Lewis, J, Molnar, A, Allsop, D, Copeland, J & Fu, S 2016, 'Rapid elimination of Carboxy-THC in a cohort of chronic cannabis users', INTERNATIONAL JOURNAL OF LEGAL MEDICINE, vol. 130, no. 1, pp. 147-152.View/Download from: Publisher's site
Molnar, A, Fu, S, Lewis, JH, Allsop, DJ & Copeland, J 2014, 'The detection of THC, CBD and CBN in the oral fluid of Sativex® patients using two on-site screening tests and LCMS/MS', Forensic Science International, vol. 238, pp. 113-119.View/Download from: Publisher's site
Sativex® is an oromucosal spray used to treat spasticity in multiple sclerosis sufferers in some European countries, the United Kingdom, Canada and New Zealand. The drug has also recently been registered by the Therapeutic Goods Administration (TGA) in Australia for treatment of multiple sclerosis. Sativex® contains high concentrations of ?9-tetrahydrocannabinol (THC) and cannabidiol (CBD), with the former being the subject of random roadside drug tests across Australia to detect cannabis use. This pilot study aims to determine whether or not patients taking Sativex® will test positive to THC using these roadside screening tests. Detectable levels of THC, CBD and cannabinol (CBN) in their oral fluid were also confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The study was a double-blind, placebo controlled design. Oral fluid was tested prior to and immediately after dosing with either Sativex® or placebo at intervals up to 2 h after the dose. Two Sativex® doses were studied. The low dose contained 5.4 mg THC, the high dose 21.6 mg THC. Results indicate that the primary screening test used in Australian roadside drug testing, the DrugWipe® II Twin, often gave a false negative response for THC, even with high concentrations present. However, secondary screening test, Cozart® DDS (used by police after a DrugWipe test gives a positive result), gave true positive results in all cases where patients were being treated with Sativex1. Confirmatory testing showed high concentrations of THC and CBD (>5356 ng/mL THC and >3826 ng/mL CBD) in the oral fluid shortly after dosing and also elevated concentrations of CBN. Levels dropped quickly but remained at detectable concentrations (>67.6 ng/mL) two hours after drug administration. The average concentration ratio of THC/CBD across all positive samples was 1.10 (%RSD 19.9) reflecting the composition of the Sativex® spray. In conclusion, Sativex® users may test positive for THC by roadside drug testing wi...
Lewis, JH, Shimmon, R & Fu, S 2013, 'Pethidinic acid: Corroboration of a doctor's denial of pethidine re-use', Journal of Analytical Toxicology, vol. 37, no. 3, pp. 179-181.View/Download from: Publisher's site
Pethidine (meperidine), a synthetic opiate, formally used as an analgesic in surgery and obstetrics, has been an abused drug of choice for some doctors. A case is presented in which a doctor, who previously admitted to using pethidine, was suspected of re-using, following a second positive urine test. A laboratory had reported the presence of pethidine in the doctor's urine; however, the doctor denied re-use. The norpethidine (normeperidine) metabolite, normally found in urine, had not been detected, raising concern over the laboratory's conclusion and necessitating an independent investigation. Because the major metabolite of pethidine is pethidinic acid (meperidinic acid), accounting for approximately 40% of the excreted dose, its presence or absence were deemed to be important criteria in interpreting the laboratory result. Pethidinic acid was synthesized by alkaline hydrolysis of pethidine and used as a control. Urine samples from a patient receiving pethidine for pain, from the previous pethidine use of the doctor, and the urine under question plus the control were analyzed for the presence of pethidinic acid using electrospray mass spectrometry. Pethidinic acid was found in all samples except the one under dispute. The absence of pethidinic acid appeared to corroborate the doctor's denial of re-use.
