Metabolism and cytotoxicity studies of the two hallucinogens 1cP-LSD and 4-AcO-DET in human liver and zebrafish larvae models using LC-HRMS/MS and a high-content screening assay

The continuous emergence of new psychoactive substances (NPS) attracted a great deal of attention within recent years. Lately, the two hallucinogenic NPS 1cP-LSD and 4-AcO-DET have appeared on the global market. Knowledge about their metabolism to identify potential metabolic targets for analysis and their cytotoxic properties is lacking. The aim of this work was thus to study their in vitro and in vivo metabolism in pooled human liver S9 fraction (pHLS9) and in zebrafish larvae (ZL) by means of liquid chromatography-high-resolution tandem mass spectrometry. Monooxygenases involved in the initial metabolic steps were elucidated using recombinant human isozymes. Investigations on their cytotoxicity were performed on the human hepatoma cell line HepG2 using a multiparametric, fluorescence-based high-content screening assay. This included measurement of CYP-enzyme mediated effects by means of the unspecific CYP inhibitor 1-aminbenzotriazole (ABT). Several phase I metabolites of both compounds and two phase II metabolites of 4-AcO-DET were produced in vitro and in vivo. After microinjection of 1cP-LSD into the caudal vein of ZL, three out of seven metabolites formed in pHLS9 were also detected in ZL. Twelve 4-AcO-DET metabolites were identified in ZL after exposure via immersion bath and five of them were found in pHLS9 incubations. Notably, unique metabolites of 4-AcO-DET were only produced by ZL, whereas 1cP-LSD specific metabolites were found both in ZL and in pHLS9. No toxic effects were observed for 1cP-LSD and 4-AcO-DET in HepG2 cells, however, two parameters were altered in incubations containing 4-AcO-DET together with ABT compared with incubations without ABT but in concentrations far above expected in vivo concentration. Further investigations should be done with other hepatic cell lines expressing higher levels of CYP enzymes.

Impact of four different extraction methods and three different reconstitution solvents on the untargeted metabolomics analysis of human and rat urine samples

Unsuitable sample preparation may result in loss of important analytes and consequently affect the outcome of untargeted metabolomics. Due to species differences, different sample preparations may be required within the same biological matrix. The study aimed to compare the in-house sample preparation method for urine with methods from literature and to investigate the transferability of sample preparation from human urine to rat urine. A total of 12 different conditions for protein precipitation were tested, combining four different extraction solvents and three different reconstitution solvents using an untargeted liquid-chromatography high resolution mass spectrometry (LC-HRMS) metabolomics analysis. Evaluation was done based on the impact on feature count, their detectability, as well as the reproducibility of selected compounds. Results showed that a combination of methanol as extraction and acetonitrile/water (75/25) as reconstitution solvent provided improved results at least regarding the total feature count. Additionally, it was found that a higher amount of methanol was most suitable for extraction of rat urine among the tested conditions. In comparison, human urine requires significantly less volume of extraction solvent. Overall, it is recommended to systematically optimize both, the extraction method, and the reconstitution solvent for the used biofluid and the individual analytical settings.

Protein profiling of conjunctival impression cytology samples of aniridia subjects

PURPOSE

Congenital aniridia is a rare disease, which is in most cases related to PAX6 haploinsufficiency. Aniridia associated keratopathy (AAK) also belongs to ocular signs of congenital aniridia. In AAK, there is corneal epithelial thinning, corneal inflammation, vascularization and scarring. In advanced stage AAK, typically, conjunctival epithelial cells slowly replace the corneal epithelium. Based on previous results we hypothesize that alterations of the conjunctival cells in congenital aniridia may also support the corneal conjunctivalization process. The aim of this study was to identify deregulated proteins in conjunctival impression cytology samples of congenital aniridia subjects.

METHODS

Conjunctival impression cytology samples of eight patients with congenital aniridia [age 34.5 ± 9.9 (17-51) years, 50% female] and eight healthy subjects [age 34.1 ± 11.9 (15-54) years, 50% female] were collected and analysed using mass spectrometry. Proteomic profiles were analysed in terms of molecular functions, biological processes, cellular components and pathway enrichment using the protein annotation of the evolutionary relationship (PANTHER) classification system.

RESULTS

In total, 3323 proteins could be verified and there were 127 deregulated proteins (p < 0.01) in congenital aniridia. From the 127 deregulated proteins (DEPs), 82 altered biological processes, 63 deregulated cellular components, 27 significantly altered molecular functions and 31 enriched signalling pathways were identified. Pathological alteration of the biological processes and molecular functions of retinol binding and retinoic acid biosynthesis, as well as lipid metabolism and apoptosis related pathways could be demonstrated.

CONCLUSIONS

Protein profile of conjunctival impression cytology samples of aniridia subjects identifies alterations of retinol binding, retinoic acid biosynthesis, lipid metabolism and apoptosis related pathways. Whether these changes are directly related to PAX6 haploinsufficiency, must be investigated in further studies. These new findings offer the possibility to identify potential new drug targets.

Adherence to heart failure treatment in patients with peripartum cardiomyopathy

AIMS

Peripartum cardiomyopathy (PPCM) is characterized by left ventricular (LV) dysfunction developing towards the end of pregnancy or in the first months postpartum. Although about 60% of women with PPCM (the majority of which are prescribed evidence based heart failure [HF] medications) show LV recovery within 6 to 12 months, others remain with persistently impaired LV function. Poor adherence to medical therapy represents a major cause of avoidable hospitalizations, disability, and death in other cardiovascular conditions. In this study, we aimed to determine drug adherence to HF therapy among women with PPCM and to identify possible associations between drug adherence and LV recovery, functional status and psychological well-being.

METHODS AND RESULTS

In this single-centre, prospective, observational study, we included 36 consecutive women with PPCM. Adherence to HF treatment was assessed by (i) verifying the collection of pharmacy refills and (ii) using liquid chromatography high-resolution mass spectrometry (LC-HRMS). Participants were thereby classified as 'adherent' (i.e. all prescribed HF drugs were detectable by LC-HRMS), 'partially adherent' (i.e. at least one prescribed drug detectable) or 'non-adherent' (i.e. none of the prescribed drugs detectable). Health state index scores were assessed by EQ-5D-5L and HADS-A/D (for anxiety/depression). Patients' median age was 32.4 years (IQR 27.6-36.1). At the adherence visit (which occurred at a median of 16 months [IQR 5-45] after PPCM diagnosis), prescription included beta-blockers (77.8%), angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers (75%), mineralocorticoid receptor antagonists (47.2%) and loop diuretics (95.2%). Less than two thirds of patients (63.9%) collected all their pharmacy refills in the 6 months prior to adherence visit. According to LC-HRMS, 23.5% participants were classified as adherent, 53.0% as partially adherent, and 23.5% as non-adherent. Adherence was associated with significantly lower LVEDD at follow-up (47 mm [IQR 46-52), vs. 56 mm [IQR 49-64] with partial adherence, and 62 mm [IQR 55-64] with non-adherence, P = 0.022), and higher LVEF at follow-up (60% [IQR 41-65]), vs. partially adherence (46% [IQR 34-50]) and non-adherence (41.0% [IQR 29-47], P = 014). Adherent patients had a lower overall EQ- 5D score (5.5 [IQR 5-7.5], vs. 6 [IQR 5-7] in partially adherent, and 10 [IQR 8-15] in non-adherent patients, P = 0.032) suggestive of a better self-rated health status.

CONCLUSIONS

Adherence to HF therapy was associated with favourable LV reverse remodelling in PPCM and better self-rated health status. Our study highlights the importance of drug adherence for functional recovery. Drug adherence should be an important component of patient communication and specific interventions in PPCM.

In Vivo and In Vitro Metabolic Fate and Urinary Detectability of Five Deschloroketamine Derivatives Studied by Means of Hyphenated Mass Spectrometry

Ketamine derivatives such as deschloroketamine and deschloro-N-ethyl-ketamine show dissociative and psychoactive properties and their abuse as new psychoactive substances (NPSs) has been reported. Though some information is available on the biotransformation of dissociative NPSs, data on deschloro-N-cyclopropyl-ketamine deschloro-N-isopropyl-ketamine and deschloro-N-propyl-ketamine concerning their biotransformation and, thus, urinary detectability are not available. The aims of the presented work were to study the in vivo phase I and II metabolism; in vitro phase I metabolism, using pooled human liver microsomes (pHLMs); and detectability, within a standard urine screening approach (SUSA), of five deschloroketamine derivatives. Metabolism studies were conducted by collecting urine samples from male Wistar rats over a period of 24 h after their administration at 2 mg/kg body weight. The samples were analyzed using liquid chromatography high-resolution tandem mass spectrometry (LC-HRMS/MS) and gas chromatography-mass spectrometry (GC-MS). The compounds were mainly metabolized by N-dealkylation, hydroxylation, multiple oxidations, and combinations of these metabolic reactions, as well as glucuronidation and N-acetylation. In total, 29 phase I and 10 phase II metabolites were detected. For the LC-HRMS/MS SUSA, compound-specific metabolites were identified, and suitable screening targets could be recommended and confirmed in pHLMs for all derivatives except for deschloro-N-cyclopropyl-ketamine. Using the GC-MS-based SUSA approach, only non-specific acetylated N-dealkylation metabolites could be detected.

Towards clinical adherence monitoring of oral endocrine breast cancer therapies by LC-HRMS-method development, validation, comparison of four sample matrices, and proof of concept

Oral endocrine therapies (OET) for breast cancer treatment need to be taken over a long period of time and are associated with considerable side effects. Therefore, adherence to OET is an important issue and of high clinical significance for breast cancer patients' caregivers. We hypothesized that a new bioanalytical strategy based on liquid chromatography and high-resolution mass spectrometry might be suitable for unbiased adherence monitoring (AM) of OET. Four different biomatrices (plasma, urine, finger prick blood by volumetric absorptive microsampling (VAMS), oral fluid (OF)) were evaluated regarding their suitability for AM of the OET abemaciclib, anastrozole, exemestane, letrozole, palbociclib, ribociclib, tamoxifen, and endoxifen. An analytical method was developed and validated according to international recommendations. The analytical procedures were successfully validated in all sample matrices for most analytes, even meeting requirements for therapeutic drug monitoring. Chromatographic separation of analytes was achieved in less than 10 min and limits of quantification ranged from 1 to 1000 ng/mL. The analysis of 25 matching patient samples showed that AM of OET is possible using all four matrices with the exception of, e.g., letrozole and exemestane in OF. We were able to show that unbiased bioanalytical AM of OET was possible using different biomatrices with distinct restrictions. Sample collection of VAMS was difficult in most cases due to circulatory restraints and peripheral neuropathy in fingers and OF sampling was hampered by dry mouth syndrome in some cases. Although parent compounds could be detected in most of the urine samples, metabolites should be included when analyzing urine or OF. Plasma is currently the most suitable matrix due to available reference concentrations.

