Glutathione-stabilized Fe3 O4 nanoparticles as the sorbent for magnetic solid-phase extraction of diazepam and sertraline from urine samples through quantitation via high-performance liquid chromatography.

The synthesis and application of glutathione-coated magnetic nanocomposite were introduced with the purpose of developing a stable, cheap, operationally convenient, simple, fast, sensitive, and selective device for the microextraction of diazepam and sertraline for the first time. The prepared glutathione@Fe3 O4 nanocomposite was used as the sorbent in the form of magnetic solid-phase extraction. Afterward, the extracted analytes were desorbed by organic solvent and analyzed by high-performance liquid chromatography-ultraviolet detection. Several influential variables such as desorption time, desorption volume, sample pH, extraction time, and sorbent amount were screened through Plackett-Burman design and then optimized via Box-Behnken design. The obtained results showed that the above-mentioned method enjoys a good linear range (0.2-500 µg/L) with the coefficient of determination higher than 0.9927, low limits of determination (0.07-0.24 µg/L), acceptable limits of quantification (0.22-0.93 µg/L), good enrichment factors (128 and 153), and good spiking recoveries (95-105%) for diazepam and sertraline under the obtained optimized condition. Analyzing the real samples results in the confirmation of the presented method and it can be applied for the analysis of various organic compounds in biological samples.

Point-of-care diagnostics for drugs of abuse in biological fluids: application of a microfabricated disposable copper potentiometric sensor.

The major objective of this work was to develop a portable, disposable, cost-effective, and reliable POC solid-state electrochemical sensor based on potentiometric transduction to detect benzodiazepine abuse, mainly diazepam (DZP), in biological fluids. To achieve that, microfabricated Cu electrodes on a printed circuit board modified with the conducting polymer poly(3-octylthiophene) (POT) have been employed as a substrate. This polymer was introduced to enhance the stability of the potential drift (0.9 mV/h) and improve the limit of detection (0.126 nmol mL-1). Nernstian potentiometric response was achieved for DZP over the concentration range 1.0 × 10-2 to 5.0 × 10-7 mol L-1 with a slope of 55.0 ± 0.4 mV/decade and E0 ~ 478.9 ± 0.9. Intrinsic merits of the proposed sensor include rapid response time (11 ± 2 s) and long life time (3 months). In order to enhance the selectivity of the potentiometric sensor towards the target drug and minimize any false positive results, calix[4]arene (CX4) was impregnated as an ionophore within the PVC plastic ion-sensing membrane. The performance of the POC sensors was assessed using electrochemical methods of analysis and electrochemical impedance spectroscopy as a surface characterization tool. The studied sensors were applied to the potentiometric determination of DZP in different biological fluids (plasma, urine, saliva, and human milk) in the presence of its metabolite with an average recovery of 100.9 ± 1.3%, 99.4 ± 1.0%, 101.8 ± 1.2%, and 99.0 ± 2.0%, respectively. Graphical abstract.

The adulterated XANAX pill: a fatal intoxication with etizolam and caffeine.

A 49-year old man was found dead at home next to a glass containing a dried, white, crystalline substance and near a bag containing pills with the imprint XANAX, the trade name of alprazolam. A comprehensive screening of material collected during the autopsy revealed the presence of etizolam and caffeine in lethal concentrations (0.77 µg/mL and 190 µg/mL) but no trace of alprazolam. Benzodiazepine analogue etizolam is rarely prescribed in Germany, and as a result there are not many reports about fatal cases. It has anxiolytic, hypnotic, sedative and muscle-relaxant properties and is used for the short-term treatment of anxiety and panic attacks. The purine alkaloid caffeine, conversely, is the most widely used central nervous system stimulant. The following report outlines potentially the first reported case of a lethal combination of the downer etizolam and the upper caffeine in medical literature.

An Experimental Study of Diazepam and Alprazolam Kinetics in Urine and Oral Fluid Following Single Oral Doses.

