A case report on fatal intoxication by tapentadol: Study of distribution and metabolism.

We report a case in which a tapentadol acute intoxication was suspected as the cause of death of a 39-year-old man: approximately two days after death, cardiac and femoral blood, as well as urine, bile, gastric content and chest hair, were collected during the autopsy. Tapentadol was detected before and after hydrolysis in femoral (530 ng/mL unconjugated and 1570 ng/mL conjugated) and cardiac (680 ng/mL unconjugated and 3440 ng/mL conjugated) blood, and additionally in bile (3200 ng/mL), urine (9300 ng/mL), chest hair (2850 pg/mg) and gastric content. LC-QTOF screening analysis confirmed the presence of five different tapentadol metabolites (tapentadol-O-glucuronide, tapentadol-O-sulfate, N-desmethyltapentadol, N-desmethyltapentadol-glucuronide and N-desmethyltapentadol-O-sulfate), in urine, bile, cardiac and femoral blood. Positivity of body hairs allowed us to conclude that the man had used tapentadol in the last weeks/months. Autopsy and toxicological results (also positive for clotiapine, diazepam and chlordesmethyldiazepam) suggested that tapentadol could have caused, even at low concentrations, a severe respiratory depression, which contributed to the death of the subject. This is one of the few cases in literature where tapentadol was detected in blood, together with its metabolites, and the only one in which the parent drug was identified in hairs.

An LC-MS/MS method for the simultaneous determination of 12 psychotropic drugs and metabolites in hair: Identification of acute quetiapine poisoning using hair root.

A rapid, sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination and quantification of 12 psychotropic drugs and metabolites in hair was developed and validated. After freeze grinding with methanol, the supernatant was determined by LC-MS/MS using an Allure PFPPropyl column (100 × 2.1 mm, 5 µm) with a gradient elution of acetonitrile and 10 mmol/L ammonium acetate with 0.1% formic acid, and in the subsequent analysis using multiple reaction monitoring (MRM) mode, two ion transitions were monitored for each analyte. The limits of detection ranged from 0.002 to 0.05 ng/mg, and the limits of quantitation were in the range of 0.005-0.1 ng/mg. Good linearity (r > 0.995) was observed for all analytes over the linear range. Acceptable intraday and interday precision (RSD ≤ 20%) and accuracy (85.3%-112.9%) were achieved. This method of detection was applied to the analysis of guinea pig hair roots after a single dose of quetiapine. Quetiapine and 7-hydroxyquetiapine were both detected in guinea pig hair roots from 5 min post administration. The concentration of quetiapine (10.3-1733.8 ng/mg) was much higher than that of 7-hydroxyquetiapine (0.1-40.6 ng/mg) in the hair roots of guinea pigs, and higher concentrations of quetiapine and 7-hydroxyquetiapine occurred in black hair root than in that of white and brown. The animal experiment demonstrated that hair roots may be a good specimen for proving acute quetiapine poisoning when other biological matrices are not available.

Analytical Challenge in Postmortem Toxicology Applied to a Human Body Found into a Lake after Three Years Immersion.

The body of a 30-year-old woman was found in Como lake at a depth of about 120 meters in her own car after 3 years of immersion. The aim of this study was to evaluate psychoactive drugs as well as alcohol biomarkers in biological matrices. The following analyses were initially performed: GC-MS systematic toxicological analysis on biological fluids and tissues; GC-MS analysis of drugs of abuse on pubic hair; direct ethanol metabolite determination in pubic hair by LC-MS/MS. After 7 years, the samples, that had been stored at -20°C, were re-analyzed and submitted to an LC-MS/MS targeted screening method, using multiple reaction monitoring mode. These analyses detected citalopram (150-3000 ng/mL), desmethylcitalopram (50-2300 ng/mL), clotiapine (20-65 ng/mL), and ethyl glucuronide (97 pg/mg). The methods showed an acceptable reproducibility, and the concentrations of citalopram and desmethylcitalopram calculated through the two analytical techniques did not significantly differ in biological fluids.

Time resolved analysis of quetiapine and 7-OH-quetiapine in hair using LC/MS-MS.

