Biomedical subjects

G Pépin

Publications and source records attributed to G Pépin.

At least 19 recordsLinked to original sources

PubMed2005

Use of drugs of abuse in less than 30-year-old drivers killed in a road crash in France: a spectacular increase for cannabis, cocaine and amphetamines.

A collaborative study was conducted in France in order to determine the prevalence of cannabinoids, opiates, cocaine metabolites and amphetamines in blood samples from drivers killed in road accidents in 2003 and 2004 and to compare these values with those of a previous study performed during the period 2000-2001 involving 900 drivers. Blood samples were provided from 2003 under 30-year-old drivers, killed in a traffic accident. Drugs of abuse were determined by gas chromatography-mass spectrometry using the same analytical procedures in all the 12 laboratories. The most frequently observed compounds were by far cannabinoids, that tested positive in 39.6% of the total number of samples. Delta9 tetrahydrocannabinol (THC), the most active of the principle constituents in marijuana (cannabis sativa), was detected in the blood of 28.9% drivers and was the single drug of abuse in 80.2% of the positive cases. It was associated with amphetamines in 7.4% and with opiates and cocaine in 1.9 and 4.8%, respectively. Amphetamines were present in 3.1% of the total number of samples, cocaine metabolites in 3.0% and opiates in 3.5%. When comparing these results with those of a previous study performed 3 years before, a significant increase is observed for THC (28.9% versus 16.9%), cocaine metabolites (3.0% versus 0.2%) and amphetamines (3.1% versus 1.4%). This study demonstrates the critical necessity of implementing in France as soon as possible systematical roadside testing for drugs of abuse.

Accidents, Traffic↗

PubMed2004

Identification of alprazolam in hair in two cases of drug-facilitated incidents.

The use of a drug to modify a person's behaviour for criminal gain is not a recent phenomenon. However, the recent increase in reports of drug-facilitated crimes (sexual assault, robbery) has caused alarm by the general public. Among the drugs that can be used, alprazolam (Xanax), an anxiolytic benzodiazepine, has been seldom observed. To document two cases involving this drug, we have developed an approach based on hair testing by LC-MS/MS. After pH 8.4 buffer incubation and extraction with methylene chloride/diethyl ether (80/20, v/v), hair extracts were separated on a XTerra MS C18 column using a gradient of acetonitrile and formate buffer. Alprazolam and diazepam-d5, used as internal standard, were detected by electrospray tandem mass spectrometry. In the first criminal case, alprazolam tested positive in two consecutive 2 cm hair segments at 4.9 and 2.4 pg/mg, from a 12-year-old girl, assaulted by her father who had sedated her three or four times. In the other case, alprazolam was detected in four consecutive 1cm hair segments at 3.1-0.4 pg/mg, obtained from an adolescent who had been forced to prostitute herself.

Adolescent↗

PubMed2003

Screening procedure for eight quaternary nitrogen muscle relaxants in blood by high-performance liquid chromatography-electrospray ionization mass spectrometry.

A screening procedure was developed for the identification and the quantification of eight quaternary nitrogen muscle relaxants, including d-tubocurarine, alcuronium, pancuronium, vecuronium, atracurium, mivacurium, rocuronium and mebezonium, in blood samples. The procedure involves ion-pair extraction with methylene chloride at pH 5.4, reversed-phase HPLC separation and electrospray ionization mass spectrometry detection. The procedure was validated in terms of linearity (0.929 5 for all the target compounds at 0.1 mg/l). The screening test was found satisfactory and applied in two fatal deaths. In the first case, toxicological investigations on biological fluids collected during the autopsy revealed the presence of vecuronium (1.2 and 0.6 mg/l in blood and urine, respectively) and its desacetylated metabolite, 3-hydroxy-vecuronium (4.4 and 0.7 mg vecuronium equivalent/l in blood and urine, respectively). In the second forensic case, blood analysis showed high levels of mebezonium (6.5 mg/l). The developed procedure was found suitable for forensic investigations.

