Choice of an ELISA assay for screening postmortem blood for amphetamine and/or methamphetamine

The object of this study was to evaluate the suitability of the Neogen Corp. microtiter plate enzyme-linked immunoassays (ELISA) for the screening of postmortem blood for amphetamine and methamphetamine and to choose the more appropriate assay for screening. Forty-seven postmortem whole blood specimens were obtained from drug-involved deaths, which had been screened and confirmed positive for methamphetamine and/or amphetamine. Eighty-five negative specimens were obtained from non-amphetamines-involved deaths, 17 of which involved decomposition. Specimens were tested using the Neogen Amphetamine Ultra and Neogen Methamphetamine/MDMA microtiter plate ELISA assays. No matrix effects were found for whole blood in these assays, and a dilution of 1:5 was chosen to facilitate pipetting and to bring the IC50 of the microtiter plate ELISA assay within the range of amphetamines concentrations encountered in medical examiner specimens. True positives, true negatives, false positives, and false negatives were determined relative to gas chromatography-mass spectrometry (GC-MS) and graphed for the ELISA. From these graphs and the receiver operating curves (ROC), the optimal cut-off for the Neogen Methamphetamine/MDMA ELISA was 50 ng/mL methamphetamine equivalents and the optimum cut-off for the Neogen Amphetamine Ultra ELISA was 100 ng/mL amphetamine equivalents. The Neogen Methamphetamine ELISA had a sensitivity of 93.6% +/- 3.5% and a specificity of 77.6% +/- 4.5% versus GC-MS at the cut-off of 50-ng/mL methamphetamine equivalents. The Neogen Amphetamine Ultra ELISA had a sensitivity of 95.7% +/- 3.0% and a specificity of 72.9% +/- 5.2% versus GC-MS at the 100-ng/mL amphetamine equivalents cut-off. The areas under the ROCs were equivalent for the two ELISA assays.

A case of fatal hemorrhage in the cerebral ventricles following intravenous use of methamphetamine

We describe a case of massive hemorrhage in the cerebral ventricles, probably caused by methamphetamine abuse. A 44-year-old male was found dead in a prone position in a hotel room. Old and new injection marks were observed in his right cubital fossa. Petechiae were observed on the conjunctiva of his right eye, laryngeal mucosa, epicardium and under the capsule of the liver (to a slight or moderate degree). The brain, weighing 1.67 kg, was heavily edematous; the lateral and fourth ventricles were filled with hematomas. Subarachnoid, intracerebral hemorrhages were not observed. Cerebral vascular abnormalities were not evident. There were no remarkable changes in other organs, other than congestion. Gas chromatographic-mass spectrometric analysis of the urine disclosed the presence of methamphetamine and amphetamine. The concentration of methamphetamine within the femoral venous blood and intraventricular hematoma was 0.347 microg/ml and 0.189 microg/g, respectively. Amphetamine was not detected in either sample. Urine contained 3.15 microg/ml methamphetamine and 0.063 microg/ml amphetamine. These results indicate that intraventricular hemorrhage might have occurred shortly after intravenous self-administration of methamphetamine. Cerebral arterial spasm and hypertension resulting from the administration of methamphetamine might have resulted in intraventricular hemorrhage.

Drug testing in blood: validated negative-ion chemical ionization gas chromatographic-mass spectrometric assay for determination of amphetamine and methamphetamine enantiomers and its application to toxicology cases

BACKGROUND

Enantioselective analysis of amphetamine (AM) or methamphetamine (MA) in urine is already a well-established tool for differentiation of illicit from therapeutic ingestion of AM or MA derivatives. However, because of the increasing importance of plasma or serum in analytical toxicology, a method for enantioselective analysis of AM and MA in these matrices is needed.

METHODS

AM and/or MA were extracted from 0.2 mL of blood plasma or serum by mixed-mode solid-phase extraction. After derivatization with S-(-)-heptafluorobutyrylprolyl chloride, the resulting diastereomers were separated by gas chromatography on a HP-5MS column during a 15-min program and detected by mass spectrometry in the negative-ion chemical ionization mode (NICI-GC-MS). The method was fully validated and applied to >50 samples from authentic toxicology cases.

