Body fluid contamination in the context of an adverse analytical finding in doping: About a case involving ostarine.

Ostarine, also known as MK-2866 or enobosarm, is a selective androgen receptor modulator (SARM). It has anabolic properties and as such is widely used in doping, accounting in 2021 for 25 % of the adverse analytical findings (AAF) among the class S1.2 "Other anabolic agents" of products banned by the World Anti-Doping Agency, to which it belongs. But in some cases, it can be responsible for an AAF following contamination. We report the case of an athlete who contaminated herself by exchanging body fluids while kissing her boyfriend, who took 25 mg per day of MK-2866 for 9 days prior to the athlete's AAF (urinary concentration evaluated at 13 ng/mL) without her knowledge. Both subjects came to our lab for hair testing. The athlete's hair was black and slightly frizzy. Six segments of 2 cm then 7 × 3 cm (33 cm) were analysed and showed increasing concentrations, from 2 pg/mg on the first segment to 17.8 pg/mg on the last segment. The boyfriend's hair, light-brown, analyzed on 4 × 2 cm, also showed increasing values, from 65 to 143 pg/mg. These gradients of concentration in the hair's athlete and in her boyfriend were compatible with external contamination of the hair, confirmed by analysis of washing baths, pillowcases (150 pg on each), and the athlete's hairbrush (250 pg). Fingernails were also contaminated, with 21 pg/mg in the athlete and 1041 pg/mg in the boyfriend, with highly contaminated washing baths, and toenails were less contaminated, with 2 pg/mg in the athlete and 17.3 pg/mg in the boyfriend. Urine samples taken 35 days after the start of MK-2866 treatment showed a value of 3690 ng/mL in the boyfriend and 5.7 ng/mL in the athlete. After 6 days off, these concentrations were 3.3 ng/mL and 0.1 ng/mL, respectively. A controlled transfer study was carried out 12 days after discontinuation (urine concentrations returned to negative level). After administration of 17 mg (the 25 mg/mL vial having been controlled at 17 mg/mL), urine samples were taken from the boyfriend and the athlete (n = 10 for each) for more than 25 h after they had been living normally with each other (regular kissing in particular). The boyfriend's urine concentrations ranged from 681 ng/mL to 12822 ng/mL (Tmax = 8:30 hrs), and the athlete's from 0.3 ng/mL to 13 ng/mL with Tmax = 8:30 hrs, i.e. at 22:30 hrs, which corresponded exactly to the time of collection of the urine that showed AAF, with a similar concentration. The dose ingested by the athlete was estimated at 15 µg. These results demonstrate the transfer of ostarine via body fluids between two subjects, with a high risk of AAF in one athlete, as observed in our case.

Study of the association between serum levels of kynurenine and cardiovascular outcomes and overall mortality in chronic kidney disease.

Background: Kynurenine is a protein-bound uremic toxin. Its circulating levels are increased in chronic kidney disease (CKD). Experimental studies showed that it exerted deleterious cardiovascular effects. We sought to evaluate an association between serum kynurenine levels and adverse fatal or nonfatal cardiovascular events and all-cause mortality in CKD patients. Methods: The CKD-REIN study is a prospective cohort of people with CKD having an estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m². Baseline frozen samples of total and free fractions of kynurenine and tryptophan were measured using a validated liquid chromatography tandem mass spectrometry technique. Cause-specific Cox models were used to estimate hazard ratios (HRs) for each outcome. Results: Of the 2406 included patients (median age: 68 years; median eGFR: 25 ml/min/1.73 m2), 52% had a history of cardiovascular disease. A doubling of serum-free kynurenine levels was associated with an 18% increased hazard of cardiovascular events [466 events, HR (95%CI):1.18(1.02,1.33)], independently of eGFR, serum-free tryptophan level or other uremic toxins, cardioprotective drugs, and traditional cardiovascular risk factors. Serum-free kynurenine was significantly associated with non-atheromatous cardiovascular events [HR(95%CI):1.26(1.03,1.50)], but not with atheromatous cardiovascular events [HR(95%CI):1.15(0.89,1.50)]. The association of serum-free kynurenine with cardiovascular mortality was also independently significant [87 events; adjusted HR(95%CI):1.64(1.10,2.40)]. However, the association of serum-free kynurenine with all-cause mortality was no more significant after adjustment on serum-free tryptophan [311 events, HR(95%CI):1.12(0.90, 1.40)]. Conclusions: Our findings imply that serum-free kynurenine, independently of other cardiovascular risk factors (including eGFR), is associated with fatal or nonfatal cardiovascular outcomes, particularly non-atheromatous cardiovascular events; in patients with CKD. Strategies to reduce serum kynurenine levels should be evaluated in further studies.