Adult↗

PubMed2001

[Urinary nandrolone metabolites in antidoping control].

The French National Laboratory of the International Olympic Committee (IOC) has detected norandrosterone (NA) and noretiocholanolone (NE) in urine samples from several sportsmen. These two substances are known to be urinary metabolites after nandrolone intake. In such cases, the NA level is always higher than the Ne level. However, in the urine samples of sportsmen tested positive, the NE concentrations were systematically higher than the NA levels. We therefore searched for other steroid precursors (commercially available capsules or tablets of dehydroepiandrosterone, 4-androstenediol, 5-androstenediol, 4-androstenedione, 19-norandrostenediol and 19-norandrostenedione, also illegally used in France) which could lead to an excretion of NA and NE and to an inverted ratio of these metabolites.

Anabolic Agents↗

PubMed2000

Analysis of corticosteroids in hair by liquid chromatography-electrospray ionization mass spectrometry.

The present study describes a confirmatory method for the quantitative determination in hair of the most common corticosteroids illegaly used as doping agents by athletes. Corticosteroids are extracted from 50 mg of powdered hairs by methanolic extraction follows by a solid-phase extraction on C18 cartridge. After extraction, the dried residue is reconstituted with 50 microl acetonitrile and injected in a liquid chromatograph. Liquid chromatography separation is performed on a reversed-phase C18 column with a binary gradient of formiate buffer pH 3-acetonitrile as mobile phase. Detection is performed with an electrospray ionization mass spectrometer in negative ion and selected-ion monitoring mode. The limits of sensitivity achieved is 0.1 ng/mg in hair. Application to hair sample collected during an antidoping control and comparison to results obtain on urines, collected on the same athletes at the same time, shows the interest and the complementarity of both matrices. Hair analysis could allow the detection of corticosteroids on a large period preceding the control, and the detection of natural corticosteroids administered as pro-drug, like hydrocortisone acetate.

Adrenal Cortex Hormones↗

PubMed2000

Compared interest between hair analysis and urinalysis in doping controls. Results for amphetamines, corticosteroids and anabolic steroids in racing cyclists.

In France during a famous bicycle race, the newspapers documented the degree in which doping seemed to be supervised in some teams by managers and doctors. Use of anabolic steroids and other substances was officially banned in the mid-seventies by sports authorities. This policy has been enforced through urine testing before competition. It is well known, however, that a latency period is all that is necessary to defeat these tests. Nevertheless, hair analysis could be a promising tool when testing for periods that are not accessible to urinalysis any more. We have developed different sensitive methods for testing hair for amphetamines, anabolic steroids and their esters and corticosteroids. For amphetamines, 50 mg of hair were digested with 1 M NaOH, extracted with ethyl acetate, derivatized with TFA and analyzed by gas chromatography positive chemical-ionization mass spectrometry. For corticosteroids, 50 mg of powdered hair were treated with methanol in an ultrasonic bath and subsequently purified using a C18 solid phase extraction column. Analysis was realized by high performance liquid chromatography coupled to electrospray-ionization tandem mass spectrometry. For anabolic steroids and their esters, 100 mg of powdered hair were treated with methanol in an ultrasonic bath for extraction of esters, then alkaline digested with 1 M NaOH for an optimum recovery of other drugs. The two liquid preparations were subsequently extracted with ethyl acetate, pooled, then finally highly purified using a twin solid phase extraction on aminopropyl and silica cartridges. Residue was derivatized with MSTFA prior to injection. Analysis was conducted by gas chromatography coupled to a triple quadrupole mass spectrometer. Thirty cyclists were sampled and tested both in hair and in urine. Amphetamine was detected 10 times in hair (out of 19 analyses) compared to 6 times in urine (out of 30 analyses). Corticosteroids were detected 5 times in hair (methylprednisolone 1 case, triamcinolone acetonide 3 cases and hydrocortisone acetate 1 case) in hair (out of 12 analyses) compared to 12 times (triamcinolone acetonide 10 cases and betamethasone 2 cases) in urine (out of 30 analyses). Anabolic steroids were detected twice (nandrolone 1 case, and testosterone undecanoate 1 case) in hair (out of 25 analyses) compared to none in urine (out of 30 analyses).