Benzodiazepines are commonly seen in samples submitted for drug testing of patients, people involved in child welfare cases, work-place drug testing, as well as in drug-facilitated assaults. Limited previous experimental studies are available regarding the excretion of benzodiazepines in urine and oral fluid. The aim of this study was to investigate the concentrations of diazepam and alprazolam in oral fluid and urine for up to 2 weeks after ingestion of a single oral dose in healthy volunteers. A total of 11 healthy volunteers ingested 10 mg diazepam at the start of the study and 0.5 mg alprazolam on Day 3 of the study. A total number of 10 oral fluid samples and 17 urine samples were collected from each participant. The samples were analyzed by liquid chromatography with tandem mass spectroscopy and ultra-high performance liquid chromatography tandem mass spectrometry methods. The median detection time was 252 h for the longest detected diazepam metabolite in urine (oxazepam, range 203-322) and 132 h in oral fluid (N-desmethyldiazepam, range 109-136). For alprazolam, the median detection time was 36 h (metabolite α-OH-alprazolam, range 26-61) in urine and 26 h (alprazolam, range 4-37) in oral fluid. These results show that detection times are only 36 h for alprazolam in urine after intake of a single therapeutic oral dose. For diazepam in urine, detection times were 11 days. Detection times were generally shorter in oral fluid compared to urine. The results could be helpful in the interpretation of diazepam or alprazolam findings in drug testing cases involving urine or oral fluid.

A silica fiber coated with a ZnO-graphene oxide nanocomposite with high specific surface for use in solid phase microextraction of the antiepileptic drugs diazepam and oxazepam.

A novel ZnO-graphene oxide nanocomposite was prepared and is shown to be a viable coating on fused silica fibers for use in solid phase microextraction (SPME) of diazepam and oxazepam from urine, this followed by thermal desorption and gas chromatographic quantitation using a flame ionization detector. A central composite design was used to optimize extraction time, salt percentage, sample pH and desorption time. Limits of detection are 0.5 µg·L-1 for diazepam and 1.0 µg·L-1 for oxazepam. Repeatability and reproducibility for one fiber (n = 4), expressed as the relative standard deviation at a concentration of 50 µg·L-1, are 8.3 and 11.3% for diazepam, and 6.7 and 10.1% for oxazepam. The fiber-to-fiber reproducibility is <17.6%. The calibration plots are linear in the 5.0-1000 µg·L-1 diazepam concentration range, and from 1.0-1000 µg·L-1 in case of oxazepam. The fiber for SPME has high chemical and thermal stability (even at 280 °C) after 50 extractions, and does not suffer from a reduction in the sorption capacity. Graphical abstract A hydrothermal method was introduced for preparation of ZnO- GO nano composite on a fused silica fiber as solid phase microextraction with high mechanical, chemical stability and long service life.

Lab on paper chip integrated with Si@GNRs for electroanalysis of diazepam.

We describe herein the fabrication of an electrochemical microfluidic paper based device (EµPAD) for the detection of diazepam, a sedative, anxiety-relieving and muscle-relaxing drug. To achieve it, silica coated gold nanorods (Si@GNRs) were synthesized and drop casted on an electrochemical microfluidic paper based device (EµPAD) for the detection of diazepam. The synthesized composites were characterized by recording its images in scanning electron microscope (SEM) and transmission electron microscope (TEM). The experimental results confirmed that Si@GNRs had good electrocatalytic activity towards diazepam. The modified paper based electrode showed a stable electrochemical response for diazepam in the concentration range of 3.5 nM to 3.5 mM. EµPAD offers many advantageous features such as facile approach, economical and have potential for commercialization. Si@GNRs modified EµPAD was also employed for determination of diazepam in spiked human urine samples. Reported facile lab paper approach integrated with Si@GNRs could be well applied for the determination of serum metabolites.

Ultrasound-assisted low-density solvent dispersive liquid-liquid microextraction for the determination of 4 designer benzodiazepines in urine samples by gas chromatography-triple quadrupole mass spectrometry.

A novel microextraction technique based on ultrasound-assisted low-density solvent dispersive liquid-liquid microextraction (UA-LDS-DLLME) had been applied for the determination of 4 designer benzodiazepines (phenazepam, diclazepam, flubromazepam and etizolam) in urine samples by gas chromatography- triple quadrupole mass spectrometry (GC-QQQ-MS). Ethyl acetate (168µL) was added into the urine samples after adjusting pH to 11.3. The samples were sonicated in an ultrasonic bath for 5.5min to form a cloudy suspension. After centrifugation at 10000rpm for 3min, the supernatant extractant was withdrawn and injected into the GC-QQQ-MS for analysis. Parameters affecting the extraction efficiency have been investigated and optimized by means of single factor experiment and response surface methodology (Box-Behnken design). Under the optimum extraction conditions, a recovery of 73.8-85.5% were obtained for all analytes. The analytical method was linear for all analytes in the range from 0.003 to 10µg/mL with the correlation coefficient ranging from 0.9978 to 0.9990. The LODs were estimated to be 1-3ng/mL. The accuracy (expressed as mean relative error MRE) was within ±5.8% and the precision (expressed as relative standard error RSD) was less than 5.9%. UA-LDS-DLLME technique has the advantages of shorter extraction time and is suitable for simultaneous pretreatment of samples in batches. The combination of UA-LDS-DLLME with GC-QQQ-MS offers an alternative analytical approach for the sensitive detection of these designer benzodiazepines in urine matrix for clinical and medico-legal purposes.

