Investigations concerning the threshold value between endogenous and exogenous GHB (liquid ecstasy)

The article describes critical investigations concerning the threshold value between endogenous and exogenous concentrations of gamma-hydroxybutyric acid (GHB/"liquid ecstasy") in human blood. The values of GHB in the blood samples of 50 blood donors and 50 postmortem cases were measured with a validated gas-chromatographic/mass-spectrometric procedure according to the guidelines of the GTFCh (Society of Toxicological and Forensic Chemistry). GHB-concentrations were found to range between 0.11 and 1.56 mg/L (mean value 0.54 mg/L/standard deviation 0.37 mg/L/coefficient of variation 68.4 %) in the donors' blood, and between 2.2 and 116 mg/L (mean value 32.4 mg/L/standard deviation 25.6 mg/L/coefficient of variation 79 %) in the postmortem samples, respectively.     

Post-mortem cases involving amphetamine-based drugs in the Netherlands: Comparison with driving under the influence cases

In this study we reviewed the post-mortem cases in the years 1999–2004 that were presented at the Netherlands Forensic Institute. The concentrations of amphetamine-based drugs in femoral blood from cases of suspected unnatural death were compared with concentrations in whole blood from non-fatal cases of driving under the influence (DUI cases) and with literature. Furthermore, the combinations with other drugs and/or alcohol were investigated. Amphetamine-based drugs were present in 70 post-mortem cases and 467 DUI cases. The most detected amphetamine-based drug was MDMA, followed by amphetamine. The presence of MDA could usually be explained by metabolism of MDMA. Methamphetamine and MDEA were rarely present. Frequently, the amphetamine-based drugs were taken in combination with alcohol and/or other non-amphetamine-based drugs such as cocaine or cannabinoids. The 70 post-mortem cases were divided into 38 amphetamine-based drug caused (i.e. the amphetamine-based drug directly caused or contributed to the death) and 32 amphetamine-based drug related deaths (i.e. death was not directly caused by the amphetamine-based drug). In the latter category, other (poly)drug intoxications and death by violence or drowning were the most frequent causes of death.In 30 cases, MDMA caused death directly. The range in blood concentrations of MDMA in these cases was substantial, i.e. 0.41–84 mg/L with a median concentration of 3.7 mg/L (n = 30). MDMA blood concentrations in the MDMA related deaths (n = 20) and in the DUI cases (n = 360) varied up to 3.7 and 4.0 mg/L, respectively. Seven victims died from the direct effects of amphetamine; the blood concentration of amphetamine ranged from 0.24 to 11.3 mg/L, with a median concentration of 1.7 mg/L (n = 7). The median concentrations of amphetamine in the amphetamine related deaths (n = 13) and the DUI cases (n = 208) were much lower, i.e. 0.28 and 0.22 mg/L, respectively. Amphetamine blood concentrations up to 6.0 and 2.3 mg/L were seen in the drug related deaths and DUI cases, respectively. The most frequently encountered amphetamine-based drugs in the investigated deaths were MDMA and amphetamine. The majority of MDMA- and amphetamine-caused deaths, i.e. 90% of these deaths, occurred with blood concentrations above 1.5 and 0.80 mg/L, respectively. MDMA and amphetamine blood concentrations in drug related deaths and DUI cases, however, overlap the range of fatal concentrations. Therefore, MDMA or amphetamine concentrations should never be used alone to establish the cause of death.     

