Influence of Body Mass Index on Hair Ethyl Glucuronide Concentrations.

AIM: Analysis of ethyl glucuronide (EtG) concentrations in hair is increasingly used to estimate the consumption of alcohol of the prior months. Linear correlations between the amount of alcohol consumed and the concentration of EtG in hair have been reported, and several variables that may influence this correlation have been investigated: e.g. cosmetic hair treatments, gender influences or hair color. Here, we investigate the influence of body mass index (BMI) on this correlation. METHODS: A post hoc analysis on the influence of BMI on the relation between amounts of alcohol consumed and the measured EtG concentrations in hair in 199 participants. RESULTS: Our data show higher EtG concentrations in participants with high BMI (≥25) compared to participants with low BMI (<25) (P = 0.001) across a wide range of amounts of alcohol consumed. CONCLUSIONS: We conclude that BMI should be taken into account when interpreting hair EtG concentrations. SHORT SUMMARY: Ethyl glucuronide concentrations in hair (hEtG) can be used to estimate the consumption of alcohol of the prior months. Body mass index (BMI) influences this relation and BMI should be taken into account when interpreting hEtG concentrations in participants with high BMI (≥25) compared to participants with low BMI (<25).

Determination of Common Antipsychotics in Quantisal-Collected Oral Fluid by UHPLC-MS/MS: Method Validation and Applicability for Therapeutic Drug Monitoring.

BACKGROUND: Oral fluid (OF) is an interesting alternative for conventional blood testing in therapeutic drug monitoring. OF can be used for screening but its value for quantification has to be established. METHODS: To evaluate the value of OF for quantification of 11 commonly used antipsychotics (APs) and 5 metabolites, an ultra-high performance liquid chromatography-tandem mass spectrometric method was validated. OF was obtained from psychiatric patients using a Quantisal collection device. OF to serum concentration ratios were determined, taking into account the exact volume of collected OF. RESULTS: Linearity was evaluated at 7 or 8 calibration levels. Accuracy criteria were fulfilled, except for pipamperone (PIP) at quality control (QC) low. The intraday precision ranged 0.88%-14.73% and interday precision ranged 1.92%-16.17%. The mean recovery from the collection pad was 37.1% at QC low and 40.3% at QC high for 1 mL of collected OF; for 0.5 mL collected OF mean recovery was 35.0% at QC low and 37.3% at QC high. When 0.1 mL OF was collected, recovery data were unreliable. Mean absolute matrix effect was 101.1% (82.0%-120.0%). OF patient samples (n = 89) containing 269 APs and metabolites were acquired and the mean volume of collected OF was 0.562 mL (0.057-1.232 mL). The OF to serum ratios were above 1 for all APs (1.54-28.50), except for aripiprazole (0.21) and zuclopenthixol (0.66). A broad range of calculated ratios for all APs was obtained. CONCLUSIONS: This validated ultra-high performance liquid chromatography-tandem mass spectrometric method can be used to reliably quantify APs in OF, even when recovery is low. Because the correlation between OF and serum concentrations was low and in addition results were highly variable, it can only be concluded that OF is a potentially interesting matrix, particularly for screening for noncompliance.

Identification of in vitro and in vivo human metabolites of the new psychoactive substance nitracaine by liquid chromatography coupled to quadrupole time-of-flight mass spectrometry.

The purpose of this work was to investigate the in vitro metabolism of nitracaine, a new psychoactive substance, using human liver microsome incubations, to evaluate the cytochrome P450 (CYP) enzyme isoforms responsible for the phase-I metabolism and to compare the information from the in vitro experiments with data resulting from an authentic user's urine sample. Accurate mass spectra of metabolites were obtained using liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) and were used in the structural identification of metabolites. Two major and three minor phase-I metabolites were identified from the in vitro experiments. The observed phase-I metabolites were formed through N-deethylation, N,N-deethylation, N-hydroxylation, and de-esterification, with CYP2B6 and CYP2C19 being the main enzymes catalyzing their formation. One glucuronidated product was identified in the phase-II metabolism experiments. All of these metabolites are reported for the first time in this study except the N-deethylation product. All the in vitro metabolites except the minor N,N-deethylation product were also present in the human urine sample, thus demonstrating the reliability of the in vitro experiments in the prediction of the in vivo metabolism of nitracaine. In addition to the metabolites, three transformation products (p-nitrobenzoic acid, p-aminobenzoic acid, and 3-(diethylamino)-2,2-dimethylpropan-1-ol) were identified, as well as several glucuronides and glutamine derived of them.