Hair and dietary supplements testing to identify contamination with roxadustat in an adverse analytical finding.

Roxadustat is an oral inhibitor of hypoxia-inducible factor (HIF) prolyl hydroxylase, which increases endogenous erythropoiesis. WADA has included roxadustat and other HIF stabilizers on its list of prohibited substances. We describe here the case of an elite athlete (female, 31 years old, 168 cm and 53 kg) with an adverse analytical finding (AAF) with concentration of roxadustat in her urine at 0.289 ng/mL in the A sample and 0.529 ng/mL in the B sample (83% higher than A). A stability study was carried out, showing total stability of roxadustat at this concentration in urine exposed to light for 50 h, so photoisomerization degradation cannot explain the difference in concentration. Her urine had been completely negative in a control test carried out three days previously, while roxadustat had been shown to be present in urine for at least 20 days after administration of pharmacologically effective doses to an athlete. Hair concentration was 0.39 and 0.35 pg/mg in the segments corresponding to the presumed period of intake, with few adjacent segments also positive (0.29-0.33 pg/mg), likely explained by cosmetic treatments. Concentrations found in a patient treated with a pharmacologically active dose (between 100 and 120 mg 3 days a week) were more than 100 times higher (between 41 and 57 pg/mg). Numerous supplements and pharmaceuticals taken by the athlete were analyzed. Only collagen powder showed the presence of roxadustat, at a very low but highly variable concentration (100 pg/g-1000 pg/g). A female volunteer (58 years old, 169 cm and 65 kg), taking this powder at the same doses as the athlete (10 g of powder 5 times for 6 days) presented 7 roxadustat-positive urine samples (although lower than those observed in the athlete) out of 34 sampled over 7 days, the difference in powder sampling location, age, weight, height, pharmacokinetic parameters variability and level of sporting activity between the athlete and the volunteer probably explaining the difference in concentrations observed. All these results could be consistent with an AAF due to contamination by dietary supplements, which are becoming increasingly common due to the current exposome of athletes in our society.

Can inhaled cannabis users accurately evaluate impaired driving ability? A randomized controlled trial.

Aims: To study the effect of inhaled cannabis on self-assessed predicted driving ability and its relation to reaction times and driving ability on a driving simulator. Participants and methods: 30 healthy male volunteers aged 18-34: 15 chronic (1-2 joints /day) and 15 occasional (1-2 joints/week) consumers. Self-assessed driving confidence (visual analog scale), vigilance (Karolinska), reaction time (mean reciprocal reaction time mRRT, psychomotor vigilance test), driving ability (standard deviation of lane position SDLP on a York driving simulator) and blood concentrations of delta-9-tétrahydrocannabinol (THC) were measured before and repeatedly after controlled inhalation of placebo, 10 mg or 30 mg of THC mixed with tobacco in a cigarette. Results: Cannabis consumption (at 10 and 30 mg) led to a marked decrease in driving confidence over the first 2 h which remained below baseline at 8 h. Driving confidence was related to THC dose and to THC concentrations in the effective compartment with a low concentration of 0.11 ng/ml for the EC50 and a rapid onset of action (T1/2 37 min). Driving ability and reaction times were reduced by cannabis consumption. Driving confidence was shown to be related to driving ability and reaction times in both chronic and occasional consumers. Conclusions: Cannabis consumption leads to a rapid reduction in driving confidence which is related to reduced ability on a driving simulator. Clinical trial registration: ClinicalTrials.gov, identifier: NCT02061020.