RESULTS

The derivatized AM and MA enantiomers were well separated and sensitively detected. The method was linear from 5 to 250 micro g/L per enantiomer with analytical recoveries, accuracy, and within- and between-run precision well within required limits. Extraction yields were 88.9-98.6%. Implications of concentrations and enantiomeric composition of AM and MA in the authentic samples were considered.

CONCLUSIONS

This sensitive, reliable, rapid NICI-GC-MS assay is suitable for enantioselective determination of AM and MA in blood plasma or serum samples.

Effect of concomitant hormone replacement therapy containing estradiol and levonorgestrel on the pharmacokinetics of selegiline

OBJECTIVE

The aim of this study was to investigate the effect of hormone-replacement therapy (HRT) on the pharmacokinetics of the selective monoamine oxidase B inhibitor selegiline and its primary metabolites desmethylselegiline and l-metamphetamine.

METHODS

In this randomised, double-blind, cross-over trial, 12 healthy female subjects received once daily for 10 days either HRT containing 2 mg estradiol valerate and 250 microg levonorgestrel or matched placebo. On day 10, they took a single 10-mg oral dose of selegiline. The serum concentrations of selegiline, desmethylselegiline and metamphetamine were measured for 32 h.

RESULTS

There was a 59% difference ( P=0.14) in the area under the serum concentration-time curve (AUC) of selegiline during the HRT compared with the placebo phase, but only a little or no concomitant reduction in the AUC of desmethylselegiline (-7%, P=0.071) or metamphetamine (2%, P=0.614) was observed. Maximum plasma concentration (C(max)) of selegiline was not changed, but a small, statistically significant, reduction in the C(max) of desmethylselegiline (-17%, P=0.03) was seen during the HRT phase. The C(max) of methamphetamine was slightly but not significantly reduced (-5%, P=0.06). The unchanged AUC ratios of desmethylselegiline/selegiline and metamphetamine/selegiline indicate that the primary metabolism of selegiline was not affected by HRT. All study treatments were well tolerated.

CONCLUSION

Unlike oral contraceptives, HRT is not likely to have clinically significant pharmacokinetic interaction with selegiline.

Multiplex assay of amphetamine, methamphetamine, and ecstasy drug using CEDIA technology

Using Microgenics unique technology, cloned enzyme donor immunoassay (CEDIA), the multiplex assay (CEDIA Amphetamines/Ecstasy) has been developed for the detection of amphetamine, methamphetamine, and ecstasy drugs at cutoff level either of 500 ng/mL or 1000 ng/mL applicable for either qualitative screening or semiquantitative measurement. The multiplex assay detects the total concentration of amphetamine, methamphetamine, and ecstasy drugs in urine samples. In addition, the assay detects metabolites of parent drugs and structurally related drugs including d,l-amphetamine (67.2%), d,l-methamphetamine (58.4%), MDA (113%), MDMA (199%), MDEA (207%), MBDB (123%), BDB (72%), PMA (24%), and PMMA (100%). The assay is highly specific and exhibits minimal cross-reactivity with the undesirable, structurally related over-the-counter amphetaminelike drugs. Imprecision results (n = 120) demonstrate an intra-assay < 6.3% CV and an interassay < 9.2% CV as performed by a modified NCCLS protocol. Using the SAMHSA mandatory guidelines of a 500-ng/mL cutoff for the immunoassay and a 250-ng/mL cutoff for GC-MS, the assay detects 164 out of 165 GC-MS-positive samples. For drug abuse testing, the multiplex assay presents an excellent method for the detection of multiple drugs with greater sensitivity and broader detection.