Adrenal Cortex Hormones↗

PubMed2000

The hair analysis proficiency testing program of the French Society of Analytical Toxicology.

In an effort to improve laboratories performing hair analysis in forensic cases, the French Society of Analytical Toxicology (S.F.T.A.) has implemented a proficiency testing program since 1992. Actually about 10 laboratories are participating. Each survey is dedicated to one analyte or one pharmacological class: opiates (6-monoacetylmorphine, morphine and codeine), cocaine and benzoylecgonine, tetrahydrocannabinol, buprenorphine and norbuprenorphine, beta-blockers (metoprolol, atenolol), beta 2-agonists (salbutamol, clenbuterol). Animal hair was tested for clenbuterol. Prior to sending, hair samples were reduced to a powdered form, well mixed to ensure homogeneity, and then tested by GC/MS or HPLC/MS. Results confirm those obtained in a preliminary study on opiates and cocaine analysis in hair: a common analytical procedure has to be used by all the participants, including hydrolysis of hair. It is essential to work on authentic drug-positive hair samples and not on spiked samples. Participation at this program is free of charge and considered as an educational tool. Comparison of the results with those of other laboratories in Europe and USA shows that the analytical methods used during this program are in accordance with all the other procedures.

Chromatography, High Pressure Liquid↗

PubMed1999

Gas chromatographic-tandem mass spectrometric determination of anabolic steroids and their esters in hair. Application in doping control and meat quality control.

We have developed a powerful and simple sensitive method for testing hair for anabolic steroids and their esters. A 100-mg amount of powdered hair was treated with methanol in an ultrasonic bath for extraction of esters, then alkaline digested with 1 M NaOH for an optimum recovery of other drugs. The two liquid preparations were subsequently extracted with ethyl acetate, pooled, then finally highly purified using a twin solid-phase extraction on amino and silica cartridges. The residue was derivatized with N-methyl-N(trimethylsilyl)-trifluoracetamide (MSTFA) prior to injection. Analysis was conducted by gas chromatography coupled to a triple quadrupole mass spectrometer. The generally chosen parent ion was the molecular ion while two daughter ions were selected for each compound with collision energies ranging from -16 to -21 eV. Internal standards were nandrolone d3 for non-esterified drugs and testosterone phenyl propionate for esters. The limits of detection calculated from an analysis of the blanks (n=30) were 0.08 pg/mg for nandrolone, 6.20 pg/mg for boldenone, 0.07 pg/mg for methyl testosterone, 0.15 pg/mg for ethinyl estradiol, 2.10 pg/mg for metandienone, 0.86 pg/mg for testosterone propionate, 0.95 pg/mg for testosterone cypionate, 1.90 pg/mg for nandrolone decanoate, 3.10 pg/mg for testosterone decanoate and 4.80 pg/mg for testosterone undecanoate. Application to doping control has been demonstrated. In a series of 18 sportsmen, two tested positive for anabolic steroids in hair whereas urinalysis was negative for both of them. The first positive case was nandrolone and the second case concerned the identification of testosterone undecanoate. Measured in 10 white males aged between 22 and 31 years, the testosterone concentration was in the range 1.7-9.2 pg/mg (mean=5.0 pg/mg). The method was also applied in meat quality control. Of the 187 analyses realized based upon hair and urine sampling in slaughter houses, 23 were positive for anabolic steroids in hair: one case for boldenone, one case for metandienone, two cases for testosterone propionate, three cases for nandrolone, five cases for testosterone decanoate and 11 cases for methyl testosterone. In the meantime, urinalysis was always negative for these drugs or their metabolites.

Adult↗

PubMed1999

Testing hair for pharmaceuticals.

