Amphetamine-type stimulants (ATS) are a group of chiral amine drugs which are commonly abused for their sympathomimetic and stimulant properties. ATS are extensively metabolised by hepatic cytochrome P450 enzymes. As metabolism of ATS has been shown to be highly stereospecific, stereoselective analytical methods are essential for the quantitative determination of ATS concentrations for both in vivo and in vitro studies of ATS metabolism. This paper describes a new stereoselective method for the simultaneous determination of amphetamine (AM), methamphetamine (MA), 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), 4-hydroxy-3-methoxymethamphetamine (HMMA), 4-hydroxy-3-methoxyamphetamine (HMA), 3,4-hydroxymethamphetamine (HHMA) and 3,4-hydroxyamphetamine (HHA) in human urine samples validated according to the United States Food and Drug Administration guidelines. In this method, analytes are simultaneously extracted and derivatized with R-(-)-α-methoxy-α-(trifluoromethyl)phenylacetyl chloride (R-MTPCl) as the chiral derivatization reagent. Following this, the analytes were subjected to a second derivatization with N-methyl-N-trimethylsilyltrifluoroacetamide (MSTFA) which targets the hydroxyl groups present in HMMA, HMA, HHMA and HHA. The derivatized analytes were separated and quantified using gas chromatography-mass spectrometry (GC-MS). The method was evaluated according to the established guidelines for specificity, linearity, precision, accuracy, recovery and stability using a five-day protocol. Intra-day precision ranged from 0.89 to 11.23% RSD whereas inter-day precision was between 1.03 and 12.95% RSD. Accuracy values for the analytes ranged from -5.29% to 13.75%. Limits of quantitation were 10 μg/L for AM, MA, MDMA, HMA and HMMA and 2μg/L for MDA, HMA and HHA. Recoveries and stability values were also within accepted values. The method was applied to authentic ATS-positive samples.
In this work, a new variation of the electromembrane extraction (EME) approach employing a hollow polymer inclusion membrane (HPIM) was developed. In this method, a HPIM was prepared by casting a solution of the desired proportions of cellulose acetate (CTA), tris(2-ethylhexyl)phosphate (TEHP) and di-(2-ethylhexyl)phosphoric acid (D2EHPA) in dichloromethane on glass capillary tubing. Three basic drugs namely amphetamine, methamphetamine, and 3,4-methylenedioxy-N-methylamphetamine (MDMA) were selected as model analytes to evaluate the extraction performance of this new approach. The drugs were extracted from human plasma samples, through a 20μm thickness HPIM, to an aqueous acceptor solution inside the lumen of the hollow membrane. Parameters affecting the extraction efficiency were investigated in detail. Under the optimized conditions, enrichment factors in the range of 97-103-fold were obtained from 3mL of sample solution with a 10min extraction time and an applied voltage of 300V across the HPIM. The detection limits of the method for the three drugs were in the range of 1.0-2.5ng/mL (at a signal/noise ratio of three), with relative standard deviations of between 6.4% and 7.9%. When the method was applied to spiked plasma samples, the relative recoveries ranged from 99.2% to 100.8%. Enrichment factors of 103, 99 and 97 were obtained for amphetamine, methamphetamine, and MDMA, respectively. A comparison was also made between the newly developed approach and EME using supported liquid membranes (SLM) as well as standard sample preparation methods (liquid-liquid extraction) used by the Toxicology Unit, Department of Chemistry, Malaysia.
