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Background Brigatinib, a next-generation anaplastic lymphoma kinase (ALK) inhibitor, targets activated, mutant forms of ALK and overcomes mechanisms of resistance to the ALK inhibitors crizotinib, ceritinib, and alectinib. Brigatinib is approved in multiple countries for treatment of patients with ALK-positive non-small cell lung cancer. Based on population pharmacokinetic (PK) analyses, no dosage adjustment is required for patients with mild or moderate renal impairment. Methods An open-label, single-dose study was conducted to evaluate the PK of brigatinib (90 mg) in patients with severe renal impairment (estimated glomerular filtration rate < 30 mL/min/1.73 m 2 ; n = 8) and matched healthy volunteers with normal renal function (estimated glomerular filtration rate ≥ 90 mL/min/1.73 m 2 ; n = 8). Plasma and urine were collected for the determination of plasma protein binding and estimation of plasma and urine PK parameters. Results Plasma protein binding of brigatinib was similar between patients with severe renal impairment (92 % bound) and matched healthy volunteers with normal renal function (91 % bound). Unbound brigatinib exposure (area under the plasma concentration-time curve from time zero to infinity) was approximately 92 % higher in patients with severe renal impairment compared with healthy volunteers with normal renal function. The renal clearance of brigatinib in patients with severe renal impairment was approximately 20 % of that observed in volunteers with normal renal function. Conclusions These findings support a brigatinib dosage reduction of approximately 50 % in patients with severe renal impairment.Trial registry: Not applicable., (© 2021. The Author(s).)

Background: The filaggrin protein is important for skin barrier structure and function. Loss-of-function (null) mutations in the filaggrin gene FLG may increase dermal absorption of chemicals., Objective: The objective of the study was to clarify if dermal absorption of chemicals differs depending on FLG genotype., Method: We performed a quantitative real-time polymerase chain reaction (qPCR)-based genetic screen for loss-of-function mutations ( FLG null) in 432 volunteers from the general population in southern Sweden and identified 28 FLG null carriers. In a dermal exposure experiment, we exposed 23 FLG null and 31 wild-type (wt) carriers to three organic compounds common in the environment: the polycyclic aromatic hydrocarbon pyrene, the pesticide pyrimethanil, and the ultraviolet-light absorber oxybenzone. We then used liquid-chromatography mass-spectrometry to measure the concentrations of these chemicals or their metabolites in the subjects' urine over 48 h following exposure. Furthermore, we used long-range PCR to measure FLG repeat copy number variants (CNV), and we performed population toxicokinetic analysis., Results: Lag times for the uptake and dermal absorption rate of the chemicals differed significantly between FLG null and wt carriers with low (20-22 repeats) and high FLG CNV (23-24 repeats). We found a dose-dependent effect on chemical absorption with increasing lag times by increasing CNV for both pyrimethanil and pyrene, and decreasing area under the urinary excretion rate curve ( AUC ( 0 - 40 h ) ) with increasing CNV for pyrimethanil. FLG null carriers excreted 18% and 110% more metabolite (estimated by AUC ( 0 - 40 h ) ) for pyrimethanil than wt carriers with low and high CNV, respectively., Conclusion: We conclude that FLG genotype influences the dermal absorption of some common chemicals. Overall, FLG null carriers were the most susceptible, with the shortest lag time and highest rate constants for skin absorption, and higher fractions of the applied dose excreted. Furthermore, our results indicate that low FLG CNV resulted in increased dermal absorption of chemicals. https://doi.org/10.1289/EHP7310.

A rapid, simple, and highly sensitive electroanalytical method was developed for the first time for the detection of ultra-trace amounts of nilotinib in sodium lauryl sulphate media. The electrochemical behavior of nilotinib was investigated on a glassy carbon electrode in the absence and presence of sodium lauryl sulphate media by cyclic voltammetry and adsorptive stripping voltammetric methods. The cyclic voltammograms proved that the electrochemical behavior of nilotinib showed irreversible and diffusion-adsorption-controlled oxidation processes in 0.1 M H 2 SO 4 . The effect of surfactant concentration on the first and second peaks of nilotinib was examined. Depending on whether the surfactants had a monomer or monolayer hemimicelle structure, they were attracted to amine moieties at related points in the nilotinib structure through the electrostatic interaction. The sensitivity of the method was markedly enhanced in the presence of surfactants using adsorptive stripping square-wave voltammetry. Under optimum conditions, nilotinib was determined in a concentration range of 2.0 × 10 -8 to 2.0 × 10 -6  mol L -1 , with a limit of detection of 6.33 × 10 -9  mol L -1 in 0.1 M H 2 SO 4 containing 2.0 × 10 -7  mol L -1 sodium lauryl sulphate. The proposed method can be applied for the sensitive determination of nilotinib in biological samples. Graphical abstract.