More than hundred pharmaceuticals, drugs of abuse or doping agents have been reported to be detectable in human hair. This article reviews the analysis of 90 drugs and drug metabolites by chromatographic procedures, including the pretreatment steps, the extraction methods, the reported limits of detection and the measured concentrations in real human hair samples. Some progress is observed in the detection of low dose drugs, like fentanyl or flunitrazepam. The general tendency in the last years, to highly sophisticated techniques (GC-MS-NCI, HPLC-MS, GC-MS-MS) illustrates well this constant fight for sensitivity. Some new findings, based on the recent experience of the authors, are also added.

Adult↗

PubMed1998

Gas chromatographic-mass spectrometric quantitation of dextropropoxyphene and norpropoxyphene in hair and whole blood after automated on-line solid-phase extraction. Application in twelve fatalities.

After conversion of norpropoxyphene (NP) to its corresponding amide, dextropropoxyphene (DP) and NP are extracted from 1 ml of blood or 50 mg of powdered hair, on C18 cartridges and eluted using methanol containing 0.5% acetic acid. Automated extraction is conducted on-line with automated device, starting from buffered and centrifuged sample. After extraction, the dried residue is reconstituted with 40 microl of methanol, and then injected in a gas chromatograph at 250 degrees C. Quantitation is carried out by gas chromatography-mass spectrometry in the selected-ion monitoring mode, lidocaine being the internal standard. The method gave relative standard deviations lower than 6.2% in whole blood, and 6.0% in hair for the entire range of calibration from 0.5 to 10 microg/ml in blood and from 1 to 20 ng/mg in hair of both compounds. Limits of detection in blood and hair for DP are, respectively, 0.07 microg/ml and 0.05 ng/mg, whereas the respective limits of detection in whole blood and hair for NP are 0.09 microg/ml and 0.04 ng/mg. The present method was used for one year in our laboratory. Postmortem concentrations of DP in blood ranged from 1.6 to 44.0 microg/ml (mean=9.8microg/ml, n = 12) and are comparable to those found in the literature. Out of 30 hair samples from people who died from heroin overdose, 13 were positive both for DP and NP with concentrations ranging from 0.2 to 27.4 ng/mg (mean 8.7 ng/mg) for DP and 0.3 to 68.9 ng/mg (mean 24.1 ng/mg) for NP.

Adult↗

PubMed1998

[Acute poisoning during substitution therapy based on high-dosage buprenorphine. 29 clinical cases--20 fatal cases].

OBJECTIVES: Buprenorphine has been an important advance in care for drug abusers, but the toxic risk may be fatal. We report here two original series of buprenorphine poisoning in opiate abusers on substitution therapy. PATIENTS: The first series included 20 males and 9 females, aged 20-35 years (mean = 27.5) with non-fatal poisoning. The second series included 20 subjects (19 males, 1 female) aged 14-48 years (mean = 26.6) with a fatal outcome. All subjects were opiate addicts taking high-dosage sublingual buprenorphine formulation as substitution therapy. RESULTS: Blood concentrations of buprenorphine were found in all cases to remain at a low level (1.0-2.3 ng/ml, m = 1.4 ng/ml, and 1.1-29.0 ng/ml, m = 8.4 ng/ml in non-fatal and fatal cases respectively). Almost all cases involved concomitant intake of psychotropic medications, especially benzodiazepines (18 non-fatal and 17 fatal cases). DISCUSSION: These observations confirm previously reported data on the danger of buprenorphine-benzodiazepine combinations. Intravenous injection of crushed tablets also appears to be a risk factor (8 deaths and 10 non-fatal poisonings). This series highlights the need for improvement in the recently developed French program for substitution therapy with high-dosage buprenorphine in heroin addicts.

Administration, Sublingual↗

PubMed1998

Evidence of polydrug use using hair analysis: a fatal case involving heroin, cocaine, cannabis, chloroform, thiopental and ketamine.