Preconcentration and determination of chlordiazepoxide and diazepam drugs using dispersive nanomaterial-ultrasound assisted microextraction method followed by high performance liquid chromatography.

Benzodiazepines (BDs) are used widely in clinical practice, due to their multiple pharmacological functions. In this study a dispersive nanomaterial-ultrasound assisted- microextraction (DNUM) method followed by high performance liquid chromatography (HPLC) was used for the preconcentration and determination of chlordiazepoxide and diazepam drugs from urine and plasma samples. Various parameters such as amount of adsorbent (mg: ZnS-AC), pH and ionic strength of sample solution, vortex and ultrasonic time (min), and desorption volume (mL) were investigated by fractional factorial design (FFD) and central composite design (CCD). Regression models and desirability functions (DF) were applied to find the best experimental conditions for providing the maximum extraction recovery (ER). Under the optimal conditions a linear calibration curve were obtained in the range of 0.005-10µgmL(-1) and 0.006-10µgmL(-1) for chlordiazepoxide and diazepam, respectively. To demonstrate the analytical performance, figures of merits of the proposed method in urine and plasma spiked with chlordiazepoxide and diazepam were investigated. The limits of detection of chlordiazepoxide and diazepam in urine and plasma were ranged from 0.0012 to 0.0015µgmL(-1), respectively.

Detection Times of Diazepam, Clonazepam, and Alprazolam in Oral Fluid Collected From Patients Admitted to Detoxification, After High and Repeated Drug Intake.

BACKGROUND: Clonazepam, diazepam, and alprazolam are benzodiazepines with sedative, anticonvulsant, and anxiolytic effects, but their prevalence in drug abuse and drug overdoses has long been recognized. When detection times for psychoactive drugs in oral fluid are reported, they are most often based on therapeutic doses administered in clinical studies. Repeated ingestions of high doses, as seen after drug abuse, are however likely to cause positive samples for extended time periods. Findings of drugs of abuse in oral fluid collected from imprisoned persons might lead to negative sanctions, and the knowledge of detection times of these drugs is thus important to ensure correct interpretation. The aim of this study was to investigate the time window of detection for diazepam, clonazepam, and alprazolam in oral fluid from drug addicts admitted to detoxification. METHODS: Twenty-five patients with a history of heavy drug abuse admitted to a detoxification ward were included. Oral fluid was collected daily in the morning and the evening and urine samples every morning for 10 days, using the Intercept device. Whole blood samples were collected if the patient accepted. The cutoff levels in oral fluid were 1.3 ng/mL for diazepam, N-desmethyldiazepam, and 7-aminoclonazepam and 1 ng/mL for clonazepam and alprazolam. In urine, the cutoff levels for quantifications were 30 ng/mL for alprazolam, alpha-OH-alprazolam, and 7-aminoclonazepam, 135 ng/mL for N-desmethyldizepam, and 150 ng/mL for 3-OH-diazepam and for all the compounds, the cutoff for the screening analyses were 200 ng/mL. RESULTS: The maximum detection times for diazepam and N-desmethyldiazepam in oral fluid were 7 and 9 days, respectively. For clonazepam and 7-aminoclonazepam, the maximum detection times in oral fluid were 5 and 6 days, respectively. The maximum detection time for alprazolam in oral fluid was 2.5 days. New ingestions were not suspected in any of the cases, because the corresponding concentrations in urine were decreasing. Results from blood samples revealed that high doses of benzodiazepines had been ingested before admission, and explains the longer detection times in oral fluids than reported previously after intake of therapeutic doses of these drugs. CONCLUSIONS: This study has shown that oral fluid might be a viable alternative medium to urine when the abuse of benzodiazepines is suspected.

A mixed MDPV and benzodiazepine intoxication in a chronic drug abuser: determination of MDPV metabolites by LC-HRMS and discussion of the case.