Tepotinib (MSC2156119J) is an oral, potent, highly selective MET inhibitor. This open-label, phase I study in healthy volunteers (EudraCT 2013-003226-86) investigated its mass balance (part A) and absolute bioavailability (part B). In part A, six participants received tepotinib orally (498 mg spiked with 2.67 MBq [ 14 C]-tepotinib). Blood, plasma, urine, and feces were collected up to day 25 or until excretion of radioactivity was <1% of the administered dose. In part B, six participants received 500 mg tepotinib orally as a film-coated tablet, followed by an intravenous [ 14 C]-tepotinib tracer dose (53-54 kBq) 4 h later. Blood samples were collected until day 14. In part A, a median of 92.5% (range, 87.1-96.9%) of the [ 14 C]-tepotinib dose was recovered in excreta. Radioactivity was mainly excreted via feces (median, 78.7%; range, 69.4-82.5%). Urinary excretion was a minor route of elimination (median, 14.4% [8.8-17.7%]). Parent compound was the main constituent in excreta (45% [feces] and 7% [urine] of the radioactive dose). M506 was the only major metabolite. In part B, absolute bioavailability was 72% (range, 62-81%) after oral administration of 500 mg tablets (the dose and formulation used in phase II trials). In conclusion, tepotinib and its metabolites are mainly excreted via feces; parent drug is the major eliminated constituent. Oral bioavailability of tepotinib is high, supporting the use of the current tablet formulation in clinical trials. Tepotinib was well tolerated in this study with healthy volunteers.

The pharmacokinetics (PK), metabolism, excretion, mass balance, and tissue distribution of [ 14 C]praliciguat were evaluated following oral administration of a 3-mg/kg dose in Sprague-Dawley rats and in a quantitative whole-body autoradiography (QWBA) study conducted in male Long-Evans rats. Plasma T max was 1 hour and the t 1/2 of total plasma radioactivity was 23.7 hours. Unchanged praliciguat accounted for 87.4%, and a minor metabolite (N-dealkylated-praliciguat) accounted for 7.6% of the total radioactivity in plasma through 48 hours (AUC 0-48 ). Tissues with the highest exposure ratios relative to plasma were liver, intestines, adrenal gland, and adipose, and those with the lowest values were seminal vesicle, blood, CNS tissues, lens of the eye, and bone. Most of the [ 14 C]praliciguat-derived radioactivity was excreted within 48 hours after oral administration. Mean cumulative recovery of the administered radioactivity in urine and feces over 168 hours was 3.7% and 95.7%, respectively. Unchanged praliciguat was not quantifiable in urine or bile of cannulated rats; however, based on the total radioactivity in these fluids, a minimum of approximately 82% of the orally administered dose was absorbed. [ 14 C]Praliciguat was metabolized via oxidative and glucuronidation pathways and the most abundant metabolites recovered in bile were praliciguat-glucuronide and hydroxy-praliciguat-glucuronide. These results indicate that praliciguat had rapid absorption, high bioavailability, extensive tissue distribution, and elimination primarily via hepatic metabolism., (© 2020 The Authors. Pharmacology Research & Perspectives published by British Pharmacological Society and American Society for Pharmacology and Experimental Therapeutics and John Wiley & Sons Ltd.)

