Is it really possible to kill with insulin without leaving traces? From lifesaver to killer, the issues surrounding the analytical characterization of postmortem insulin illustrated by an exemplary case.

Evidence of an insulin overdose is very complicated in the medico-legal field. The analysis and subsequent interpretation of results is complex, especially when treating postmortem blood samples. The instability of insulin, the special pre-analytical conditions and the absence of specific analytical methods has led most laboratories not to analyze insulin in their routine with a consequent underestimation of cases. This paper aims to assess the difficulties associated with the analytical characterization of insulin by describing a case that typically represents most of the inconveniences encountered following a suspected insulin overdose. The case concerns a man found dead at home by his brother. After an external examination, which did not reveal a specific cause of death, toxicological analysis was requested which did not reveal any substance of toxicological interest. Only 9 months later, it was reported to the toxicologist that the subject was diabetic, on insulin lispro treatment and that three empty syringes were found next to his body. Following analysis by LC-high-resolution mass spectrometry, the presence of insulin lispro at a concentration of 1.1 ng/mL, a therapeutic concentration, was evidenced. Despite the low concentration found, overdose cannot be excluded and this paper will describe the criteria evaluated to reach this conclusion. This case highlights that the interpretation of a postmortem insulin concentration is very complex and requires the evaluation of various elements including the circumstances of death, the subject's medical history, the interval between death and sampling and the sample storage.

Testing for Kratom alkaloids in fingernail clippings - not only mitragynine.

Kratom (Mitragyna speciosa) is a species of large tree that grows in Southeast Asia and is part of the Rubiaceae family. Its fresh leaves are harvested for their medicinal properties and used for their psychoactive effects. Kratom contains many biologically active alkaloids, including mitragynine and 7-OH-mitragynine, which are considered the two most important psychoactive components and constitute approximately 66% and 2% of the total alkaloid content. Other alkaloids are present in the plant, such as speciogynine, speciociliatine and paynantheine, but have less psychoactive activity. Over the past decade, the sale of kratom powder has increased on the Internet. This led to a significant increase in forensic cases. Given the lack of data existing in the literature, and the total absence of data in nails, the authors report a study to determine the best target alkaloids for documenting kratom consumption in this matrix. Fingernail clippings from a supposed kratom powder user were analyzed after liquid-liquid extraction, chromatography separation using a HSS C18 column and performed on an ultra-high performance liquid chromatography coupled to a tandem mass spectrometer. In the specimen, mitragynine was quantified at 229 pg/mg, speciogynine and paynantheine were both quantified at 2 pg/mg, and speciociliatine was quantified at 19 pg/mg. 7-OH-mitragynine was not detected. The interpretation of these concentrations is complex, since there is currently no reference in the literature, as this is the first identification of mitragynine and other kratom alkaloids in nails. Nevertheless, in view of the high concentration of mitragynine, the subject seems to be a repetitive user of kratom. According to the measured concentrations, it seems that mitragynine remains the best target to document kratom consumption, but the identification of the other alkaloids would enhance the specificity of the test.

Evidence of exposure to flecainide in a newborn by keratinous matrices testing and interpretation of the findings.

Pediatric poisoning represents a serious problem all around the world. Abuse or neglect of children by adults must be highlighted in children exposed to drugs to which they would not normally have access. Usually, segmental hair analysis would allow in these contexts to determine whether the exposure was unique or repetitive. Hair and nail samples from a 9-month-old girl were received in our laboratory for analysis, after the child was hospitalized due to severe dehydration caused by her mother's neglect. At the admission, flecainide, an antiarrhythmic never prescribed to the child, was identified in the daughter urine. Using an LC-MS/MS method, flecainide tested positive in the child's hair at the following concentrations: 66 pg/mg (root to 1 cm), 61 pg/mg (1-2 cm), and 125 pg/mg (2-3 cm). Traces below the limit of quantification (1 pg/mg) were also present in the nail clippings. These concentrations are much lower than those obtained in adults under daily treatment. Given the different pharmacokinetic and dynamic parameters in children, the different rate of hair growth, and the greater porosity of the hair, which makes it more prone to external contamination, the interpretation of hair findings in children remains very complicated. In this case, it can be assumed that the presence of the drug in the urine indicates systemic incorporation and that administration had occurred for some months (three positive segments). The interpretation of hair tests from young children needs a global review of all the findings, as a positive result cannot stand alone to claim repetitive exposures.