Comparison of reversed-phase, hydrophilic interaction, and porous graphitic carbon chromatography columns for an untargeted toxicometabolomics study in pooled human liver microsomes, rat urine, and rat plasma

INTRODUCTION

Untargeted metabolomics studies are expected to cover a wide range of compound classes with high chemical diversity and complexity. Thus, optimizing (pre-)analytical parameters such as the analytical liquid chromatography (LC) column is crucial and the selection of the column depends primarily on the study purpose.

OBJECTIVES

The current investigation aimed to compare six different analytical columns. First, by comparing the chromatographic resolution of selected compounds. Second, on the outcome of an untargeted toxicometabolomics study using pooled human liver microsomes (pHLM), rat plasma, and rat urine as matrices.

METHODS

Separation and analysis were performed using three different reversed-phase (Phenyl-Hexyl, BEH C18, and Gold C18), two hydrophilic interaction chromatography (HILIC) (ammonium-sulfonic acid and sulfobetaine), and one porous graphitic carbon (PGC) columns coupled to high-resolution mass spectrometry (HRMS). Their impact was evaluated based on the column performance and the size of feature count, amongst others.

RESULTS

All three reversed-phase columns showed a similar performance, whereas the PGC column was superior to both HILIC columns at least for polar compounds. Comparing the size of feature count across all datasets, most features were detected using the Phenyl-Hexyl or sulfobetaine column. Considering the matrices, most significant features were detected in urine and pHLM after using the sulfobetaine and in plasma after using the ammonium-sulfonic acid column.

CONCLUSION

The results underline that the outcome of this untargeted toxicometabolomic study LC-HRMS metabolomic study was highly influenced by the analytical column, with the Phenyl-Hexyl or sulfobetaine column being the most suitable. However, column selection may also depend on the investigated compounds as well as on the investigated matrix.

Bioisosteric analogs of MDMA with improved pharmacological profile

3,4-Methylenedioxymethamphetamine (MDMA, ' ecstasy' ) is re-emerging in clinical settings as a candidate for the treatment of specific psychiatric disorders (e.g. post-traumatic stress disorder) in combination with psychotherapy. MDMA is a psychoactive drug, typically regarded as an empathogen or entactogen, which leads to transporter-mediated monoamine release. Despite its therapeutic potential, MDMA can induce dose-, individual-, and context-dependent untoward effects outside safe settings. In this study, we investigated whether three new methylenedioxy bioisosteres of MDMA improve its off-target profile. In vitro methods included radiotracer assays, transporter electrophysiology, bioluminescence resonance energy transfer and fluorescence-based assays, pooled human liver microsome/S9 fraction incubation with isozyme mapping, and liquid chromatography coupled to high-resolution mass spectrometry. In silico methods included molecular docking. Compared with MDMA, all three MDMA bioisosteres (ODMA, TDMA, and SeDMA) showed similar pharmacological activity at human serotonin and dopamine transporters (hSERT and hDAT, respectively) but decreased activity at 5-HT 2A/2B/2C receptors. Regarding their hepatic metabolism, they differed from MDMA, with N -demethylation being the only metabolic route shared, and without forming phase II metabolites. Additional screening for their interaction with human organic cation transporters (hOCTs) and plasma membrane transporter (hPMAT) revealed a weaker interaction of the MDMA analogs with hOCT1, hOCT2, and hPMAT. Our findings suggest that these new MDMA analogs might constitute appealing therapeutic alternatives to MDMA, sparing the primary pharmacological activity at hSERT and hDAT, but displaying a reduced activity at 5-HT 2A/2B/2C receptors and reduced hepatic metabolism. Whether these MDMA bioisosteres may pose lower risk alternatives to the clinically re-emerging MDMA warrants further studies.

Experimental capture of miRNA targetomes: disease-specific 3'UTR library-based miRNA targetomics for Parkinson's disease

The identification of targetomes remains a challenge given the pleiotropic effect of miRNAs, the limited effects of miRNAs on individual targets, and the sheer number of estimated miRNA-target gene interactions (MTIs), which is around 44,571,700. Currently, targetome identification for single miRNAs relies on computational evidence and functional studies covering smaller numbers of targets. To ensure that the targetome analysis could be experimentally verified by functional assays, we employed a systematic approach and explored the targetomes of four miRNAs (miR-129-5p, miR-129-1-3p, miR-133b, and miR-873-5p) by analyzing 410 predicted target genes, both of which were previously associated with Parkinson's disease (PD). After performing 13,536 transfections, we validated 442 of the 705 putative MTIs (62,7%) through dual luciferase reporter assays. These analyses increased the number of validated MTIs by at least 2.1-fold for miR-133b and by a maximum of 24.3-fold for miR-873-5p. Our study contributes to the experimental capture of miRNA targetomes by addressing i) the ratio of experimentally verified MTIs to predicted MTIs, ii) the sizes of disease-related miRNA targetomes, and iii) the density of MTI networks. A web service to support the analyses on the MTI level is available online ( https://ccb-web.cs.uni-saarland.de/utr-seremato ), and all the data have been added to the miRATBase database ( https://ccb-web.cs.uni-saarland.de/miratbase ).

Time series of chicken stool metagenomics and egg metabolomics in changing production systems: preliminary insights from a proof-of-concept

BACKGROUND

Different production systems of livestock animals influence various factors, including the gut microbiota.

METHODS

We investigated whether changing the conditions from barns to free-range chicken farming impacts the microbiome over the course of three weeks. We compared the stool microbiota of chicken from industrial barns after introducing them either in community or separately to a free-range environment.

RESULTS

Over the six time points, 12 taxa-mostly lactobacilli-changed significantly. As expected, the former barn chicken cohort carries more resistances to common antibiotics. These, however, remained positive over the observed period. At the end of the study, we collected eggs and compared metabolomic profiles of the egg white and yolk to profiles of eggs from commercial suppliers. Here, we observed significant differences between commercial and fresh collected eggs as well as differences between the former barn chicken and free-range chicken.

CONCLUSION

Our data indicate that the gut microbiota can undergo alterations over time in response to changes in production systems. These changes subsequently exert an influence on the metabolites found in the eggs. The preliminary results of our proof-of-concept study motivate larger scale observations with more individual chicken and longer observation periods.

Investigations on the in vitro and in vivo metabolic fate of the new synthetic opioid desmethylmoramide using HPLC-HRMS/MS for toxicological screening purposes

New synthetic opioids are an increasing challenge for clinical and forensic toxicologists that developed over the recent years. Desmethylmoramide (DMM), a structural analogue of methadone, is one of the most recent appearances on the drug market. This study investigated its metabolic fate in rat and pooled human liver S9 fraction (pHLS9) to allow the identification of suitable urinary screening targets beyond the parent compound. The analysis of rat urine after the administration of DMM revealed five metabolites, which were the result of pyrrolidine ring or morpholine ring hydroxylation and combinations of them. Additionally, an N',N-bisdesalkyl metabolite was formed. Incubations of DMM using pHLS9 revealed a pyrrolidine hydroxy metabolite, as well as an N-oxide. No Phase II metabolites were detected in either rat urine or incubations using pHLS9. The metabolism of DMM did in part comply with that of its archetype dextromoramide (DXM). Although morpholine ring hydroxylation and N-oxidation were described for DXM and detected for DMM, phenyl ring hydroxylation was not found for DMM but described for DXM. An analysis of 24 h pooled rat urine samples after DMM administration identified the hydroxy and dihydroxy metabolite as the most abundant excretion products, and they may, thus, serve as screening targets, as the parent compound was barely detectable.

Sample Matrices for Mass Spectrometry-Based Adherence Monitoring: A Systematic Critical Review

BACKGROUND

Analytical monitoring of adherence using mass spectrometry (MS) plays an important role in clinical toxicology. Unambiguous detection of drugs (of abuse) and/or their metabolites in body fluids is needed to monitor intake of medication as prescribed or to monitor abstinence as a follow-up to detoxification procedures. This study focused on the advantages and disadvantages of different sample matrices used for MS-based adherence monitoring.

METHODS

Relevant articles were identified through a literature search in the PubMed database. English articles published between January 01, 2017, and December 31, 2022, were selected using the keywords "adherence assess*" or "adherence monit*" or "compliance assess*" or "compliance monit*" in combination with "mass spectrom*" in the title or abstract.

RESULTS

A total of 51 articles were identified, 37 of which were within the scope of this study. MS-based monitoring was shown to improve patient adherence to prescribed drugs. However, MS analysis may not be able to assess whether treatment was rigorously followed beyond the last few days before the sampling event, except when hair is the sample matrix. For medication adherence monitoring, blood-based analyses may be preferred because reference plasma concentrations are usually available, whereas for abstinence control, urine and hair samples have the advantage of extended detection windows compared with blood. Alternative sample matrices, such as dried blood samples, oral fluid, and exhaled breath, are suitable for at-home sampling; however, little information is available regarding the pharmacokinetics and reference ranges of drug (of abuse) concentrations.

CONCLUSIONS

Each sample matrix has strengths and weaknesses, and no single sample matrix can be considered the gold standard for monitoring adherence. It is important to have sufficient information regarding the pharmacokinetics of target substances to select a sample matrix in accordance with the desired purpose.