Fatal Overdose of Gamma‐hydroxybutyrate Acid After Ingestion of 1,4‐Butanediol

We report a case of fatal intoxication from 1,4‐butanediol (1,4‐BD), which was ingested by a young and “naïve” gamma‐hydroxybutyrate (GHB) consumer during a party with the co‐ingestion of alcohol, cannabis, and methylene‐dioxy‐methamphetamine. The following drug concentrations were found using gas chromatography coupled with mass spectrometry on autopsy samples and on a cup and a glass found at the scene: 20,350 mg/L (bottle) for 1,4‐BD; 1020 mg/L (femoral blood), 3380 mg/L (cardiac blood), 47,280 mg/L (gastric content), and 570 mg/L (vitreous humor) for GHB. The concentration of GHB is difficult to interpret in forensic cases due to the possibility of an endogenous production of GHB. The variable tolerance of the user may also modify the peri‐ and postmortem GHB concentrations. This case underscores the need to have many different sources of toxicology samples analyzed to avoid the hypothesis of endogenous production of GHB.     

Determination of γ-hydroxybutyrate (GHB) and its precursors in blood and urine samples: A salting-out approach

γ-Hydroxybutyrate (GHB) is an increasingly popular drug of abuse that causes stimulation, euphoria, anxiolysis or hypnosis, depending on the dose used. Low doses of the drug are used recreationally, and also implicated in drug-facilitated sexual assaults. Because of the unusually steep dose–response curves, accidental GHB overdosing, leading to coma, seizures or death can occur. Being a controlled substance, GHB is often substituted with its non-scheduled precursors γ-butyrolactone (GBL) and 1,4-butanediol (BD), which are rapidly metabolized into GHB in the body. Here we describe an assay for GHB, GBL and BD in blood and/or urine samples. GHB and BD were extracted from diluted 200 μL aliquots of samples with t-butylmethylether (plus internal standard benzyl alcohol) in test tubes preloaded with NaCl. After acidification and centrifugation the solvent phase was transferred to a test tube preloaded with Na₂SO₄, incubated for 30 min, centrifuged again, and evaporated in vacuum. The residue was mixed with N-methyl-N-trimethylsilyl-trifluoroacetamide (MSTFA) in acetonitrile, and injected into a GC–MS. When analyzing GBL, the salting-out step was omitted, and analysis was performed with a GC–FID apparatus. As revealed by the validation data this procedure is suitable for quantitative determination of GHB and its precursors in blood and/or urine samples.     

A hydrophilic interaction liquid chromatography electrospray tandem mass spectrometry method for the simultaneous determination of γ-hydroxybutyrate and its precursors in forensic whole blood

A liquid-chromatography-tandem-mass-spectrometry method using pneumatically assisted electrospray ionisation (LC-ESI-MS/MS) was developed for the simultaneous determination of γ-hydroxybutyric acid (GHB), γ-butyrolactone (GBL) and 1,4-butanediol (1,4-BD) in human ante-mortem and post-mortem whole blood. The blood proteins were precipitated using a mixture of methanol and acetonitrile, and the extract was cleaned-up by passage through a polymeric strong cation exchange sorbent. Separation of the analytes and their structural isomers was obtained using a column with a zwitterionic stationary phase. Matrix-matched calibrants, combined with isotope dilution, were used for quantitative analysis. GHB was determined in both positive and negative ion modes. The relative intra-laboratory reproducibility standard deviations were better than 10% and 6% for blood samples at concentrations of 2mg/L and 20-150mg/L, respectively. The mean true extraction recoveries were 80% for GHB and greater than 90% for GBL and 1,4-BD at concentration levels of 20-50mg/L. The limits of detection were approximately 0.5mg/L for GHB and GBL, and 0.02mg/L for 1,4-BD in ante-mortem blood. The corresponding lower limits of quantification were less than 1mg/L for GHB and GBL, and less than 0.1mg/L for 1,4-BD. GBL was unstable in whole blood freshly preserved with a sodium fluoride oxalate mixture, but the stability could be improved significantly by preservation with a sodium fluoride citrate EDTA mixture.     