Testing for clomiphene in keratinous matrices using LC-MS/MS in doping purpose: Is a single intake of clomiphene detectable in hair and nail clippings?

Clomiphene is a selective estrogen receptor modulator. It is indicated for the treatment of female infertility issues but in sport, it can be misused to stimulate endogenous testosterone secretion in men. Therefore, it has been prohibited at all times by the World Anti-doping Agency. The aim of this study was to get data to be able to interpret concentrations in athletes. A healthy volunteer (male, 62 years-old) ingested a single therapeutic dose of clomiphene (Clomid™, 50 mg). Strands of hair (blond, 4 cm) were collected one month after the ingestion. Body hair (beard, axillary, pubic and chest hair), and finger and toenails were collected over 4-5 months. A previous method was modified to identify and quantify clomiphene in keratinous matrices. 30 mg of specimen were sonicated and incubated in 1 mL of methanol, in presence of 200 pg of clomiphene-D5 (internal standard). After centrifugation and evaporation of the organic phase, the samples were analyzed using LC-MS/MS. Linearity was verified in hair and nail clippings between 1 and 500 pg/mg. The limits of detection and quantification were determined at 0.3 and 1 pg/mg respectively. The study demonstrated that clomiphene tested positive in all the analyzed specimens at 9 pg/mg in head hair, from 28 to 486 pg/mg (body hair) and from 4 to 57 pg/mg (nails). Clomiphene was identified for the first time in multiple keratinous matrices. This study demonstrated that a single oral therapeutic dose is detectable in keratinous matrices over a long period of time.

Intentional overdose of glargine insulin: Determination of the parent compound in postmortem blood by LC-HRMS.

Insulin glargine is a long-acting insulin analog that is converted after enzymatic cleavage of the arginine pair of the ß-chain into its main metabolite M1 (21A -Gly-insulin), which is responsible for the hypoglycemic activity. In all the overdose cases described in the literature, only M1 concentrations have been reported, whereas insulin glargine was always absent or below the limit of quantitation. In this study, we present a case of suicide of a young nurse by injection of insulin glargine in which the parent molecule was found at a toxic concentration in blood. The determination and the discrimination of insulin glargine from human insulin and other synthetic analogs in the blood specimen were performed by liquid chromatography coupled to high-resolution mass spectrometry (Waters XEVO G2-XS QToF) and extraction after precipitation in the presence of bovine insulin (internal standard), with a mixture of acetonitrile/methanol +1% formic acid followed by purification on solid phase extraction cartridges C18. Glargine insulin tested highly positive in the blood with a concentration of 1.06 mg/L. Due to the difficulty in obtaining a M1 pure standard, the metabolite could not be dosed. This unique presence of the parent molecule, reported for the first time, can be explained by inter-individual variability in the rate of conversion to metabolite. Intravenous injection versus subcutaneous injection can also explain the presence of insulin glargine. Finally, the dose injected may have been so high that saturation of the proteolytic enzymes responsible for conversion to M1 should have occurred.

First identification of dapagliflozin in human hair: Development of a new liquid chromatography with tandem mass spectrometry method.

Sodium-glucose cotransporter 1 inhibitors are a new class of drugs used for the treatment of type II diabetes. Due to their diuretic capabilities and the glycosuria they induce, these molecules cause effective weight loss that could attract the interest of a wider public than diabetics with all the health consequences knowing the adverse effects of these substances. In order to reveal a past exposure to these substances, hair analysis can be very useful especially in the medicolegal context. There are no data in the literature about gliflozin testing in hair. In this study, a method was developed for the analysis of three molecules belonging to the gliflozin family (dapagliflozin, empagliflozin and canagliflozin) using a liquid chromatography system coupled to tandem mass spectrometry. After decontamination with dichloromethane, gliflozins were extracted from hair following incubation in methanol in the presence of dapagliflozin-d5. Validation showed acceptable linearity for all compounds between 10 and 10,000 pg/mg, with limit of detection and limit of quantification at 5 and 10 pg/mg, respectively. Repeatability and reproducibility were below 20% at three concentrations for all analytes. The method was subsequently applied to the hair of two diabetic subjects under dapagliflozin treatment. In one of the two cases, the result was negative, while in the second case, the concentration was 12 pg/mg. Due to the absence of data, it is difficult to explain the absence of dapagliflozin in the hair of the first case. Physico-chemical characteristics of dapagliflozin could explain its bad incorporation in hair, making detection difficult even after daily treatment.