Determination of MDMA and its metabolites in blood and urine by gas chromatography-mass spectrometry and analysis of enantiomers by capillary electrophoresis

A gas chromatography-mass spectrometry (GC-MS) method was used for the simultaneous quantitation of 3,4-methylenedioxymethamphetamine (MDMA) and the 3,4-methylenedioxyamphetamine (MDA), 4-hydroxy-3-methoxymethamphetamine (HMMA), and 4-hydroxy-3-methoxyamphetamine (HMA) metabolites in plasma and urine samples after the administration of 100 mg MDMA to healthy volunteers. Samples were hydrolyzed prior to a solid-phase extraction with Bond Elut Certify columns. Analytes were eluted with ethyl acetate (2% ammonium hydroxide) and analyzed as their trifluoroacyl derivatives. Linear calibration curves were obtained at plasma and urine concentration ranges of 25-400 ng/mL and 250-2000 ng/mL for MDMA and HMMA, and of 2.5-40 ng/mL and 100-1000 ng/mL for MDA and HMA. Following the same urine preparation procedure but without the derivatization step, a capillary electrophoresis (CE) method for enantiomerical resolution of compounds was developed using (2-hydroxy)propyl-beta-cyclodextrin at two different concentrations (10 and 50mM in 50mM H3PO4, pH 2.5) as chiral selector. Calibration curves for the CE method were prepared with the corresponding racemic mixture and were linear between 125 and 2000 ng/mL, 50 and 1000 ng/mL, and 125 and 1500 ng/mL for each enantiomer of MDMA, MDA, and HMMA, respectively. Stereoselective disposition of MDMA and MDA was confirmed. HMMA disposition seems to be in apparent contradiction with MDMA findings as the enantiomer ratio is close to 1 and constant over the time.

On-column derivatization for determination of amphetamine and methamphetamine in human blood by gas chromatography-mass spectrometry

A simple determination method of amphetamine (AP) and methamphetamine (MA) in human blood was developed using on-column derivatization and gas chromatography-mass spectrometry (GC-MS). AP and MA were adsorbed on the surface of Extrelut and then derivatized the N-propoxycarbonyl derivatives using propylchloroformate. Pentadeuterated MA was used as an internal standards. The recoveries of AP and MA from the spiked blood were 89.7 and 90.3%, respectively. The calibration curves showed linearity in the range of 12.5-2000 ng/g for AP and MA in blood. The coefficients of variation of intraday and interday were 0.42-4.58%. Furthermore, this proposed method was applied to some medico-legal cases of MA intoxication. MA and its metabolite AP were detected in the blood samples, and the correlation of the blood level of amphetamines and the behaviors of the victims was in good agreement with the criteria proposed by Nagata [Jpn. J. Legal Med. 37 (1983) 513].

Negative ion chemical ionization gas chromatography-mass spectrometry and atmospheric pressure chemical ionization liquid chromatography-mass spectrometry of low-dosed and/or polar drugs in plasma

In clinical and forensic toxicology, doping control, and therapeutic drug monitoring, specific and sensitive detection and precise quantification of xenobiotics in biosamples are great challenges. Today, mass spectrometry techniques, coupled with gas chromatography or liquid chromatography, are the most powerful methods in analytic toxicology. The pros and cons of electron ionization (EI) and negative ion chemical ionization (NICI) gas chromatography-mass spectrometry (GC-MS) and of atmospheric pressure chemical ionization liquid chromatography-mass spectrometry (APCI-LC-MS) are described for determination of the low-dosed benzodiazepine flunitrazepam and its 7-amino and its nor-metabolite in plasma. In addition, application of NICI-GC-MS is described for sensitive chiral determination of amphetamine derivatives in plasma and application of APCI-LC-MS for screening, library-assisted identification, and validated quantification of oral antidiabetics and for validated quantification of the neuroleptic risperidone and its 9-hydroxy metabolite. These examples show that NICI-GC-MS and LC-MS are powerful tools for determination of low-dosed and/or rather polar drugs or poisons, thus becoming indispensable supplements to classic EI-GC-MS in clinical and forensic toxicology as well as in doping control.