A stereospecific gas chromatography-mass spectrometry analysis method for amphetamine-type stimulants in human urine was recently developed. For maximum efficiency, liquid-liquid extraction and chiral derivatization of the analytes using (R)-(-)-alpha-methoxy-alpha-(trifluoromethyl)phenylacetyl chloride were performed simultaneously. The effects of (1) use of saturated sodium chloride in 2.0 M sodium hydroxide, (2) extraction solvent volume, (3) percentage of triethylamine, (4) derivatization reagent volume, (5) sample mixing time, (6) incubation temperature and (7) incubation time on method sensitivity and variability were assessed using a two-level, eight-run Plackett-Burman design followed by a fold-over design. The use of saturated sodium chloride solution and the derivatization reagent volume were significant factors (ANOVA, p<0.01). The saturated sodium chloride solution decreased sensitivity whereas an increased volume of derivatization reagent increased sensitivity. Calibration curves for all analytes were linear between 5 and 500 microg/L, with correlation coefficients of >0.99. Detection limits were
Screening for drugs of abused were conducted by using Gas chromatography-Mass spectrometry (GCMS) fitted with capillary column. Urine samples supplied by Centre of Inmigrant Studies, University of Malaya were processed upon arrival and screened for the following drugs. Amphetamines, methamphetamines, aphedrine, hydroxy-amphetamines, ecstasy, benzamphetamines, codeine, morphine, heroine, cocaine and diazepam. The analysis was done using Shimadzu QP5000 Gas chromatograph-mass spectrometer by selected ion monitoring with BPX35 column, 15 m length, 0.32 ID, helium gas as carrier and quadropole mass detector at 1.60 kV electron gain. Analysis were performed using selected ion monitoring (SIM) mode and quantitations were based on area under the curve of individual standards at various concentrations. The method is sensitive to nanogram levels and are able to detect the presence of these drugs in both urine and plasma. From this study (n-100), none of the urine were found positive for the drugs screened. The major problem encountered were adulterated with water based on the clearness and the colour of the urine. Based on this suspicion we would like to suggest that the testing be done on blood samples as this would be more confirmative and quantitative.
This is a review of research done in the area of substance abuse in Malaysia. There were 109 articles related to substance abuse found in a search through a database dedicated to indexing all original data relevant to medicine published in Malaysia between the years 2000-2013. Only 39 articles were reviewed, and case series, case report, reviews and reports were excluded. Research reviewed include the epidemiology of substance abuse, genetics, treatment and its relation to health behaviour, and health management. Studies have shown that more males than females use drugs. There was also a high prevalence of blood-bourne virus diseases and sexually transmitted diseases among drug users. Two studies showed some genetic polymorphism (Cyp 3a4 gene and FAAH Pro129Thr) among heroin and amphetamine users respectively that may contribute to drug dependence. Study on pharmacological treatment for substance abuse were limited to methadone and it was shown to improve the quality of life of heroin dependant patients. Alternative treatments such as acupunture and spiritual approach play a role in the management of substance abuse. Data also showed that treatment centres for substance abuse are lacking facilities for screening, assessment and treatment for medical illness related to substance use, e.g. Hepatitis C and tuberculosis. Studies on the effectiveness of current drug rehabilitation centres were inconclusive.
Neuropsychiatric disorders (NPDs) exert a devastating impact on an individual's personal and social well-being, encompassing various conditions and brain anomalies that influence affect, cognition, and behavior. Because the pathophysiology of NPDs is multifactorial, the precise mechanisms underlying the development of such disorders remain unclear, representing a unique challenge in current neuropsychopharmacotherapy. Transient receptor potential vanilloid (TRPV) type channels are a family of ligand-gated ion channels that mainly include sensory receptors that respond to thermal, mechanical and chemical stimuli. TRPV channels are abundantly present in dopaminergic neurons, thus playing a pivotal role in the modulation of the reward system and in pathophysiology of diseases such as stress, anxiety, depression, schizophrenia, neurodegenerative disorders and substance abuse/addiction. Recent evidence has highlighted TRPV channels as potential targets for understanding modulation of the reward system and various forms of addiction (opioids, cocaine, amphetamines, alcohol, nicotine, cannabis). In this review, we discuss the distribution, physiological roles, ligands and therapeutic importance of TRPV channels with regard to NPDs and addiction biology.
Tobacco and substance use is a great public health concern in Asia. The prevalence of tobacco smoking, while steadily declined in Western countries over past few decades, has increased in many regions of Asia, especially in low- and middle-income countries. And high-income countries in the region have reported rapid growth rates in e-cigarette use in recent years. Furthermore, illicit drugs, specially cannabis, amphetamines, and opioids, have begun to threaten the health of the people in the region like never before. To better understand the landscape of the two primary public health concerns in Asia, tobacco and substance use, this special issue examines cigarette/e-cigarette use and tobacco control policies for five selected countries (Singapore, China, South Korea, Japan, and Laos People's Democratic Republic); and explores substance use related issues focused on prevention, influencing factors, and policies of three countries (Hon Kong, Malaysia, and India). The research, policy, and clinical implications from this issue will contribute to mitigating the global burden of tobacco and substance use-related public health issues in Asia.