Hair analysis is a powerful tool for retrospective drug analysis and has a wide application window. This article describes the simultaneous determination and quantification of the short-acting atypical antipsychotic drug quetiapine and its main metabolite 7-OH quetiapine in hair. A sensitive and accurate method for the determination of these two compounds was developed using high-performance liquid chromatography coupled to tandem mass spectrometry detection (LC-MS/MS). The method was applied to 10 real case samples. For five patients, a time resolved hair analysis was done. Results varied from 0.35 ng/mg to 10.21 ng/mg hair for quetiapine and from 0.02 ng/mg to 3.19 ng/mg hair for 7-OH-quetiapine.

Possibilities and limitations of capillary electropherosis in pharmaceutical analysis.

Capillary electropherosis (CE) has been proved to be an important alternative to high-performance liquid chromatography (HPLC) in pharmaceutical analysis. However, when it comes to the analysis of compounds, e.g. impurities or metabolites, of very different polarity and water solubility CE and the related techniques come to its limits. This is demonstrated for the antipsychotic drug quetiapine and its impurities. A nonaqueous capillary electrophoresis (NACE) method was developed using a background electrolyte (BGE) composed of ammonium acetate dissolved in a mixture of acetonitrile and methanol including acetic acid to protonate the substances. The NACE method gave an excellent separation of all components. Since the conductivity of the BGE used in the NACE method is quite low and problems with current occurred, an additional aqueous capillary zone electrophoresis (CZE) method was developed for quetiapine and the two water soluble derivatives, using phosphate buffer as BGE. The method was validated with regard to repeatability and limit of detection.

Stability of some atypical antipsychotics in human plasma, haemolysed whole blood, oral fluid, human serum and calf serum.

Long-term stability data of atypical antipsychotics in different matrices are not widely available. The aim of this work was to assess the stability of amisulpride, aripiprazole and dehydroaripiprazole, clozapine and norclozapine, olanzapine, quetiapine, risperidone and 9-hydroxyrisperidone, and sulpiride in human EDTA plasma, heparinised haemolysed human whole blood, oral fluid, human serum, and newborn calf serum stored in tightly capped plastic containers under a range of conditions. Measurements were performed by LC-MS/MS. Analyte instability was defined as a deviation of 15% or greater from the expected concentration. All analytes were stable following 3 freeze-thaw cycles in human plasma, and were stable in this matrix for at least 5 days at ambient temperature (olanzapine, 3 days); 4 weeks at 2-8°C (olanzapine, 2 weeks), and 2 years at -20°C (except for dehydroaripiprazole, olanzapine, and quetiapine, 1 year). In human serum, aripiprazole, dehydroaripiprazole, norclozapine, olanzapine, quetiapine, risperidone, 9-hydroxyrisperidone, and sulpiride were unstable after 5 days at ambient temperature, 3 weeks at 2-8°C, and 9 months at -20°C. Olanzapine was unstable in whole blood and oral fluid under most conditions studied, although prior addition of ascorbic acid had a moderate stabilising effect. All other analytes were stable in whole blood and oral fluid for at least 2 days at ambient temperature, 1 week at 2-8°C, and 2 months at -20°C (clozapine and norclozapine, 1 month whole blood). These results confirm that plasma (EDTA anticoagulant) is the sample of choice for TDM of atypical antipsychotics. Delayed (more than 1 week) analysis of patient samples should be undertaken with caution, especially with serum and with haemolysed whole blood. With olanzapine, only plasma collected and stored appropriately is likely to give reliable quantitative results.

LC-MS/MS of some atypical antipsychotics in human plasma, serum, oral fluid and haemolysed whole blood.