[Cardiac lesions in methamphetamine abusers]

Various cardiac lesions such as hypertrophy, disarray and fibrosis similar to HCM, were often found in the heart of methamphetamine (MA) abusers. Myolysis, eosinophilic changes, contraction band necrosis and small round cell infiltration were also observed. Male ddy mouse were administered MA 1 mg/kg subcutaneously every day for 4 weeks. Their hearts revealed many cardiac changes such as hypertrophy, myolysis, contraction band necrosis, disarrangement of myofibers, saw-like cytoplasm, side-to-side connection of cardiac cells and vascuolative degeneration microscopically, and crysterosis of mitochondria, enlargement of sarcoplasmic reticulum and hypercontraction electronmicroscopically. These changes are thought to be similar to that of MA abusers, so it is certified that MA has toxic effect on the heart. Moreover, these changes could not be found when beta-blocker or calcium antagonist was premedicated. To elucidate the mechanisms of MA cardiac toxicity, we have designed some experiments. When MA (15 mg or 20 mg/kg) was administered on rats, cardiac lipid peroxidates, as a marker of free radical, increased rapidly. When rats were feeded for 7 weeks with Vitamin E deficient diet, 10 mg/kg MA administration was enough to increase lipid peroxidates. Simultaneous ECG observation revealed various arrhythmia such as VPB, A-V block and intraventricular conduction delay. In the investigation of contractile protein, although we could not find differences in the isozyme pattern of myosin heavy chain between MA groups (1 mg/kg for 8 and 12 weeks) and control group, Mg2+ ATPase activity of myocardial actomyosin at 0.1 microM Ca2+ increased significantly in 12 weeks MA group. We also found MA induced cardiac toxicity in cultured myocytes. Primary cultured adult rat myocytes were exposed to MA (1 x 10(-5) M and 1 x 10(-3) M) for 1 to 24 h in the presence and absence of 1 x 10(-5) M propranolol. After 24-h MA treatment, cellular granulation, swelling and hypercontraction and release of CPK were observed both with and without propranolol treatment. These findings suggest that MA may exert direct toxic effects on the heart.

Selegiline pharmacokinetics are unaffected by the CYP3A4 inhibitor itraconazole

OBJECTIVE

To characterise the effects of itraconazole, a potent inhibitor of CYP3A4, on the pharmacokinetics of selegiline in healthy volunteers.

METHODS

In this randomised, placebo-controlled crossover study with two phases, 12 healthy volunteers took either 200 mg itraconazole or matched placebo once daily for 4 days. On day 4, a single 10-mg oral dose of selegiline hydrochloride was administered. Serum concentrations of selegiline and its primary metabolites desmethylselegiline and l-methamphetamine were determined up to 32 h. A caffeine test was performed on day 3 of both phases, by measuring the plasma paraxanthine/caffeine concentration ratio 6 h after caffeine intake, to examine the role of CYP1A2 in selegiline pharmacokinetics. In addition, the effects of itraconazole on the metabolism of selegiline in vitro were characterised by using human liver microsomes.

RESULTS

Itraconazole had no significant effects on the pharmacokinetic variables of selegiline, desmethylselegiline or l-methamphetamine, with the exception that the AUC of desmethylselegiline was increased by about 10% (P < 0.05). There was a significant correlation between the AUC(desmethylselegiline)/AUC(selegiline) ratio and the paraxanthine/caffeine ratio (r = 0.41; P < 0.05), suggesting involvement of CYP1A2 in the formation of desmethylselegiline. In experiments with human liver microsomes, itraconazole had no inhibitory effect on the formation of either desmethylselegiline or l-methamphetamine from selegiline.

CONCLUSIONS

The pharmacokinetics of selegiline in healthy volunteers were unaffected by the potent CYP3A4 inhibitor itraconazole. In addition, itraconazole showed no inhibitory effect on the biotransformation of selegiline to desmethylselegiline and l-methamphetamine by human liver microsomes. These findings suggest that selegiline is not susceptible to interaction with CYP3A4 inhibitors.

Comparison of ELISAs for opiates, methamphetamine, cocaine metabolite, benzodiazepines, phencyclidine, and cannabinoids in whole blood and urine

BACKGROUND

ELISAs are widely utilized in forensic drug analysis. A comparative assessment of microtiter plate assays for the detection of six common classes of drug in blood and urine is described.