Quantitative Analysis of Gamma‐Hydroxybutyrate at Endogenous Concentrations in Hair using Liquid Chromatography Tandem Mass Spectrometry

Abstract: A method capable of quantifying endogenous concentrations of gamma‐hydroxybutyrate (GHB) in human head hair was developed and validated using liquid chromatography/mass spectrometry/mass spectrometry (LC/MS/MS). Hair was digested under alkaline conditions, and GHB was isolated using liquid–liquid extraction. LC/MS/MS was performed using atmospheric pressure chemical ionization in the negative mode, multiple reaction monitoring, and deuterated internal standard (GHB‐D₆). Linearity was observed between 0.1 and 100 ng/mg GHB (R² = 1.000). The limits of detection and quantitation in human hair were 0.2 and 0.4 ng/mg, respectively. Accuracy at 2 ng/mg and 10 ng/mg was determined to be 97% and 94%, and intra‐assay CVs at these concentrations were 5.2% and 7.4% (n = 4). Beta‐hydroxybutyrate (BHB), alpha‐hydroxybutyrate, gamma‐butyrolactone, and 1,4‐butanediol did not produce an interference, and there was negligible ion suppression or enhancement from the matrix.     

A Multi-Drug Intoxication Fatality Involving Xyrem® (GHB)

Abstract:  Gamma-hydroxybutyrate (GHB) is best known as a recreational depressant drug, whose use has also been implicated in drug facilitated sexual assault cases. It is also available as a therapeutic agent (Xyrem^®) used for the treatment of daytime sleepiness or cataplexy associated with narcolepsy. This is a report of a case of a 53-year-old woman undergoing treatment with Xyrem^® for narcolepsy. The decedent was also prescribed tramadol, gabapentin, cetirizine, modafinil, carisoprodol, and Xyrem^®. Toxicological analysis of the blood revealed GHB 165.6 mg/L, and 90.7 mg/L in the urine. Blood GHB concentrations in the range 156–260 mg/L have been reported to induce moderately sound sleep. The combined use of central nervous system depressant drugs, together with her problematic sleep apnea, and snoring (both contraindications for GHB use) were determined to have caused this subject's death. The manner of death was determined to be accidental.     

Acute Benztropine Intoxication and Fatality

A woman was found unresponsive with an empty bottle of Cogentin^® prescribed to another. Admitted to an area hospital, her condition steadily declined until death 29 h after admission. Following toxicological screening on hospital (admission) whole blood, the only significant compound detected was benztropine. Benztropine was confirmed at 0.28 mg/L – the highest antemortem blood concentration recorded in a case of toxicity or fatality uniquely associated with benztropine. A second serum antemortem specimen showed a benztropine concentration of 0.19 mg/L. Despite over 24 h in the hospital, benztropine was also found in the postmortem specimens collected at autopsy. Peripheral blood, central blood, liver, and gastric concentrations were 0.47 mg/L, 0.36 mg/L, 9.6 mg/kg, and 44 mg, respectively. These results indicate that benztropine exhibited a potential difference between whole‐blood and serum (plasma) concentrations. Additionally, in consideration of literature data, benztropine was found indicative of a compound prone to at least some postmortem redistribution.     

Determination of Herbicides Paraquat,Glyphosate, and Aminomethylphosphonic Acid in Marijuana Samples by Capillary Electrophoresis

In this work, two methods were developed to determine herbicides paraquat, glyphosate, and aminomethylphosphonic acid (AMPA) in marijuana samples by capillary electrophoresis. For paraquat analysis, sample was extracted with aqueous acetic acid solution and analyzed by capillary zone electrophoresis with direct UV detection. The running electrolyte was 50 mmol/L phosphate buffer (pH 2.50). For glyphosate and AMPA, indirect UV/VIS detection was used, as these substances do not present chromophoric groups. Samples were extracted with 5 mmol/L hydrochloric acid. The running electrolyte was 10 mmol/L gallic acid, 6 mmol/L TRIS, and 0.1 mmol/L CTAB (pH = 4.7). The methods presented good linearity, precision, accuracy, and recovery. Paraquat was detected in 12 samples (n = 130), ranging from 0.01 to 25.1 mg/g. Three samples were positive for glyphosate (0.15–0.75 mg/g), and one sample presented AMPA as well. Experimental studies are suggested to evaluate the risks of these concentrations to marijuana user.     