Characterization of extensive 2-fluorodeschloroketamine metabolism in pooled human liver microsomes, urine and hair from an addicted patient using high-resolution accurate mass spectrometry.

2-Fluorodeschloroketamine (2F-DCK) is a ketamine derivative involved in acute intoxications and deaths. The aim of this study is to investigate its metabolism using pooled human liver microsomes (pHLMs) and to apply it to authentic samples (urine, hair and seized materials) from a drug user. 2F-DCK (100 µM) incubates with pHLMs were analyzed by liquid chromatography-high-resolution accurate mass (LC-HRAM; Q-Exactive, Thermo Fisher Scientific®) according to a previously published protocol. Spectra annotation was performed using Compound Discoverer® software and the metabolic scheme was drawn using ChemDraw software. Urine (200 µL) and hair (previously decontaminated using dichloromethane and segmented into three segments: A, 0-3 cm; B, 3-6 cm; C, 6-9 cm) were extracted with a mixture of hexane:ethyl acetate (1:1) and chloroform:isopropanol (4:1). About 10 µL of both reconstituted residues were analyzed by LC-HRAM. Hair was also analyzed by LC-MS-MS (TSQ Vantage, Thermo Fisher Scientific®) for 2F-DCK and deschloroketamine (DCK) quantification. The two presumed 2F-DCK crystals consumed by the patient were dissolved in methanol (1 mg/mL) and 10 µL were analyzed by LC-MS-MS (Quantum Access Max, Thermo Fisher Scientific®). Twenty-six putative 2F-DCK metabolites were identified, 15 being reported for the first time. Thirteen metabolites were detected in pHLMs, 10 confirmed in both the patient's urine and hair and all were found in at least one of the two samples. Twenty-three metabolites were detected in urine and 20 in hair. Our research confirms the reliability of nor-2F-DCK as a target analyte and suggests OH-dihydro-nor-2F-DCK and dehydro-nor-2F-DCK as new target analytes in urine and hair, respectively. This is the first study to report DCK as a 2F-DCK metabolite using pHLMs and to determine its concentrations in hair (A/B/C, 885/1,500/1,850 pg/mg) following chronic use. Finally, the two seized crystals contained 2F-DCK at 67% and 96% with traces of DCK (0.4% and 0.6%) related to cross-contamination by container exchange.

First detection/quantification of roxadustat in hair with a new liquid chromatography with tandem mass spectrometry method: Application to a treated patient.

Roxadustat is an oral inhibitor of hypoxia-inducible factor prolyl hydroxylase which increases erythropoiesis. It can therefore be used as a doping agent. No data are available on how to measure roxadustat in hair and on the concentration found in treated patients. The aim of this study was to develop a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of roxadustat in hair and to apply it to a chronically treated patient. After decontamination with dichloromethane, testosterone-D3 used as an internal standard and phosphate buffer pH 5.0 were added to 20 mg of hair and incubated for 10 min at 95 °C. Four ml of dichloromethane were used for extraction and reconstituted into the mobile phase, 10 µL were injected into the chromatographic system. The method was linear in the range 0.5-200 pg/mg, accurate and precise (evaluated at 3 levels) and was successfully applied to measure roxadustat in a brown-haired patient treated pharmacologically with 100-120 mg 3 days a week. Results were stable between 41 and 57 pg/mg in the 6 proximal 1 cm segments. This first method describing the measurement of roxadustat in hair appears to be suitable for the quantification of this compound in clinical or doping control cases.

Proton-Pump Inhibitors and Serum Concentrations of Uremic Toxins in Patients with Chronic Kidney Disease.