Molnar, A, Lewis, JH & Fu, S 2013, 'Recovery of spiked 9-tetrahydrocannabinol in oral fluid from polypropylene containers', Forensic Science International, vol. 227, pp. 69-73.View/Download from: Publisher's site
Oral fluid is currently used by Australian and international law enforcement agencies and employers to detect recent use of cannabis and other drugs of abuse. The main psychoactive constituent of cannabis, ?9-tetrahydrocannabinol (THC), is highly lipophilic and losses occur when in contact with plastic, possibly due to its adsorption onto the plastic surface. This study aims to investigate factors governing the interaction of THC with plastic and search for ways of overcoming such interaction so to improve THC recovery. As polypropylene is one of the most common types of plastic used in collection devices, it was the focus of this study. All experiments were done by preparing neat oral fluid samples spiked with THC in 2-mL polypropylene centrifuge tubes. Samples were transferred with or without prior addition of Triton® X-100 (0.25%) to glass tubes containing d3-THC as internal standard and 0.1M phosphate buffer was then added. Samples were extracted by liquidliquid extraction using hexane/ethyl acetate (9:1, v/v), dried and analysed by gas chromatographymass spectrometry (GCMS) after derivatisation. No significant difference was found in terms of THC loss to plastic when the concentration ranged from 25 to 1000ng/mL in the same volume of oral fluid. Varying the oral fluid volume (0.51.5mL) while keeping THC at a constant concentration showed an upward trend with more loss associated with lower volumes. The use of Triton® X-100 significantly decreased the adherence of THC to the plastic tubes and increased the THC transfer (>96%) at all volumes tested. Degradation of THC during storage was also studied over a 4-week period and it was found that azide did not seem to play a significant role in preserving THC in oral fluid.
Allsop, DJ, Copeland, J, Norberg, MM, Fu, S, Molnar, A, Lewis, JH & Budney, AJ 2012, 'Quantifying the clinical significance of cannabis withdrawal', PLoS One, vol. 7, no. 9, p. e44864.View/Download from: Publisher's site
Abstract: Background and Aims: Questions over the clinical significance of cannabis withdrawal have hindered its inclusion as a discrete cannabis induced psychiatric condition in the Diagnostic and Statistical Manual of Mental Disorders (DSM IV). This study aims to quantify functional impairment to normal daily activities from cannabis withdrawal, and looks at the factors predicting functional impairment. In addition the study tests the influence of functional impairment from cannabis withdrawal on cannabis use during and after an abstinence attempt. Methods and Results: volunteer sample of 49 non-treatment seeking cannabis users who met DSM-IV criteria for dependence provided daily withdrawal-related functional impairment scores during a one-week baseline phase and two weeks of monitored abstinence from cannabis with a one month follow up. Functional impairment from withdrawal symptoms was strongly associated with symptom severity (p = 0.0001). Participants with more severe cannabis dependence before the abstinence attempt reported greater functional impairment from cannabis withdrawal (p = 0.03). Relapse to cannabis use during the abstinence period was associated with greater functional impairment from a subset of withdrawal symptoms in high dependence users. Higher levels of functional impairment during the abstinence attempt predicted higher levels of cannabis use at one month follow up (p = 0.001). Conclusions: Cannabis withdrawal is clinically significant because it is associated with functional impairment to normal daily activities, as well as relapse to cannabis use. Sample size in the relapse group was small and the use of a non-treatment seeking population requires findings to be replicated in clinical samples. Tailoring treatments to target withdrawal symptoms contributing to functional impairment during a quit attempt may improve treatment outcomes.
Molnar, A, Lewis, JH, Doble, PA, Hansen, G, Prolov, T & Fu, S 2012, 'A Rapid And Sensitive Method For The Identification Of Delta-9-Tetrahydrocannabinol In Oral Fluid By Liquid Chromatography-Tandem Mass Spectrometry', Forensic Science International, vol. 215, no. 1-3, pp. 92-96.View/Download from: Publisher's site
A fast and sensitive method was developed for detecting delta-9-tetrahydrocannabinol (THC) in oral fluid by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The method is suitable for samples of small volume and low concentration. For method de
Fu, S, Molnar, A, Bowron, P, Lewis, JH & Wang, H 2011, 'Reduction of temazepam to diazepam and lorazepam to delorazepam during enzymatic hydrolysis', Analytical and Bioanalytical Chemistry, vol. 400, no. 1, pp. 153-164.View/Download from: Publisher's site
It has been previously reported that treatment of urinary oxazepam by commercial ß-glucuronidase enzyme preparations, from Escherichia coli, Helix pomatia and Patella vulgata, results in production of nordiazepam (desmethyldiazepam) artefact. In this study, we report that this unusual reductive transformation also occurs in other benzodiazepines with a hydroxyl group at the C3 position such as temazepam and lorazepam. As determined by liquid chromatography-mass spectrometry analysis, all three enzyme preparations were found capable of converting urinary temazepam into diazepam following enzymatic incubation and subsequent liquidliquid extraction procedures. For example, when H. pomatia enzymes were used with incubation conditions of 18 h and 50 °C, the percentage conversion, although small, was significantapproximately 1% (0.591.54%) in both patient and spiked blank urines. Similarly, using H. pomatia enzyme under these incubation conditions, a reductive transformation of urinary lorazepam into delorazepam (chlordesmethyldiazepam) occurred. These findings have both clinical and forensic implications. Detection of diazepam or delorazepam in biological samples following enzyme treatment should be interpreted with care.
