Case Studies of Postmortem Quetiapine: Therapeutic or Toxic Concentrations?

Vitreous humor in the forensic toxicology of quetiapine and its metabolites

PURPOSE

Τhe aim of the present study was to investigate the use of vitreous humor as an alternative biological material in forensic toxicology for the determination of quetiapine, 7-hydroxy-quetiapine, and nor-quetiapine. The distribution of these substances in vitreous humor was studied by determining and correlating their concentrations in vitreous humor with the respective concentrations in blood.

METHODS

During this study, a method for the determination of these substances was developed, validated and applied to postmortem samples obtained from 16 relative forensic cases. The sample preparation procedure included the isolation of the analytes from vitreous humor and blood samples using solid-phase extraction, with Bond Elut LRC C18 columns followed by derivatization with BSTFA with 1% TMCS prior to GC/MS analysis.

RESULTS

The developed method is characterized by a dynamic range of 10.0-1000.0 ng/mL (R2 ≥ 0.991) for the three substances, with a limit of detection and quantification of 3.0 and 10.0 ng/mL, respectively. Accuracy and precision were below 8.09% and 8.99%, respectively, for both biological materials, while absolute recovery for the three substances was greater than 81%. According to the results, quetiapine, 7-hydroxy-quetiapine, and nor-quetiapine are easily distributed in vitreous humor.

CONCLUSION

The results of the study indicate the usefulness of vitreous humor in toxicological analysis for the determination of these substances, especially when the traditional biological materials are not available. The levels of quetiapine and its metabolites in vitreous humor as well as the vitreous humor to blood concentration ratios can provide important information for a more thorough toxicological investigation of forensic cases.

Quetiapine-Related Deaths: In Search of a Surrogate Endpoint

Quetiapine is a second-generation antipsychotic drug available for two and half decades. Due to increased misuse, prescription outside the approved indications, and availability on the black market, it is being encountered in medicolegal autopsies more frequently. For instance, it has been linked to increased mortality rates, most likely due to its adverse effects on the cardiovascular system. Its pharmacokinetic features and significant postmortem redistribution challenge traditional sampling in forensic toxicology. Therefore, a systematic literature review was performed, inclusive of PubMed, the Web of Science-core collection, and the Scopus databases; articles were screened for the terms "quetiapine", "death", and "autopsy" to reevaluate each matrix used as a surrogate endpoint in the forensic toxicology of quetiapine-related deaths. Ultimately, this review considers the results of five studies that were well presented (more than two matrices, data available for all analyses, for instance). The highest quetiapine concentrations were usually measured in the liver tissue. As interpreted by their authors, the results of the considered studies showed a strong correlation between some matrices, but, unfortunately, the studies presented models with poor goodness of fit. The distribution of quetiapine in distinct body compartments/tissues showed no statistically significant relationship with the length of the postmortem interval. Furthermore, this study did not confirm the anecdotal correlation of peripheral blood concentrations with skeletal muscle concentrations. Otherwise, there was no consistency regarding selecting an endpoint for analysis.

Identification and Quantification of Antipsychotics in Blood Samples by LC-MS-MS: Case Reports and Data from Three Years of Routine Analysis

Antipsychotic drugs (AP) are widely prescribed for the treatment of schizophrenia and psychosis. The pharmacological treatment of schizophrenia is often performed with the simultaneous use of two or more antipsychotic agents to achieve the desired control of psychotic symptoms Available AP include both conventional (typical) and new (atypical) antipsychotic medications. Atypical AP, such as quetiapine, now account for the vast majority of AP prescriptions. In forensic toxicology, AP are of considerable interest because of their potential abuse and their involvement in intoxications and suicides. The authors retrospectively examined AP positive cases detected in samples collected during autopsies performed in the Forensic Clinical and Pathology Service of National Institute of Legal Medicine and Forensic Sciences Centre Branch or in other autopsies carried out in the central region of Portugal, between January 2016 and December 2018. A quantitative liquid chromatography-tandem mass spectrometry assay was developed for the simultaneous determination of 16 AP (amisulpride, aripiprazole, chlorpromazine, clozapine, cyamemazine, fluphenazine, haloperidol, levomepromazine, melperone, olanzapine, paliperidone, promethazine, quetiapine, risperidone, sulpiride and ziprasidone) in blood samples of postmortem cases. The Laboratory of Forensic Chemistry and Toxicology received 3,588 requests for toxicological analysis: 1,413 cases were positive for drugs from which 351 (24.8%) cases were positive for AP, 60.1% from male individuals and 39.9% from female. Quetiapine was the most prevalent AP (36.5%) followed by olanzapine (20.8%). During this period, there were 25 postmortem cases with AP blood concentrations above therapeutic range, in which 36% of those are in agreement with the information received (psychological history or acute intoxication suspicion) and the manner of death was suicide. Our results point that antipsychotics are an increasingly prevalent class of drugs. AP must be measured not only in toxic concentrations but also in therapeutic levels in postmortem cases; therefore, it is important to come up with a sensitive method to cover the low therapeutic range in which AP are usually present.