The presence of gamma-hydroxybutyric acid (GHB) and gamma-butyrolactone (GBL) in alcoholic and non-alcoholic beverages

Gamma-hydroxybutyric acid (GHB) and its precursor gamma-butyrolactone (GBL) are regularly implicated in instances of surreptitious drug administration, particularly in beverages (so-called "spiked drinks"). In order to assist in the interpretation of cases where analysis of the actual beverage is required, over 50 beverages purchased in the UK were analysed for the presence of GHB and GBL. It was found that naturally occurring GHB and GBL were detected in those beverages involving the fermentation of white and particularly red grapes. No GHB or GBL was detected in other drinks such as beer, juice, spirits or liqueurs. GHB/GBL was detected in red wine vermouth (8.2 mg/L), sherry (9.7 mg/L), port (GBL), red wine (4.1-21.4 mg/L) and white wine (<3-9.6 mg/L). The presence of GHB/GBL did not appear to be influenced by the alcohol content or the pH of the beverage. In addition, the concentration in wines did not appear to be related to the geographical origin of the grape type. This is believed to be the first published data concerning the endogenous presence of GHB and GBL in the beverages described.     

GHB and driving impairment.

Gamma hydroxybutyrate (GHB) was identified in the blood of 13 subjects arrested for impaired driving. GHB concentrations ranged from 26 to 155 mg/L (mean 87 mg/L, median 95 mg/L). In eight cases, GHB was the only drug detected, and signs of impairment were consistent with those of a CNS depressant, including erratic driving (weaving, swerving, ignoring road signs), confusion, incoherent speech, unresponsiveness, lack of balance, unsteady coordination, poor performances on field sobriety tests, and varying states of wakefulness. Given the ability of GHB to induce sleep and unconsciousness, it is evident from these cases that recreational use of the drug has the potential to impair a person's driving ability.     

Gamma-hydroxybutyric acid stability and formation in blood and urine

Gamma-hydroxybutyric acid (GHB) can cause problems in interpretation of toxicological findings due to its endogenous nature, significant production in tissues after death and potential formation in stored samples. Our study was designed to determine the influence of storage conditions on GHB levels and its possible in vitro formation in blood and urine in cases where no exogenous use of GHB or its precursors was suspected. The samples were prepared by validated method based on liquid-liquid reextraction with adipic acid internal standard and MSTFA derivatization and assayed on a GC-MS operating in EI SIM mode. The first part of the study was performed with pooled blood and urine samples obtained from living and deceased subjects stored with and without NaF (1% w/v) at 4 and -20 degrees C over 8 months. In ante-mortem samples (both blood and urine) no significant GHB production was found. After 4 months of storage, the substantial GHB rise up to 100 mg/Lwas observed in post-mortem blood stored at 4 degrees C without NaF with subsequent gradual decrease in following months. The inhibition of GHB production was apparent during storage in NaF treated frozen blood samples. In post-mortem urine only slight temporary GHB levels were ascertained (up to 8 mg/L). The second part of our study was aimed to analyse 20 individual post-mortem blood samples stored at 4 degrees C for 16-27 days between autopsy and analysis without preservation followed by storage at 4 degrees C with NaF for 4 months. The temporary GHB production with maximum of 28 mg/Lwas detected in some samples.     

GHB. Club drug or confusing artifact?