Analytical toxicology of the semi-synthetic cannabinoid hexahydrocannabinol studied in human samples, pooled human liver S9 fraction, rat samples and drug products using HPLC-HRMS-MS

Hexahydrocannabinol (HHC) is an emerging semi-synthetic cannabinoid, which is obtained from cyclization of cannabidiol and subsequent hydrogenation. As a potentially legal alternative of ∆9-tetrahydrocannabinol (∆9-THC), it is increasingly seized in the USA and Europe. The aims of this study were to investigate the metabolism of HHC in pooled human liver S9 fraction (pHLS9), rat and human samples. Additionally, a locally obtained low-THC cannabis product was investigated, which was advertised with an elevated concentration of HHC. Overall, HHC formed an 11-hydroxy (HO) metabolite, as well as a carboxy metabolite. While only the parent compound was detected in rat urine and feces, the hydroxy metabolite was additionally detected in pHLS9 and human plasma. The carboxy metabolite was only detectable in human plasma. The metabolism corresponded well to that of ∆9-THC, although glucuronidation and the formation of an 8-HO metabolite were not observed. Detectability of HHC and its carboxy metabolite in rat urine was investigated using gas chromatography-mass spectrometry, but neither the parent compound nor the metabolite were detectable. The investigated low-THC cannabis product appeared to be an actual cannabis product since, in addition to HHC, cannabinol, cannabidiol and ∆9-THC were detected after qualitative analysis. Estimation of its content revealed not only 30.6% of HHC but also 4% of ∆9-THC.

Quantitative analysis of drugs of abuse and cognitive enhancers in influent wastewater by means of two chromatographic methods

Sewage-based epidemiology using influent wastewater is used to estimate the consumption trends of (illicit) drugs over a short or long period of time in a subpopulation. The current study aimed to develop two separate methods for the quantitative analysis of selected drugs of abuse (DOA) and cognitive enhancers in influent wastewater using reversed-phase (RP) or hydrophilic interaction liquid chromatography (HILIC) coupled to high-resolution tandem mass spectrometry (LC-HRMS/MS). The performance of RP and HILIC column was evaluated. A simple solid phase extraction was used for sample preparation. Short runtimes of 10 and 15 min on the RP and the HILIC column, respectively, allowed sufficient throughput. A six-point calibration was used for quantification with calibration ranges between 10 and 100 ng/L for all analytes except for benzoylecgonine (BZE, 30-300 ng/L). Method validation was performed according to ICH guideline M10. Analytes such as amphetamine (AMPH), BZE, cocaethylene (CE), cocaine (COC), ethyl sulfate, 4-hydroxy-3-methoxymethamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), methamphetamine, methylphenidate (MPH), and ritalinic acid (RA) were included in method development and validation. Two different column types were necessary for sufficient chromatographic resolution. The analytical setup allowed detection of all other analytes at concentration levels between 1 ng/L for methylphenidate to 10 ng/L for amphetamine. A method for the detection and quantification of DOA, cognitive enhancers, and their biomarkers in wastewater was successfully developed and validated. Moreover, six proof-of-concept samples were analyzed in which AMPH, BZE, COC, MDMA, MPH, and RA were identified and further quantified.

Hidden sodium in effervescent-tablet dietary supplements and over-the-counter drugs: a comparative cross-sectional study

OBJECTIVE

Dietary sodium intake represents a risk factor for cardiovascular disease and mortality. The study sought to analyse the sodium content of effervescent dietary supplements and drugs in Germany and the USA.

DESIGN

Comparative cross-sectional study.

SETTING AND METHODS

The sodium content of 39 dietary supplement effervescent tablets available in Germany was measured in May and June 2022 using optical emission spectrometry with inductively coupled argon plasma. The sodium content of 33 common pharmacy-only effervescent tablets (over-the-counter (OTC) drugs) in Germany was obtained from the summary of product characteristics. We compared the sodium content of the measured German dietary supplement effervescent tablets to that of 51 dietary supplement effervescent tablets available in the USA (data: National Institutes of Health's Dietary Supplement Label Database).

RESULTS

The measured sodium content in the German dietary supplements was 283.9±122.6 mg sodium/tablet, equivalent to 14±6% of the maximum recommended daily sodium intake (MRDSI). Vitamin products had the highest (378.3±112.8 mg, 19±6% of MRDSI), and calcium products had the lowest mean sodium content (170.4±113.2 mg, 9±6% of MRDSI). Vitamin products contained significantly more sodium than magnesium (378.3 mg vs 232.7 mg; p=0.004), calcium (378.3 mg vs 170.4 mg; p=0.006) and mineral products (378.3 mg vs 191.6 mg; p=0.048). The sodium content measured in products available in Germany was higher when compared with the declared sodium content on the label of the products sold in the USA (283.9 mg vs 190.0 mg; p<0.001). The median summary of product characteristics-declared sodium content of a single dose of the German OTC drugs was 157.0 mg (IQR: 98.9-417.3 mg); pain/common cold drugs contained the most sodium (median: 452.1 mg; IQR: 351.3-474.0 mg).

CONCLUSION

Effervescent tablets of nutritional supplements and OTC drugs contain high amounts of sodium, which often is not disclosed.

A randomized, placebo-controlled, trial to assess the photosensitizing, phototoxic and carcinogenic potential of hydrochlorothiazide in healthy volunteers

BACKGROUND AND AIMS

Pharmacovigilance reports, associating hydrochlorothiazide (HCT) with skin cancer, resulted in a significant decrease of HCT prescriptions for hypertension and heart failure. Whether HCT exhibits phototoxic properties thereby causing skin cancer remains unknown. This study aimed to examine the photosensitizing, phototoxic and carcinogenic potential of HCT in a randomized, placebo-controlled, double-blind trial in vivo and also in vitro .

METHODS

The trial assigned 30 healthy, normotensive adult volunteers in a 2:1 ratio to either HCT 25 mg/day or placebo for 15 days. Photosensitivity of the skin with and without the effect of HCT treatment were assessed. Following whole-body ultraviolet A (UVA) and B (UVB, 311 nm) irradiation, phototoxic and carcinogenic reactions by measuring urinary excretion of pyrimidine dimers were evaluated. For the in-vitro studies, human keratinocytes (HaCaT) were incubated with HCT, irradiated with UVB, and analysed for markers of inflammation, apoptosis and carcinogenesis.

RESULTS

Skin photosensitivity following exposure to UVA and UVB remained unchanged from baseline to 15-day follow-up in both groups (UVA change HCT 0.0 J/cm 2 vs. placebo 0.0 J/cm 2 ; P  = 0.99; UVB change HCT 0.0 J/cm 2 vs. placebo -0.2 J/cm 2 ; P  = 0.06). Pyrimidine dimers were not detected in either group. In vitro , combination of HCT and UVB irradiation did not induce the expression of oxidative stress marker proteins, inflammatory proteins, apoptotic proteins or activation of oncoproteins.

CONCLUSION

HCT did not increase photosensitivity for UVA or UVB in healthy volunteers compared with placebo, and was not associated with phototoxic or carcinogenic reactions. In vitro , HCT was also not associated with phototoxicity or carcinogenesis (NCT04654312).

Ovulation is triggered by a cyclical modulation of gonadotropes into a hyperexcitable state

Gonadotropes in the anterior pituitary gland are essential for fertility and provide a functional link between the brain and the gonads. To trigger ovulation, gonadotrope cells release massive amounts of luteinizing hormone (LH). The mechanism underlying this remains unclear. Here, we utilize a mouse model expressing a genetically encoded Ca2+ indicator exclusively in gonadotropes to dissect this mechanism in intact pituitaries. We demonstrate that female gonadotropes exclusively exhibit a state of hyperexcitability during the LH surge, resulting in spontaneous [Ca2+]i transients in these cells, which persist in the absence of any in vivo hormonal signals. L-type Ca2+ channels and transient receptor potential channel A1 (TRPA1) together with intracellular reactive oxygen species (ROS) levels ensure this state of hyperexcitability. Consistent with this, virus-assisted triple knockout of Trpa1 and L-type Ca2+ subunits in gonadotropes leads to vaginal closure in cycling females. Our data provide insight into molecular mechanisms required for ovulation and reproductive success in mammals.

Optimization of Mass Spectrometry Imaging for Drug Metabolism and Distribution Studies in the Zebrafish Larvae Model: A Case Study with the Opioid Antagonist Naloxone

Zebrafish (ZF; Danio rerio) larvae have emerged as a promising in vivo model in drug metabolism studies. Here, we set out to ready this model for integrated mass spectrometry imaging (MSI) to comprehensively study the spatial distribution of drugs and their metabolites inside ZF larvae. In our pilot study with the overall goal to improve MSI protocols for ZF larvae, we investigated the metabolism of the opioid antagonist naloxone. We confirmed that the metabolic modification of naloxone is in high accordance with metabolites detected in HepaRG cells, human biosamples, and other in vivo models. In particular, all three major human metabolites were detected at high abundance in the ZF larvae model. Next, the in vivo distribution of naloxone was investigated in three body sections of ZF larvae using LC-HRMS/MS showing that the opioid antagonist is mainly present in the head and body sections, as suspected from published human pharmacological data. Having optimized sample preparation procedures for MSI (i.e., embedding layer composition, cryosectioning, and matrix composition and spraying), we were able to record MS images of naloxone and its metabolites in ZF larvae, providing highly informative distributional images. In conclusion, we demonstrate that all major ADMET (absorption, distribution, metabolism, excretion, and toxicity) parameters, as part of in vivo pharmacokinetic studies, can be assessed in a simple and cost-effective ZF larvae model. Our established protocols for ZF larvae using naloxone are broadly applicable, particularly for MSI sample preparation, to various types of compounds, and they will help to predict and understand human metabolism and pharmacokinetics.

Efficacy of Antihypertensive Drugs of Different Classes After Renal Denervation in Spontaneously Hypertensive Rats

BACKGROUND

Renal denervation (RDN) lowers blood pressure (BP) in patients with uncontrolled hypertension. Limited data exist on the effectiveness of different antihypertensive medications following RDN on BP and maladaptive cardiac phenotypes.

METHODS

Eighty-nine male spontaneously hypertensive rats with continuous BP recording underwent RDN or sham operation. Ten days postsurgery, spontaneously hypertensive rats were randomized to receive no antihypertensive medication, amlodipine, olmesartan, hydrochlorothiazide, bisoprolol, doxazosin, or moxonidine for 28 days. Cardiac remodeling was determined histologically, and activation of the renin-angiotensin-aldosterone system was explored.