A case is presented involving a young woman on several illicit drugs (heroin, cocaine and cannabis) as well as two medications and a solvent used for their anesthetic and narcotic properties: thiopental, ketamine and chloroform. This complex drug use was supported by hair analysis over a 10.5 cm segment of the hair taken at autopsy. The average measured concentrations in hair were: thiopental = 5.3 ng/mg, pentobarbital = 10.0 ng/mg, ketamine = 11.3 ng/mg norketamine = 1.0 ng/mg, diazepam = 1.2 ng/mg, nordiazepam = 0.1 ng/mg, 6-acetylmorphine = 4.4 ng/mg, morphine = 3.4 ng/mg, codeine = 1.2 ng/mg, cocaine = 5.5 ng/mg, benzoylecgonine = 1.5 ng/mg and methylecgonine ester = 1.0 ng/mg. While the ketamine/norketamine ratio is consistent with that already reported on drug detection in hair, the thiopental/pentobarbital ratio seems to be inverted.

Adult↗

PubMed1998

Diagnosis of drowning by combined computer-assisted histomorphometry of lungs with blood strontium determination.

The aim of our study was to examine the combined contribution of computer-assisted histomorphometry of lungs with blood strontium (BS) measurement to the diagnosis of drowning in cadavers recovered from fresh water. The study population comprised 116 drowned subjects. The results for this group were compared with those obtained for three non-drowned groups: 22 subjects who died from causes other than asphyxia, 13 subjects who died of asphyxia (strangulation or hanging); and 23 healthy living subjects in whom normal BS level was measured. Samples of water where the bodies had been found were analyzed in order to establish a relation with the BS concentration of the drowned subjects. Histologically, each type of pulmonary lesion (congestion, edema, alveolar macrophages, alveolar hemorrhage, and emphysema aquosum) was evaluated semiquantitatively using a score according to the severity of the pathology. Then, a quantitative histomorphometric study was performed using a computer-assisted image analyzer to measure the length and thickness of the alveolar walls, and the area and density of the alveolar cavities. The mean values of the BS levels in the 116 drowned subjects and of the water strontium concentrations were found to be much higher than in the living individuals. Although the ranges were wide, we found no overlap between values found in drowned subjects and those in non-drowned subjects. Emphysema aquosum and to a lesser extent alveolar hemorrhage were found to be the most significant histologic changes in the drowned and asphyxia groups compared with the nonasphyxia control groups.

Drowning↗

PubMed1997

Detection of illegal clenbuterol use in calves using hair analysis. Application in meat quality control.

This study describes a real-life situation involving nine calves, 106 days old, which received oral doses of clenbuterol administered through their milk. Powdered skim milk containing 6.7 mg of clenbuterol was given daily for fifteen days under supervision (i.e. 100 mg per calf for the whole study) to seven calves, and two calves did not receive the drug. Hair samples and urine were taken and subjected to analysis by gas chromatography-mass spectrometry. Hairs were pulverized in a ball mill and 100 mg were incubated in a mildly acidic medium. The sample clean-up procedure involved solid-phase extraction on C18 cartridges. Metoprolol was used as the internal standard for quantitation, after formation of methylboronate derivatives. The calibration curve for clenbuterol in hair was linear in the range 20-5000 pg/mg. The limit of detection of clenbuterol was 16 pg/mg in hair and 0.14 ng/ml in urine. Hair testing was effective after 7-10 days of treatment, and concentrations were in the range of 20 to 4372 pg/mg. Urinalysis can detect clenbuterol for up to two weeks after discontinuation of the drug. Conveniently, this is around the time when the hair samples attain greatest sensitivity. Therefore, the combination of the two matrices appears to be the method of choice for testing for the illegal use of drugs in meat-producing animals.

Administration, Oral↗

PubMed1997

Moclobemide fatalities: report of two cases and analytical determinations by GC-MS and HPLC-PDA after solid-phase extraction.

We have described a rapid and simple solid-phase extraction on C18 cartridges of moclobemide suitable for the analysis of post-mortem whole blood and urine. The methods used for identification were GC-MS and HPLC-PDA. Quantification was performed by the HPLC-PDA technique with detection at 238 nm. The limit of detection was 0.012 microgram/ml in blood. A between-day precision study gave relative standard deviations which were always less than 4.7% over the entire range of calibration (0.2 to 20.0 micrograms/ml). The method was applied in a case of moclobemide overdose due to a deliberate ingestion of 4.5 g of the drug. A second case concerned a polyintoxication including moclobemide as one of the main toxins. The post-mortem whole blood concentrations were 15.5 and 13.8 micrograms/ml respectively. Determination of the drug in other biological specimens is also reported.