GHB can be produced either as a pre- or postmortem artifact. The authors describe two cases in which GHB was detected and discuss the problem of determining the role of GHB in each case. In both cases, NaF-preserved blood and urine were analyzed using gas chromatography. The first decedent, a known methamphetamine abuser, had GHB concentrations similar to those observed with subanesthetic doses (femoral blood, 159 microg/ml; urine, 1100 microg/ml). Myocardial fibrosis, in the pattern associated with stimulant abuse, was also evident. The second decedent had a normal heart but higher concentrations of GHB (femoral blood, 1.4 mg/ml; right heart, 1.1 mg/ml; urine, 6.0 mg/ml). Blood cocaine and MDMA levels were 420 and 730 ng/ml, respectively. Both decedents had been drinking and were in a postabsorptive state, with blood to vitreous ratios of less than 0.90. If NaF is not used as a preservative, GHB is produced as an artifact. Therefore, the mere demonstration of GHB does not prove causality or even necessarily that GHB was ingested. Blood and urine GHB concentrations in case 1 can be produced by a therapeutic dose of 100 mg, and myocardial fibrosis may have had more to do with the cause of death than GHB. The history in case 2 is consistent with the substantial GHB ingestion, but other drugs, including ethanol, were also detected. Ethanol interferes with GHB metabolism, preventing GHB breakdown, raising blood concentrations, and making respiratory arrest more likely. Combined investigational, autopsy, and toxicology data suggest that GHB was the cause of death in case 2 but not case 1. Given the recent discovery that postmortem GHB production occurs even in stored antemortem blood samples (provided they were preserved with citrate) and the earlier observations that de novo GHB production in urine does not occur, it is unwise to draw any inferences about causality unless (1) blood and urine are both analyzed and found to be elevated; (2) blood is collected in NaF-containing tubes; and (3) a detailed case history is obtained.     

Determination of Nitrite in Whole Blood by High‐Performance Liquid Chromatography with Electrochemical Detection and a Case of Nitrite Poisoning

Although nitrite is widely used in meat processing, it is a major toxicity hazard to children and is responsible for the blue‐baby syndrome. A simple and effective method to determine nitrite in whole blood has been devised using ion chromatography with suppressed conductivity detection. The blood sample was deproteinized by adding acetonitrile and purified with mini‐cartridges to remove hydrophobic compounds, chloride ions, and metal ions. An aliquot of the filtrate was injected onto the ion chromatography. The retention time for nitrite was 13.8 min and the detection limit of nitrite in whole blood was 0.4 μmol/L. The calibration curve was linear (r² = 0.9999) over the concentration working range. The blood nitrite concentration of a victim who attempted suicide by ingesting sodium nitrite powder was determined using the present method. The basal levels for nitrite in human blood was determined with 7.1 ± 0.9 μmol/L (n = 12).     

Fatal intoxication with tianeptine (Stablon)

Tianeptine (Stablon^®), although structurally similar to tricyclic antidepressants, acts by enhancing the reuptake of serotonin. A fatal case is presented involving a 26-year-old man, found lying in bed with a “mushroom of foam” around his mouth. Empty blister packs of Stablon^® and a suicide note were found next to the body. A liquid–liquid extraction procedure with n-hexane: ethyl acetate and n-hexane: 2-propanol, followed by LC-DAD-MS analysis, using positive mode electrospray ionization was performed. The detection limit was 0.001 μg/mL. The toxicological results revealed the following tianeptine concentrations in the post-mortem samples: blood 5.1 μg/mL; urine 2.0 μg/mL; liver 23 μg/g; stomach contents 22 mg. Femoral blood analyses also revealed an ethanol concentration of 0.53 g/L. The present method was also developed and validated for the other post-mortem specimens, since no previous published data had confirmed the post-mortem distribution of tianeptine. The absence of other suitable direct causes of death (macroscopic or histological) and the positive results achieved with the toxicological analysis led the pathologist to rule that death was due to an intoxication caused by the suicidal ingestion of tianeptine in combination with alcohol.     