Quetiapine and other antipsychotics combined with opioids in legal autopsy cases: A random finding or cause of fatal outcome?

Opioid poisoning is a frequent cause of death in drug addicts and occurs with opioid treatment. Quetiapine is often found in forensic autopsies and may increase the risk of fatal opioid poisoning by enhancing sedation, respiratory depression, hypotension and QT prolongation. We systematically searched for studies of acute toxicity of quetiapine or other antipsychotics combined with morphine or methadone. Case reports describing toxicity of quetiapine combined with morphine or methadone were also included. We retrieved one human study that observed pharmacokinetic interaction between quetiapine and methadone, and 16 other human studies. Fourteen investigated the combination of droperidol and morphine in treatment doses, and some indicated an additive sedative effect. Five animal studies with acepromazine in combination with morphine or methadone were located and indicated an additive effect on sedation and hypotension. Six forensic case reports in which death could have been caused solely by quetiapine, the opioid, or other drugs were found. Thus, acute toxicity of quetiapine combined with morphine or methadone has not been studied. Because of quetiapine's effects on alpha-adrenoceptors, muscarinic and histamine receptors, human ether-a-go-go-channels and methadone kinetics, we suggest further research to clarify if the indicated additive effects of opioids and droperidol or acepromazine are also true for quetiapine.

Finding of Hyperostosis Frontalis Interna During the Autopsy Procedure: Forensic Issues

Hyperostosis frontalis interna is a common phenomenon, which may have been overrated in its significance in the past, and may, currently be underrated in its significance. We present three cases of hyperostosis frontalis interna found during medicolegal autopsies and discuss their forensic considerations. The patients were all middle-aged women with metabolic and endocrine manifestations and psychiatric ailments; thickening of the inner table of the frontal bone of the skull was found during each autopsy. We describe the relationship between hyperostosis frontalis interna, metabolic manifestations, and neuropsychiatric symptoms as part of Morgagni-Stewart-Morel syndrome. There is still considerable disagreement in the scientific community as to whether this syndrome is a clinical entity. Nonetheless, awareness of Morgagni-Stewart-Morel syndrome can be of help in understanding the circumstances surrounding death. In some other cases, hyperostosis frontalis interna could be used by forensic pathologists as criteria for sexing and aging a skeleton.

Abuse of Prescription Drugs in the Context of Novel Psychoactive Substances (NPS): A Systematic Review

Recently, a range of prescription and over-the-counter drugs have been reportedly used as Novel Psychoactive Substances (NPS), due to their potential for abuse resulting from their high dosage/idiosyncratic methods of self-administration. This paper provides a systematic review of the topic, focusing on a range of medications which have emerged as being used recreationally, either on their own or in combination with NPS. Among gabapentinoids, pregabalin may present with higher addictive liability levels than gabapentin, with pregabalin being mostly identified in the context of opioid, polydrug intake. For antidepressants, their dopaminergic, stimulant-like, bupropion activities may explain their recreational value and diversion from the therapeutic intended use. In some vulnerable clients, a high dosage of venlafaxine (‘baby ecstasy’) is ingested for recreational purposes, whilst the occurrence of a clinically-relevant withdrawal syndrome may be a significant issue for all venlafaxine-treated patients. Considering second generation antipsychotics, olanzapine appears to be ingested at very large dosages as an ‘ideal trip terminator’, whilst the immediate-release quetiapine formulation may possess proper abuse liability levels. Within the image- and performance- enhancing drugs (IPEDs) group, the beta-2 agonist clenbuterol (‘size zero pill’) is reported to be self-administered for aggressive slimming purposes. Finally, high/very high dosage ingestion of the antidiarrhoeal loperamide has shown recent increasing levels of popularity due to its central recreational, anti-withdrawal, opiatergic effects. The emerging abuse of prescription drugs within the context of a rapidly modifying drug scenario represents a challenge for psychiatry, public health and drug-control policies.

Is There a Potential of Misuse for Quetiapine?: Literature Review and Analysis of the European Medicines Agency/European Medicines Agency Adverse Drug Reactions' Database

PURPOSE/BACKGROUND

A recent years' increase in both prescribing and availability of second-generation antipsychotics (SGAs) has been observed. According to the literature, typically made up by case studies/series, quetiapine seems to be the most commonly misused SGA, with both intranasal and intravenous intake modalities having been described. Another SGA that has been anecdotally reported to be misused is olanzapine. For these molecules, both a previous history of drug misuse and being an inmate have been described as factors associated with misuse. Hence, while providing here an updated literature review of the topic, we aimed at assessing all cases of quetiapine misuse/abuse/dependence/withdrawal as reported to the European Medicines Agency's EudraVigilance (EV) database; this was carried out in comparison with the reference drug olanzapine.