Latt, N, Jurd, S, Tennant, C, Lewis, JH, Macken, L, Joseph, A, Grochulski, A & Long, L 2011, 'Alcohol and substance use by patients with psychosis presenting to an emergency department: changing patterns', Australasian Psychiatry, vol. 19, no. 4, pp. 354-359.View/Download from: Publisher's site
Objectives: The aim of this study was to determine the incidence of alcohol and other substance use in patients presenting to an emergency department with acute psychiatric illnesses and to clarify the role of urine drug screens. Method: This was an unbl
Fu, S, Lewis, JH, Wang, H, Keegan, J & Dawson, M 2010, 'A Novel Reductive Transformation Of Oxazepam To Nordiazepam Observed During Enzymatic Hydrolysis', Journal Of Analytical Toxicology, vol. 34, no. 5, pp. 243-251.View/Download from: Publisher's site
ß-Glucuronidase is an enzyme often employed to de-conjugate ß-glucuronides during urinary drug testing for benzodiazepines. It is commonly accepted that use of ß-glucuronidase is a preferred method of hydrolysis over acid-catalyzed hydrolysis, which is known to induce benzodiazepine degradation and transformation. Literature to date, however, has not reported any cases of benzodiazepine transformation initiated by commercial ß-glucuronidase products. In this study, urine specimens containing either oxazepam or oxazepam glucuronide were incubated with ß-glucuronidase enzymes obtained from Escherichia coli, Helix pomatia, and Patella vulgata under various incubation conditions. After liquid-liquid extraction, the extract was analyzed by both liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry for the presence of benzodiazepines. All three enzyme preparations examined were capable of reducing oxazepam or oxazepam glucuronide into nordiazepam (desmethyldiazepam). Nordiazepam formation was positively correlated with incubation temperature, incubation time, oxazepam concentration, and enzyme concentration. Under all enzymatic hydrolysis conditions investigated, the percentage of nordiazepam formation is < 2.5% relative to the amount of oxazepam present in the system. The findings of this study have both clinical and forensic implications, and it is clear that the detection of nordiazepam in biological samples subjected to testing involving enzyme-catalyzed hydrolysis should be interpreted with care.
Fu, S, Molnar, A, Bowron, P, Wang, H, Dawson, M & Lewis, JH 2010, 'Reductive transformation of temazepam and lorazepam during b-glucuronidase treatment of urine specimens', TIAFT Bulletin, Annual Meeting of the International-Association-of-Forensic-Toxicologists (TIAFT), GI Printing & Graphics, Germany, pp. 53-55.
B-Glucuronidase is on enzyme often employed to deconjugate B-glucuronides during urinary drug testing for benzodiozepines. It is commonly accepted that use of B-glucuronidase is a preferred method of hydrolysis over acid-catalyzed hydrolysis, which is known to induce benzodiozepine degradation and transformation. Very recently, we have reported that B-glucuronidase catalyzed hydrolysis is also a source of artefact production. We found that either oxazepam glucuronide present in patient urine or free oxazepam added in blank urine could be reduced to nordiozepom (desmethyldiozepom) during incubation with commercial B-glucuronidase enzymes. Formation of nordiozepom artefact was positively correlated with incubation temperature, incubation time, oxazepam concentration and enzyme concentration.
Molnar, A, Fu, S, Doble, PA & Lewis, JH 2010, 'A sensitive method to detect and quantify delta-9 tetrahydrocannabinol in oral fluid by liquid chromatography - tandem mass spectrometry', TIAFT Bulletin, Annual Meeting of the International-Association-of-Forensic-Toxicologists (TIAFT), GI Printing & Graphics, Bonn, Germany, pp. 45-47.
Delta9 -tetrahydrocannabinol (THC) is the major psychoactive constituent of cannabis. It causes a decrease in motor function and concentration making it hazardous for an individual to drive whilst under the inftuence of this drug. Roadside testing procedures for cannabis are therefore necessary since it is the most widely used illicit drug in Australia and around the world and is commonly implicated in drug-driving offences.