RESULTS

Before initiation of antihypertensive drugs, RDN reduced mean arterial pressure (-12.6 mm Hg [95% CI, -14.4 to -10.8]; P<0.001). At study end, mean arterial pressure was lower in RDN compared with sham operation in drug-naïve controls (P=0.006), olmesartan (P=0.002), amlodipine (P=0.0004), hydrochlorothiazide (P=0.006), doxazosin (P=0.001), and bisoprolol (P=0.039) but not in animals receiving moxonidine (P=0.122). Compared with pooled BP change of all other drug classes, mean arterial pressure change was largest for olmesartan (-15.9 mm Hg [95% CI, -18.6 to -13.2]; P<0.001) and amlodipine (-12.0 mm Hg [95% CI, -14.7 to -9.3]; P<0.001). In drug-naïve controls, RDN reduced plasma renin activity (-5.6%¸ P=0.03) and aldosterone concentration (-53.0%; P=0.005). In the presence of antihypertensive medication, plasma renin activity and aldosterone remained unchanged after RDN. Cardiac remodeling was not affected by RDN alone. In animals receiving olmesartan after RDN, cardiac perivascular fibrosis was attenuated. Amlodipine and bisoprolol following RDN reduced cardiomyocyte diameter.

CONCLUSIONS

Following RDN, treatment with amlodipine and olmesartan resulted in the largest BP reduction. Antihypertensive medications mediated heterogeneous effects on renin-angiotensin-aldosterone system activity and cardiac remodeling.

Evaluation of extraction methods for untargeted metabolomic studies for future applications in zebrafish larvae infection models

Sample preparation in untargeted metabolomics should allow reproducible extractions of as many molecules as possible. Thus, optimizing sample preparation is crucial. This study compared six different extraction procedures to find the most suitable for extracting zebrafish larvae in the context of an infection model. Two one-phase extractions employing methanol (I) and a single miscible phase of methanol/acetonitrile/water (II) and two two-phase methods using phase separation between chloroform and methanol/water combinations (III and IV) were tested. Additional bead homogenization was used for methods III and IV (III_B and IV_B). Nine internal standards and 59 molecules of interest (MoInt) related to mycobacterial infection were used for method evaluation. Two-phase methods (III and IV) led to a lower feature count, higher peak areas of MoInt, especially amino acids, and higher coefficients of variation in comparison to one-phase extractions. Adding bead homogenization increased feature count, peak areas, and CVs. Extraction I showed higher peak areas and lower CVs than extraction II, thus being the most suited one-phase method. Extraction III and IV showed similar results, with III being easier to execute and less prone to imprecisions. Thus, for future applications in zebrafish larvae metabolomics and infection models, extractions I and III might be chosen.

Simultaneous analysis of antihyperglycemic small molecule drugs and peptide drugs by means of dual liquid chromatography high-resolution mass spectrometry

OBJECTIVES

The study aimed to evaluate dual liquid chromatography (LC) coupled to high-resolution mass spectrometry (HRMS) for the simultaneous analysis of small and large molecule drugs by development and application of a validated bioanalytical method.

METHODS

The oral antihyperglycemic drugs (OAD) dapagliflozin, empagliflozin, glibenclamide, glimepiride, metformin, pioglitazone, repaglinide, saxagliptin, sitagliptin, and vildagliptin, as well as the antihyperglycemic peptides exenatide, human insulin, insulin aspart, insulin degludec, insulin detemir, insulin glargine, insulin glulisine, insulin lispro, and semaglutide were included in the analytical procedure. Analytes were extracted using a combination of protein precipitation and solid-phase extraction. Two identical reversed-phase columns were used for separation followed by Orbitrap high-resolution mass spectrometry. The whole procedure was validated according to international recommendations.

RESULTS

Different MS parameters had to be used for the two analyte groups, but dual LC separation allowed elution of all analytes within 12 min using the same column type. The analytical procedure was accurate and precise for most of the compounds except for exenatide, semaglutide, and insulin glargine, which were included qualitatively in the method. Analysis of proof-of-concept samples revealed OAD concentrations mostly within their therapeutic range, insulins could be detected in five cases but at concentrations below the lower limit of quantification except for one case.

CONCLUSIONS

Dual LC in combination with HRMS was shown to be a suitable platform to analyze small and large molecules in parallel and the current method allowed the determination of a total of 19 antihyperglycemic drugs in blood plasma within 12 min.

Are the (New) Synthetic Opioids U-47700, Tramadol and Their Main Metabolites Prone to Time-Dependent Postmortem Redistribution?-A Systematic Study Using an In Vivo Pig Model

The interpretation of analytical results in forensic postmortem (PM) cases often poses a great challenge, in particular, due to possible PM redistribution (PMR) phenomena. In terms of new synthetic opioids, such data are usually not available and, if so, they are from case reports without the exact knowledge of dose, user habits, time of consumption or PM interval (PMI). Hence, a controlled toxicokinetic pig study was performed allowing the examination of PM tissue distribution and possible PMR of U-47700, tramadol and the main metabolites N-desmethyl-U-47700 and O-desmethyltramadol (ODT). For this purpose, 12 domestic pigs received an intravenous dose of 100 µg/kg body weight (BW) U-47700 or 1,000 µg/kg BW tramadol, respectively. The animals were put to death with T61 8 h after administration, and relevant organs, tissues and body fluids were sampled. Subsequently, the animals were stored at room temperature (RT), and the samples were taken again after 24, 48, and 72 h PM. Following homogenization and solid-phase extraction, quantification was performed applying a standard addition approach and liquid chromatography-tandem mass spectrometry. Only low-to-moderate concentration changes of U-47700, tramadol and their main metabolites were found in the analyzed tissue specimens and body fluids during storage at RT depending on the chosen PMI. On the contrary, a remarkable concentration increase of tramadol was observed in the liver tissue. These findings indicate that both synthetic opioids and their main metabolites are only slightly prone to PMR and central blood might be the matrix of choice for quantification of these substances.

In vitro metabolic fate of the synthetic cannabinoid receptor agonists (quinolin-8-yl 4-methyl-3-(morpholine-4-sulfonyl)benzoate [QMMSB]) and (quinolin-8-yl 4-methyl-3-((propan-2-yl)sulfamoyl)benzoate [QMiPSB]) including isozyme mapping and carboxylesterases activity testing

The synthetic cannabinoid receptor agonists (SCRAs) (quinolin-8-yl 4-methyl-3-(morpholine-4-sulfonyl)benzoate [QMMSB]) and (quinolin-8-yl 4-methyl-3-((propan-2-yl)sulfamoyl)benzoate [QMiPSB], also known as SGT-46) are based on the structure of quinolin-8-yl 4-methyl-3-(piperidine-1-sulfonyl)benzoate (QMPSB) that has been identified on seized plant material in 2011. In clinical toxicology, knowledge of the metabolic fate is important for their identification in biosamples. Therefore, the aim of this study was the identification of in vitro Phase I and II metabolites of QMMSB and QMiPSB in pooled human liver S9 fraction (pHLS9) incubations for use as screening targets. In addition, the involvement of human monooxygenases and human carboxylesterases (hCES) was examined. Analyses were performed by liquid chromatography coupled with high-resolution tandem mass spectrometry. Ester hydrolysis was found to be an important step in the Phase I metabolism of both SCRAs, with the carboxylic acid product being found only in negative ionization mode. Monohydroxy and N-dealkyl metabolites of the ester hydrolysis products were detected as well as glucuronides. CYP2C8, CYP2C9, CYP3A4, and CYP3A5 were involved in hydroxylation. Whereas enzymatic ester hydrolysis of QMiPSB was mainly catalyzed by hCES1 isoforms, nonenzymatic ester hydrolysis was also observed. The results suggest that ester hydrolysis products of QMMSB and QMiPSB and their glucuronides are suitable targets for toxicological screenings. The additional use of the negative ionization mode is recommended to increase detectability of analytes. Different cytochrome P450 (CYP) isozymes were involved in the metabolism; thus, the probability of drug-drug interactions due to CYP inhibition can be assessed as low.

In Vitro Metabolic Fate of the Synthetic Cannabinoid Receptor Agonists 2F-QMPSB and SGT-233 Including Isozyme Mapping and Carboxylesterases Activity Testing

Quinolin-8-yl 3-(4,4-difluoropiperidine-1-sulfonyl)-4-methylbenzoate (2F-QMPSB) and 3-(4,4-difluoropiperidine-1-sulfonyl)-4-methyl-N-(2-phenylpropan-2-yl)benzamide (SGT-233) belong to a new group of synthetic cannabinoid receptor agonists containing a sulfamoyl benzoate or sulfamoyl benzamide core structure. 2F-QMPSB was identified in herbal material seized in Europe in 2018. The aims of this study were the identification of in vitro Phase I and II metabolites of 2F-QMPSB and SGT-233 to find analytical targets for toxicological screenings. Furthermore, the contribution of different monooxygenases and human carboxylesterases to Phase I metabolism was investigated. Liquid chromatography coupled to high-resolution tandem mass spectrometry was used for analysis. Ester hydrolysis was found to be an important step in the metabolism of 2F-QMPSB, which was catalyzed mainly by human carboxylesterases (hCES)1 isoforms. Additionally, nonenzymatic ester hydrolysis was observed in case of 2F-QMPSB. Notably, the carboxylic acid product derived from ester hydrolysis and metabolites thereof were only detectable in negative ionization mode. In case of SGT-233, mono- and dihydroxy metabolites were identified, as well as glucuronides. The cytochrome P450 (CYP) isozymes CYP2C8, CYP2C9, CYP2C19, CYP3A4 and CYP3A5 were found to be involved in the hydroxylation of both compounds. The results of these in vitro experiments suggest that the ester hydrolysis products of 2F-QMPSB and their glucuronides are suitable targets for toxicological screenings. In the case of SGT-233, the mono- and dihydroxy metabolites were identified as suitable screening targets. The involvement of various CYP isoforms in the metabolism of both substances reduces the likelihood of drug-drug interactions due to CYP inhibition.