Ethyl glucuronide concentrations in hair: a controlled alcohol-dosing study in healthy volunteers.

Ethyl glucuronide (EtG) is a minor phase II metabolite of alcohol that accumulates in hair. It has been established as a sensitive marker to assess the retrospective consumption of alcohol over recent months using a cut-off of ≥7 pg/mg hair to assess repeated alcohol consumption. The primary aim was to assess whether amounts of alcohol consumed correlated with EtG concentrations in hair. Additionally, we investigated whether the current applied cut-off value of 7 pg/mg hair was adequate to assess the regular consumption of low-to-moderate amounts of alcohol. A prospective controlled alcohol-dosing study in 30 healthy individuals matched on age and gender. Individuals were instructed to drink no alcohol (N = 10), 100 g alcohol per week (N = 10) or 150 g alcohol per week (N = 10) for 12 consecutive weeks, before and after which hair was collected. Throughout the study, compliance to daily alcohol consumption was assessed by analyzing urine EtG three times weekly. Participants in the non-drinking group had median EtG concentrations of 0.5 pg/mg hair (interquartile range (IQR) 1.7 pg/mg; range < 0.21-4.5 pg/mg). Participants consuming 100 and 150 g alcohol per week showed median EtG concentrations of 5.6 pg/mg hair (IQR 4.7 pg/mg; range 2.0-9.8 pg/mg) and 11.3 pg/mg hair (IQR 5.0 pg/mg; range 7.7-38.9 pg/mg), respectively. Hair EtG concentrations between the three study groups differed significantly from one another (p < 0.001). Hair EtG concentrations can be used to differentiate between repeated (low-to-moderate) amounts of alcohol consumed over a long time period. For the assessment of repeated alcohol use, we propose that the current cut-off of 7 pg/mg could be re-evaluated.

Therapeutic drug monitoring of common antipsychotics.

The aim of this review is to provide information for interpreting outcome results from monitoring of antipsychotics in biological samples. A brief overview of the working mechanisms, pharmacological effects, drug interactions, and analytical methods of classical and atypical antipsychotics is given. Nineteen antipsychotics were selected based on their importance in the worldwide market as follows: amisulpride, aripiprazole, asenapine, bromperidol, clozapine, flupenthixol, haloperidol, iloperidone, lurasidone, olanzapine, paliperidone, perphenazine, pimozide, pipamperone, quetiapine, risperidone, sertindole, sulpiride, and zuclopenthixol. A straightforward relationship between administered dose, plasma or serum concentration, clinical outcome, or adverse effects is often lacking. Nowadays, focus lies on therapeutic drug monitoring and individualized therapy to find adequate treatment, to explain treatment failure or nonresponse, and to check patient compliance. However, extensive research in this field is still mandatory.

Qualitative and semi-quantitative screening of selected psychoactive drugs in blood: Usefulness of liquid chromatography - triple quadrupole and quadrupole time-of-flight mass spectrometry in routine toxicological analyses.

Routine toxicological analysis requires broad screening for a large number of therapeutically prescribed and other compounds, and/or their metabolites. This article specifically focuses on three classes of psychoactive substances: antidepressants (ADs), antipsychotics (APs) and benzodiazepines and Z-drugs (BZDs). Two screening methods were compared for their ease-of-use in a routine setting, based upon the analysis of 105 medico-legal case samples. Analytes of interest were extracted using liquid-liquid extraction and separated using liquid chromatography with a total run time of 12 min per sample. A first detection method used targeted triple quadrupole mass spectrometry, operated in triggered multiple reaction monitoring mode (tMRM). False negative results were noted for 15% of the total number of detected analytes only, the majority of which were either present at sub- to low therapeutic levels or were metabolites of other analytes in the samples. The occurrence of false positive results was rare. A second screening method used quadrupole time-of-flight mass spectrometry (QTOF) for untargeted data acquisition. Data analysis was facilitated by the creation of an in-house, subset mass spectral database. As was seen for the tMRM screening, false negative results were observed in less than 20% of the total number of detected analytes, either for compounds at low concentrations or of which metabolites could be identified in the samples. More false positive results were observed due to an observed bias for prothipendyl. Determination of the exact concentration in a sample may only be required depending on the specific case circumstances. For this purpose, semi-quantification using each of the screening methods was investigated. Excellent results were observed using the tMRM method in combination with a small number of labelled internal standards (n = 12). Semi-quantification using the QTOF screening method was more laborious, but limited results on selected compounds indicated equally good results. Overall, the developed semi-quantitative screening methods performed well and - following further validation on case samples - could be implemented for most compounds in routine toxicological analysis without the need for highly trained or specialised personnel.

