Influence of ethanol on the pharmacokinetic properties of Δ9-tetrahydrocannabinol in oral fluid.

Oral fluid (OF) tests aid in identifying drivers under the influence of drugs. In this study, 17 heavy cannabis users consumed alcohol to achieve steady blood alcohol concentrations of 0 to 0.7 g/L and smoked cannabis 3 h afterward.

Neurophysiological functioning of occasional and heavy cannabis users during THC intoxication.

Rationale: Experienced cannabis users demonstrate tolerance to some of the impairing acute effects of cannabis.

Objectives: The present study investigates whether event-related potentials (ERPs) differ between occasional and heavy cannabis users after acute Δ9-tetrahydrocannabinol (THC) administration, as a result of tolerance.

Methods: Twelve occasional and 12 heavy cannabis users participated in a double-blind, placebo-controlled, crossover study.

MDMA (ecstasy) effects on actual driving performance before and after sleep deprivation, as function of dose and concentration in blood and oral fluid.

Rationale: Experimental research has shown that 3,4-methylenedioxymethamphetamine (MDMA) can improve some psychomotor driving skills when administered during the day. In real life, however, MDMA is taken during the night, and driving may likely occur early in the morning after a night of "raving" and sleep loss.

Objectives: The present study assessed the effects of MDMA on road-tracking and car-following performance in on-the-road driving tests in normal traffic.

Influence of ethanol on cannabinoid pharmacokinetic parameters in chronic users.

Cannabis is not only the most widely used illicit drug worldwide but is also regularly consumed along with ethanol. In previous studies, it was assumed that cannabis users develop cross-tolerance to ethanol effects. The present study was designed to compare the effects of ethanol in comparison to and in combination with a cannabis joint and investigate changes in pharmacokinetics.

Application of LC-TOF MS to analysis of hemoglobin acetaldehyde adducts in alcohol detoxification patients.

Acetaldehyde adducts of hemoglobin have been regarded as potential biochemical markers of alcohol exposure. In this study a novel sensitive method using liquid chromatography coupled to time-of-flight mass spectrometry (LC-TOF MS) has been used to investigate changes in adduct levels in alcohol detoxification patients. Hemoglobin and authentic blood samples from 66 adults with an alcohol-dependence syndrome and from 12 children were analyzed for acetaldehyde modifications with and without trypsin digestion using LC-TOF MS.

Influence of ethanol on the pharmacokinetics of methylphenidate's metabolites ritalinic acid and ethylphenidate.

In view of the widespread application of methylphenidate for attention-deficit/ hyperactivity disorder (ADHD) therapy its interaction with alcohol was investigated in an in-vitro assay and in a study involving 9 male volunteers. The study conditions were: methylphenidate (20 mg) only, methylphenidate followed by ethanol (0.8 g/kg body weight) and ethanol followed by methylphenidate.

Pharmacokinetic properties of delta9-tetrahydrocannabinol in oral fluid of occasional and chronic users.

Saliva is of continuing interest in detecting the influence of drugs while driving. Commercial tests are currently available where cannabis detectability is a major challenge. The present study aids in the understanding of tetrahydrocannabinol (THC) pharmacokinetics in oral fluid.

Cantharidin and demethylcantharidin (palasonin) content of blister beetles (Coleoptera: Meloidae) from southern Africa.

In two species of meloid beetles, Hycleus oculatus and Hycleus tinctus, from southern Africa, cantharidin and demethylcantharidin (palasonin) were assayed quantitatively. For cantharidin the mean value per specimen was about 1 mg for H. oculatus and 0.

Comparison of cannabinoid pharmacokinetic properties in occasional and heavy users smoking a marijuana or placebo joint.

Cannabinoid pharmacokinetics in occasional users is well studied, but the interpretation of data from heavy users is difficult. In the present study, blood pharmacokinetic properties were investigated in occasional and heavy users in cannabis and placebo conditions. The results obtained with occasional users were in contrast to those of the heavy users who admitted cannabis use on 4-25 occasions during the previous week.

Criminal poisoning of commuters in Bangladesh: prospective and retrospective study.

Travel-related poisoning is an emerging social and public health emergency in Bangladesh but its cause and significance have not been determined. To investigate this syndrome we performed a prospective clinical study and retrospective analysis of hospital records in a general medicine unit of a public tertiary care teaching hospital in Dhaka, Bangladesh, using toxicological analysis by fluorescence polarization immunoassay (FPIA) and liquid chromatography coupled to time-of-flight mass spectrometry (LC-TOF MS). The participants of the prospective study were 130 consecutive patients aged 16-80 years who were admitted with central nervous system depression (Glasgow Coma Score 3-14) after using public transportation, in the absence of other abnormalities, from January through June 2004, and a convenience sample of 15 such patients admitted during 3 days in May 2006.

Determination of clopidogrel main metabolite in plasma: a useful tool for monitoring therapy?

This study was performed to determine whether analysis of clopidogrel and its main carboxylic acid metabolite in plasma provides additional information about the wide variability of platelet aggregation inhibition in clopidogrel-treated patients with peripheral arterial occlusive disease. Consecutive outpatients (n = 56) with stable peripheral arterial occlusive disease treated with 75 mg clopidogrel daily, without co-administration of aspirin, were investigated. With use of a standardized questionnaire, the time of drug intake was documented.