Therapeutic drug monitoring (TDM) of atypical antipsychotics is common, but published methods often specify relatively complex sample preparation and analysis procedures. The aim of this work was to develop and validate a simple liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the analysis of amisulpride, aripiprazole and dehydroaripiprazole, clozapine and norclozapine, olanzapine, quetiapine, risperidone and 9-hydroxyrisperidone, and sulpiride in small (200 µL) volumes of plasma or serum for TDM purposes. The applicability of the method as developed to haemolysed whole blood and to oral fluid was also investigated. Analytes and internal standards were extracted into butyl acetate:butanol (9+1, v/v) and a portion of the extract analysed by LC-MS/MS (100 mm × 2.1 mm i.d. Waters Spherisorb S5SCX; eluent: 50 mmol/L methanolic ammonium acetate, pH* 6.0; flow-rate 0.5 mL/min; positive ion APCI-SRM, two transitions per analyte). Assay calibration (human plasma, oral fluid, and haemolysed whole blood calibration solutions) was performed by plotting the ratio of the peak area of the analyte to that of the appropriate internal standard. Assay validation was as per FDA guidelines. Assay calibration was linear across the concentration ranges studied. Inter- and intra-assay precision and accuracy were within 10% for all analytes in human plasma. Similar results were obtained for oral fluid and haemolysed whole blood, except that aripiprazole and dehydroaripiprazole were within 15% accuracy at low concentration (15 µg/L) in oral fluid, and olanzapine inter-assay precision could not be assessed in these matrices due to day-by-day degradation of this analyte. Recoveries varied between 16% (sulpiride) and 107% (clozapine), and were reproducible as well as comparable between human plasma, human serum, calf serum and haemolysed whole blood. For oral fluid, recoveries were reproducible, but differed slightly from those in plasma suggesting the need for calibration solutions to be prepared in this medium if oral fluid is to be analysed. LLOQs were 1-5 µg/L depending on the analyte. Neither ion suppression/enhancement, nor interference from some known metabolites of the antipsychotics studied has been encountered. The method has also been applied to the analysis of blood samples collected post-mortem after dilution (1+1, 1+3; v/v) in analyte-free calf serum.

A novel electrochemical sensor for assaying of antipsychotic drug quetiapine.

A novel electrochemical sensor based on poly(2-hydroxy-5-[(4-sulfophenyl)azo]benzoic acid) film modified glassy carbon electrode for fast and simple quantification of trace amount of quetiapine fumarate (QF) was developed. It exhibits excellent enhancement effects on the electrooxidation of QF facilitating preconcentration of drug molecules on the electrode surface. Based on its strong adsorptive activity, the concentration of QF in pharmaceutical formulations and biological fluids was determined directly by voltammetry with excellent sensitivity and high selectivity. The introduction of carboxylated and sulfonated functionalities in polymer film improves the uniform selectivity for positively charged target QF molecules. The calibration curve is linear in QF concentration range of 8.0 × 10(-8) to 7.5 × 10(-6)M with detection limit 1.9 × 10(-8) and sensitivity 8.96 × 10(5) µA M(-1). The presented sensor has long term stability and good reproducibility with benefits of fast response time, ease of preparation and regeneration of the surface that makes the proposed method useful in the determination of QF in real samples.

Use of hyphenated LC-MS/MS technique for characterization of impurity profile of quetiapine during drug development.

As a part of an integrated quality concept in drug development, the multidimensional evaluation of impurity profiles by LC-MS/MS is presented for quetiapine--an active pharmaceutical ingredient (API). LC-UV is commonly employed for the determination of impurities and degradation products. In this work LCMS/MS technique is proposed as a modern alternative for the characterization of these compounds. The use of this technique allowed to develop methods for the separation and identification of the impurities resulting from both, synthesis and degradation processes.

Preliminary evaluation of monolithic column high-performance liquid chromatography with tris(2,2'-bipyridyl)ruthenium(II) chemiluminescence detection for the determination of quetiapine in human body fluids.

High-performance liquid chromatography (HPLC) with tris(2,2'-bipyridyl)ruthenium(II) chemiluminescence detection methodology is reported for the determination of the atypical antipsychotic drug quetiapine and the observation of its major active and inactive metabolites in human urine and serum. The method uses a monolithic chromatographic column allowing high flow rates of 3 mLmin(-1) enabling rapid quantification. Flow injection analysis (FIA) with tris(2,2'-bipyridyl)ruthenium(II) chemiluminescence detection and HPLC time of flight mass spectrometry (TOF-MS) were used for the determination of quetiapine in a pharmaceutical preparation to establish its suitability as a calibration standard. The limit of detection achieved with FIA was 2 x 10(-11) molL(-1) in simple aqueous solution. The limits of detection achieved with HPLC were 7 x 10(-8) and 2 x 10(-10) molL(-1) in urine and serum, respectively. The calibration range for FIA was between 5 x 10(-9) and 1 x 10(-6) molL(-1). The calibration ranges for HPLC were between 1 x 10(-7)-1 x 10(-4) and 1 x 10(-8)-1 x 10(-4) molL(-1) in urine and serum, respectively. The quetiapine concentrations in patient samples were found to be 3 x 10(-6) molL(-1) in urine and 7 x 10(-7) molL(-1) in serum. Without the need for preconcentration, the HPLC detection limits compared favourably with those in previously published methodologies. The metabolites were identified using HPLC-TOF-MS.