Multi-analyte LC-MS/MS quantification of 38 antipsychotics and metabolites in plasma: Method validation & application to routine analyses.

The past decades have seen a rise in the prescription of antipsychotic drugs in the European population, despite the risk of extra-pyramidal, metabolic and cardiac side effects. A multi-analyte liquid chromatography - triple quadrupole mass spectrometry method was developed for the quantification of 38 antipsychotic drugs in plasma. Samples were extracted by a straightforward liquid-liquid extraction with methyl-tertiary-butyl-ether and the compounds of interest were chromatographically separated within 6 min. Calibration curves covered the recommended therapeutic range for all compounds, in addition to sub- and supratherapeutic concentrations for most. The method was successfully validated according to the European Medicines Agency guidelines on bioanalytical method validation. Analysis of medico-legal samples confirmed the relatively common use of the second generation antipsychotics quetiapine and olanzapine, as well as the continued presence of the first generation antipsychotic haloperidol.

Quantification of 54 Benzodiazepines and Z-Drugs, Including 20 Designer Ones, in Plasma.

Benzodiazepines are widely used in the treatment of sleep and anxiety disorders, as well as epileptic seizures and alcohol withdrawal because of their broad therapeutic index and low cost. Due to their central nervous system depressant effects they are also often implicated in traffic accidents and drug-related intoxications. With an increasing number of designer benzodiazepines used in a recreational setting, there is a need for analytical methods to be able to quantify both the prescribed and designer benzodiazepines. A liquid chromatography-triple quadrupole mass spectrometry method was developed for the quantification of 34 prescribed and 20 designer benzodiazepines in plasma. Different sample preparation strategies, including protein precipitation, liquid-liquid extraction, solid-phase extraction and mini-QuEChERS, were tested. The best recoveries for all compounds of interest were obtained with a liquid-liquid extraction using methyl-tertiary-butyl-ether and 500 µL plasma. The method was fully validated according to the European Medicines Agency guidelines for all compounds, except pivoxazepam, which is included for qualitative purposes only. In-sample stability issues were observed for cloxazolam, both at ambient temperature and during long-term storage at -20°C. Due to the large number of compounds included, the simple and time-efficient sample preparation and the relatively inexpensive instrumentation used, the presented method can be readily implemented in both therapeutic drug monitoring and forensic analyses.

When clozapine appears at a dance event .

Objectives: The content of substances sold and consumed as party drugs is often unknown. They may contain inactive, contaminated or unexpected ingredients, and the dosage of the active components may vary considerably. Obviously, these phenomena increase the chances of a wrong or delayed therapy. To illustrate this point, we report 3 cases of clozapine intoxication at a dance event where most likely clozapine tablets were sold as party drugs.Methods: The three cases were part of a prospective toxicology study at a nocturnal indoor dance event.Results: One patient had to be intubated after obstructive breathing with desaturation and bradycardia, while the 2 other patients presented with syncope and altered mental status. All patients recovered after 20 minutes to 8 hours. Systematic toxicological analysis of the blood samples revealed the presence of clozapine (73-244 ng/ml) and its metabolite norclozapine (9-59 ng/ml). A pill, found in a pocket of one patient, was identified as Leponex® 100 mg (clozapine). This neuroleptic drug is mainly prescribed for treatment-resistant schizophrenia. In clozapine-naive subjects, orthostatic hypotension, bradycardia and syncope have been reported with a single 25 mg oral dose. Serum clozapine concentrations of the 3 cases were below the defined therapeutic range (350-600ng/ml) and the clozapine:norclozapine ratios were suggestive for recent drug intake.Conclusion: Routine drug screening may be unable to detect the toxic agent(s) involved. Whenever unusual symptoms are observed in an intoxicated patient, blood and urine samples should be sent to a reference toxicology laboratory.

Lessons to be learned from toxicological analyses in intoxicated patients and seized materials at an electronic music dance festival.