The Power of Keratinous Matrices (Head Hair, Body Hair and Nail Clippings) Analysis in a Case of Death Involving Anabolic Agents.

A 29-year-old man with no previous medical history was found dead at home. Anabolic products (tablets and oily solutions) and syringes were found at the scene. The man was known to train regularly at a fitness club and to use anabolic drugs. Following an unremarkable autopsy with normal histology, toxicological analyses were requested by the local prosecutor to provide further information. Blood, head hair (5 cm, black), body hair (axillary and leg) and toe and finger nail clippings were submitted to liquid and gas chromatography coupled to tandem mass spectrometry (LC and GC-MS-MS) methods to test for anabolic steroids. Blood tested positive for testosterone (4 ng/mL), boldenone (26 ng/mL), stanozolol (3 ng/mL) and trenbolone (<1 ng/mL). Segmental head hair tests (2 × 2.5 cm) revealed a repeated consumption of testosterone (65-72 pg/mg), testosterone propionate (930-691 pg/mg), testosterone isocaproate (79 pg/mg to <5 pg/mg), nandrolone decanoate (202-64 pg/mg), boldenone (16 pg/mg), stanozolol (575-670 pg/mg), trenbolone (4 pg/mg-not detected), drostanolone (112-30 pg/mg), drostanolone enanthate (26-5 pg/mg) and drostanolone propionate (15-4 pg/mg). In addition to the substances identified in head hair, testosterone decanoate, testosterone cypionate and nandrolone were identified in both body hair and nails. The experts concluded that the manner of death can be listed as toxic due to massive repetitive use of anabolic steroids during the previous months. For anabolic agents, blood does not seem to be the best matrix to document a fatal intoxication. Indeed, these products are toxics when abused long term and are known to cause cardiac, hepatic and renal diseases. When compared to blood, hair and nails have a much larger window of detection. Therefore, keratinous matrices seem to be the best approach to test for anabolic steroids when a sudden death is observed in the context of possible abuse of steroids.

Pregnancy denial and unplanned home delivery: Considerations about fetal death causes and maternal drug use imputability.

Determining fetal death causes is a complex problem for the forensic pathologist. Beyond the medico-legal context, the expert must be able to evaluate the viability of the fetus at the time of death, to eliminate in-utero fetal death and to determine if the death is related to a fetal, a maternal, a placental cause, or simply related to obstetrical complications. The authors present the case of a 21-year-old woman who unexpectedly gave birth to a fetus during a party. As pregnancy was not acknowledged by the mother (regular menstrual cycles and use of hormonal contraception), no obstetrical check-up had been performed. She would have presented violent abdominal pain and expelled a mass in the toilet. The fetus body, enclosed in the amniotic pouch, and the placenta were found in the toilet. A forensic autopsy was performed jointly by a forensic pathologist and a specialist in fetal pathology. Histological, toxicological and genetic samples were collected. Body morphometry and bone maturation indicated a gestational age of 31-32 weeks of amenorrhea. A significant asphyxia syndrome and non-specific multi-visceral congestion were noted at autopsy. Histological analysis of the fetal tissues revealed a lung and skeletal muscle maturation in accordance with the estimated term. At the brain level, there were signs of anoxia and abnormal cortical development with periventricular nodular heterotopia areas. The placenta microscopic analysis revealed acute chorioamniotitis, the probable cause of the premature fetal expulsion. Toxicological analyses revealed the presence of ecstasy (48 ng/mL) and its metabolite MDA (2 ng/mL) in fetal blood. Although negative in blood, THC-COOH tested positive in urine (9 ng/mL). The fetus was repetitively exposed to cannabis, as Δ9-THC tested positive in hair (51 pg/mg). Maternal hair analysis on 4 × 3 cm evidenced a long-term use of cannabis, while results support single massive exposure to ecstasy. In this article, the authors try to explain the reflexive pathway carried out to establish death causes and the maternal toxic consumption imputability on the cerebral malformations and fetal death. This case illustrates both the interest of toxicological analyses in cases of fetal death and the importance of a collaborative work between forensic and fetal pathologists and toxicologists, which appeared critical to answer in the best conditions to the magistrates questions, as well as to the bereaved families.