Day-night expression patterns of clock genes in the human pineal gland.

Rhythm generation within the mammalian circadian system is achieved by clock genes and their protein products. As an integral part of this system, the pineal gland serves the need to tune the body to the temporal environment by the rhythmic synthesis and release of melatonin. A number of human disorders and syndromes are associated with alterations in circadian rhythms of clock genes and their protein products and/or a dysfunction in melatonin synthesis.

Pharmacokinetic properties of delta9-tetrahydrocannabinol in serum and oral fluid.

In a study on the effects of smoked cannabis (18.2 +/- 2.8 mg as low and 36.

Lack of bufadienolides in the skin secretion of red bellied toads, Melanophryniscus spp. (Anura, Bufonidae), from Uruguay.

The South-American red bellied toads (Melanophryniscus spp.) belonging to the Bufonidae family contain toxic alkaloids in their skin, predominantly of the pumiliotoxin group. Whole animal methanolic extracts of individual specimens of three species (Melanophryniscus atroluteus, M.

Assay of Delta9-tetrahydrocannabinol (THC) in oral fluid-evaluation of the OraSure oral specimen collection device.

Oral fluid is considered to be an alternative to urine testing for the detection of acute ingestion of drugs. The OraSure Intercept DOA Oral Specimen Collection Device (OSCD) has been used in studies for the quantitation of Delta9-tetrahydrocannabinol (THC), but concerns have been raised. In the present study, we investigated whether the volume of oral fluid can be determined and how much THC remains adsorbed on the device.

Characterization of human melatonin synthesis using autoptic pineal tissue.

The mammalian pineal gland synthesizes rhythmically the hormone melatonin, which provides the body with a signal coding the duration of the night period. The ultimate enzymatic step in melatonin synthesis is achieved by the hydroxyindole O-methyltransferase (HIOMT); the rate-limiting enzyme is, however, the arylalkylamine N-acetyltransferase (AA-NAT). In contrast to the central importance of a transcriptional regulation of the Aa-nat gene for rodent melatonin synthesis, mechanisms in the human pineal gland are elusive.

Driving under the influence of drugs -- evaluation of analytical data of drugs in oral fluid, serum and urine, and correlation with impairment symptoms.

A study was performed to acquire urine, serum and oral fluid samples in cases of suspected driving under the influence of drugs of abuse. Oral fluid was collected using a novel sampling/testing device (Dräger DrugTest System). The aim of the study was to evaluate oral fluid and urine as a predictor of blood samples positive for drugs and impairment symptoms.

Screening for drugs of abuse in oral fluid--correlation of analysis results with serum in forensic cases.

The testing of saliva or oral fluid at the roadside could be a powerful tool to detect drivers under the influence of drugs and has several advantages over urine screening. In 177 cases of individuals suspected of driving under the influence of drugs, oral fluid was collected at the roadside and analyzed in parallel to serum samples. The study was performed to investigate the variability of oral fluid analysis results in relation to blood/serum.

Determination of naltrexone and 6-beta-naltrexol in human plasma following implantation of naltrexone pellets using gas chromatography-mass spectrometry.

An alternative to detoxification by oral therapy with the narcotic antagonist naltrexone is the subcutaneous implantation of naltrexone pellets. From detoxified patients with naltrexone implants (1g) 26 blood samples were collected up to 73 days after implantation. The assay for naltrexone and 6-beta-naltrexol in plasma was developed using automated mixed-mode solid-phase extraction, catalysed trimethylsilylation and gas chromatography-mass spectrometry in single ion monitoring mode with naloxone as internal standard.

Driving under the influence of khat--alkaloid concentrations and observations in forensic cases.

The use of the herbal stimulant khat (Catha edulis FORSK) is maintained by immigrants from countries where it is part of their cultural life (Arabian Peninsula and eastern Africa). In western countries the drug and its effects are largely unknown and no experience in evaluating impairment symptoms due to the khat-alkaloids, e.g.

Effects of ABCB1 (multidrug resistance transporter) gene mutations on disposition and central nervous effects of loperamide in healthy volunteers.

Objective: Mutations in the ABCB1 gene have been associated with decreased expression and net function of P-glycoprotein (P-gp). We investigated the modulation of the central nervous effects of loperamide resulting from ABCB1 genetic variants.

Methods: On two occasions, 20 healthy volunteers received 24 mg loperamide suspension orally and, in a double-blind randomized two-way crossover fashion, 800 mg quinidine or placebo orally 1 h before loperamide.

Artifact production in the assay of anhydroecgonine methyl ester in serum using gas chromatography-mass spectrometry.

The detection of the pyrolysis product anhydroecgonine methyl ester (AEME, methylecgonidine) after cocaine smoking using gas chromatography-mass spectrometry is hampered by the artifactual production of AEME. The amount of AEME increases with the amount of cocaine used producing false positive values in authentic samples. A method for the correction of quantitative values was established using calibration of pyrolysis and estimation of the artifactual AEME.

Pharmacokinetics of cathinone, cathine and norephedrine after the chewing of khat leaves.

Aim: The stimulating herbal drug khat is habitually used in East Africa and the Arabian peninsula but is also imported into other countries. The aim was to study the pharmacokinetics of its alkaloids cathinone, cathine and norephedrine.

Methods: Four volunteers chewed khat leaves in an amount equivalent to one-quarter of that used in a typical khat session.