We report on a case of repeated MDPV consumptions that resulted in severe psychosis and agitation prompting the concomitant abuse of benzodiazepines. A 27-year-old man was found irresponsive in his apartment and was brought to the emergency department (ED) of a local hospital. When in ED, he rapidly recovered and self-reported to have recently injected some doses of MDPV that he had bought in the Internet. He left the hospital without medical cares. 15 days after, he was again admitted to the same ED due to severe agitation, delirium and hallucinations, and reported the use of MDPV and pharmaceutical drugs during the preceding week. He was sedated with diazepam and chlorpromazine. Urine samples collected in both occasions were sent for testing using liquid chromatography-high resolution mass spectrometry (LC-HRMS) and liquid chromatography-high resolution multiple mass spectrometry (LC-HRMS/MS) on an Orbitrap. The LC-HRMS analysis revealed the presence of MDPV and its phase I and phase II metabolites (demethylenyl-MDPV, demethylenyl-methyl-MDPV, demethylenyl-methyl-oxo-MDPV, demethylenyl-hydroxy-alkyl-MDPV, demethylenyl-methyl-hydroxy alkyl-MDPV, demethylenyl-oxo-MDPV and their corresponding glucuronides), alprazolam and alprazolam metabolite at the first ED admission; at the time of the second ED access, the same MDPV metabolites, alprazolam, temazepam, and chlordiazepoxide were detected together with diazepam and metabolites. LC-HRMS/MS was use to determine the following concentrations, respectively on his first and second admission: MDPV 55ng/mL, alprazolam 114ng/mL, α-hydroxyalprazolam 104ng/mL; MDPV 35ng/mL, alprazolam 10.4ng/mL, α -hydroxyalprazolam 13ng/mL; chlordiazepoxide 13ng/mL, temazepam 170ng/mL, diazepam 1.3ng/mL, nordiazepam 61.5, oxazepam 115ng/mL. The toxicological findings corroborated the referred concomitant use of multiple pharmaceutical drugs and benzodiazepines. Confirmation of previous hypothesis on human metabolism of MDPV could be inferred by the analysis of urine.

Urinary diazepam metabolite distribution in a chronic pain population.

Diazepam is often used as an adjuvant to pain therapy. Cytochrome P450 (CYP) 3A4 and 2C19 metabolize diazepam into the active metabolites: nordiazepam, temazepam and oxazepam. Owing to diazepam's side-effect profile, mortality risk and potential for drug-drug interactions with CYP 3A4 and/or CYP 2C19 inhibitors, urine drug testing (UDT) could be a helpful monitoring tool. This was a retrospective data analysis that evaluated urine specimens from pain management practices for the distribution of diazepam metabolites with and without CYP 3A4 and 2C19 inhibitors. Intersubject nordiazepam, temazepam and oxazepam geometric mean fractions were 0.16, 0.34 and 0.47, respectively. Intrasubject geometric mean fractions were 0.157, 0.311 and 0.494, respectively. Sex, but not age or urinary pH, had an effect on metabolite fractions. Methadone significantly increased temazepam and oxazepam urinary fractions via CYP3A4 inhibition, whereas fluoxetine and esomeprazole increased nordiazepam fractions via CYP2C19 inhibition. Although more studies are needed, these results suggest the viability of UDT for increased monitoring for therapy and possible drug-drug interactions.

A new chemiluminescence method for determination of clonazepam and diazepam based on 1-Ethyl-3-Methylimidazolium Ethylsulfate/copper as catalyst.

A novel chemiluminescence (CL) reaction, Benzodiazepines-H2O2-1-Ethyl-3-Methylimidazolium Ethylsulfate/copper, for determination of clonazepam and diazepam at nanogram per milliliter level in batch-type system have been described. The method relies on the catalytic effect of 1-Ethyl-3-Methylimidazolium Ethylsulfate/copper on the chemiluminescence reaction of Benzodiazepines, the oxidation of Benzodiazepines with hydrogen peroxide in natural medium. The influences of various experimental parameters such as solution pH, the ratio of 1-Ethyl-3 Methylimidazolium ethylsulfate concentration to copper ion, the type of buffer and the concentration of CL reagents were investigated. Under the optimum condition, the proposed method was satisfactorily applied for the determination of these drugs in tablets and urine without the interference of their potential impurities.

Extending the detection window of diazepam by directly analyzing its glucuronide metabolites in human urine using liquid chromatography-tandem mass spectrometry.