METHODS

All spontaneous, European Medicines Agency database reports relating to both quetiapine (2005-2016) and olanzapine (2004-2016) misuse/abuse/dependence/withdrawal issues were retrieved, and a descriptive analysis was performed.

RESULTS

From the EV database, 18,112 (8.64% of 209,571) and 4178 (7.58% of 55,100) adverse drug reaction reports of misuse/abuse/dependence/withdrawal were associated with quetiapine and olanzapine, respectively. The resulting proportional reporting ratio values suggested that the misuse/abuse-, dependence-, and withdrawal-related adverse drug reactions were more frequently reported for quetiapine (1.07, 1.01, and 5.25, respectively) in comparison with olanzapine.

CONCLUSIONS

Despite data collection limitations, present EV data may suggest that, at least in comparison with olanzapine, quetiapine misuse may be a cause for concern.

Analytical data supporting the "theoretical" postmortem redistribution factor (Ft ): a new model to evaluate postmortem redistribution

The concepts of postmortem redistribution (PMR, F) factor, and "theoretical" PMR (Ft ) - based upon a drug's characteristic L/P ratio - have been defined to express the direct relationship between postmortem peripheral blood and the corresponding antemortem whole-blood concentration. This paper applies recent data describing liver/peripheral blood (L/P) ratios for many commonly detected drugs to assess these models, and provide a ranking of drugs' propensity for (and degree of) PMR.

Vitreous humor analysis for the detection of xenobiotics in forensic toxicology: a review

Vitreous humor (VH) is a gelatinous substance contained in the posterior chamber of the eye, playing a mechanical role in the eyeball. It has been the subject of numerous studies in various forensic applications, primarily for the assessment of postmortem interval and for postmortem chemical analysis. Since most of the xenobiotics present in the bloodstream are detected in VH after crossing the selective blood-retinal barrier, VH is an alternative matrix useful for forensic toxicology. VH analysis offers particular advantages over other biological matrices: it is less prone to postmortem redistribution, is easy to collect, has relatively few interfering compounds for the analytical process, and shows sample stability over time after death. The present study is an overview of VH physiology, drug transport and elimination. Collection, storage, analytical techniques and interpretation of results from qualitative and quantitative points of view are dealt with. The distribution of xenobiotics in VH samples is thus discussed and illustrated by a table reporting the concentrations of 106 drugs from more than 300 case reports. For this purpose, a survey was conducted of publications found in the MEDLINE database from 1969 through April 30, 2015.

Collection of biological samples in forensic toxicology

Forensic toxicology is the study and practice of the application of toxicology to the purposes of the law. The relevance of any finding is determined, in the first instance, by the nature and integrity of the specimen(s) submitted for analysis. This means that there are several specific challenges to select and collect specimens for ante-mortem and post-mortem toxicology investigation. Post-mortem specimens may be numerous and can endow some special difficulties compared to clinical specimens, namely those resulting from autolytic and putrefactive changes. Storage stability is also an important issue to be considered during the pre-analytic phase, since its consideration should facilitate the assessment of sample quality and the analytical result obtained from that sample. The knowledge on degradation mechanisms and methods to increase storage stability may enable the forensic toxicologist to circumvent possible difficulties. Therefore, advantages and limitations of specimen preservation procedures are thoroughfully discussed in this review. Presently, harmonized protocols for sampling in suspected intoxications would have obvious utility. In the present article an overview is given on sampling procedures for routinely collected specimens as well as on alternative specimens that may provide additional information on the route and timing of exposure to a specific xenobiotic. Last, but not least, a discussion on possible bias that can influence the interpretation of toxicological results is provided. This comprehensive review article is intented as a significant help for forensic toxicologists to accomplish their frequently overwhelming mission.

Late-onset seizures associated with quetiapine poisoning

INTRODUCTION

Quetiapine, a second-generation antipsychotic, acts at multiple brain neurotransmitter receptors and has the potential for serious complications. Although seizures have been described in the literature, delayed seizure onset has not been reported. We report the first case of delayed seizures after a significant quetiapine overdose.

CASE REPORT

A 27-year-old female presented to the emergency department following an overdose of approximately 30 g of quetiapine. Twenty-four hours after arrival, the patient had 2 seizures. The patient was then intubated and remained in the ICU for four days. EEG was negative for epileptiform activity. The serum quetiapine levels (MedTox, St. Paul, MN) were 8.67 mg/L on hospital day one and 3.28 mg/L on hospital day three.

DISCUSSION

Quetiapine poisoning, with serum levels, associated with seizures has been reported in one prior case. Our case report represents late-onset seizures with serum levels above therapeutic range (>1 mg/L). The serum concentrations of quetiapine in this case were consistent with those in postmortem case reports.