METHODS

ELISAs for opiates, methamphetamine, benzodiazepines, cocaine metabolite, phencyclidine (PCP), and tetrahydrocannabinol (THC) metabolite were evaluated in a side-by-side study. The analytical performance of 12 commercially available ELISAs was determined in terms of binding characteristics, dose-response curves, limits of detection, sensitivity, intra- and interassay imprecision, and lot-to-lot reproducibility. Assay performance was also compared using 855 forensic casework samples.

RESULTS

Detection limits in whole blood for morphine, D-methamphetamine, nordiazepam, benzoylecgonine, nordiazepam, PCP, and L-11-nor-9-carboxy-delta9-THC were 3, 2, <4, 5, 25, and 3 microg/L, respectively, for the STC ELISAs. Corresponding detection limits for Immunalysis ELISAs were <1, <2, <4, 5, <1, and 1 microg/L, respectively. Intraassay CVs (n = 8) at the immunoassay cutoff concentrations were 4.1-5.6% and 3.5-11% for STC and Immunalysis ELISAs, respectively. Corresponding interassay CVs were 3.1-10% and 6.5-20%. Of the 855 casework samples, there were a total of 92 discordant results (44 cannabinoid, 15 opiate, 15 methamphetamine, 11 benzodiazepine, and 7 cocaine metabolite). Gas chromatography-mass spectrometry analysis indicated a total of three unconfirmed positive results for Immunalysis assays and one unconfirmed positive for STC assays.

CONCLUSIONS

A comparative assessment of drugs-of-abuse assays from two manufacturers indicated some key differences in analytical performance. Overall, Immunalysis assays offered superior binding characteristics and detection limits, whereas STC assays offered improved overall precision and lot-to-lot reproducibility.

Relevance of pharmacokinetic parameters in animal models of methamphetamine abuse

Although the behavioral consequences of methamphetamine (METH) abuse have been extensively documented, a more precise and thorough understanding of underlying neurobiological mechanisms still requires the use of animal models. To study these biochemical processes in experimental animals requires consideration for the broad range of human METH abuse patterns and the many factors that have been identified to profoundly influence the behavioral and neurochemical effects of exposure to METH-like stimulants. One potentially critical issue relates to pharmacokinetic differences between the species. In this review, METH plasma pharmacokinetic profiles after single and multiple dose intravenous METH administration are compared for the rat and human. Significant differences in elimination half-life between the two species (t1/2: rat-70 min, human-12 h) result in markedly dissimilar profiles of METH exposure. However, the plasma profile of a human METH binge pattern can be approximated in the rat by increasing METH dose frequency. Consideration of METH pharmacokinetics in animal models should permit a closer simulation of the temporal profile of METH exposure in the human CNS and should provide further insight into the mechanisms contributing to the addiciton and psychopathology associated with METH abuse.

Highly sensitive analysis of methamphetamine and amphetamine in human whole blood using headspace solid-phase microextraction and gas chromatography-mass spectrometry

A simple and highly sensitive method for analysis of derivatized methamphetamine (MA) and amphetamine (AM) in whole blood was developed using headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry electron impact ionization selected ion monitoring (GC-MS-EI-SIM). A whole blood sample, deuterated-MA (d(5)-MA), as an internal standard (IS), tri-n-propylamine and pentafluorobenzyl bromide were placed in a vial. The vial was heated and stirred at 90 degrees C for 30min. Then the extraction fiber of the SPME was exposed at 90 degrees C for 30min in the headspace of the vial while being stirred. The derivatives adsorbed on the fiber were desorbed by exposing the fiber in the injection port of a GC-MS. The calibration curves showed linearity in the range of 0.5-1000ng/g for both MA and AM. The time for analysis was about 80min per sample. In addition, this proposed method was applied to two autopsy cases where MA ingestion was suspected. In one case, MA and AM concentrations in the mixed left and right heart blood were 165 and 36.9ng/g, respectively. In the other case, MA and AM concentrations were 1.79 and 0.119 microg/g in the left heart blood, and 1.27 and 0.074 microg/g in the right heart blood, respectively.