Fingerprints: A New Specimen for Innovative Applications for the Detection of Xenobiotics.

Fingerprints are invisible traces that result from a deposition of sweat and sebum present on the papillary ridges. As sweat and sebum contain drugs, fingerprints are promising since collection is rapid, non-invasive and difficult to falsify. Very limited data are available in the literature, and therefore, it seems opportune to study the transfer of xenobiotics onto the items taken in hand via the fingerprints. Two studies were implemented using the ballpoint pen as a model. The objective of the first study was to compare the nicotine concentrations found on the pens of three smokers and three non-smokers. Five pens, belonging to each subject and used regularly, were rubbed with a cotton swab dipped in methanol and analyzed by liquid chromatography coupled with tandem mass spectrometry (LC-MS-MS). The second study was to analyze the transfer via fingerprints of four volunteers, after administration of 30 mg of codeine. The objective was to determine the feasibility of this study and the time corresponding to the highest concentration of codeine. Over a 24-h period, new pens were handled for 5 min by the four volunteers, rubbed with a cotton swab dipped in methanol, and then analyzed by LC-MS-MS. The nicotine study showed a major difference between the nicotine concentrations obtained from smokers (between 6 and 276 ng/pen) and non-smokers (between 2 and 4 ng/pen). After administration of 30 mg of codeine, the analysis of the pens of the four volunteers allowed to demonstrate the presence of codeine up to 24 h between 9 and 544 pg/pen. Normal hygiene practices did not influence the final result. The highest concentration was observed after 2 h. Morphine was also detected (between 19 and 33 pg/pen). These preliminary results should be considered a demonstration of the interest of fingerprints testing to document drug exposure.

Influence of Preservatives on Insulin in Postmortem Blood: Application to a Case of Insulin Aspart Suicide.

Insulin aspart (NovoRapid®, NovoMix®, Novolog® and Fiasp®) is a fast-acting analog of human insulin, indicated in the treatment of type I and II diabetes. It is administered before meals to mimic the physiological insulin secretion that follows a rise in blood glucose. Its misuse for the purposes of suicide and murder and in the context of factitious order has often been described. In forensic medicine, the identification of insulin in biological samples has always been complex. In this paper, we present a case of suicide of a 64-year-old man who died after the injection of insulin aspart. He was suffering from terminal lung cancer and left a letter explaining the reasons for his suicide. Four empty NovoRapid® pens were found near the body. Body examination was unremarkable, and the femoral blood was collected in two dry Vacutainer™ tubes (red cap) and two sodium fluoride (NaF) tubes (gray cap). A liquid chromatography coupled to high-resolution mass spectrometry method was used to identify and discriminate insulin aspart from human insulin after immunopurification in the blood samples and in the pens. Blood specimens tested positive for insulin aspart with the concentrations of 36 and 37 ng/mL in dry tubes and 58 and 71 ng/mL in tubes containing NaF when tested ∼3 weeks after the collection of the specimens. The contents of the pens also matched with insulin aspart. The stability of insulin in blood is a critical point in the interpretation of the concentrations due to their rapid decrease caused by the activity of proteases in blood. During a degradation study implemented to compare three preservatives and dry tubes, suitable insulin aspart stability was observed with disodium salt of ethylenediaminetetracetic acid and NaF. Given that NaF is standard in forensic toxicology for measuring blood alcohol concentrations, the authors suggest its use for blood collection when insulin intoxication is suspected.

Development of a new LC-MS/MS method for the simultaneous identification and quantification of 13 antidiabetic drugs in human hair.