Use of proton-pump inhibitors (PPIs) is common in patients with chronic kidney disease (CKD). PPIs and many uremic toxins (UTs) are eliminated by the kidney's tubular organic anion transporter system. In a cross-sectional study, we sought to evaluate the association between PPI prescription and serum concentrations of various UTs. We studied a randomly selected sub-group of participants in the CKD-REIN cohort (adult patients with a confirmed diagnosis of CKD and estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2) with available frozen samples collected at baseline. PPI prescription was recorded at baseline. Serum concentrations of 10 UTs were measured using a validated liquid chromatography tandem mass spectrometry technique. Multiple linear regression was performed, with the log UT concentration as the dependent variable. Of the 680 included patients (median age: 68 years; median eGFR: 32 mL/min/1.73 m2), 31% had PPI prescriptions at baseline. Patients using PPIs had higher levels of certain UTs in comparison to other patients, including total and free indoxyl sulfate (IS), total and free p-cresylsulfate, total and free p-cresylglucuronide (PCG), phenylacetylglutamine (PAG), free kynurenine, and free hippuric acid. After adjustment for baseline co-morbidities, number of co-prescribed drugs, and laboratory data, including eGFR, associations between PPI prescription and elevated serum concentrations of free and total IS, free and total PCG, and PAG remained significant. Our results indicate that PPI prescription is independently associated with serum UT retention. These findings are interesting to better understand the factors that may modulate serum UT concentration in CKD patients, however, they will need to be confirmed by longitudinal studies.

Characterization of 3-Hydroxyeticyclidine (3-HO-PCE) Metabolism in Human Liver Microsomes and Biological Samples Using High-Resolution Mass Spectrometry.

3-Hydroxyeticyclidine (3-HO-PCE) is a ketamine derivative that produces dissociative, hallucinogenic, and euphoric effects when consumed, but little is known about its pharmacological properties, metabolism, and toxicity compared to other designer ketamine analogs. To address this gap in knowledge, this study explored for the first time the metabolism of 3-HO-PCE. Based on this investigation, it is hypothesized that combining the use of Human Liver Microsomes (HLM) as an In vitro model with urine and hair samples from drug users may enable the identification of key analytes that can extend the detection window of 3-HO-PCE, particularly in cases of overdose. The analysis identified 15 putative metabolites, 12 of which are produced through phase I metabolism involving N-dealkylation, deamination, and oxidation, and 3 through phase II O-glucuronidation. The metabolism of 3-HO-PCE is similar to that of O-PCE, another designer ketamine of the eticyclidine family. The study identified M2a and hydroxy-PCA as reliable biomarkers for untargeted screening of the eticyclidine family in urine and hair, respectively. For targeted screening of 3-HO-PCE, M10 is recommended as the target analyte in urine, and M5 shows promise for long-term monitoring of 3-HO-PCE using hair analysis.

Correlation between Saliva Levels and Serum Levels of Free Uremic Toxins in Healthy Volunteers.

The objective of the present study was to investigate the putative correlation between the saliva concentration and free serum concentration for 10 uremic toxins (UTs; eight protein-bound solutes: 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid (CMPF), hippuric acid (HA), indole-3-acetic acid (3-IAA), indoxyl sulfate (I3S), kynurenic acid (KA), kynurenine (KYN), p-cresyl glucuronide (pCG), and p-cresyl sulfate (pCS); two free, water-soluble, low-molecular weight solutes: phenylacetylglutamine (PAGN) and trimethylamine N-oxide (TMAO); and three precursors: tyrosine (Tyr), phenylalanine, and tryptophan). Saliva samples and blood samples were collected simultaneously from 18 healthy volunteers. After the addition of internal standards, 50 µL of saliva or serum were precipitated with methanol. UTs and precursors were quantified using a validated LC-MS/MS method. The saliva-serum correlation was statistically significant (according to Spearman's coefficient) for six UTs (TMAO, HA, I3S, pCS, 3-IAA, and CMPF). Tyr presented a weak saliva-serum correlation (p = 0.08), whereas the other two precursors did not show a saliva-serum correlation. For three UTs (KYN, KA and pCG), we were unable to test the correlation since the saliva or serum levels were too low in many of the volunteers. The present study is the first to report on the saliva concentrations of TMAO, KYN, HA, PAGN, pCG, and 3-IAA.