Medical problems related to illicit drug use are frequently encountered at electronic dance music (EDM) events. In this prospective study, the medical problems and toxicological analyses on intoxicated persons and seized materials are described jointly. The aim of this study is to find out to what extent these efforts may assist in developing prevention strategies and organising on-site care at EDM events. The most frequently encountered clinical presentation in the 121 included patients was: agitation/aggression (26%), drunkenness (25%), depressed level of consciousness (24%) and hallucinations (9%). Only five patients were transported by ambulance to a hospital. In 100 of the 121 included patients (83%) an ethanolemia of at least 0.50 g/L was measured (with ethanol as the only drug found in 47 cases). 3,4-methylenedioxymethamphetamine (MDMA) was detected in 54% of the blood samples, cocaine in 11%, gamma-hydroxybutyric acid (GHB) in 11%, amphetamine in 7%, ketamine in 6% and a new psychoactive substance (NPS) in 4%. Except for 8 MDMA-users poly drug use was found in all these cases. The 178 seized samples most frequently contained MDMA (31%), cannabis (28%) or no active substance (15%). In 11 samples (6%) an NPS was detected. Of particular interest was a tablet containing 4-chloromethamphetamine (a previously unknown neurotoxic NPS), 4-chloroamphetamine, para-methoxyamphetamine, para-methoxymethamphetamine and ethylone. Our data show that at EDM events ethanol and MDMA are still the party drugs causing most health hazards and that NPS only play a minor role. Regarding the toxicological efforts, we recommend to analyse all seized materials from an EDM event, but only blood samples from the most severely intoxicated patients.

Suspect and non-target screening workflows to investigate the in vitro and in vivo metabolism of the synthetic cannabinoid 5Cl-THJ-018.

The use of synthetic cannabinoids causes similar effects as Δ9 -tetrahydrocannabinol and long-term (ab)use can lead to health hazards and fatal intoxications. As most investigated synthetic cannabinoids undergo extensive biotransformation, almost no parent compound can be detected in urine, which hampers forensic investigations. Limited information about the biotransformation products of new synthetic cannabinoids makes the detection of these drugs in various biological matrices challenging. This study aimed to identify the main in vitro biotransformation pathways of 5Cl-THJ-018 and to compare these findings with an authentic urine sample of a 5Cl-THJ-018 user. The synthetic cannabinoid was incubated with pooled human liver microsomes and cytosol to simulate phase I and phase II biotransformations. Resulting extracts were analyzed with liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). Three different data analysis workflows were applied to identify biotransformation products. A suspect screening workflow used an in-house database built from literature data and in silico biotransformation predictions. Two non-target screening workflows used a commercially available software and an open-source software for mass spectrometry data processing. A total of 23 in vitro biotransformation products were identified, with hydroxylation, oxidative dechlorination, and dihydrodiol formation pathways as the main phase I reactions. Additionally, five glucuronidated and three sulfated phase II conjugates were identified. The predominant in vivo pathway was through oxidative dechlorination and in total six metabolites of 5Cl-THJ-018 were identified. Biotransformation products both in vitro and in vivo were successfully identified using complementary suspect and non-target screening workflows.

Optimization of a liquid chromatographic separation for the simultaneous determination of four anthracyclines and their respective 13-S-dihydro metabolites.

The optimization of a liquid chromatographic separation of four anthracyclines (doxorubicin, epirubicin, daunorubicin and idarubicin) and their respective 13-S-dihydro metabolites (doxorubicinol, epirubicinol, daunorubicinol and idarubicinol) is described. Inclusion of epidaunorubicin in the assay allows internal standardization. Potential chromatographic interference of aglycones (doxorubicinone, daunorubicinone, idarubicinone, doxorubicinolone, daunorubicinolone and idarubicinolone) was investigated and tackled. The analyses were performed on a C18 RP column and gradient elutions were performed with a mixture of 0.1% formic acid in water and 0.1% formic acid in ACN. The analytes were measured by fluorescence detection with an excitation wavelength of 480 nm and emission wavelength of 555 nm, respectively. The separation will potentially allow a broad field of applications, ranging from therapeutic drug monitoring and kinetic studies in cancer patients to monitoring hospital personnel and effluents.

Validation of a simple, fast liquid chromatography-tandem mass spectrometry method for the simultaneous quantification of 40 antidepressant drugs or their metabolites in plasma.