Oral antidiabetics are the drugs used to control blood sugar in diabetic subjects. The greatest risk of using these drugs is hypoglycaemia, which can be fatal if managed inappropriately. The diagnosis of hypoglycemia may be simple in diabetic subjects but can become a challenge in subjects with no history of exposure to these drugs. The major interest of testing for these compounds in hair is in the case of unexpected hypoglycaemias, as it enables discrimination between hypoglycaemias caused by antidiabetics and other reasons (e.g. insulinoma). Therefore it is important for a toxicology laboratory to screen for antidiabetics in hair due to the large window of detection this matrix allows associated to its long stability over time. In this study, a method has been developed and validated using liquid-chromatography coupled to tandem mass spectrometry for the analysis of 13 oral antidiabetics in hair. After addition of three different internal standards (hydroxy-tolbutamide-d9 for sulfonylureas, repaglinide-ethyl-d5 for glinides and vildagliptin-d3 for gliptins) and incubation in an ultrasonic bath in methanol, the hair was dissolved in NaOH and then subjected to liquid-liquid extraction. The validation procedure demonstrated an acceptable linearity for all compounds between 1 and 50,000 pg/mg. LOD and LOQ were between 0.5 and 5 pg/mg and 1-10 pg/mg respectively. Repeatability and reproducibility were below 20 % at two concentrations for all the analytes. The method was successfully applied to the hair of 18 diabetic patients under treatment of oral antidiabetics. The hair tested positive for gliclazide (3-21,400 pg/mg), sitagliptin (1.4-1.8 pg/mg), vildagliptin (3.3 - 1,740 pg/mg) and repaglinide (14.1 pg/mg).

Analysis of Cocaine and Its Metabolites in Urine after Consumption of Coca Tea by Five Subjects and Subsequent Hair Testing.

Coca tea is a popular drink in some countries of South America where it is reputed to have medicinal properties. This preparation is composed of natural cocaine (COC) alkaloids and therefore can be banned in some countries. During an anti-doping control in Peru the urine of an athlete tested positive for benzoylecgonine (BZE) ecgonine methyl ester (EME) and COC (400 180 and 0.5 ng/mL respectively). The athlete indicated that she had consumed coca tea in the morning before the competition. As her lawyer contacted us to assess the scientific aspects of the possible involvement of coca tea to explain the adverse analytical finding a study was implemented with similar tea bags urine specimens were collected for each subject for 3 days to follow the elimination of COC and metabolites (BZE and EME). All samples were analyzed byultra high performance liquid chromatography tandem mass spectrometry after alkaline extraction. Maximum detection times for COC was 20 h with concentrations ranging from 6 to 91 ng/mL. Maximum detection times for BZE and EME were 70 h and 60 h respectively with concentrations ranging from 6 to 3,730 ng/mL and from 6 to 1,738 ng/mL. The concentration profiles were identical for the five volunteers. This study supports the athlete's claims. In addition, the sample of hair strands of the five subjects was collected a month later and all the hair tests showed a negative result for COC with a limit of decision of 10 pg/mg. Although it is accepted that a 4 mg dose of COC has no significant pharmacological effect the consumption of coca tea can lead to significant legal consequences since the measured urine concentrations sometimes cannot be considered incidental. Therefore, discrimination between coca tea consumption and recreational COC abuse relies primarily on hair analysis.

Determination of 3-MeO-PCP in human blood and urine in a fatal intoxication case, with a specific focus on metabolites identification.

3-Methoxyphencyclidine (3-MeO-PCP) is a new psychoactive substance that belongs to the phencyclidines family, first identified in Europe in 2012. This drug presents a stronger binding to N-methyl-D-aspartate (NMDA) receptors when compared to phencyclidine, which results in more potent effects, even at low concentrations. Very few articles have been published regarding 3-MeO-PCP in forensic toxicology. In this paper, the authors present a fatal 3-MeO-PCP intoxication case. In addition to the detection of the parent drug, metabolites were investigated in urine and, for the first time in the scientific literature, in blood. 3-MeO-PCP and its metabolites were quantitated by liquid chromatography-tandem mass spectrometry system (LC-MS/MS). Identification was confirmed by liquid chromatography-high resolution mass spectrometry (LC-HRMS). 3-MeO-PCP tested positive in femoral blood (3 525 ng/mL) and urine (7 384 ng/mL). The femoral blood concentration was higher than the fatal concentrations range already reported in the literature (from 50 to 3 200 ng/mL). 3-MeO-PCP metabolites, including O-demethyl-3-MeO-PCP, piperidine-OH-3-MeO-PCP, O-demethyl-piperidine-di-OH-3-MeO-PCP and piperidine-di-OH-3-MeO-PCP, were detected in blood. In addition, two new metabolites, O-demethyl-piperidine-OH-3-MeO-PCP and O-demethyl-cyclohexyl-OH, were identified in both blood and urine. Unfortunately, due to the lack of reference material on the market, it was not possible to measure the concentration of these metabolites. However, the ratios between the metabolites and the parent drug were useful to estimate their analytical response and prevalence. At this time, considering the low ratios (<1) between metabolites and parent drug, metabolites testing does not seem useful to increase the detection window of the drug.