Indoxyl sulfate impairs erythropoiesis at BFU-E stage in chronic kidney disease.

Chronic kidney disease (CKD) is a global health condition characterized by a progressive deterioration of kidney function. It is associated with high serum levels of uremic toxins (UT), such as Indoxyl Sulfate (IS), which may participate in the genesis of several uremic complications. Anemia is one of the major complications in CKD patients that contribute to cardiovascular disease, increase morbi-mortality, and is associated with a deterioration of kidney failure in these patients. Our study aimed to characterize the impact of IS on CKD-related erythropoiesis. Using cellular and pre-clinical models, we studied cellular and molecular effects of IS on the growth and differentiation of erythroid cells. First, we examined the effect of clinically relevant concentrations of IS (up to 250 µM) in the UT7/EPO cell line. IS at 250 µM increased apoptosis of UT7/EPO cells at 48 h compared to the control condition. We confirmed this apoptotic effect of IS in erythropoiesis in human primary CD34+ cells during the later stages of erythropoiesis. Then, in IS-treated human primary CD34+ cells and in a (5/6 Nx) mice model, a blockage at the burst-forming unit-erythroid (BFU-E) stage of erythropoiesis was also observed. Finally, IS deregulates a number of erythropoietic related genes such as GATA-1, Erythropoietin-Receptor (EPO-R), and ß-globin. Our findings suggest that IS could affect cell viability and differentiation of erythroid progenitors by altering erythropoiesis and contributing to the development of anemia in CKD.

Validation of Liquid Chromatography Coupled with Tandem Mass Spectrometry for the Determination of 12 Tyrosine Kinase Inhibitors (TKIs) and Their Application to Therapeutic Drug Monitoring in Adult and Pediatric Populations.

Tyrosine kinase inhibitors (TKIs) are used as targeted cancer therapies in adults and have an off-label pediatric application for the treatment of Langerhans cell histiocytosis. A multitarget LC-MS/MS method was developed and validated for the determination of alectinib, alectinib-M4, binimetinib, cobimetinib, crizotinib, dabrafenib, encorafenib, imatinib, lorlatinib, osimertinib, AZ5104, and trametinib. A total of 150 µL of internal standard methanolic solution was added to 50 µL of plasma sample to precipitate proteins. After centrifugation, 10 µL of the supernatant was injected into the chromatographic system. The chromatographic separation was conducted on a Kinetex C18 Polar column with a gradient of 2 mM ammonium formate in 0.1% formic acid and acetonitrile over 5 min. Limits of detection and quantification, linearity, accuracy, precision, selectivity, carryover, matrix effect, recovery, and stability were evaluated and satisfied EMA guidelines on bioanalytical methods. This method has been successfully applied to the therapeutic drug monitoring (TDM) of adults with melanoma and lung cancer, as well as children with histiocytosis, to improve the pharmacokinetic data for these drugs, with the aim of enhancing the therapeutic management and follow-up of patients. Blood concentrations of trametinib and binimetinib were different in the two groups, highlighting the age-related inter-individual variability of these molecules and the need for TDM.

The association between TMAO, CMPF, and clinical outcomes in advanced chronic kidney disease: results from the European QUALity (EQUAL) Study.