INTRODUCTION: Antidepressant (AD) use has increased significantly over the last decades. Therapeutic drug monitoring is recommended for compliance, toxicity and treatment efficiency. ADs also show a high prevalence in forensic cases. Few methods have been developed that combine a fast, easy sample clean-up with a quantification based on liquid chromatography-triple quadrupole mass spectrometry (LC-QQQ). METHODOLOGY: A liquid-liquid extraction (LLE) was performed using 200 µL of plasma. The evaporated and reconstituted upper fraction was injected on a LC-QQQ system monitoring 3 transitions per compound. The method was fully validated according to international guidelines. RESULTS & DISCUSSION: The chromatographic run time was under 12 min. The LLE was successful in removing interferences with minimal sensitivity loss. Calibration curves ranged from sub-therapeutic to toxic concentrations. Quality control samples showed high accuracy (81%-119%) and precision (≤14%) within and between batches. Stability was tested at ambient temperature and -20 °C. The method was successfully applied to external quality control and case samples. CONCLUSION: The presented method successfully quantifies 40 compounds of interest. Because of a simple sample clean-up, a relatively short chromatographic run and a wide calibration range this method can be implemented in therapeutic drug monitoring, forensic research and related fields.

In vitro Phase I and Phase II metabolism of the new designer benzodiazepine cloniprazepam using liquid chromatography coupled to quadrupole time-of-flight mass spectrometry.

Designer benzodiazepines have recently emerged as a class of new psychoactive substances. These substances are used in recreational settings and as alternatives to prescription benzodiazepines as self-medication for patients suffering from anxiety or other mental disorders. Due to the limited information available on the metabolic fate of these new substances, it is challenging to reliably detect their usage in bioanalytical (e.g. clinical and forensic) settings. The objective of this study was to investigate the in vitro Phase I and Phase II metabolism of the new designer benzodiazepine cloniprazepam and identify potential biomarkers for its detection in human biological fluids. Cloniprazepam was incubated with human liver microsomes and cytosolic fractions to generate both Phase I and II metabolites. The extracts were analysed using liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. Identification of the metabolites was performed using two complementary workflows, including a suspect screening based on in silico predictions and a non-targeted screening. A total of nine metabolites were identified, eight Phase I metabolites and one Phase II metabolite, of which five were specific for cloniprazepam. Clonazepam was the major metabolite of cloniprazepam. Hydroxy-cloniprazepam, dihydroxy-cloniprazepam, 3-keto-cloniprazepam, 7-amino-cloniprazepam, hydroxy-clonazepam, 7-amino-clonazepam and 3-hydroxy-7-amino-clonazepam were formed through oxidation, hydroxylation, and/or reduction of the nitro-group. Glucuronidated hydroxy-cloniprazepam was the only Phase II metabolite detected. Five metabolites were specific for cloniprazepam. This study provided a set of human in vitro biotransformation products which can assist specific detection of cloniprazepam consumption in future studies.

Medical Emergencies Related to Ethanol and Illicit Drugs at an Annual, Nocturnal, Indoor, Electronic Dance Music Event.

Introduction Medical problems are frequently encountered during electronic dance music (EDM) events. Problem There are uncertainties about the frequencies and severity of intoxications with different types of recreational drugs: ethanol, "classical" illicit party drugs, and new psychoactive substances (NPS). METHODS: Statistical data on the medical problems encountered during two editions of an indoor electronic dance event with around 30,000 attendants were retrieved from the Belgian Red Cross (Mechelen, Belgium) database. Data on drug use were prospectively collected from the patient (or a bystander), the clinical presentation, and/or toxicological screening. RESULTS: In the on-site medical station, 487 patients were treated (265 in 2013 and 222 in 2014). The most frequent reasons were trauma (n=171), headache (n=36), gastro-intestinal problems (n=44), and intoxication (n=160). Sixty-nine patients were transferred to a hospital, including 53 with severe drug-related symptoms. Analysis of blood samples from 106 intoxicated patients detected ethanol in 91.5%, 3,4-methylenedioxymethamphetamine (MDMA) in 34.0%, cannabis in 30.2%, cocaine in 7.5%, amphetamine in 2.8%, and gamma-hydroxybutyric acid (GHB) in 0.9% of patients (alone or in combination). In only six of the MDMA-positive cases, MDMA was the sole substance found. In 2014, the neuroleptic drug clozapine was found in three cases and ketamine in one. Additional analyses for NPS were performed in 20 cases. Only in one agitated patient, the psychedelic phenethylamines 25B-NBOMe and 25C-NBOMe were found. CONCLUSIONS: At this particular event, recreational drug abuse necessitated on-site medical treatment in one out of 350 attendants and a hospital transfer in one out of 1,000. Ethanol remains the most frequently abused (legal) drug, yet classical illicit recreational drugs are also frequently (co-) ingested. The most worrying observation was high-risk poly-drug use, especially among MDMA users. Regarding NPS, the number of cases was low and the clinical presentations were rather mild. It should be stressed that these observations only apply to this particular event and cannot be generalized to other EDM events. Calle P , Sundahl N , Maudens K , Wille SMR , Van Sassenbroeck D , De Graeve K , Gogaert S , De Paepe P , Devriese D , Arno G , Blanckaert P . Medical emergencies related to ethanol and illicit drugs at an annual, nocturnal, indoor, electronic dance music event. Prehosp Disaster Med. 2018;33(1):71-76.