Background: Surufatinib is a potent small-molecule tyrosine kinase inhibitor and exhibited significant efficacy in the treatment of neuroendocrine tumors in clinical trials., Objective: The absorption, metabolism and excretion of surufatinib were investigated in rats and human volunteers following a single oral dose of [14C] surufatinib., Methods: The radioactivity was measured in plasma, urine, feces and bile by liquid scintillation counting, and the metabolites were characterized by liquid chromatography coupled to mass spectrometry., Results: Surufatinib was orally absorbed similarly in rats and human volunteers, with the median Tmax of 4 hours post-dose. The estimated t1/2 appeared longer in humans than in rats (mean t1/2: 3.12 hour for male rats, 6.48 hours for female rats and 23.3 hours for male human volunteers). The excretion of surufatinib was almost complete in rats and human volunteers in the studies, with the total radioactivity recovery of >90% of the dose. Similarly, in rats and humans, fecal excretion predominated (approximately 87% of the dose recovered in feces and only 5% in urine). The parent drug was the major radioactive component detected in the plasma extracts of rats and humans, and no single circulating metabolite accounted for >10% of the total radioactivity. Unchanged drug was a minor radioactive component in the excreta of rats and humans., Conclusion: Fecal excretion was the predominant way for the elimination of surufatinib and its metabolites in rats and humans. No disproportionate circulating metabolite was observed in humans., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Diacylglycerol acyltransferase (DGAT) enzymes are involved in triglyceride (TG) biosynthesis. GSK3008356 is a potent and selective DGAT1 inhibitor that was administered orally in a 2-part study as double-blind, randomized, placebo-controlled single doses (SDs) and repeat doses (RDs) in healthy subjects to investigate its pharmacokinetics, pharmacodynamics, and safety/tolerability. Gastrointestinal adverse events were considered drug related and increased with dose and when given as multiple doses. In the SD part (n = 80), GSK3008356 was dosed from 5 to 200 mg as single or multiple doses per day. In the RD part (n = 24), GSK3008356 was dosed twice daily at 1, 3, and 10 mg for 14 days. GSK3008356 was generally well tolerated in the SD and RD parts. With single doses, absorption was rapid (median t max , 0.5-1.5 hours), whereas single-day divided dosing resulted in higher t max . Following 14-day RD oral administration, GSK3008356 was also rapidly absorbed, with median t max ranging from 0.5 to 0.75 hours on days 1 and 14. Estimated mean half-life ranged from 1.5 to 4.6 hours with SDs and 1.3 to 2.1 hours with RDs. Exposure of GSK3008356 was largely dose proportional after RDs. At higher doses, there was a trend toward lower absolute postprandial TG level in some subjects., (© 2019, The American College of Clinical Pharmacology.)

1. Leniolisib is a novel oral phosphatidylinositol-3-kinase (PI3K) delta inhibitor, currently in clinical development for the treatment of inflammatory and autoimmune diseases. 2. We investigated the absorption, metabolism, and excretion of leniolisib in healthy subjects after a single oral 400 mg dose as part of a first-in-human clinical study. The parent drug and metabolites were quantified by 19 F-NMR in plasma, urine and faeces after liquid chromatography separation, and structures were determined by liquid chromatography coupled to tandem mass spectrometry. 3. Drug-related material was mainly excreted as oxidative metabolites in urine and faeces, providing evidence that elimination occurs mainly by metabolism. No metabolites were abundant in plasma relative to the parent drug. An average mass balance of 66% was obtained, demonstrating that relatively extensive elimination/excretion data can be obtained by 19 F-NMR in a first in human clinical study without the use of a radiolabeled drug.

Aims This two-part, phase I study evaluated the mass balance, excretion, pharmacokinetics and safety of the investigational aurora A kinase inhibitor, alisertib, in three patients with advanced malignancies. Methods Part A; patients received a single 35-mg dose of [ 14 C]-alisertib oral solution (~80 μCi total radioactivity [TRA]). Serial blood, urine, and fecal samples were collected up to 336 h post-dose for alisertib mass balance and pharmacokinetics in plasma and urine by liquid chromatography-tandem mass spectrometry, and mass balance/recovery of [ 14 C]-radioactivity in urine and feces by liquid scintillation counting. Part B; patients received non-radiolabeled alisertib 50 mg as enteric-coated tablets twice-daily for 7 days in 21-day cycles. Results In part A, absorption was fast (median plasma T max , 1 h) for alisertib and TRA. Mean plasma t 1/2 for alisertib and TRA were 23.4 and 42.0 h, respectively. Mean plasma alisertib/TRA AUC 0-inf ratio was 0.45, indicating presence of alisertib metabolites in circulation. Mean TRA blood/plasma AUC 0-last ratio was 0.60, indicating preferential distribution of drug-related material in plasma. On average, 87.8% and 2.7% of administered radioactivity was recovered in feces and urine, respectively (total recovery, 90.5% by 14 days post-dose). In part B, patients received a median 3 cycles of alisertib. The most common any-grade adverse events were fatigue and alopecia. Conclusions Findings suggest that alisertib is eliminated mainly via feces, consistent with hepatic metabolism and biliary excretion of drug-related material. Further investigation of alisertib pharmacokinetics in patients with moderate-severe hepatic impairment is warranted to inform dosing recommendations in these patient populations.