Clinical Toxicological Follow-Up Analysis of a Suicide Attempt Using Chloroquine

Chloroquine, a drug approved for the treatment of malaria, is frequently used to commit suicide. We report about a suicide attempt by ingesting a high dose of chloroquine in combination with other drugs. Findings of the emergency toxicology screening of blood and urine and those of the follow-up analyses in blood are discussed. Systematic toxicological analysis approaches revealed the presence of chloroquine, butylscopolamine, cafedrine, diazepam, lorazepam, metoclopramide, nordazepam, norephedrine and 11-nor-9-carboxy-∆9-tetrahydroxycannabinol in blood and/or urine of the subject. Suicide due to a combination of chloroquine and benzodiazepines is known as the so-called "Kusch method" in German-speaking countries. The initial chloroquine plasma concentration was determined to be 9.6 mg/L after precipitation and analysis by liquid chromatography-high-resolution tandem mass spectrometry. The analytical procedure was developed ad hoc and validated in accordance with international recommendations. Clinical toxicological follow-up analyses in blood were performed over a period of 3 weeks. The chloroquine concentration remained above the therapeutic range (up to 0.5 mg/L) for 2 weeks and dropped to 0.3 mg/L after 3 weeks. Furthermore, monodesethylchloroquine (MDCQ) and bisdesethylchloroquine (BDCQ) were determined to be the most abundant metabolites in plasma. Within 3 weeks, the area ratios of MDCQ and chloroquine increased 4-fold (from 0.090 to 0.350), and those of BDCQ and chloroquine increased 100-fold (from 0.002 to 0.218). This information may help to estimate the chloroquine excretion progress in the future.

Outside the limit: questioning the distance restrictions for cooperative miRNA binding sites

Among the concepts in biology that are widely taken granted is a potentiated cooperative effect of multiple miRNAs on the same target. This strong hypothesis contrasts insufficient experimental evidence. The quantity as well as the quality of required side constraints of cooperative binding remain largely hidden. For miR-21-5p and miR-155-5p, two commonly investigated regulators across diseases, we selected 15 joint target genes. These were chosen to represent various neighboring 3'UTR binding site constellations, partially exceeding the distance rules that have been established for over a decade. We identified different cooperative scenarios with the binding of one miRNA enhancing the binding effects of the other miRNA and vice versa. Using both, reporter assays and whole proteome analyses, we observed these cooperative miRNA effects for genes that bear 3'UTR binding sites at distances greater than the previously defined limits. Astonishingly, the experiments provide even stronger evidence for cooperative miRNA effects than originally postulated. In the light of these findings the definition of targetomes specified for single miRNAs need to be refined by a concept that acknowledges the cooperative effects of miRNAs.

Analytical toxicology of yew constituents in human blood and urine by liquid chromatography-high-resolution tandem mass spectrometry

The active, poisonous constituents in Taxus baccata, the yew plants, are taxine alkaloids whose main action is suggested to be a block of calcium and sodium channels. The main alkaloids are taxine B (30%) and taxine A (1.3%). Symptoms can include bradycardia, bradypnea, diastolic, and cardiac standstill. The current investigation reports the analytical toxicology of human blood and urine to confirm a suspected ingestion of yew needles. This includes the qualitative detection of several yew ingredients, including the main alkaloids, the validated quantification of 3,5-dimethoxyphenol, and the discussion of suitable analytical targets. After analyzing human specimens and yew needle extracts using the developed procedures, the five alkaloids 1-deotaxine B, taxicatin, taxine A, taxine B, and taxine I could be detected and tentatively identified. Finally, taxine A and B can be recommended as analytical targets besides 3,5-dimethoxyphenol.

Closing the gap - development of an analytical methodology using volumetric absorptive microsampling of finger prick blood followed by LC-HRMS/MS for adherence monitoring of antihypertensive drugs

Volumetric absorptive microsampling (VAMS), an emerging microsampling technique, is a promising tool for adherence monitoring. This study focused on development of an analytical methodology to improve VAMS-based strategies for adherence assessment by analyzing angiotensin-converting-enzyme (ACE) inhibitors, loop diuretics, a potassium-sparing diuretic, and a thiazide diuretic. Development included sample preparation, chromatographic conditions, mass spectrometry settings, validation, and demonstrating proof of concept. Quantification of analytes, by name furosemide, hydrochlorothiazide, lisinopril, torasemide, and the active metabolites, canrenone, enalaprilat, and ramiprilat in finger prick blood (FPB), was validated based on international guidelines. Selectivity, carryover, and within/between-run accuracy and precision were in accordance with the recommendations. The matrix effect was evaluated at three different hematocrit levels (HT: 20%, 40%, 60%) and the coefficients of variation did not exceed 15%. Dilution integrity (1:10 and 1:20) was given for all analytes except lisinopril, yet for lisinopril, the therapeutic range was already covered by the calibration range. Long-term stability in VAMS tips was tested for 2 weeks at 24 °C in the dark and revealed no degradation of analytes. The proof of concept was performed by analyzing 35 intakes of ACE-inhibitors and diuretics in 18 VAMS and matched plasma samples. Hereby, determined concentration in FPB and plasma cannot be used interchangeably, and thus specific reference ranges for whole blood must be established. Nevertheless, the VAMS-based strategy was shown to be suitable for assessing adherence of all classes of antihypertensive drugs used in the guidelines to manage hypertension.

In vitro metabolic characterization of the SARS-CoV-2 papain-like protease inhibitors GRL0617 and HY-17542

The SARS-CoV-2 pandemic requires a new therapeutic target for viral infection, and papain-like protease (Plpro) has been suggested as a druggable target. This in-vitro study was conducted to examine the drug metabolism of the GRL0617 and HY-17542, Plpro inhibitors. Metabolism of these inhibitors was studied to predict the pharmacokinetics in human liver microsomes. The hepatic cytochrome P450 (CYP) isoforms responsible for their metabolism were identified using recombinant enzymes. The drug-drug interaction potential mediated by cytochrome P450 inhibition was estimated. In human liver microsomes, the Plpro inhibitors had phase I and phase I + II metabolism with half-lives of 26.35 and 29.53 min, respectively. Hydroxylation (M1) and desaturation (-H2, M3) of the para-amino toluene side chain were the predominant reactions mediated with CYP3A4 and CYP3A5. CYP2D6 is responsible for the hydroxylation of the naphthalene side ring. GRL0617 inhibits major drug-metabolizing enzymes, including CYP2C9 and CYP3A4. HY-17542 is structural analog of GRL0617 and it is metabolized to GRL0617 through non-cytochrome P450 reactions in human liver microsomes without NADPH. Like GRL0617 and HY-17542 undergoes additional hepatic metabolism. The in-vitro hepatic metabolism of the Plpro inhibitors featured short half-lives; preclinical metabolism studies are needed to determine therapeutic doses for these inhibitors.

In Vitro and In Vivo Toxicometabolomics of the Synthetic Cathinone PCYP Studied by Means of LC-HRMS/MS

Synthetic cathinones are one important group amongst new psychoactive substances (NPS) and limited information is available regarding their toxicokinetics and -dynamics. Over the past few years, nontargeted toxicometabolomics has been increasingly used to study compound-related effects of NPS to identify important exogenous and endogenous biomarkers. In this study, the effects of the synthetic cathinone PCYP (2-cyclohexyl-1-phenyl-2-(1-pyrrolidinyl)-ethanone) on in vitro and in vivo metabolomes were investigated. Pooled human-liver microsomes and blood and urine of male Wistar rats were used to generate in vitro and in vivo data, respectively. Samples were analyzed by liquid chromatography and high-resolution mass spectrometry using an untargeted metabolomics workflow. Statistical evaluation was performed using univariate and multivariate statistics. In total, sixteen phase I and one phase II metabolite of PCYP could be identified as exogenous biomarkers. Five endogenous biomarkers (e.g., adenosine and metabolites of tryptophan metabolism) related to PCYP intake could be identified in rat samples. The present data on the exogenous biomarker of PCYP are crucial for setting up analytical screening procedures. The data on the endogenous biomarker are important for further studies to better understand the physiological changes associated with cathinone abuse but may also serve in the future as additional markers for an intake.

Hydrochlorothiazide does not lead to phototoxic reactions and DNA damage in healthy volunteers the HCTox study

Purpose

Hypertension represents the most common cardiovascular risk factor for premature death worldwide. Hydrochlorothiazide (HCTZ) is one of the most commonly used antihypertensive and diuretic drug worldwide. Recently, pharmacoepidemiologic studies associated the use of HCTZ with increased risk of skin cancer. As a result, prescriptions of HCTZ decreased, leading to worsening of blood pressure therapy in a significant proportion of patients. However, whether HCTZ causes skin cancer remains elusive. We aimed to examine the photosensitive potential of HCTZ in vivo. To further enlighten the pathophysiologic mechanisms of carcinogenesis and phototoxicity caused by HCTZ in vitro, we conducted a series of laboratory experiments.

Methods

This randomized, double-blinded, placebo-controlled clinical trial assessed the phototoxic properties of HCTZ. We randomly assigned 30 healthy adult volunteers in a 2:1 ratio to either HCTZ 25 mg daily or placebo once daily for 15 days. Skin photosensitivity by phototesting for UV-A and UV-B radiation, office blood pressure, serum-vitamin-D status and urinary excretion of thymidine-dimers were measured. To further assess the pathophysiologic mechanisms of possibly HCTZ induced photosensitivity, human keratinocytes (HaCaT) were incubated with HCTZ and then irradiated with UV-B radiation (311 nm one burst of 100 J/cm2). rt-PCR-testing and western blots were performed to analyze reactive oxygen species, inflammation and carcinogenesis.

Results

All 30 participants were adherent to the protocol, as confirmed by toxicological analysis of serum and urine. Skin photosensitivity to exposure of UV-A and UV-B radiation remained unchanged in both groups (UVB-MED: HCTZ Δ = 0.0 J/cm2 vs. placebo Δ = −0.2 J/cm2; p=0.06). No thymidine-dimers were detected in urine of either group. Systolic blood pressure decreased in both groups but was not different between HCTZ and placebo (HCTZ Δ = −5.2 mmHg vs. placebo Δ = −5.4 mmHg; p=0.94). The same was found for diastolic blood pressure (HCTZ Δ = −1.9 mmHg vs. placebo Δ = −4.3 mmHg; p=0.34). Serum-vitamin-D increased in both groups (HCTZ Δ = +2.7 ng/ml vs. placebo Δ = 0.9 ng/ml; p=0.56). In addition, combination of HCTZ and a high intensity burst of UV-B radiation did not increase expression of inflammatory proteins or increase formation of reactive oxygen species (SOD-1, SOD-2, and catalase).

Conclusions

HCTZ did not significantly increase photosensitivity for UV-A or UV-B radiation in healthy volunteers compared with placebo. Moreover, no relevant DNA-damages were detected in either group. HCTZ alone did not increase inflammation, formation of reactive oxygen species or carcinogenesis in human keratinocytes. Furthermore, the combination of a UV-B burst of 100 J/cm2 and HCTZ was not associated with additive effects on inflammation, reactive oxygen species or carcinogenisis.