Attempted Murder of a Young Child Followed by an Attempted Suicide of the Mother by Injection of Insulin Aspart: Identification of Quantification of Insulin by LC-HRMS and UPLC-MS/MS in Blood of the Two Cases.

The identification and quantification of insulin and its analogues have always been a challenge in the forensic field. Murder, suicide attempts and induced hypoglycemia in the context of factitious disorders have been described with the use of synthetic analogues of human insulin. There is very few information in the literature about aspart insulin concentrations in overdose cases. In this paper, we present a case of a nurse who tried to murder her 10-year-old daughter by injecting her aspart insulin and who, later, tried to commit suicide by injecting herself the same hormone. Two empty syringes and a FIASP ® Flextouch pen were found in the woman's apartment. A LC-HRMS method was developed in order to identify and discriminate aspart insulin from human insulin in blood samples as well as in syringes and pen, while an LC-MS/MS method was developed for the quantification of insulin in blood samples. Aspart insulin tested positive at 5.7 and 2.4 ng/mL in the blood specimens of the mother and the child, respectively. The contents of the syringes and pen also corresponded to aspart insulin. Although the mother claims to have injected an overdose of aspart insulin, the concentrations found were in the therapeutic range for subjects under therapy. Due to the high instability of insulin and the long time elapsed between sampling and forensic analysis (8 months) due to administrative reasons, the concentration at the time of collection was probably much higher. In this case, it was possible to identify aspart insulin and discriminate it from human insulin in a context of attempted murder and subsequent attempted suicide using high-resolution mass spectrometry, which is of paramount importance in forensic medicine.

Toxicological Investigations in a Death Involving 2,5-Dimethoxy-4-Chloamphetamine (DOC) Performed on an Exhumed Body.

During a party in another country, several adults sniffed a powder presented as being lysergic acid diethylamide (LSD). The next morning, two subjects, including a French citizen, were found dead. After a body examination that concluded that the death was due to respiratory and cardiac collapses, the French citizen's corpse was returned to France and buried. Four years later, the body was exhumed, and an autopsy that did not reveal traumatic injury was performed. During the autopsy, biological specimens were collected. A comprehensive toxicological screening, followed by confirmation using ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS-MS) revealed the presence of 2,5-dimethoxy-4-chloamphetamine (DOC) in all specimens: liver (99 ng/g), spleen (28 ng/g), bone (14 ng/g), lung (15 ng/g) and pubic hair (32 pg/mg). No other drug, including pharmaceuticals and drugs of abuse were identified, but the circumstances of specimen collection can influence drug stability. Literature survey about DOC stability in biological material did not contribute in interpretation as there is no data dealing with storage for about 4 years before quantitative analysis. A stability study was performed at the laboratory. Blank blood was spiked with DOC at 1 mg/L, stored at + 4°C and -20°C and regularly tested over 6 months. The percentages of concentration remaining from the initial concentration of DOC stored for 6 months at + 4°C and -20°C were 53% and 59%, respectively. To characterize the metabolite(s) of DOC, the drug was incubated with a pool of human hepatic microsomes and the cofactors required to ensure the functioning of the main phase I enzymes. The incubation media were analyzed by liquid chromatography (LC) coupled to high-resolution mass spectrometry (MS), and the results showed hydroxy-DOC. However, the hydroxy-metabolite was not identified in the liver or spleen of the subject. Although the French pathologist considered that it was more likely than not a toxic death, it is difficult to attribute the death to DOC alone, as it was impossible to test for ethanol and other chemically instable drugs. This case presents original data, which can be useful to increase the knowledge in designer drug toxicity.

Specific interpretation of hair concentrations in 2 fatal metformin intoxication cases.