A method for the simultaneous direct analysis of diazepam oxazepam glucuronide, temazepam glucuronide, oxazepam, nordiazepam, and temazepam in human urine was developed and validated. Urine sample was purified by solid phase extraction (SPE), and the analysis was achieved using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) system equipped with an electrospray ionization source (ESI). Multiple reaction monitoring (MRM) mode was used to analyze the target compounds. Extraction recoveries were 65-122% for all the analytes. The method showed acceptable intra-assay and inter-assay precision (both relative standard deviation (RSD)≤11.2%) for quality control (QC) samples. The limits of detections (LODs) were in the range of 0.1-2 ng/mL. The present assay was applied to analyze the urine obtained from three volunteers after oral administration of a single dose 5mg of diazepam. The results showed that, the detection periods of oxazepam glucuronide and temazepam glucuronide were much longer than diazepam and other metabolites.

Evaluation of diazepam-molecularly imprinted microspheres for the separation of diazepam and its main metabolite from body fluid samples.

Molecularly imprinted microspheres (MIMs) for the drug diazepam and its main metabolite (nordiazepam) were prepared and used to separate the two species from urine and serum samples via molecularly imprinted solid-phase extraction. The specific binding capacity for diazepam was determined to be 1.97 mg/g, resulting in an imprinting factor of 5.8. The MIMs exhibit highly selective binding affinity for tricyclic benzodiazepines. Water-acetonitrile-acetone mixtures were used as the washing solvent and resulted in complete baseline separation, with a recovery of >87% for diazepam and of 88% for nordiazepam. The limits of detection are 21.5 and 24.5 ng/mL, respectively.

[Comparison of four immunoassay screening devices for detection of benzodiazepine and its metabolites in urine: mainly detection of etizolam, thienodiazepine and its metabolites].

The immunoassay screening of benzodiazepines in urine is one of the most important methods of drug analysis in clinical and forensic laboratories. We experienced an unusual case of poisoning wherein the result of Triage DOA immunoassay screening was negative, although Depas (etizolam) was detected in the blood of the victim who had been suspected to prescribe Depas by gas chromatography-mass spectrometry. Depas has been widely used for the treatment of anxiety in Japan. Three immunoassay screening devices (AccuSign BZO, Monitect-3, and Fastect II) were evaluated for their specificity for etizolam, its 2 major metabolites M-III and M-VI, and other metabolites of benzodiazepines in urine. With AccuSign BZO, etizolam, M-III, and M-VI could be detected at concentrations of 1,000 ng/mL in urine; however, they could not be detected even at concentrations of 25,000 ng/mL with the other kits. In the case of etizolam poisoning, the result of AccuSign BZO was positive; however, Triage DOA, which is mainly used for the detection of drugs in urine at intensive care units (ICUs) or forensic laboratories, showed negative result for benzodiazepines. The concentrations of etizolam and its metabolites in urine were measured by the established high-performance liquid chromatographic method. The concentrations of M-III and M-V were 700 and 1,600 ng/mL, respectively. AccuSign BZO demonstrated higher specificity-than the other screening kits for the detection of etizolam and its metabolites in urine. Therefore, the types of drugs detected would be increased by combining Triage DOA with AccuSign BZO in ICUs or forensic laboratories.

Evaluation of a differential mobility spectrometer/miniature mass spectrometer system.

A planar differential mobility spectrometer (DMS) was coupled to a Mini 10 handheld rectilinear ion trap (RIT) mass spectrometer (MS) (total weight 10 kg), and the performance of the instrument was evaluated using illicit drug analysis. Coupling of DMS (which requires a continuous flow of drift gas) with a miniature MS (which operates best using sample introduction via a discontinuous atmospheric pressure interface, DAPI), was achieved with auxiliary pumping using a 5 L/min miniature diaphragm sample pump placed between the two devices. On-line ion mobility filtering showed to be advantageous in reducing the background chemical noise in the analysis of the psychotropic drug diazepam in urine using nanoelectrospray ionization. The combination of a miniature mass spectrometer with simple and rapid gas-phase ion separation by DMS allowed the characteristic fragmentation pattern of diazepam to be distinguished in a simple urine extract at lower limits of detection (50 ng/mL) than that achieved without DMS (200 ng/mL). The additional separation power of DMS facilitated the identification of two drugs of similar molecular weight, morphine (average MW = 285.34) and diazepam (average MW = 284.70), using a miniature mass spectrometer capable of unit resolution. The similarity in the proton affinities of these two compounds resulted in some cross-interference in the MS data due to facile ionization of the neutral form of the compound even when the ionic form had been separated by DMS.

Quantitation of benzodiazepines in blood and urine using gas chromatography-mass spectrometry (GC-MS).