HCTZ in a cumulative dose of 375 did not increase photosensitivity or DNA-damages in vivo.

Funding Acknowledgement

Type of funding sources: None.

New Psychoactive Substances: Which Biological Matrix Is the Best for Clinical Toxicology Screening?

BACKGROUND

Every year, more new psychoactive substances (NPSs) emerge in the market of the drugs of abuse. NPSs belong to various chemical classes, such as synthetic cannabinoids, phenethylamines, opioids, and benzodiazepines. The detection of NPSs intake using different types of biological matrices is challenging for clinical toxicologists because of their structural diversity and the lack of information on their toxicokinetics, including their metabolic fate.

METHODS

PubMed-listed articles reporting mass spectrometry-based bioanalytical approaches for NPSs detection published during the past 5 years were identified and discussed. Furthermore, the pros and cons of using common biological matrices in clinical toxicology (CT) settings to screen for NPSs are highlighted in this review article.

RESULTS

Twenty-six articles presenting multianalyte screening methods for use in the field of CT were considered. The advantages and disadvantages of different biological matrices are discussed with a particular view of the different analytical tasks in CT, especially emergency toxicology. Finally, an outlook introduces the emerging trends in biosamples used in CT, such as the exhaled breath.

CONCLUSIONS

Blood and urine represent the most common biological matrices used in a CT setting; however, reports concerning NPSs detection in alternative matrices are also available. Noteworthy, the selection of the biological matrix must depend on the clinician's enquiry because the individual advantages and disadvantages must be considered.

Going deeper into the toxicokinetics of synthetic cannabinoids: in vitro contribution of human carboxylesterases

Synthetic cannabinoids (SC) are new psychoactive substances known to cause intoxications and fatalities. One reason may be the limited data available concerning the toxicokinetics of SC, but toxicity mechanisms are insufficiently understood so far. Human carboxylesterases (hCES) are widely known to play a crucial role in the catalytic hydrolysis of drugs (of abuse). The aim of this study was to investigate the in vitro contribution of hCES to the metabolism of the 13 SC 3,5-AB-5F-FUPPYCA, AB-5F-P7AICA, A-CHMINACA, DMBA-CHMINACA, MBA-CHMINACA, MDMB-4F-BINACA, MDMB-4en-PINACA, MDMB-FUBICA, MDMB-5F-PICA, MMB-CHMICA, MMB-4en-PICA, MMB-FUBINACA, and MPhP-5F-PICA. The SC were incubated with recombinant hCES1b, hCES1c, or hCES2 and analyzed by liquid chromatography-ion trap mass spectrometry to assess amide or ester hydrolysis in an initial activity screening. Enzyme kinetic studies were performed if sufficient hydrolysis was observed. No hydrolysis of the amide linker was observed using those experimental conditions. Except for MDMB-5F-PICA, ester hydrolysis was always detected if an ester group was present in the head group. In general, SC with a terminal ester bearing a small alcohol part and a larger acyl part showed higher affinity to hCES1 isozymes. Due to the low hydrolysis rates, enzyme kinetics could not be modeled for the SC with a tert-leucine-derived moiety, but hydrolysis reactions of MPhP-5F-PICA and of those containing a valine-derived moiety followed classic Michaelis-Menten kinetics. In conclusion, drug-drug/drug-food interactions or hCES polymorphisms may prolong the half-life of SC and the current results help to estimate the risk of toxicity in the future after combining them with activity and clinical data.

A simplified strategy to assess the cytotoxicity of new psychoactive substances in HepG2 cells using a high content screening assay - Exemplified for nine compounds

New psychoactive substances (NPS) are an issue of global concern posing a serious threat to the healthcare systems. Consumption of some NPS has been associated with toxic effects on the liver amongst others. However, data concerning their (cyto-)toxicity are usually not available. For a straightforward assessment of their cytotoxic potential, a simplified strategy measuring six different cytotoxicity indicating parameters simultaneously by a high content screening assay (HCSA) was developed. Its applicability was further investigated using nine NPS from heterogeneous chemical classes. HepG2 cells were incubated with NPS for 48 h at a low and high concentration (7.81 and 125 µM), respectively. To study metabolism-mediated effects on their cytotoxicity, cells were additionally incubated with the unspecific cytochrome (CYP) P450 inhibitor 1-aminobenzotriazole. Four fluorescence dyes were used to monitor cell count, nuclear size, and nuclear intensity (all Hoechst33342), mitochondrial membrane potential (TMRM), cytoplasmic calcium levels (CAL-520), and plasma membrane integrity (TOTO-3). Amongst the investigated NPS, ephylone, CUMYL-CBMICA, and dibutylone showed a strong cytotoxic potential, affecting two parameters at 7.81 µM. 5-MeO-MiPT showed moderate effects by impairing one parameter at 7.81 and one at 125 µM. Furthermore, at the high concentration of 5-MeO-MiPT, an effect of metabolism on cytotoxicity was observed. The HCSA confirmed the cytotoxic potential of ephylone and 5-MeO-MiPT, as the investigated concentrations were in the range of their published blood concentrations which induced liver damages after intake. The mitochondrial membrane potential was the parameter with the highest sensitivity and thus considered as suitable "cytobiomarker". In turn, parameters showing a high variability or unexpected effects such as cytosolic calcium levels and plasma membrane integrity might be omitted in the future. Even though 5-MeO-MiPT showed metabolism-based effects, HepG2 are known to have limited metabolic activity compared to cell lines such as HepaRG. Therefore, in further experiments cell lines with higher CYP-expression needs to be included and findings compared. Nevertheless, the simplified HCSA-based strategy allowed to screen NPS from diverse chemical groups for a first assessment of the cytotoxic properties of the parent compound. This information is crucial for a thorough risk assessment of NPS not only for public health authorities.

Photoinduced skin reactions of cardiovascular drugs-a systematic review

This systemic review aims to provide a practical overview of the prevalence, clinical manifestation, and management of adverse photoinduced skin reactions caused by frequently used cardiovascular drugs and to assess their potential relevance for skin cancer development. Data search included PubMed, Web of Science, and the Cochrane Library. A systematic review of peer-reviewed studies reporting the photosensitizing and/or skin cancer-inducing properties of common cardiovascular drugs was performed and a guide to clinical management of photoinduced skin eruptions by cardiovascular drugs was provided. Study quality was assessed for major methodological biases. A total of 58 studies were identified (i.e. 23 case reports, 14 observational studies, 10 review articles, 10 experimental studies, and 1 meta-analysis). Most commonly, drug-associated adverse photoinduced cutaneous reactions were caused by phototoxic and photoallergic mechanisms. There is evidence suggesting that amiodarone and dronedarone, thiazide diuretics, thiazide-like diuretics, angiotensin receptor blockers, dihydropyridine-type calcium channel blockers, and certain angiotensin-converting enzyme inhibitors and statins may cause photoinduced adverse cutaneous reactions. Other drugs such as anticoagulants, antiplatelets, aldosterone antagonists, and fibrates have not been linked with photosensitizing reactions or adverse cutaneous reactions. Some drugs, i.e. thiazides and thiazide-like diuretics, were associated with an increased risk of non-melanoma skin cancers (basal cell carcinoma and squamous cell carcinoma). Certain commonly used cardiovascular drugs have been associated with adverse photoinduced cutaneous reactions. If they occur, further diagnosis and treatment might be needed, depending on the severity and progress. Whether photosensitizing drugs increase the risk of skin cancer remains elusive and further randomized controlled trials are required.

Induction of Liver Size Reduction in Zebrafish Larvae by the Emerging Synthetic Cannabinoid 4F-MDMB-BINACA and Its Impact on Drug Metabolism

Zebrafish (ZF; Danio rerio) larvae have become a popular in vivo model in drug metabolism studies. Here, we investigated the metabolism of methyl 2-[1-(4-fluorobutyl)-1H-indazole-3-carboxamido]-3,3-dimethylbutanoate (4F-MDMB-BINACA) in ZF larvae after direct administration of the cannabinoid via microinjection, and we visualized the spatial distributions of the parent compound and its metabolites by mass spectrometry imaging (MSI). Furthermore, using genetically modified ZF larvae, the role of cannabinoid receptor type 1 (CB1) and type 2 (CB2) on drug metabolism was studied. Receptor-deficient ZF mutant larvae were created using morpholino oligonucleotides (MOs), and CB2-deficiency had a critical impact on liver development of ZF larva, leading to a significant reduction of liver size. A similar phenotype was observed when treating wild-type ZF larvae with 4F-MDMB-BINACA. Thus, we reasoned that the cannabinoid-induced impaired liver development might also influence its metabolic function. Studying the metabolism of two synthetic cannabinoids, 4F-MDMB-BINACA and methyl 2-(1-(5-fluoropentyl)-1H-pyrrolo[2,3-b]pyridine-3-carboxamido)-3,3-dimethylbutanoate (7′N-5F-ADB), revealed important insights into the in vivo metabolism of these compounds and the role of cannabinoid receptor binding.

Evaluation and analytical applicability of a novel volumetric absorptive microsampling strategy for adherence monitoring of antihypertensive drugs by means of LC-HRMS/MS

Volumetric absorptive microsampling (VAMS), an emerging microsampling technique, is expected to overcome some disadvantages of dried blood spots. This study aimed to develop and evaluate a VAMS-based strategy for quantifying ten frequently prescribed antihypertensive drugs (AHD) (amlodipine, bisoprolol, candesartan, carvedilol, lercanidipine, losartan carboxylic acid, metoprolol, nebivolol, telmisartan, valsartan) in finger prick blood (FPB) within the scope of adherence monitoring. The straightforward workflow consisted of VAMS tip hydration and subsequent precipitation. Samples were analyzed by using reversed phase ultra-high performance liquid chromatography coupled to orbitrap mass spectrometry operating in parallel reaction monitoring mode. The analytical procedure was successfully validated based on international recommendations for most of the analytes. Selectivity and within/between-run accuracy and precision were in accordance with the recommendations. Internal standard normalized matrix factor met recommended criteria for all analytes at HT 20%, 40%, and 60% except for amlodipine were the CV exceeded 15% at HT 20% (CV 18%). Dilution integrity was given for all substances, covering the quantification in the upper part of the therapeutic range of selected AHD. Long-term stability in VAMS tips was tested and revealed degradation of lercanidipine after one week of storage at 24 °C. A proof of concept of the analytical applicability was done by quantification of selected AHD in VAMS tips and matched plasma samples. Results revealed that determined concentration in FPB by VAMS and plasma cannot be used interchangeably, and thus that specific reference ranges have to be established. However, a novel VAMS application was implemented in the context of adherence monitoring for at least the investigated AHD.