Pyrimethanil (PYM) is a fungicide used pre- and post-harvest on many crops. It has a low acute toxicity but is of toxicological concern because of its antiandrogenic properties. The aim of the current work was to investigate some metabolism and estimate elimination kinetics of PYM in humans after experimental oral and dermal exposure. A liquid chromatography triple quadrupole mass spectrometry (LC-MS-MS) method was developed and validated for the analysis of PYM and its metabolite 4-hydroxypyrimethanil (OH-PYM) in human urine. The method was applied to analyze urine obtained from two volunteers experimentally exposed to PYM. The elimination of OH-PYM seemed to follow first-order kinetics and a two-phase excretion. After the oral exposure, the elimination half-life of OH-PYM in the rapid phase was 5 and 3 h for the female and male volunteer, respectively. In the slower phase, it was 15 h in both volunteers. After the dermal exposure, the half-life in the rapid phase was 8 h in both volunteers. In the slower phase, it was 30 and 20 h, respectively. About 80% of the oral dose was recovered as urinary OH-PYM in both volunteers. The dermal dose recovered as urinary OH-PYM was 9.4% and 19%, in the female and male volunteer, respectively. OH-PYM was mainly found as a conjugate of sulfonate and glucuronic acid. No free PYM was found. The analytical method showed good within-run, between-run and between-batch precision with a coefficient of variation between 6% and 12%. A limit of detection of 0.1 ng/mL and a limit of quantification of 0.4 ng/mL were achieved for both the analytes. The method was applied to biomonitor PYM exposure in populations in Sweden. OH-PYM was detected in nearly 50% and 96% of samples from the environmentally and occupationally exposed populations, respectively., (© The Author(s) 2018. Published by Oxford University Press.)

Dihydropyrimidinase deficiency is a rare autosomal recessive disease affecting the second step of pyrimidine degradation. It is caused by mutations in the DPYS gene. Only approximately 30 cases have been reported to date, with a phenotypical variability ranging from asymptomatic to severe neurological illness. We report a case of dihydropyrimidinase deficiency incidentally detected by urine metabolome analysis. Gas chromatography-mass spectrometry-based urine metabolomics demonstrated significant elevations of dihydrouracil and dihydrothymine, which were subsequently confirmed by a quantitative analysis using liquid chromatography-tandem mass spectrometry. Genetic testing of the DPYS gene revealed two mutations: a novel mutation (c.175G > T) and a previously reported mutation (c.1469G > A). Dihydropyrimidinase deficiency is probably underdiagnosed, considering its wide phenotypical variability, nonspecific neurological presentations, and an estimated prevalence of 2/20,000. As severe 5-fluorouracil-associated toxicity has been reported in patients and carriers of congenital pyrimidine metabolic disorders, urinary pyrimidine analysis should be considered for those who will undergo 5-fluorouracil treatment., (Copyright © 2018 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

Background: Di-2-ethylhexyl terephthalate (DEHTP) is used as a replacement plasticizer for other phthalates, including di-2-ethylhexyl phthalate (DEHP). Use of consumer products containing DEHTP may result in human exposure to DEHTP., Objective: To assess exposure to DEHTP in a nationally representative sample of the U.S. general population 3 years and older from the 2015-2016 National Health and Nutrition Examination Survey (NHANES)., Method: We quantified two DEHTP metabolites, mono-2-ethyl-5-hydroxyhexyl terephthalate (MEHHTP) and mono-2-ethyl-5-carboxypentyl terephthalate (MECPTP) in 2970 urine samples by using online solid-phase extraction coupled with isotope dilution-high-performance liquid chromatography-tandem mass spectrometry. We used linear regression to examine associations between MEHHTP and MECTPP and several parameters including age, sex, race/ethnicity, and household income. We also compared the MEHHTP and MECPTP results to those of their corresponding DEHP metabolite analogs, namely mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP) and mono-2-ethyl-5-carboxypentyl phthalate (MECPP)., Results: The weighted detection frequencies were 96% (MEHHTP) and 99.9% (MECPTP); urinary concentrations of the two metabolites correlated significantly (Pearson correlation coefficient = 0.89, p < 0.0001). MECPTP concentrations were higher than MEHHTP in all age, sex, race/ethnicity groups examined. Furthermore, MECPTP adjusted geometric mean (GM) concentrations were significantly higher in samples collected in the evening than in the morning or afternoon. Females had significantly higher adjusted GM concentrations of MEHHTP and MECPTP than males. We observed no significant associations between the adjusted GM concentrations of the metabolites and race/ethnicity. Both metabolite adjusted GM concentrations increased significantly with household income, and decreased significantly with age. Only household income was significantly associated with the concentrations of MECPP, but not of MEHHP, the two DEHP metabolites. The adjusted GM of the [MEHHTP]:[MECPTP] molar concentrations ratio increased with age, and was significantly higher in samples collected in the morning than in those collected in the afternoon or evening., Conclusions: Exposure to DEHTP is widespread in the U.S. general population 3 years and older. These data represent the first U.S. population-based representative background exposure to DEHTP., (Published by Elsevier Ltd.)