The benzodiazepine assay utilizes gas chromatography-mass spectrometry (GC-MS) for the analysis of diazepam, nordiazepam, oxazepam, temazepam, lorazepam, alpha-hydroxyalprazolam, and alpha-hydroxytriazolam in blood and urine. A separate assay is employed for the analysis of alprazolam. Prior to solid phase extraction, urine specimens are subjected to enzyme hydrolysis. The specimens are fortified with deuterated internal standard and a five-point calibration curve is constructed. Specimens are extracted by mixed-mode solid phase extraction. The benzodiazepine extracts are derivatized with N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide (MTBSFTA) producing tert-butyldimethyl silyl derivatives; the alprazolam extracts are reconstituted in methanol without derivatization. The final extracts are then analyzed using selected ion monitoring GC-MS.

Metabolic studies of tetrazepam based on electrochemical simulation in comparison to in vivo and in vitro methods.

During the last 2 years, the knowledge on the metabolic pathway of tetrazepam, a muscle relaxant drug, was expanded by the fact that diazepam was identified as a degradation product of tetrazepam. The present study demonstrates that this metabolic conversion, recently discovered by in vivo studies, can also be predicted on the basis of a purely instrumental method, consisting of an electrochemical cell (EC) coupled to online liquid chromatography (LC) and mass spectrometry (MS). By implementing a new electrochemical cell type into the EC-LC-MS set-up and by an enhanced oxidation potential range up to 2V, one limitation of the electrochemical metabolism simulation, the hydroxylation of alkanes and alkenes, has been overcome. Instead of commonly used flow-through cell with a porous glassy carbon working electrode, a wall-jet cell with exchangeable electrode material was used for this study. Thereby, the entire metabolic pathway of tetrazepam, in particular including the hydroxylation of the tetrazepam cyclohexenyl moiety, was simulated. The electrochemical results were not only compared to microsomal incubations, but also to in vivo experiments, by analysing urine samples from a patient after tetrazepam delivery. For structure elucidation of the detected metabolites, MS/MS experiments were performed. The comparison of electrochemistry to in vitro as well as to in vivo experiments underlines the high potential of electrochemistry as a fast screening tool in the prediction of metabolic transformations in drug development.

Unraveling the metabolic transformation of tetrazepam to diazepam with mass spectrometric methods.

The metabolic transformation pathways of the 1,4-benzodiazepine tetrazepam (C(16)H(17)ClN(2)O, average mass: 288.772) were studied with capillary LC-QqTOF-MS and -MS/MS by analyzing human plasma and urine samples collected from healthy volunteers. Each volunteer took 50 mg of tetrazepam, given in the form of one tablet of Myolastan (Sanofi-Synthelabo, Vienna, Austria). Accurate molecular mass measurements in full-scan mode (scan range: 50-700) were used to survey the collected samples for putative metabolic transformation products. Full-scan fragment ion mass spectra were collected in subsequent LC/MS/MS experiments. Each spectrum was matched to a spectral library containing 3759 MS/MS-spectra of 402 compounds, including eighteen different benzodiazepines, to prove the structural relatedness of a tentative metabolite to tetrazepam. This "similarity search" approach provided a rapid and powerful tool to exclude non-drug-related species, even without any knowledge of the fragmentation chemistry. Interpretation of tandem mass spectrometric data was only required in order to elucidate the site of transformation. Using this strategy, 11 major classes of tetrazepam metabolites were identified. Possible metabolic routes from tetrazepam to diazepam (C(16)H(13)ClN(2)O, average mass: 284.740) via repeated hydroxylation and dehydration of the cylohexenyl moiety were discovered. No evidence for extensive hydroxylation of tetrazepam at position 3 of the diazepine ring was found. In contrast to what is commonly believed, this distinct transformation reaction may be of only minor importance. Furthermore, the occurrence of demethylation, hydration, and glucuronidation reactions was proven.

Urine monitoring of diazepam abuse- new intake or not?

Testing for drugs-of-abuse in urine is requested for multiple reasons, including legal and workplace policies. Two cases were studied in which there was a suspicion that the patients continued to abuse diazepam, because of repeatedly positive urine samples. In these cases, diazepam metabolites were measured in urine samples by gas or liquid chromatography coupled to mass spectrometry. The concentrations of diazepam metabolites were subsequently creatinine correlated. Very long elimination times were found in the described cases. None of them had in fact ingested diazepam again during the study period. By the use of pharmacogenetic typing, one of the subjects was found to have a slow metabolism for CYP2C9 as well as for CYP2C19. In the second case, there was a possible drug interaction between diazepam and zolpidem.