Plasma and brain methamphetamine concentrations in neonatal rats

D-Methamphetamine (D-MA) treatment during the neonatal period has been shown to induce acoustic startle hyperreactivity and Morris maze spatial learning deficits, but not to significantly affect Cincinnati maze sequential learning. In order to characterize the internal dose in these experiments, MA was measured in plasma and brain of neonatal rats at one of two ages, and using one of three dose schedules, two of which were selected to be representative of those used in previously published neurobehavioral studies. Plasma parameters showed few age and dose-frequency effects; however, brain concentrations showed more consistent age-dependent effects. Brain area under the concentration (AUC) values were consistently higher, regardless of dosing schedule, in offspring treated on postnatal day (P) 1 compared to those treated on P11. Previous results with the multiple-dose schedules have shown that Morris maze spatial learning deficits only occur in those exposed beginning on P11, whereas acoustic startle hyperreactivity is associated with exposure beginning on either P1 or P11. The pharmacokinetic parameters did not predict the long-term spatial learning and memory effects of neonatal MA administration, nor are they well correlated to the acoustic startle effects. The plasma concentrations obtained in rats are within the range for human MA abusers based on extrapolations from human low-dose values to those expected for heavy users.

Age-dependent differential responses of monoaminergic systems to high doses of methamphetamine

Abuse of methamphetamine (METH) by adolescents is a major public health issue in the U.S.A. Because of the neurotoxic potential of METH, we examined the response of CNS monoaminergic systems in young (adolescent) animals [postnatal day (PND) 40] to high-dose treatments (10 mg/kg, four injections, 2-h intervals) of this drug and contrasted these effects to those seen in older (young adult) rats (PND 90). Consistent with previous reports, we observed that PND 40 animals did not manifest the long-term (7-day) deficits in extrapyramidal dopamine (DA) parameters observed in PND 90 rats. In contrast, METH-induced rapid (1-h) reduction in the activity of striatal DA transporters occurred in both age groups. In addition, both persistent (7-day) and rapid (1-h) deficits in serotonergic systems (measured as reductions in tryptophan hydroxylase activity) were observed in PND 40 and 90 rats. Age-related differences in METH-induced hyperthermia did not appear to be a principal cause for our observations; however, age-dependent pharmacokinetics of this drug might have contributed to the differential METH monoaminergic responses by PND 40 and 90 animals.

Determination of amphetamine and methamphetamine in serum via headspace derivatization solid-phase microextraction-gas chromatography-mass spectrometry

This study evaluates solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS) to determine trace levels of amphetamine and methamphetamine in serum. Headspace post-derivatization in a laboratory-made design with heptafluorobutyric anhydride vapor following SPME was compared with that without derivatization SPME. The SPME experimental procedures to extract amphetamine and methamphetamine in serum were optimized with a relatively non-polar poly(dimethylsiloxane) coated fiber at pH 9.5, extraction time for 40 min and desorption at 260 degrees C for 2 min. Experimental results indicate that the concentration of the serum matrix diluted to a quarter of original (1:3) ratio by using one volume of buffer solution of boric acid mixed with sodium hydroxide and two volumes of water improves the extraction efficiency. Headspace derivatization following SPME was performed by using 6 microl 20% (v/v) heptafluorobutyric anhydride ethyl acetate solution at an oil bath temperature of 270 degrees C for 10 s. The precision was below 7% for analysis for without derivatization and below 17% for headspace derivatization. Detection limits were obtained at the ng/l level, one order better obtained in headspace derivatization than those achieved without derivatization. The feasibility of applying the methods to determine amphetamine and methamphetamine in real samples was examined by analyzing serum samples from methamphetamine abused suspects. Concentrations of the amphetamine and methamphetamine ranged from 6.0 microg/l (amphetamine) to 77 microg/l (methamphetamine) in serum.