The widespread use of phosphodiesterase-5 inhibitors has attracted broad attention of counterfeiters to develop illicit erectile products with inaccurate amounts, unknown toxicity, and purity of active ingredients. Correspondingly, intake of these products endangers consumer health and needs to be screened for precautionary actions to reduce this risk. Therefore, in this study, a sensitive and rapid analytical method has been developed for simultaneous determination of selected phosphodiesterase-5 inhibitors present in illicit erectile medications and human urine. Quantification of the analytes was performed by liquid chromatography coupled with quadrupole-time-of-flight tandem mass spectrometry system. The chromatographic separation was successfully achieved with a run period of 8 min. Low detection limits were obtained in the range of 1.63-9.81 ng/g with relative standard deviations below 7.72% obtained using the replicate measurements of lowest concentration in calibration plots. The analytical performance of the proposed method proved good linearity, low detection limits, good accuracy and precision with high percent recoveries for human urine samples. Developed method was successfully applied to real samples including four different brands of illicit erectile medications. The results obtained revealed the presence of high levels of sildenafil in analyzed samples. The behaviors of selected phosphodiesterase-5 inhibitors were also studied in simulated gastric conditions., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

β-Ureidopropionase (βUP) deficiency is an autosomal recessive disease caused by abnormal changes in the pyrimidine-degradation pathway. This study aimed to investigate the mutation of β-ureidopropionase gene (UPB1) gene and clinical features of 7 Chinese patients with βUP deficiency.We reported 7 Chinese patients with βUP deficiency who were admitted at Tianjin Children's Hospital. Urine metabolomics was detected by gas chromatography-mass spectrometry (GC-MS). Then genetic testing of UPB1 was conducted by polymerase chain reaction (PCR) method.The patients presented with developmental delay, seizures, autism, abnormal magnetic resonance imaging, and significantly elevated levels of N-carbamyl-β-alanine and N-carbamyl-β-aminoisobutyric acid in urine. Subsequent analysis of UPB1 mutation revealed 2 novel missense mutations (c.851G>T and c.853G>A), 3 previously reported mutations including 2 missense mutations (c.977G>A and c.91G>A) and 1 splice site mutation (c.917-1 G>A).The results suggested that the UPB1 mutation may contribute to βUP deficiency. The c.977G>A is the most common mutation in Chinese population.

Objective: The aim of this study was to summarise the pharmacokinetic findings from eight phase I studies in healthy volunteers given oral AZD5069, a selective small-molecule CXCR2 antagonist., Methods: 240 healthy volunteers across eight phase I studies received single (0.1-200 mg) or multiple once- or twice-daily (10-120 mg) oral AZD5069 as solution, suspension, capsules or tablets. Pharmacokinetics were evaluated using non-compartmental analysis methods., Results: AZD5069 was rapidly absorbed (time to maximum concentration ~ 2 h) under fasting conditions. A high-fat, high-calorie meal delayed and reduced the peak plasma AZD5069 concentration (C max ) by 50%, but total exposure (AUC) was unchanged (fed:fasting geometric mean ratio 90% confidence interval within 0.80-1.25). The plasma concentration of AZD5069 declined with an initial half-life of 4 h and terminal half-life of 11 h. Steady-state plasma concentrations were achieved within 2-3 days and accumulation was ~ 1.1-fold with twice-daily dosing. Systemic exposure was approximately proportional to dose. Intra- and inter-subject variability in AUC was 3-11 and 29-64%, respectively. Less than 5% of the AZD5069 dose was excreted as parent drug in the urine. Elderly subjects had 39% higher AZD5069 AUC and 21% higher C max than younger adults. Japanese subjects had similar or slightly higher exposure to AZD5069 than Caucasian subjects. Co-administration with ketoconazole resulted in 2.1-fold higher AUC and 1.6-fold higher C max . All formulations had similar bioavailability., Conclusions: AZD5069 demonstrated predictive linear pharmacokinetics with low intra- and moderate inter-subject variability and no major influences from ethnicity, age, food or formulation. Half-life data indicated suitability for twice-daily dosing. CLINICALTRIALS., Gov Identifiers: NCT00953888, NCT01051505, NCT01083238, NCT01100047, NCT01332903, NCT01480739, NCT01735240, NCT01989520.