Are the N-demethylated metabolites of U-47700 more active than their parent compound? In vitro μ-opioid receptor activation of N-desmethyl-U-47700 and N,N-bisdesmethyl-U-47700

Studies on the tissue distribution of the new synthetic opioid U-47700 and its main metabolite N-desmethyl-U-47700 revealed about sixfold higher metabolite concentrations in pig brain as compared with the parent compound. To better assess the toxic potential of this drug, the aim of this study was to assess the in vitro μ-opioid receptor (MOR) activation potential of the main metabolites of U-47700, N-desmethyl-U-47700, and N,N-bisdesmethyl-U-47700, using a live cell-based reporter assay based on NanoLuc Binary Technology®. Cells stably expressing human MOR and β-arrestin 2 (βarr2), each fused via a flexible linker to two complementary inactive subunits of the nanoluciferase, were seeded on poly-d-lysine-coated 96-well plates and treated with N-desmethyl-U-47700, N,N-bisdesmethyl-U-47700, U-47700, or hydromorphone as reference standard. MOR activation results in functional complementation of the nanoluciferase, which can be assessed via luminescence monitoring. The potency of the metabolites is lower than that of U-47700 (EC₅₀ of 186 nM for U-47700, 3770 nM for N-desmethyl-U-47700, and >5 μM for N,N-bisdesmethyl-U-47700). The maximal efficacy (E_max ) observed (relative to hydromorphone, set arbitrarily at 100%) decreased from 183% to 127% and 39.2% for U-47700, N-desmethyl-U-47700, and N,N-bisdesmethyl-U-47700, respectively. Thus, the loss of one or two methyl groups reduced the MOR activation potential, which was more pronounced if both methyl groups were removed. It is thus anticipated that the impact on MOR exerted by the higher metabolite concentration in brain has only little-if any relevance for the strong toxic effects of U-47700.

Toxic plants-Detection of colchicine in a fast systematic clinical toxicology screening using liquid chromatography-mass spectrometry

Colchicum autumnale, which can be mistaken for Allium ursinum, contains the alkaloid colchicine potentially leading to life-threatening up to fatal intoxications. We report two cases of acute intoxications with unexplained circumstances. Using the authors' systematic screening approaches, colchicine could be detected in blood plasma and urine samples using liquid chromatography coupled to linear ion trap mass spectrometry (LC-ITMSⁿ ) and high-resolution tandem mass spectrometry (LC-HRMS/MS). Metabolites of colchicine could be identified in urine for confirmation of screening results. Gas chromatography-mass spectrometry (GC-MS) analysis was also conducted, but colchicine could not be detected. Furthermore, colchicine concentration was estimated via LC-HRMS/MS in plasma samples. Results of the systematic screening indicated the ingestion of colchicine from both subjects. In both cases, the parent compound was detected in blood plasma and urine using the LC-HRMS/MS and LC-ITMSⁿ system. An O-demethylation metabolite was identified in urine samples of both subjects using LC-HRMS/MS; the N-deacetylation product was also found in urine samples of both cases via LC-HRMS/MS and LC-ITMSⁿ . The use of LC-ITMSⁿ resulted only in the detection of the O-demethylation product in case 2. Plasma concentrations were estimated at 2.5 ng/ml and 4.7 ng/ml for cases 1 and 2, respectively. We demonstrated the detection of this highly toxic alkaloid in blood plasma and urine using a time-saving and reliable clinical systematic screening. Furthermore, we identified metabolites of colchicine being rarely discussed in literature, which can be used as additional screening targets.

Can a Recently Developed Pig Model Be Used for In Vivo Metabolism Studies of 7-Azaindole-Derived Synthetic Cannabinoids? A Study Using 5F-MDMB-P7AICA

New psychoactive substances (NPS), especially synthetic cannabinoids (SC) remain a public health concern. Due to ethical reasons, systematic controlled human studies to elucidate their toxicodynamics and/or toxicokinetics are usually not possible. However, such knowledge is necessary, for example, for determination of screening targets and interpretation of clinical and forensic toxicological data. In the present study, the feasibility of the pig model as an alternative for human in vivo metabolism studies of SC was investigated. For this purpose, the metabolic pattern of the SC methyl-2-{[1-(5-fluoropentyl)-1H-pyrrolo[2,3-b]pyridine-3-carbonyl]amino}-3,3-dimethylbutanoate (5F-MDMB-P7AICA) was elucidated in pig urine following inhalative administration (dosage: 200 µg/kg of body weight). The results were compared with human and pig liver microsomal assays and literature. In addition, different incubations with isolated cytochrome-P450 (CYP) monooxygenases were conducted to identify the involved isozymes. In total, nine phase I and three phase II metabolites were identified in pig urine. The most abundant reactions were ester hydrolysis, ester hydrolysis combined with glucuronidation and ester hydrolysis combined with hydroxylation at the tert-butyl moiety. The parent compound was only found up to 1 h after administration in pig urine. The metabolite formed after hydroxylation and glucuronidation was detectable for 2 h, the one formed after ester hydrolyzation and defluorination for 4 h after administration. All other metabolites were detected during the whole sampling time. The most abundant metabolites were also detected using both microsomal incubations and monooxygenase screenings revealed that CYP3A4 catalyzed most reactions. Finally, pig data showed to be in line with published human data. To conclude, the main metabolites recommended in previous studies as urinary targets were confirmed by using pig urine. The used pig model seems therefore to be a suitable alternative for in vivo metabolism studies of 7-azaindole-derived SC.

Can the Intake of a Synthetic Tryptamine be Detected Only by Blood Plasma Analysis? A Clinical Toxicology Case Involving 4-HO-MET

Tryptamines represent a group of hallucinogenic new psychoactive substances with increasing prevalence. Unfortunately, only limited data concerning their toxicology and bioanalysis is available as tryptamines are not included in routine screening procedures in many laboratories. In order to expand the current knowledge, we report a non-fatal clinical toxicology case involving the synthetic tryptamine 4-HO-MET (4-hydroxy-N-methyl-N-ethyl-tryptamine, 3-{2-[ethyl(methyl)amino]ethyl}-1H-indol-4-ol, metocin, or methylcybin). Only blood was available and our systematic blood plasma screening approaches based on gas chromatography-mass spectrometry (GC-MS) and liquid chromatography (LC) coupled to low-resolution linear ion trap mass spectrometry (ITMSn) or high-resolution tandem mass spectrometry (HRMS/MS) were conducted. The ingestion of the synthetic tryptamine 4-HO-MET could be revealed by blood plasma analysis using both LC-based systematic screening approaches, but not using GC-MS. Furthermore, the detection of metabolites, which may be used to confirm an intake of the parent compound 4-HO-MET, was only successful using LC-HRMS/MS most probably due to its increased sensitivity compared to LC-ITMSn. A total of four metabolites were detected in blood including N-demethyl-, oxo-, and hydroxy-4-HO-MET, as well as the N-oxide. Finally, LC-HRMS/MS analysis revealed a plasma concentration of 193 ng/mL for 4-HO-MET using the standard addition method. The presented data may help clinical and forensic toxicologists with the interpretation of future cases involving synthetic tryptamines, especially if only blood samples are available.

Further development of a liquid chromatography-high-resolution mass spectrometry/mass spectrometry-based strategy for analyzing eight biomarkers in human urine indicating toxic mushroom or Ricinus communis ingestions

Recently, we presented a strategy for analysis of eight biomarkers in human urine to verify toxic mushroom or Ricinus communis ingestions. However, screening for the full panel is not always necessary. Thus, we aimed to develop a strategy to reduce analysis time and by focusing on two sets of analytes. One set (A) for biomarkers of late-onset syndromes, such as phalloides syndrome or the syndrome after castor bean intake. Another set (B) for biomarkers of early-onset syndromes, such as pantherine-muscaria syndrome and muscarine syndrome. Both analyses should be based on hydrophilic-interaction liquid chromatography coupled with high-resolution mass spectrometry (MS)/MS (HILIC-HRMS/MS). For A, urine samples were prepared by liquid-liquid extraction using dichloromethane and subsequent solid-phase extraction of the aqueous supernatant. For B urine was precipitated using acetonitrile. Method A was validated for ricinine and α- and β-amanitin and method B for muscarine, muscimol, and ibotenic acid according to the specifications for qualitative analytical methods. In addition, robustness of recovery and normalized matrix factors to matrix variability measured by urinary creatinine was tested. Moreover, applicability was tested using 10 urine samples from patients after suspected mushroom intoxication. The analytes α- and β-amanitin, muscarine, muscimol, and ibotenic acid could be successfully identified. Finally, psilocin-O-glucuronide could be identified in two samples and unambiguously distinguished from bufotenine-O-glucuronide via their MS² patterns. In summary, the current workflow offers several advantages towards the previous method, particularly being more labor-, time-, and cost-efficient, more robust, and more sensitive.

Method development for quantitative determination of seven statins including four active metabolites by means of high-resolution tandem mass spectrometry applicable for adherence testing and therapeutic drug monitoring

Background Statins are used to treat and prevent cardiovascular diseases (CVDs) by reducing the total serum cholesterol concentration. Unfortunately, dose-related side effects and sub-optimal response, attributed to non-adherence amongst others, were described. Therefore, a fast and sensitive liquid chromatography-high-resolution tandem mass spectrometry (LC-HRMS/MS) method for adherence testing and therapeutic drug monitoring of all currently marketed statins and their active metabolites in human blood plasma should be developed, validated and tested for applicability. Methods Atorvastatin, fluvastatin, lovastatin, pitavastatin, pravastatin, rosuvastatin, and simvastatin, as well as ortho- and para-hydroxy-atorvastatin, lovastatin hydroxy acid and simvastatin hydroxy acid were included and several internal standards (IS) tested. Validation was performed according to the guideline of the European Medicines Agency including selectivity, carry-over, accuracy, precision, matrix effects, dilution integrity and analyte stability. Finally, applicability was tested using 14 patient samples submitted for regular toxicological analysis. Results Due to an analytical interference of atorvastatin-d5, diazepam-d5 and pentobarbital-d5 were chosen as IS for positive and negative ionization mode, respectively. All statins and metabolites fulfilled the validation acceptance criteria except for fluvastatin, which could not be quantified reliably and reproducibly, most probably due to instability. Analyses of human plasma samples revealed concentrations of statins and metabolites below the reference plasma concentrations in the case of eight patients. However, nothing was known concerning patients' adherence and time between intake and sampling. Conclusions An LC-HRMS/MS method for identification and quantification of atorvastatin, lovastatin, pitavastatin, pravastatin, rosuvastatin, simvastatin and four active metabolites was successfully developed and applicability demonstrated.