Dual-label time-resolved fluoroimmunoassay of psychopharmaceuticals and stimulants in serum

A new method to measure two different drugs simultaneously by time-resolved fluoroimmunoassay (TR-FIA) has been developed. In the TR-FIA reported here, psychopharmaceuticals [chlorpromazine (CPZ) and desipramine (DSP)] and methamphetamine (MA) contained in serum are assayed by a combined use of a new europium (Eu) chelate and a samarium (Sm) chelate, as labels. The drug concentrations were determined by the competition between a labeled antigen with Eu(3+) or biotin and a sample antigen. A microtiter plate coated with a mixture of rabbit IgGs (anti-MA and anti-CPZ or anti-MA and anti-DSP) was used. In the assay of MA and CPZ, Eu(3+) labeled MA-bovine serum albumin conjugate (MA-BSA) and biotinylated CPZ-BSA were added to the well with their non-labeled standard solutions or samples. MA was assayed by measuring the fluorescence intensity of Eu(3+) at 615 nm. After incubation of the Sm(3+) labeled streptavidin, CPZ was assayed by measuring the fluorescence of Sm(3+) at 643 nm. In the assay of MA and DSP, Eu(3+) labeled DSP-BSA and biotinylated MA-BSA were used. In our dual-assay, the minimum detection limits of these drugs were 1ng/ml for MA, 10 ng/ml for CZP and 10 ng/ml for DSP. Since the simultaneous detection of different drugs by TR-FIA is time and sample saving, the method can be employed in rapid and sensitive screening tests.

Determination of chronic methamphetamine abuse by hair analysis

A 30-year-old male truck driver, known to be asthmatic, was found dead at the roadside lying near his car. A nebulizer bottle of Berotec (fenoterol hydrobromide) was found near his hand. The anatomic cause of death was suspected to be asthma. Toxicological screening of urine using Triage demonstrated the presence of methamphetamine. The blood concentration of methamphetamine was 0.4 microg/ml, and fenoterol was not detected. Hair analysis clearly indicated chronic methamphetamine abuse and medium dependency during the 2 months before death. We conclude that death might have been induced by the interaction of fenoterol and methamphetamine.

Simple and simultaneous analysis of fenfluramine, amphetamine and methamphetamine in whole blood by gas chromatography-mass spectrometry after headspace-solid phase microextraction and derivatization

A simple and sensitive method for the simultaneous analysis of fenfluramine, amphetamine and methamphetamine in whole blood was developed using a headspace-solid phase microextraction (SPME) and derivatization. A 0.5 g whole blood sample, 5 microl d(5)-methamphetamine (50 micrig/ml) as an internal standard, and 0.5 ml sodium hydroxide (1 M) were placed into a 12 ml vial, and sealed rapidly with a silicone septum and an aluminum cap. Immediately after the vial was heated to 70 degrees C in an aluminium block heater, the needle of the SPME device was inserted through the septum of the vial, and the extraction fiber was exposed in the headspace for 15 min. First, heptafluorobutyric anhydride was injected into the injection port of the GC-MS, and the compounds extracted by the fiber were then desorbed and derivatized simultaneously by exposing the fiber in the injection port. The calibration curves, using an internal standard method, demonstrated good linearity throughout the concentration range from 0.01 to 1.0 microg/g. The detection limits of this method were 5.0 ng/g for fenfluramine and methamphetamine, and 10 ng/g for amphetamine. No interferences were found, and the time for analysis was about 30 min for one sample. This method was applied to a suicide case in which the victim ingested fenfluramine. Fenfluramine was detected in the blood sample collected from the victim at the concentration of 7.7 microg/g.

Multiple-dose pharmacokinetics of selegiline and desmethylselegiline suggest saturable tissue binding

The goal of this study was to examine the multiple-dose pharmacokinetics of selegiline and its metabolites desmethylselegiline, 1-methamphetamine, and 1-amphetamine after oral administration of selegiline HCl. Twelve healthy volunteers received 10 mg of selegiline HCl once daily for 8 days. The pharmacokinetic profiles of selegiline and the metabolites were examined from serum samples for 24 hours (i.e., the dosing interval, tau) on days 1, 4, and 8. The results indicated significant apparent accumulation of selegiline and desmethylselegiline during the 8-day period of selegiline administration. The AUC tau S of selegiline and desmethylselegiline were increased 2.7 fold (p < 0.001) and 1.5 fold (p < 0.001), respectively, from day 1 to day 8. However, the half-lives of selegiline (range, 1.5-3.5 h) and desmethylselegiline (range, 3.4-5.3 h) were found to be relatively short. Accordingly, the short half-lives of these compounds failed to predict the apparent accumulation. With both of the 1-amphetamine metabolites of selegiline, steady state was reached by day 4. We suggest that the most likely explanation for the apparent accumulation of selegiline and desmethylselegiline was the saturation of the MAO-B binding sites in tissues, although decreased first-pass metabolism of selegiline cannot be ruled out. The observed increase in selegiline and desmethylselegiline concentrations on multiple dosing is not likely to significantly increase the pharmacodynamic effect or adverse effects of selegiline compared with what has been found after a single 10-mg dose.