Aim: Although regulatory guidances require human metabolism information of drug candidates early in the development process, the human mass balance study (or hADME study), is performed relatively late. hADME studies typically involve the administration of a 14 C-radiolabelled drug where biological samples are measured by conventional scintillation counting analysis. Another approach is the administration of therapeutic doses containing a 14 C-microtracer followed by accelerator mass spectrometry (AMS) analysis, enabling hADME studies completion much earlier. Consequently, there is an opportunity to change the current drug development paradigm., Materials & Methods: To evaluate the applicability of the MICADAS-cAMS method, we successfully performed: the validation of MICADAS-cAMS for radioactivity quantification in biomatrices and, a rat ADME study, where the conventional methodology was assessed against a microtracer MICADAS-cAMS approach., Results & Discussion: Combustion AMS (cAMS) technology is applicable to microtracer studies. A favorable opinion from EMA to complete the hADME in a Phase I setting was received, opening the possibilities to change drug development.

1. The human urinary excretory amounts of total drug (parent + metabolites) were predicted for nine drugs with diverse chemical structures using simple allometry. The drugs used for scaling were cephapirin, olanzapine, labetolol, carisbamate, voriconazole, tofacitinib, nevirapine, ropinirole, and cyclindole. 2. The traditional allometric scaling was attempted using Y = aW b relationship. The corresponding predicted urinary amounts were converted into % recovery by using appropriate human dose. Appropriate statistical tests comprising of fold-difference (predicted/observed values) and error calculations (MAE and RMSE) were performed. 3. The interspecies scaling of all nine drugs tested showed excellent correlation (r > 0.9672). The predictions for eight out of nine drugs (exception was cephaphirin) were contained within 0.80-1.25 fold-differences. The MAE and RMSE were within ± 18% and 14.64%, respectively. 4. The present work supported the potential application of prospective allometry scaling to predict the urinary excretory amounts of the total drug and gauge any issues for the renal handling of the total drug.

Objective: Chemotherapy is less often prescribed in older individuals due to concerns about post-treatment morbidity and quality of life. We evaluated the physical performance of breast cancer survivors treated with and without adjuvant chemotherapy., Materials and Methods: We conducted a case-control study in 56 estrogen receptor positive breast cancer survivors (BCS) on adjuvant aromatase inhibitors 1-2years after definitive surgery. Cases had received adjuvant chemotherapy (n=27; age 70.5±3.6years) versus age-matched controls who had not (n=29; age 70.0±4.3years). Measures of grip strength, physical activity and performance, walking speed, fatigue, and self-reported physical function were collected. Biological correlates of inflammation, frailty and markers of DNA and RNA oxidation were compared., Results: Grip strength (controls: 21±7.4 vs., Cases: 29.7±5.0kg, p=0.20), physical activity (5403±3204 vs. 6801±9320steps/day, p=0.45), physical performance (short physical performance battery score: 10.1±1.8 vs. 10.4±1.1, p=0.52) and long-distance walking speed (1.2±0.21 vs. 1.3±0.41m/s, p=0.17) were similar between the two groups. Self-reported physical function was marginally lower in cases than controls (controls: 72±24 vs., Cases: 57±34AU, p=0.07). Fatigue disruptiveness was not different between groups (controls: 11.1±13.0 vs., Cases: 15.7±16.2AU, p=0.24). Similarly, the inflammation, oxidation, and frailty markers did not present a significant difference between groups, except for vitamin D levels (p=0.04)., Conclusion: Older women who received chemotherapy reported having slightly lower physical function, but a similar physical performance compared to women who did not. These data suggest that older BCS treated with chemotherapy recover to an extent similar to survivors who only received hormonal therapy., Competing Interests: and Conflict of Interest Statements: The authors have no conflicts to report., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Autism spectrum disorder (ASD) is still diagnosed through behavioral observation, due to a lack of laboratory biomarkers, which could greatly aid clinicians in providing earlier and more reliable diagnoses. Metabolomics on human biofluids provides a sensitive tool to identify metabolite profiles potentially usable as biomarkers for ASD. Initial metabolomic studies, analyzing urines and plasma of ASD and control individuals, suggested that autistic patients may share some metabolic abnormalities, despite several inconsistencies stemming from differences in technology, ethnicity, age range, and definition of "control" status., Methods: ASD-specific urinary metabolomic patterns were explored at an early age in 30 ASD children and 30 matched controls (age range 2-7, M:F = 22:8) using hydrophilic interaction chromatography (HILIC)-UHPLC and mass spectrometry, a highly sensitive, accurate, and unbiased approach. Metabolites were then subjected to multivariate statistical analysis and grouped by metabolic pathway., Results: Urinary metabolites displaying the largest differences between young ASD and control children belonged to the tryptophan and purine metabolic pathways. Also, vitamin B 6 , riboflavin, phenylalanine-tyrosine-tryptophan biosynthesis, pantothenate and CoA, and pyrimidine metabolism differed significantly. ASD children preferentially transform tryptophan into xanthurenic acid and quinolinic acid (two catabolites of the kynurenine pathway), at the expense of kynurenic acid and especially of melatonin. Also, the gut microbiome contributes to altered tryptophan metabolism, yielding increased levels of indolyl 3-acetic acid and indolyl lactate., Conclusions: The metabolic pathways most distinctive of young Italian autistic children largely overlap with those found in rodent models of ASD following maternal immune activation or genetic manipulations. These results are consistent with the proposal of a purine-driven cell danger response, accompanied by overproduction of epileptogenic and excitotoxic quinolinic acid, large reductions in melatonin synthesis, and gut dysbiosis. These metabolic abnormalities could underlie several comorbidities frequently associated to ASD, such as seizures, sleep disorders, and gastrointestinal symptoms, and could contribute to autism severity. Their diagnostic sensitivity, disease-specificity, and interethnic variability will merit further investigation.