Adult↗

PubMed1997

Meprobamate overdosage: a continuing problem. Sensitive GC-MS quantitation after solid phase extraction in 19 fatal cases.

We describe a simple method for the urinary identification and blood quantitation of meprobamate suitable for any toxicological laboratory. After urinary screening using GC-MS technology, quantitation is performed by GC-MS in the selected-ion monitoring mode. Isolation of the drug is achieved by solid phase extraction on a C-18 cartridge. A specific elution is obtained by three volumes of acetone:triethylamine (99:1 v/v). Lidocaine is used as internal standard. RSDs (%) of the within-day and between-day precision studies are always less than 7.2 on the entire range of calibration. Linearity is inspected using an analysis of variance ANOVA. Homogeneity of the variances is tested using Hartley's test. Weighted linear regression is then computed. Limits of detection and quantification are given by an analysis of the blanks. The present method was applied in our laboratory over a period of 1 year. Meprobamate appeared as a drug which still has a significant frequency (5.5%) and is the most frequently involved in fatal pharmaceutical overdoses (15.3%). Post mortem concentrations ranged from 41 to 397 mg/l (mean = 182) and are compared to those of the literature.

Analysis of Variance↗

PubMed1997

Simultaneous solid-phase extraction on C18 cartridges of opiates and cocainics for an improved quantitation in human hair by GC-MS: one year of forensic applications.

We have developed a new solid-phase extraction (SPE) on C18 cartridges which allows a very simple protocol of manipulation and a single elution of opiates and cocainics from human hair samples. The method involved decontamination in a phosphate buffer and dichloromethane, pulverization in a ball mill, addition of deuterated internal standards, heated acid hydrolysis and SPE. Quantitation utilized gas chromatography and mass spectrometry. Between days precise study gave relative standard deviations always inferior to 8.9% for each compound at 4 ng/mg (except methylecgonine ester = 15.7%). Accuracy was tested using a t-statistic versus a reference material from the NIST. Limits of detection were calculated from an analysis of the blanks which contained between 0.12 and 0.28 ng/mg for each drug. The method was applied in forensic cases for 1 year of toxicological activity. Among the 108 analyses performed, 30 were positive for cocaine and 33 for opiates. Concentrations were in the range 0.9-242.0 ng/mg (cocaine), 0.3-71.3 ng/mg (benzoylecgonine), 0.0-9.8 ng/mg (methylecgonine ester), 0.0-2.9 ng/mg (cocaethylene), 0.1-11.5 ng/mg (codeine), 0.4-44.6 ng/mg (morphine) and 0.7-131.2 ng/mg (6-acetylmorphine). Ratios of the metabolites to parent drugs were proposed to avoid risk of external contamination.

Cocaine↗

PubMed1997

Use of high-performance liquid chromatography with photodiode-array UV detection for the creation of a 600-compound library. Application to forensic toxicology.

A high-performance liquid chromatographic method is described with photodiode array detection for systematic toxicological analysis in human blood and urine. After a single step liquid-liquid extraction using Toxi-Tube A, drugs are analyzed with a multi step gradient (phosphate pH 3.8-acetonitrile) on a Symmetry C8 5-microns column (250 mm x 4.6 mm I.D.) (Waters), operated at 30 degrees C. The flow-rate is varied during the run from 1 ml/min to 1.5 ml/min. Full UV spectra are recorded on-line during the 28 min chromatographic run. Enhanced performances for drug detection are obtained with this method due to (a) reduction of peak-tailing for basic drugs, (b) lower identification limits, (c) more stable retention times and (d) larger number of referenced drugs (684 spectrum registered). Application of real samples has been demonstrated.

Adult↗