Identification and characterization of potential impurities of quetiapine fumarate.

Seven potential impurities, including by-products, starting materials and intermediates were identified in pharmaceutical substance quetiapine fumarate and characterized by spectroscopic methods (MS, IR, NMR). Based on these methods the structures of the impurities were assigned or confirmed as: impurity I: 2-(phenylthio)aniline; impurity II: phenyl N-[2-(phenylthio)phenyl]carbamate; impurity III: N,N'-bis[2-(phenylthio) phenyl]urea; impurity IV: N-[2-(phenylthio)phenyl]-1-piperazinecarboxamide hydrochloride; impurity V: N,N'-bis[(2-phenylthio)phenyl]-1,4-piperazinedicarboxamide; impurity VI: 11-(1-piperazinyl) dibenzo[b,f][1,4]thiazepine fumarate; impurity VII: 1,4-bis(dibenzo[b,f][1,4] thiazepin-11-yl)piperazine. Structural elucidation of compounds, proposed MS fragmentation pathway and possible ways of formation of the impurities are also discussed.

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 microg/L. The limit of detection (LOD) and the limit of quantification (LOQ) were found to be 2 and 6 microg/L for the GC-NPD method and 5 and 15 microg/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 microg/L (mean 46 microg/L), and for the autopsy cases between 22 and 341 microg/L (mean 123 microg/L).

Identification of an unknown trace-level impurity in bulk drug of Seroquel by high-performance liquid chromatography combined with mass spectrometry.

An impurity was detected in bulk drug Seroquel at about 0.4% level by the reversed-phase high-performance liquid chromatography with UV detection. The accurate mass of impurity was measured by FTICR equipped with electrospray ionization interface, and the structure of impurity was characterized on the basis of the on-line multi-stage mass spectrometric evidences. The proposed structure was further confirmed by multi-stage mass spectrometry of Seroquel and four related compounds.

Quetiapine and breast feeding.

OBJECTIVE: To quantify the relative infant dose of quetiapine during breast feeding, describe the milk:plasma (M:P) ratio, and determine the well-being of the exposed infant. CASE SUMMARY: A 26-year-old mother and her 3-month-old son were studied over a 24 hour quetiapine dose interval at steady-state. Quetiapine concentrations were quantified by high-performance liquid chromatography. Infant exposure was calculated as the concentration in milk multiplied by an estimated milk production of 0.15 L/kg/day and normalized to the weight-adjusted maternal dose. The average concentration in milk was 41 microg/L, the M:P ratio (measured using average concentrations in the elimination phase) was 0.29, and the relative infant dose was 0.09% of the maternal weight-adjusted dose (7273 microg/kg/day). The infant plasma concentration of 1.4 microg/L was some 6% of the corresponding maternal plasma concentration. No adverse effects were noted in the infant. DISCUSSION: Our findings of an infant exposure to quetiapine of less than 0.1% of the maternal dose and a lack of adverse effects confirm and extend the findings of 2 previous studies. CONCLUSIONS: Although limited, the data shown here support the prescription of quetiapine to a breast-feeding mother following a careful individual risk/benefit analysis. We suggest regular monitoring of infant progress and occasional measurement of quetiapine in the infant's plasma.

Ultra-performance liquid chromatography-tandem mass spectrometry for the determination of atypical antipsychotics and some metabolites in in vitro samples.

The ultra-performance liquid chromatography-electrospray tandem mass spectrometry (UPLC-ESI-MS/MS) method has been developed to perform the determination of quetiapine, perospirone, aripiprazole and quetiapine sulfoxide in in vitro samples in less than 3 min. The UPLC separation was carried out using an Acquity UPLC BEH C18 column (100 mm x 2.1mm i.d., 1.7 microm particle size) that provided high efficiency and resolution in combination with high linear velocities. The UPLC system was coupled to a Waters Micromass Quattro Premier XE tandem quadrupole mass spectrometer. This system permits high-speed data acquisition without peak intensity degradation, and produces sharp and narrow chromatographic peaks (w(h) about 2.5s) of compounds. The determination was performed in multiple reaction monitoring (MRM) mode. The quantification parameters of the developed method were established, obtaining instrumental LODs lower than 0.005 microg/l and a repeatability at a low concentration level lower than 10% CV (n=10). Finally, the method was successfully applied to the analysis of atypical antipsychotics and some metabolites in in vitro samples.