Hair analysis is very useful for toxicological investigations since, by providing a wider detection window, it gives the possibility to perform a retrospective study on the historical consumption of a substance. Unfortunately, there are no data available for hair concentrations in metformin-related deaths. In this study, the authors present 2 cases of fatal metformin intoxication in which, for the first time, hair analysis was performed using a specific GC-MS/MS method. Metformin was tested positive in femoral blood (112.3 mg/L and 64.7 mg/L respectively) and cardiac blood (226.9 and 203.2 mg/L) of the two subjects. For case 1, other samples were also tested positive, including vitreous humor (31.1 mg/L) and gastric contents (773.5 mg/L). In case 2, metformin was measured at 844.9 mg/L in urine. Metformin hair concentrations were 28.3-44.8 and 22.5 ng/mg for both cases, respectively. The concentrations found in the 2 fatal cases are clearly higher than those obtained in a previous study with subjects under treatment (0.3-3.8 ng/mg) or those found in 3 post-mortem cases where metformin death was excluded (0.6-1.4 ng/mg). Excessive sweating during the agonal phase due to fatal hypoglycemia could explain these elevated concentrations as sweat can have contaminated the hair.

Development of a new GC-MS/MS method for the determination of metformin in human hair.

Diabetes mellitus is one of the most important public health challenges. Metformin (1,1-dimethylbiguanide) represents the "gold standard" for the treatment of diabetes mellitus type 2. Despite its important role in reducing mortality and morbidity in the diabetic population, metformin is associated with an increased risk of stroke. To document exposure to a drug, hair is considered to be the specimen of choice to complement blood and urine, since it provides historical detail of a subject's chronic exposure to drug(s). Measuring hair concentration of metformin can be important for forensic toxicologists investigating criminal poisoning or Munchausen's syndrome by proxy. In clinical toxicology, drug monitoring using hair to document metformin observance has not yet been described. To document the interest of hair analysis for metformin, the authors have developed and validated a method using a gas-chromatography tandem mass spectrometry system and applied it to authentic hair obtained from 9 diabetic patients under daily treatment. The validation procedure demonstrated a LOD an LOQ of 1 and 100 pg/mg, respectively and acceptable linearity, repeatability and reproducibility. The hair of the 9 patients tested positive in the low ng/mg range with concentrations ranging from 0.3 to 3.8 ng/mg. It seems obvious, in comparison with other drugs, that metformin is badly incorporated into hair, as the daily dosage varied from 1 to 3 g. Although limited in the number of subjects, the study allowed to postulate a possible correlation between daily dose and concentration in dark hair, while for light hair no correlation was found.

Hair testing for doping agents. What is known and what remains to do.

Hair testing is a complementary approach to document doping agent(s) use All prohibited substances but hormones should be detectable in hair Interest and limitations of hair testing for doping agents are reviewed based on the authors' experience Although a lot of data are available for drugs of abuse, controlled studies are missing for anabolic steroids, diuretics and some unusual classes of substances.

Testing for AB-PINACA in human hair: Distribution in head hair versus pubic hair.

Synthetic cannabinoid receptor agonists were first identified in herbal products in 2008 advertised as a legal replacement for cannabis. These herbal incense are usually called "spice" and among these, one product in particular has gained popularity: AB-PINACA (N-[(2S)-1-Amino-3-methyl-1-oxobutan-2-yl]-1-pentyl-1H-indazole-3-carboxamide). This drug has been discovered to have a stronger binding to human cannabinoid CB1 and CB2 receptors than ∆9 -THC.While some articles have been published regarding the presence of AB-PINACA in biological fluids such as blood and urine, none reports the presence of AB-PINACA in hair. We have developed and validated a method for detection of AB-PINACA in hair using a liquid chromatography-tandem mass spectrometry system and applied it to head and pubic hair obtained in a case of intoxication. The validation procedure demonstrated a limit of detection and a limit of quantification of 0.5 and 1 pg/mg, respectively and acceptable linearity, repeatability, and reproducibility. AB-PINACA tested positive in the blood (5.7 ng/mL) and less than 1 ng/mL was found in urine. The analysis of the hair specimens resulted in an unusual distribution of the drug between head and pubic hair. AB-PINACA was identified at a higher concentration in head hair (195 pg/mg) versus in pubic hair (5 pg/mg). The very low concentration of AB-PINACA in the urine after consumption, due to rapid metabolism, could explain this infrequent distribution, as pubic hair can be contaminated by urine. In any case, it cannot be excluded that the high concentration in head hair may be due to environmental contamination.