Background and Objectives: The aim of this study was to investigate the pharmacokinetics, safety, and tolerability of riociguat after single and multiple oral doses of 1 or 2 mg three times daily (tid), and to determine the effect of smoking on riociguat pharmacokinetics in Chinese men., Methods: In a randomized, double-blind, placebo-controlled, single-center study stratified for smokers and non-smokers, healthy Chinese men aged 18-45 years received two riociguat doses: Dose Step 1 (1 mg) then Dose Step 2 (2 mg) conducted after the safety and tolerability at Dose Step 1 was confirmed. For each step, 12 subjects received riociguat and six received placebo. A single dose was given on Day 1, followed by a 48-h pharmacokinetic profile. Multiple-dose treatment tid was then given for 6 days (Days 3-8), with a last single dose on Day 9, followed by a 72-h pharmacokinetic profile. Primary outcomes were pharmacokinetic parameters for riociguat after single and multiple dosing., Results: Thirty-six subjects (18 smokers; 18 non-smokers) were randomized and provided valid pharmacokinetic data. Riociguat and its pharmacologically active metabolite M1 (BAY 60-4552) showed nearly dose-proportional pharmacokinetics. Accumulation was minimal in smokers and approximately two-fold in non-smokers. Exposure for riociguat was decreased by ≥60% in smokers. No serious or significant adverse events occurred during the study., Conclusions: Riociguat pharmacokinetics showed dose proportionality in healthy Chinese men, as previously demonstrated in healthy white male individuals. Exposure to riociguat was substantially decreased in smokers compared with non-smokers. Riociguat was well tolerated in Chinese men.

Pyrimidine diseases result from deficiencies in pyrimidine de novo synthesis, degradation, and salvage pathways. Enzymatic deficiencies in pyrimidine catabolism lead to mitochondrial neurogastrointestinal encephalopathy (MNGIE), pyrimidinuria, dihydropyrimidinuria, ureidopropionic aciduria, and other disorders. While MNGIE presents with gastrointestinal dysmotility, cachexia, and leukoencephalopathy, pyrimidinuria and dihydropyrimidinuria may show symptoms of epilepsy, autism, mental retardation, and dysmorphic features. The application of HPLC-MS/MS facilitates rapid screening of pyrimidine metabolites. Here we describe an LCMS method for determination of uracil, thymine, thymidine, dihydrouracil, and dihydrothymine that are diagnostic biomarkers of MNGIE, pyrimidinuria, and dihydropyrimidinuria.

1. The metabolism of the endothelin receptor antagonist macitentan has been characterized in bile duct-cannulated rats and dogs. 2. In both species, macitentan was metabolized along five primary pathways, i.e. conjugation with glucose (M9), oxidative depropylation (M6), aliphatic hydroxylation (M7), oxidative cleavage of the ethylene glycol linker (M4) and hydrolysis of the sulfamide moiety (M3). Most of the primary metabolites underwent subsequent biotransformation including conjugation with glucuronic acid or glucose, hydrolysis of the sulfamide group or secondary oxidation of the ethylene glycol moiety. 3. Though there were species differences in their relative importance, all metabolic pathways were present in rat and dog. The depropylated M6 was the only metabolite present in plasma of both species. 4. Metabolism was a prerequisite for macitentan excretion as relevant amounts of parent drug were neither detected in bile nor urine. Biliary excretion was the major elimination pathway, while renal elimination was of little importance.