Quetiapine augmentation in lactation: a series of case reports.

Treating psychiatric disorders with pharmacotherapy in the breast-feeding period presents a dilemma as such treatment carries the risk of infant exposure to medication through breast milk. However, failure to institute pharmacotherapy in postnatal women in need of such treatment exposes both mother and baby to detrimental effects of the illness. Because women presenting with psychiatric disorders during the postpartum period often have complex sets of symptoms, monotherapy may not be sufficient for symptom resolution. In this case series of 6, we examined levels of psychotropic medications secreted in breast milk and performed developmental assessments of the exposed babies with the Bayley Scales of Infant Development, Second Edition. In 3 of the 6 cases, no medication was detected in the breast milk; in all but 1 case, estimated levels of infant medication exposure were calculated to be less than 0.01 mg/kg per day for each medication. Four of the 6 babies scored as being within normal limits on the Bayley Scales of Infant Development, Second Edition, whereas 2 showed mild developmental delays. In comparison to the 4 cases of typical development, the 2 showing mild delays did not have higher estimated levels of psychotropic medication exposure through breast milk. Based on these results, in our limited sample, there appears to be low levels of infant exposure to the medications through breast milk; no association was seen between developmental outcomes and exposure through breast milk of multiple pharmacological agents. These results should be interpreted with caution, and vigilance should be exercised when advising women on combinations of medications for severe mental illness who choose to nurse.

Case studies of postmortem quetiapine: therapeutic or toxic concentrations?

The focus of this study was to determine if the analysis of a variety of postmortem biological specimens would aid in the toxicological interpretation of quetiapine in the cause and manner of death determinations. Postmortem quetiapine concentrations were examined in 21 medical examiner cases using liquid-liquid extraction and high-performance liquid chromatography analysis. Specimens analyzed were peripheral blood, central blood, liver, vitreous humor, and gastric contents, when available. Findings from this study suggest that therapeutic postmortem quetiapine concentrations may be less than 1 mg/L in both peripheral and central blood, less than 0.5 mg/L in vitreous, and less than 5 mg/kg in liver. Quetiapine concentrations indicative of toxicity were estimated at greater than 1 mg/L in peripheral and central blood, greater than 0.5 mg/L in vitreous, and greater than 5 mg/kg in the liver. Liver concentrations appeared to be particularly helpful in determining the potential for toxicity when compared with blood concentrations. Cases in which quetiapine was determined to play a significant role in the death indicated postmortem liver concentrations greater than 5 mg/kg. Cases in which quetiapine concentrations were considered incidental or noncontributory in the death had liver concentrations 2 mg/kg or less.

Disposition of quetiapine in biological specimens from postmortem cases.

Quetiapine is a new atypical antipsychotic that was approved in 1997 by the U.S. Food and Drug Administration for the treatment of schizophrenia. It possesses a high affinity for 5-HT2 receptors and a low affinity for D1 and D2 dopamine receptors. Because quetiapine has only been released recently to the U.S. market, little information exists regarding therapeutic, toxic, and lethal concentrations. This study reports the detection of quetiapine in 13 postmortem cases. Following a basic liquid-liquid extraction, quetiapine was identified and quantitated by capillary gas chromatography with nitrogen phosphorus detection. Confirmation was accomplished by full scan electron impact gas chromatography/mass spectrometry. Heart blood quetiapine concentrations ranged from 0.07 to 18.37 mg/L (N = 12, mean +/- SD = 3.42 +/- 5.67, median 0.62) and femoral blood concentrations ranged from 0.06 to 19.25 mg/L (N = 10. mean +/- SD = 3.89 +/- 6.12, median 0.81). The average heart blood/femoral blood ratio was 1.31 (range 0.55 to 2.57, N = 10). Urine, bile, and gastric contents were assayed in all cases in which they were submitted. In three cases, the cause of death was determined to be quetiapine toxicity. In these cases heart blood concentrations ranged from 0.72 to 18.37 mg/L (N = 3). These data may provide a basis for establishing levels associated with quetiapine toxicity as well as therapeutic concentrations in postmortem specimens.