonly used drugs for treatment of insomnia in Norway. Z-hypnotics are recommended for short-term treatment not exceeding 4 weeks. We aimed to study the use of z-hypnotics in the adult population in Norway with focus on recurrent use in new users, treatment intensity and co-medication with benzodiazepines and opioids in long-term users.

Determination of dopamine concentrations in brain extracellular fluid using microdialysis with short sampling intervals, analyzed by ultra high performance liquid chromatography tandem mass spectrometry.

Introduction: An increase in striatal dopamine is considered essential for the rewarding and reinforcing effects of drugs of abuse. We have developed and validated an ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method for the analysis of dopamine in rat brain extracellular fluid (ECF) sampled with microdialysis. The method was applied to monitor changes in dopamine concentrations over time after an intravenous bolus injection of heroin.

Codeine to morphine concentration ratios in samples from living subjects and autopsy cases after incubation.

The codeine to morphine concentration ratio is used in forensic toxicology to assess if codeine has been ingested alone or if morphine and/or heroin have been ingested in addition. In our experience, this interpretation is more difficult in autopsy cases compared with samples from living persons, since high morphine concentrations are observed in cases where only codeine is assumed to have been ingested. We have investigated if codeine and morphine glucuronides are subject to cleavage to the same extent in living and autopsy cases in vitro.

The interference of ethanol with heroin-stimulated psychomotor activation in mice is not related to changed brain concentrations of the active metabolites 6MAM or morphine.

It has been suggested that the potentiating effect observed in human beings when combining alcohol and heroin may be due to an interference of ethanol with the pharmacokinetics of heroin, leading to accumulation of the biologically active metabolites, 6-monoacetylmorphine (6MAM) and morphine. However, experimental evidence for this hypothesis is lacking. In this study, we used mice and examined the effect of ethanol on the metabolism of heroin by combining a locomotor activity test, which is a behaviour model representative of psychomotor stimulation, with pharmacokinetic studies in blood and brain tissue.

Levels of heroin and its metabolites in blood and brain extracellular fluid after i.v. heroin administration to freely moving rats.

Background And Purpose: Heroin, with low affinity for μ-opioid receptors, has been considered to act as a prodrug. In order to study the pharmacokinetics of heroin and its active metabolites after i.v.