Blood, brain, and hair GHB concentrations following fatal ingestion

Despite the increasing incidence of illicit use of gamma-hydroxybutyrate (GHB), little information is available documenting levels of the drug in GHB fatalities. We measured GHB levels in postmortem blood, brain and hair specimens from a suspected overdose case by gas chromatography/mass spectrometry (GC/MS) following solid phase extraction (SPE) and derivatization with bis(trimethyl-silyl) trifluoroacetamide (BSTFA). Examination found 330 microg/mL GHB in femoral blood and 221 ng/mg GHB in frontal cortex brain tissue, values higher than those typically reported in the literature. The hair shaft was negative for GHB whereas the plucked root bulbs with outer root sheath attached (2,221 ng/mg) and root bulbs after washing and removal of the outer root sheath (47 ng/mg) contained the drug. Our results are consistent with an acute single dose of GHB and, as the toxicology screen was negative for other drugs of abuse, emphasize the significant danger of this drug.     

Determination and distribution of clotiapine (Entumine) in human plasma, post-mortem blood and tissue samples from clotiapine-treated patients and from autopsy cases

The antipsychotic drug clotiapine (Entumine^®) has been marketed for more than 35 years, however there is little published data on the therapeutic and toxic concentrations of this drug. To fill this gap, two rapid and sensitive methods were developed for the determination of clotiapine (2-chloro-11-(4-methyl-1-piperazinyl)dibenzo-[b,f][1,4]-thiazepine), in human plasma and post-mortem blood and tissue samples. After simple liquid–liquid extraction at pH 9.5 with n-hexane/dichloromethane (85/15, v/v), clotiapine was quantitated by HPLC-DAD and by GC-NPD. The calibration curve was linear between 10 and 1000 μg/L. The limit of detection (LOD) and the limit of quantification (LOQ) were found to be 2 and 6 μg/L for the GC-NPD method and 5 and 15 μg/L for the HPLC-method, respectively. These methods were applied to 12 plasma samples from patients treated with clotiapine, to seven autopsy cases and to one case of driving under the influence of drugs (DUID). Concentrations ranged for the clotiapine-treated patients between 6 and 155 μg/L (mean 46 μg/L), and for the autopsy cases between 22 and 341 μg/L (mean 123 μg/L).     

Methyl tert‐Butyl Ether (MTBE) Detected in Abnormally High Concentrations in Postmortem Blood and Urine from Two Persons Found Dead Inside a Car Containing a Gasoline Spill

Two deep frozen persons, a female and a male, were found dead in a car. There had been an explosive fire inside the car which had extinguished itself. On the floor inside the car were large pools of liquid which smelled of gasoline. The autopsy findings and routine toxicological analyses could not explain the cause of death. Carboxyhemoglobin levels in the blood samples were <10%. Analysis with a headspace gas chromatography revealed methyl tert‐butyl ether (MTBE) concentrations of 185 mg/L (female victim) and 115 mg/L (male victim) in peripheral blood. The urine MTBE concentrations were 150 mg/L and 256 mg/L, respectively. MTBE is a synthetic chemical which is added to gasoline as a fuel oxygenate. Gasoline poisoning is likely to be the cause of the death in these two cases, and MTBE can be a suitable marker of gasoline exposure, when other volatile components have vaporized.     

Contributory and Incidental Blood Concentrations in Deaths Involving Citalopram

All cases presenting to the New South Wales Department of Forensic Medicine between January 1, 2001 and December 31, 2010 in which citalopram was detected were retrieved. A total of 348 cases were identified. Citalopram contributed to death in 21.0%, and was incidental in 79.0%. Cases in which citalopram was contributory to death had significantly higher blood citalopram concentrations than incidental cases (0.50 mg/L vs. 0.30 mg/L). Citalopram concentrations varied significantly by contributory status: sole citalopram toxicity (median = 1.30 mg/L), citalopram/other drug toxicity (0.50 mg/L), and incidental cases (0.30 mg/L). Citalopram concentrations also varied by suicide status, with the highest concentration found in suicides where citalopram contributed to death (0.70 mg/L) compared with 0.50 mg/L for nonsuicide cases where citalopram contributed to death. In almost all contributory cases (69/73), other psychoactive substances were also detected, most commonly benzodiazepines (47.9%), alcohol (45.2%), and opioids (40.1%).