BACKGROUND: Trimethylamine N-oxide (TMAO), a metabolite from red meat and fish consumption, plays a role in promoting cardiovascular events. However, data regarding TMAO and its impact on clinical outcomes are inconclusive, possibly due to its undetermined dietary source. OBJECTIVES: We hypothesized that circulating TMAO derived from fish intake might cause less harm compared with red meat sources by examining the concomitant level of 3-carboxy-4-methyl-5-propyl-2-furanpropionate (CMPF), a known biomarker of fish intake, and investigated the association between TMAO, CMPF, and outcomes. METHODS: Patients were recruited from the European QUALity (EQUAL) Study on treatment in advanced chronic kidney disease among individuals aged ≥65 y whose estimated glomerular filtration rate (eGFR) had dropped for the first time to ≤20 mL/min per 1.73 m2 during the last 6 mo. The association between TMAO, CMPF, and outcomes including all-cause mortality and kidney replacement therapy (KRT) was assessed among 737 patients. Patients were further stratified by median cutoffs of TMAO and CMPF, suggesting high/low red meat and fish intake. RESULTS: During a median of 39 mo of follow-up, 232 patients died. Higher TMAO was independently associated with an increased risk of all-cause mortality (multivariable HR: 1.46; 95% CI: 1.17, 1.83). Higher CMPF was associated with a reduced risk of both all-cause mortality (HR: 0.79; 95% CI: 0.71, 0.89) and KRT (HR: 0.80; 95% CI: 0.71, 0.90), independently of TMAO and other clinically relevant confounders. In comparison to patients with low TMAO and CMPF, patients with low TMAO and high CMPF had reduced risk of all-cause mortality (adjusted HR: 0.49; 95% CI: 0.31, 0.73), whereas those with high TMAO and high CMPF showed no association across adjusted models. CONCLUSIONS: High CMPF conferred an independent role in health benefits and might even counteract the unfavorable association between TMAO and outcomes. Whether higher circulating CMPF concentrations are due to fish consumption, and/or if CMPF is a protective factor, remains to be verified.

Validation of a liquid chromatography coupled to tandem mass spectrometry method for simultaneous quantification of tryptophan and 10 key metabolites of the kynurenine pathway in plasma and urine: Application to a cohort of acute kidney injury patients.

A sensitive and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous determination of tryptophan (Trp) and ten metabolites of kynurenine pathway, including kynurenine (Kyn), 3-hydroxy-kynurenine (3-HK), kynurenic acid (KA), xanthurenic acid (XA), 3-Hydroxy-anthranilic acid (3-HANA), quinolinic acid (QA), nicotinic acid mononucleotide (NaMN), picolinic acid (Pic), nicotinamide (NAM) and nicotinic acid (NA) in both plasma and urine. This LC-MS/MS method was used to predict the occurrence of acute kidney injury (AKI) in a cohort of patients with cardiac surgery under cardiopulmonary bypass (CPB). Urinary concentrations of Pic, as well as Pic to Trp and Pic to 3-HANA ratios were highly predictive of an AKI episode the week after CPB, indicating that Pic could be a predictive biomarker of AKI. Thus, monitoring the kynurenine pathway activity with this LC-MS/MS method is a clinically relevant tool to identify new biomarkers of kidney injury.

Glyphosate and aminomethylphosphonic acid in human hair quantified by an LC-MS/MS method.

An LC-MS/MS method for hair testing of glyphosate and aminomethylphosphonic acid (AMPA), its main biodegradation product, has been developed. After decontamination, 50 mg of hair was ground and sonicated in water for 2 h. The method was fully validated in the 5-500 pg/mg range for glyphosate and 10-500 pg/mg for AMPA, and the limits of detection were 2 and 5 pg/mg, respectively. Matrix effect for glyphosate and AMPA was compensated by an isotope-labeled internal standard. Hair samples from four farmers who regularly used glyphosate and one farmer who used glyphosate but not his wife and 14 hair samples from nonoccupationally exposed subjects were tested. Glyphosate was found in head hair of three farmers, with concentration in the range 14-188 pg/mg. The fourth was found negative but with hair colored in red. Glyphosate was detected in 10 of 14 hair samples from nonoccupationally exposed subjects at concentrations of 11.5 pg/mg or lower and only in one segment (0-3 cm) of the farmer's spouse (6 pg/mg). AMPA was detected in five subjects, above the limit of quantification only in two of three occupationally exposed subjects with positive glyphosate. Further studies should be conducted to validate this potential new biomarker that could be useful for assessing long-term exposure to glyphosate.

The relationship between uremic toxins and symptoms in older men and women with advanced chronic kidney disease.