Malaysia has been experiencing significant drug abuse problems since the 1970s, and drug abuse is the major driver of HIV transmission in Malaysia. We investigated risk factors for HIV associated with use of amphetamine type stimulants (ATS) among not-in-treatment opiate injectors in Malaysia.
The past decade has seen a marked increase in the popularity of ATS use, particularly methamphetamine, within East Asia,and the Pacific region. In Malaysia, the National Anti Drug Agency has identified 8,870 addicts (from January till August 2008) out of which 1,126 was ATS dependence. During the same period, the police have arrested 46,388 people under the Dangerous Drug Act 1952. They also has seize 283kg of syabu, 545kg of ecstacy powder, 66194 tablets of esctacy pills and 222,376 tablets of yaba pills from Jan till August this year. The occurrence of psychosis arising from the use of ATS was first reported in the late 1930's. With growing ATS use, particularly methamphetamine, ATS-induced psychosis has become a major impact on public health.Symptoms of ATS-induced psychosis: Methamphetamine use produces a variety of effects, ranging from irritability, to physical aggression, hyperawareness, hypervigilance, and psychomotor agitation. Repeated or high-dose use of the stimulant can cause drug-induced psychosis resembling paranoid schizophrenia, characterized by hallucinations, delusions and thought disorders. When used in long term, methamphetamine may lead to development of psychiatric symptoms due to dopamine depletion in the striatum. The most common lifetime psychotic symptoms among methamphetamine psychotic patients - as reported in a cross-country study involving Australia, Japan, the Philippines and Thailand - are persecutory delusion, auditory hallucinations, strange or unusual beliefs and thought reading. Those patients were also reported to suffer from impaired speech, psychomotor retardation, depression and anxiety. An ATS psychosis can be distinguished from primary psychotic disorders by time. In ATS-induced psychosis symptoms usually resolve after the drug is discontinued. If symptoms do not resolve within 2 weeks after cessation of stimulant use, a primary psychiatric disorder should be suspected. When compared with other stimulants, such as cocaine, psychosis is induced more commonly by ATS, possibly due to the longer duration of action produced by amphetamines.For example, while smoking cocaine produces a high that lasts for 20-30 minutes, smoking methamphetamine produces a high that lasts 8-24 hours. Other symptoms of ATS-induced psychosis reported include affective blunting,(6) violent behavior, and self-mutilation and self-injurious behavior.
Introduction: There has been a global increase in illicit drug use among young people. The aim of this study was to estimate the prevalence of lifetime cannabis and amphetamine use, as well as to explore factors associated with substance use among adolescents in five Asian countries: Iraq, Kuwait, Malaysia, Mongolia, and Vietnam.
Methods: 38,941 school children (mean age 15.4 years, SD=1.5) completed the cross-sectional Global School-Based Student Health Survey (GSHS). Topics covered in the questionnaire included cannabis and amphetamine use. Personal, parental, and environmental attributes were explored as predictors of cannabis and amphetamine use. Logistic regression was used to assess the contribution of potential predictors on lifetime cannabis and lifetime amphetamine use.
Results: Overall, the prevalence of lifetime cannabis use was 0.9% and lifetime amphetamine use was 1.0% among research participants. Cannabis use was influenced by male gender (Kuwait, Mongolia), parental smoking habits (Kuwait, Iraq), and current cigarette smoking in all countries. Amphetamine use was associated with suicidal ideation (Kuwait, Malaysia, Vietnam), school truancy (Malaysia, Mongolia, Vietnam), being a victim of physical assault (Kuwait, Mongolia), bullying victimization (Iraq, Malaysia, Vietnam), as well as anxiety and current cigarette use in all countries.
Conclusions: Our preliminary results show the importance of personal attributes such as mental distress and environmental stressors on lifetime cannabis and lifetime amphetamine use. Future prospective studies are needed to identify causal relationships among personal attributes, parental attributes, environmental stressors, and illicit substance use.
Study name: Global School-Based Student Health Survey (GSHS)