Traces of phosgene in chloroform: consequences for extraction of anthracyclines.

Chloroform is commonly used to extract anthracyclines from various biological matrices. However, their determination can be seriously compromised by phosgene traces present as a result of failing stabilization of chloroform. Out of the three varieties in which chloroform exists (not stabilized, stabilized with an alcohol and stabilized with a hydrocarbon) only the ethanol stabilized type minimizes chances on creating artifacts. Chromatographic separation after extraction of four anthracyclines (doxorubicin, epirubicin, daunorubicin and idarubicin) and two metabolites (13-S-dihydrodoxorubicin and 13-S-dihydroepirubicin) with chloroform under various conditions indicate that the appropriate choice of stabilizer in this extraction solvent is highly relevant.

Development of a solid phase extraction for 13 'new' generation antidepressants and their active metabolites for gas chromatographic-mass spectrometric analysis.

A solid phase extraction procedure (SPE) for 13 'new' antidepressants (venlafaxine, fluoxetine, viloxazine, fluvoxamine, mianserin, mirtazapine, melitracen, reboxetine, citalopram, maprotiline, sertraline, paroxetine and trazodone) together with eight of their metabolites (O-desmethylvenlafaxine, norfluoxetine, desmethylmianserine, desmethylmirtazapine, desmethylcitalopram, didesmethylcitalopram, desmethylsertraline and m-chlorophenylpiperazine) from plasma is optimized using HPLC-DAD as monitoring system. Special attention has been paid to the choice of washing and eluting solvent, resulting in a highly concentrated, clean and moisture free extract, also suitable for GC-MS. A total number of 10 sorbents (apolar, polymeric, ion-exchange and mixed mode) was evaluated. Based on recovery, reproducibility and absence of interfering substances the strong cation exchanger gave the best results. Recoveries were determined at low and high therapeutic and toxic levels and ranged between 70 and 109% for all compounds, except for trazodone (39%).

A Non-Fatal Self-Poisoning Attempt with Sildenafil.

The phosphodiesterase type 5 inhibitor, sildenafil, is not generally known for its use as a self-poisoning drug. However, intoxication cases with lethal outcome have been described. The case presented here is of a 56-year-old man who claimed to have undertaken an unsuccessful suicide attempt by mono-ingestion of 65 tablets of 100 mg sildenafil. He arrived at the emergency department 24 h after intake with severe vomiting and symptoms of blurred vision. Clinical examination revealed no priapism. Of note was a sinus tachycardia of 100 bpm without signs of hypotension. To quantify the sildenafil concentration in serum, an high-performance liquid chromatography photo-diode array method was developed and validated according to European Medicines Agency guidelines. The intoxicated patient had a serum concentration of 22.2 µg/mL sildenafil, at the time of presentation, which is far above the therapeutic peak concentration. The serum concentration further declined to 9.2 and 2.3 µg/mL, respectively, 5 and 14 h later, revealing a biological half-life of 4.2 h. To the best of our knowledge, this patient took the highest sildenafil dose, which resulted in the highest serum concentration, ever reported. In this subject, sildenafil showed good tolerability because few symptoms occurred and only moderate supportive therapy was needed for full recovery without sequelae.

Advances in detection of antipsychotics in biological matrices.

Measuring antipsychotic concentrations in human matrices is important for both therapeutic drug monitoring and forensic toxicology. This review provides a critical overview of the analytical methods for detection and quantification of antipsychotics published in the last four years. Focus lies on advances in sample preparation, analytical techniques and alternative matrices. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is used most often for quantification of antipsychotics. This sensitive technique makes it possible to determine low concentrations not only in serum, plasma or whole blood, but also in alternative matrices like oral fluid, dried blood spots, hair, nails and other body tissues. Current literature on analytical techniques for alternative matrices is still limited and often requires a more thorough validation including a comparison between conventional and alternative results to determine their actual value. Ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) makes it possible to quantify a high amount of compounds within a shorter run time. This technique is widely used for multi-analyte methods. Only recently, high-resolution mass spectrometry has gained importance when a combination of screening of (un)known metabolites, and quantification is required.