Background: Patients with stage 4/5 chronic kidney disease (CKD) suffer from various symptoms. The retention of uremic solutes is thought to be associated with those symptoms. However, there are relatively few rigorous studies on the potential links between uremic toxins and symptoms in patients with CKD. Methods: The EQUAL study is an ongoing observational cohort study of non-dialyzed patients with stage 4/5 CKD. EQUAL patients from Germany, Poland, Sweden and the UK were included in the present study (n = 795). Data and symptom self-report questionnaires were collected between April 2012 and September 2020. Baseline uric acid and parathyroid hormone and 10 uremic toxins were quantified. We tested the association between uremic toxins and symptoms and adjusted P-values for multiple testing. Results: Symptoms were more frequent in women than in men with stage 4/5 CKD, while levels of various uremic toxins were higher in men. Only trimethylamine N-oxide (TMAO; positive association with fatigue), p-cresyl sulfate (PCS) with constipation and 3-carboxy-4-methyl-5-propyl-2-furanpropionic acid (negative association with shortness of breath) demonstrated moderately strong associations with symptoms in adjusted analyses. The association of phenylacetylglutamine with shortness of breath was consistent in both sexes, although it only reached statistical significance in the full population. In contrast, TMAO (fatigue) and PCS and phenylacetylglutamine (constipation) were only associated with symptoms in men, who presented higher serum levels than women. Conclusion: Only a limited number of toxins were associated with symptoms in persons with stage 4/5 CKD. Other uremic toxins, uremia-related factors or psychosocial factors not yet explored might contribute to symptom burden.

Population Pharmacokinetics of Hydroxychloroquine and 3 Metabolites in COVID-19 Patients and Pharmacokinetic/Pharmacodynamic Application.

We develop a population pharmacokinetic model for hydroxychloroquine (HCQ) and three of its metabolites (desethylhydroxychloroquine, Des HCQ; desethylchloroquine, DesCQ; and didesethylchloroquine, didesCQ) in COVID-19 patients in order to determine whether a pharmacokinetic (PK)/pharmacodynamic (PD) relationship was present. The population PK of HCQ was described using non-linear mixed effects modelling. The duration of hospitalization, the number of deaths, and poor clinical outcomes (death, transfer to ICU, or hospitalization ≥ 10 d) were evaluated as PD parameters. From 100 hospitalized patients (age = 60.7 ± 16 y), 333 BHCQ and M were available for analysis. The data for BHCQ were best described by a four-compartment model with a first-order input (KA) and a first-order output. For M, the better model of the data used one compartment for each metabolite with a first-order input from HCQ and a first-order output. The fraction of HCQ converted to the metabolites was 75%. A significant relationship was observed between the duration of hospitalization and BHCQ at 48 h (r2 = 0.12; p = 0.0052) or 72 h (r2 = 0.16; p = 0.0012). At 48 h or 72 h, 87% or 91% of patients vs. 63% or 62% had a duration < 25 d with a BHCQ higher or below 200 µg/L, respectively. Clinical outcome was significantly related to BHCQ at 48 h (good outcome 369 +/- 181 µg/L vs. poor 285 +/- 144 µg/L; p = 0.0441) but not at 72 h (407 +/- 207 µg/L vs. 311 +/- 174 µg/L; p = 0.0502). The number of deaths was not significantly different according to the trough concentration (p = 0.972 and 0.836 for 48 h and 72 h, respectively).

Poppers, by Inducing HHV-8 Virion Production, Can Act as a Promoter for HHV-8 Transmission in Men Who Have Sex With Men.

Environmental factors were reported to increase the risk of human herpesvirus 8 (HHV-8) transmission. In a population of men who have sex with men (MSM), we found evidence that chemsex was associated with human herpesvirus 8 seropositivity in vivo and that poppers induced HHV-8 virion production in vitro. Our finding may explain the higher HHV-8 transmission in MSM.

Analysis of pharmaceutical products and dietary supplements seized from the black market among bodybuilders.