Perimortem Distribution of U-47700, Tramadol and their Main Metabolites in pigs Following Intravenous Administration

In spite of a decreasing number of new releases, New Synthetic Opioids (NSO) are gaining increasing importance in postmortem (PM) forensic toxicology. For the interpretation of analytical results, toxicokinetic (TK) data, e.g. on tissue distribution, are helpful. Concerning NSO, such data are usually not available due to the lack of controlled human studies. Hence, a controlled TK study using pigs was carried out and the tissue distribution of U-47700 and tramadol as reference was examined. Twelve pigs received an intravenous dose of 100 µg/kg body weight (BW) U-47700 or 1000 µg/kg BW tramadol, respectively. Eight hours after administration, the animals were put to death with T61. Relevant organs, body fluids and tissues were sampled. After homogenization and solid-phase extraction, quantification was performed applying standard addition and liquid chromatography-tandem mass spectrometry. At the time of death, the two parent compounds were determined in all analyzed specimens. Regarding U-47700, concentrations were highest in duodenum content, bile fluid and adipose tissue (AT). Concerning tramadol, next to bile fluid and duodenum content, highest concentrations were determined in the lung. Regarding the metabolites, N-desmethyl-U-47700 and O-desmethyltramadol (ODT) were detected in all analyzed specimens except for AT (ODT). Higher metabolite concentrations were found in specimens involved in metabolism. N-desmethyl-U-47700 showed much higher concentrations in routinely analyzed organs (lung, liver, kidney) than U-47700. To conclude, besides the routinely analyzed specimens in PM toxicology, AT, bile fluid and duodenum content could serve as alternative matrices for blood, urine or standard specimens such as kidney or liver. In case of U-47700, quantification of the main metabolite N-desmethyl-U-47700 is highly recommendable.

Abuse of nutmeg seeds: Detectable by means of liquid chromatography-mass spectrometry techniques?

Numerous case reports of intoxications with nutmeg seeds (Myristica fragrans, Houtt.) can be found in literature often following their abuse, as psychotropic effects were described after ingestions of large doses. The successful detection of the main ingredients of the nutmeg seeds essential oil elemicin, myristicin, and safrole, as well as their metabolites in human urine by gas chromatography coupled to mass spectrometry (GC-MS) was already described. The aim of this study was to investigate the detectability of the main ingredients of nutmeg seeds and their metabolites in human blood and urine samples using liquid chromatography coupled to linear ion trap mass spectrometry (LC-LIT-MSⁿ ) and liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS/MS) after nutmeg seed abuse. Sample material of three individuals was retrospectively investigated after a systematic screening approach indicated an intoxication with nutmeg seeds as a likely cause of symptoms. Metabolic patterns in plasma and urine using GC-MS were comparable with those described in earlier publications. Investigations using hyphenated liquid chromatography techniques lead to the detection of myristicin and safrole, as well as further metabolites not described using GC-MS and revealed sulfation as an additional Phase II metabolic pathway. These results might help to detect or confirm future intoxications with nutmeg seeds by using LC-MS techniques.

Drug adherence and psychosocial characteristics of patients presenting with hypertensive urgency at the emergency department

OBJECTIVE

To identify potentially targetable psychosocial factors associated with nonadherence to prescribed antihypertensive medications in patients presenting with hypertensive urgencies at an emergency department.

METHODS

This prospective study included patients treated with antihypertensive drugs who presented with hypertensive urgencies (SBP ≥180 mmHg and/or DBP ≥110 mmHg) at the emergency department of a tertiary referral clinic between April 2018 and April 2019. Health literacy was assessed using the Newest Vital Sign test. The Hospital Anxiety and Depression Scale (HADS) was used to quantify symptoms of anxiety and depression. Patients were classified nonadherent if less than 80% of the prescribed antihypertensive drugs were detectable in urine or plasma using liquid chromatography-high-resolution mass spectrometry.

RESULTS

A total of 104 patients (62% women) presenting with hypertensive urgencies with a median SBP of 200 mmHg (IQR 190-212) and DBP of 97.5 mmHg (IQR 87-104) were included. Twenty-five patients (24%) were nonadherent to their antihypertensive medication. Nonadherent patients were more often men (66 versus 23%, P = 0.039), prescribed higher numbers of antihypertensive drugs (median 3, IQR 3-4 versus 2, IQR 1-3; P < 0.001), and more often treated with calcium channel blockers (76 versus 25%; P < 0.001) and/or diuretics (64 versus 40%; P = 0.030). There was no difference in health literacy (P = 0.904) or the scores on the HADS subscales for depression (P = 0.319) and anxiety (P = 0.529) between adherent and nonadherent patients.

CONCLUSION

Male sex, higher numbers of antihypertensive drugs, and treatment with diuretics and/or calcium channel blockers were associated with nonadherence. We did not identify a specific psychosocial characteristic associated with nonadherence.

Assessing Adherence to Antihypertensive Medication by Means of Dose-Dependent Reference Plasma Concentration Ranges and Ultra-High Performance Liquid Chromatography-Ion Trap Mass Spectrometry Analysis

Poor adherence to antihypertensive drug therapy is a well-recognized problem and can be assessed by mass spectrometry-based analyses of body fluids. However, contrary statements exist whether drug quantification in blood or qualitative screening in urine is more suitable. The present pilot study aimed to further elucidate the power of blood plasma drug concentrations for adherence monitoring by developing and validating a quantification procedure for nine antihypertensive drugs (amlodipine, bisoprolol, candesartan, canrenone, carvedilol, metoprolol, olmesartan, torasemide, and valsartan) in blood plasma using liquid–liquid extraction and an ultra-high-performance liquid chromatography-ion trap mass spectrometry analysis. The procedure should then be used for an adherence assessment and compared with the results of an established qualitative urine screening. Selectivity, carryover, matrix effect, accuracy, precision, dilution integrity, and stability were successfully validated, except for amlodipine. The applicability was demonstrated by analyzing 19 plasma samples containing 28 antihypertensive drugs and comparing the measured concentrations with calculated dose-dependent reference plasma concentration ranges. The interpretation of plasma concentrations was found to be more sophisticated and time-consuming than that of urine screening results, and adherence could not be assessed in two cases (10%) due to measured plasma concentrations below the lower limit of quantification. However, 14 out of 19 subjects were classified as adherent (75%) and three as nonadherent (15%), in contrast to 19 (100%) that were claimed to be adherent based on the results of the qualitative urine screening. Nevertheless, further data is needed to estimate whether plasma quantification is superior in terms of assessing adherence to antihypertensive medication.

Studies on the In Vitro and In Vivo Metabolic Fate of the New Psychoactive Substance N-Ethyl-N-Propyltryptamine for Analytical Purposes

Prerequisites for the reliable identification of substances in terms of forensic and clinical toxicology or doping control include knowledge about their metabolism and their excretion patterns in urine. N-Ethyl-N-propyltryptamine (N-ethyl-N-[2-(1H-indol-3-yl)ethyl]propan-1-amine, EPT) is an N,N-dialkylated tryptamine derivative, sold as new psychoactive substance, and supposed to act as a partial agonist at the 5-HT2A receptor. The aims of the presented study were to elucidate in vitro metabolites of EPT after incubations with pooled human liver S9 fraction (pS9) and in vivo metabolites excreted into rat urine. Finally, suitable analytical target compounds should be identified. Analysis of pS9 incubations using liquid chromatography-high-resolution tandem mass spectrometry revealed EPT metabolites formed after N-dealkylation as well as alkyl and aryl hydroxylation and formation of a hydroxy sulfate. Investigations using rat urine after oral dosing showed that the metabolic pathways of EPT shifted from in vitro hydroxylation of the alkyl amine group to an increased in vivo hydroxylation of the indole ring with several N-dealkyl metabolites. A glucuronic acid conjugate after hydroxylation of the indole ring was additionally found in vivo. The parent compound could not be detected in the rat urine samples. Therefore, analytical methods using mass spectrometry should include hydroxy-EPT and two hydroxy-EPT glucuronide isomers for reliable identification.

Systematic Studies on Temperature-Dependent in Vitro Stability During Storage and Smoking of the Synthetic Cannabinoid 5F-MDMB-P7AICA

Metabolism studies have shown that the synthetic cannabinoid (SC) 5F-MDMB-P7AICA is predominantly degraded by ester hydrolysis to 5F-MDMB-P7AICA dimethyl butanoic acid. To investigate the stability of 5F-MDMB-P7AICA during storage for a certain period of time or smoking, in vitro stability tests were performed. Blood and serum samples were collected repeatedly during a toxicokinetic study using a pig model and were retested after a 5 and 12 months storage at different temperatures (-20 °C, 4 °C, or room temperature, RT). Analysis was performed using fully validated liquid chromatography tandem mass spectrometry methods following liquid-liquid extraction and protein precipitation. One set of samples was analyzed immediately following the experiment (WS). In the WS samples, 5F-MDMB-P7AICA and 5F-MDMB-P7AICA dimethyl butanoic acid were present in every sample collected throughout the whole experiment. Analysis of the blood and serum samples stored for 5 and 12 months at -20 °C and 4 °C revealed relatively stable concentrations of the parent substance and the dimethyl butanoic acid metabolite. Regarding the samples stored at RT, concentrations of 5F-MDMB-P7AICA decreased, whilst concentrations of the hydrolysis product increased. This change could particularly be observed in samples with a high initial concentration of the analytes. A further screening of the samples stored at RT revealed no other degradation products. In conclusion, the SC 5F-MDMB-P7AICA could be detected even after 12 months of storage at RT and therefore seems to be more stable than its isomer, 5F-ADB. Regarding the smoke condensate, beside the parent compound only trace amounts of dimethyl butanoic acid were found.