Screening postmortem blood and tissues for nine classes [correction of cases] of drugs of abuse using automated microplate immunoassay

A commercially available enzyme-linked immunosorbant assay (ELISA) was evaluated as a screening procedure for the detection of nine classes of abused drugs in postmortem blood and tissue specimens. Specifically, postmortem blood, fluid and/or tissue homogenates were screened for amphetamine (AMP), methamphetamine (MET), barbiturates (BARB), benzodiazepines (BZD), cannabinoids (CNB), cocaine (benzoylecgonine; BE), morphine-specific (MOR), opiates (class; OPI), phencyclidine (PCP) and lysergic acid diethylamide (LSD) by ELISA and by coated tube radioimmunoassay (CTR) (BARB, BE, OPI, PCP, LSD) or double-antibody radioimmunoassay (DAR) (AMP/METH, BZD, CNB). Specimens that screened 'positive' by any method were confirmed and quantitated by gas chromatography/mass spectrometry (GC/MS). The only assay that appeared to perform less optimally than RIA was the MOR assay (five false negatives). However, this assay is very specific for free morphine while the GC/MS confirmation method provided a total morphine value. The OPI assay was more sensitive, producing fewer false negatives, and is recommended for broad class opiate screening. EIA is an adequate alternative to RIA for screening postmortem specimens, including blood and tissue, for nine major classes of drugs.

Liquid-liquid-liquid microextraction for sample preparation of biological fluids prior to capillary electrophoresis

Methamphetamine as a model compound was extracted from 2.5-mL aqueous samples adjusted to pH 13 (donor solution) through a thin phase of 1-octanol inside the pores of a polypropylene hollow fiber and finally into a 25-microL acidic acceptor solution inside the hollow fiber. Following this liquid-liquid-liquid microextraction (LLLME), the acceptor solutions were analyzed by capillary zone electrophoresis (CE). Extractions were performed in simple disposable devices each consisting of a conventional 4-mL sample vial, two needles for introduction and collection of the acceptor solution, and a 8-cm piece of a porous polypropylene hollow fiber. From 5 to 20 different samples were extracted in parallel for 45 min, providing a high sample capacity. Methamphetamine was preconcentrated by a factor of 75 from aqueous standard solutions, human urine, and human plasma utilizing 10(-1) M HCl as the acceptor phase and 10(-1) M NaOH in the donor solution. In addition to preconcentration, LLLME also served as a technique for sample cleanup since large molecules, acidic compounds, and neutral components were not extracted into the acceptor phase. Utilizing diphenhydramine hydrochloride as internal standard, repetitive extractions varied less than 5.2% RSD (n = 6), while the calibration curve for methamphetamine was linear within the range 20 ng/microL to 10 micrograms/mL (r = 0.9983). The detection limit of methamphetamine utilizing LLLME/CE was 5 ng/mL (S/N = 3) in both human urine and plasma.

[Study on the analysis of methamphetamine and its metabolite amphetamine in blood and urine]

The methods using GC/MS,GC/FID,GC/NPD for identification and quantification of Methamphetamined(MAMP) and Amphetamine (AMP) in human blood and urine were developed. Using 4-phenylbutylamine as the internal standard, the samples were extracted with 200 microliters cyclohexane and then the 2 microliters cyclohexane was injected into GC or the extracts were derivaized by using microwave irradiation. The methods given allowed simple and rapid procedure, the recoveries were greater than 80% and the sensitivity limits were 2-5 ng/ml. The methods for d/L Enantiomer of MAMP and AMP in human urine was also described, which can be used to determine the source of Amphetamines and determine the toxic effect in the case.