Substandard/counterfeit drugs are a growing global problem. According to the World Health Organisation, counterfeit medicines are medicines that are mislabelled deliberately and fraudulently regarding their identity and/or source. In high income countries, drugs seized are mainly represented by performance and image enhancing drugs (PIEDs). The aim of this study was to present the qualitative and quantitative results of toxicological analyses of pharmaceutical and dietary supplements seized from the black market among bodybuilders in France. All dietary supplements and pharmaceuticals seized from the black market and addressed to the laboratory for a qualitative and quantitative analysis between January 2016 and December 2019 were included in the study. A screening was carried out by gas chromatography-mass spectrometry and liquid chromatography-high resolution mass spectrometry. Identified compounds were quantified by liquid chromatography-tandem mass spectrometry. One hundred and ten products were seized and submitted to the laboratory for identification of active compounds and quantification: 75 pharmaceuticals and 35 dietary supplements. This included 39 oily and 3 aqueous solutions for intramuscular injection, 34 tablets, 13 capsules, 14 powders, 4 liquids and 3 lyophilizates. Among the pharmaceuticals, 25/75 (33%) were substandard (dosage not on the acceptable range defined for original products), 24/75 (32%) were counterfeit (qualitative formulation does not match the label) and 14/75 (19%) were original (qualitative formulation and levels of active ingredients fully matches the declared formulation. The analysis of the 12 remaining products revealed a correct qualitative content for 11/75 (15%), but quantitation could not be carried out because of the lack of reference standards at the time of the analysis. Fifty-four pharmaceuticals contained anabolic-androgenic steroids (AAS). Four out of 54 (7.4%) AAS were found as original, 8/54 (15%) could not be quantified (one with wrong active ingredient), corresponding to 43/54 (80%) AAS being non-original. In contrast, only 1/35 dietary supplement (3%) was adulterated, with a doping substance (1,3-dimethylbutylamine, DMBA). This work allows to show that France is not spared by the trafficking of PIEDs. The use of counterfeit drugs in mainstream population is an underestimated public health issue.

Atropine-induced toxicity after off-label sublingual administration of eyedrop for sialorrhoea treatment in neurological disabled patients.

Sialorrhea is a troublesome and disabling symptom defined by the unintentional loss of saliva from the mouth, usually associated with swallowing disorders. Today there is no consensus about the management of sialorrhoea, but off-label use of ophthalmic atropine eyedrop administered sublingually may offer benefits, despite limited safety data. We report 2 cases of atropine overdose after sublingual administration illustrating that atropine can expose to severe adverse effects when administered sublingually. The noncompartmental pharmacokinetic study of atropine performed in 1 patient highlighted that systemic absorption of sublingual atropine was effective (Cmax [1 h] = 2.2 ng mL-1 ; approximately) after a single dose of 1 mg.

Metabolic profiling of deschloro-N-ethyl-ketamine and identification of new target metabolites in urine and hair using human liver microsomes and high-resolution accurate mass spectrometry.

The aim of this study was to identify new markers of deschloro-N-ethyl-ketamine (O-PCE), a ketamine analogue that has been involved in acute intoxications with severe outcomes including death and whose metabolism has never been studied before. In vitro study after 2-h incubation with pooled human liver microsomes (HLMs) cross-checked by the analysis of urine and hair from a 43-year-old O-PCE user (male) were performed by liquid chromatography-high resolution mass spectrometry (LC-HRMS). Acquired data were processed by the Compound Discoverer® software, and a full metabolic profile of O-PCE was proposed. In total, 15 metabolites were identified, 10 were detected in vitro (HLMs) and confirmed in vivo (urine and/or hair), two were present only in HLMs, and the remaining three metabolites were identified only in biological specimens. While O-PCE was no longer detected in urine, nine metabolites were identified allowing to increase its detection window. In descending order of metabolites abundance, we suggest using 2-en-PCA-N-Glu (34%, first), M3 (16%, second), O-PCA-N-Glu (15.4%, third), OH-O-PCE (15%, fourth) and OH-PCE (11.9%, fifth) as target metabolites to increase the detection window of O-PCE in urine. In hair, nine metabolites were identified. OH-PCA was the major compound (78%) with a relevant metabolite to parent drug ratio (=6) showing its good integration into hair and making it the best marker for long-term monitoring of O-PCE exposure.