Bipolar disorder (BD) is a complex debilitating mental disorder that is often misdiagnosed as major depressive disorder (MDD). Therefore, a large percentage of BD subjects are incorrectly treated with antidepressants in clinical practice. To address this challenge, objective laboratory-based tests are needed to discriminate BD from MDD patients. Here, a combined gas chromatography-mass spectrometry (GC-MS)-based and nuclear magnetic resonance (NMR) spectroscopic-based metabonomic approach was performed to profile urine samples from 76 MDD and 43 BD subjects (training set) to identify the differential metabolites. Samples from 126 healthy controls were included as metabolic controls. A candidate biomarker panel was identified by further analyzing these differential metabolites. A testing set of, 50 MDD and 28 BD subjects was then used to independently validate the diagnostic efficacy of the identified panel using an area under the receiver operating characteristic curve (AUC). A total of 20 differential metabolites responsible for the discrimination between MDD and BD subjects were identified. A panel consisting of six candidate urinary metabolite biomarkers (propionate, formate, (R*,S*)2,3-dihydroxybutanoic acid, 2,4-dihydroxypyrimidine, phenylalanine, and β-alanine) was identified. This panel could distinguish BD from MDD subjects with an AUC of 0.913 and 0.896 in the training and testing sets, respectively. These results reveal divergent urinary metabolic phenotypes between MDD and BD. The identified urinary biomarkers can aid in the future development of an objective laboratory-based diagnostic test for distinguishing BD from MDD patients.

The article presents data concerning new technique of diagnostic of diseases of metabolism of purines and pyrimidines using high performance liquid chromatography combined with electro-spray mass-spectrometry. The procedure of analysis is described in detail: from pre-analytical stage to interpretation of data of liquid chromatography mass-spectrometry, control of quality of data analysis, mass-spectrometry parameters and chromatographic conditions of analysis of purines, pyrimidines and their metabolites. The reference values are presented for purine and pyrimidine nucleosides and bases in urine of healthy individuals. The chemical structure of purines, pyrimidines and their metabolites and examples of chromato-mass-spectrograms under various hereditary disorders of metabolism of purines and pyrimidines are presented as well. The article is targeted to pediatricians of all profiles, medical geneticists and physicians of laboratory diagnostic.

Evasion of apoptosis is one of the six initially proposed hallmarks of cancer, and as such, a method to detect apoptosis in a tumour would be of considerable interest in both clinical trials of new cancer therapeutics, as well as for routine patient management. Activation of caspase-3/7 is a key biomarker of cellular apoptosis. Herein we describe the design, synthesis and initial characterisation of the first pyrimidoindolone compound for detection of caspase-3/7 activation using positron emission tomography.

Organic anion transporting polypeptides (OATPs) mediate hepatic drug uptake and serve as the loci of drug-drug interactions (DDIs). Consequently, there is a major need to develop animal models and refine in vitro-in vivo extrapolations. Therefore, the in vivo disposition of a model OATP substrate, [(3)H]rosuvastatin (RSV), was studied in the cynomolgus monkey and reported for the first time. After monkeys had received a 3-mg/kg oral dose, mass balance was achieved after bile duct cannulation (mean total recovery of radioactivity of 103.6%). Forty-two percent of the RSV dose was recovered in urine and bile, and the elimination pathways were similar to those reported for human subjects; 61.7%, 39.0%, and 2.9% of the dose was recovered in the feces, bile, and urine, respectively. The high levels of unchanged RSV recovered in urine and bile (26% of the dose) and the relatively low levels of metabolites observed indicated that RSV was eliminated largely by excretion. Also, for the first time, the in vitro inhibitory potential of cyclosporin A (CsA) toward cynomolgus monkey OATPs and sodium-taurocholate cotransporting polypeptide was studied in vitro (primary hepatocytes and transporter-transfected cells). It is concluded that one can study the CsA-RSV DDI in the cynomolgus monkey. For example, the in vitro IC50 values were within 2-fold (monkey versus human), and the increase (versus vehicle control) in the RSV AUC0-inf (6.3-fold) and Cmax (10.2-fold) with CsA (100 mg/kg) was similar to that reported for humans. The results further support the use of the cynomolgus monkey as a model to assess interactions involving OATP inhibition., (Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.)

A new, novel, rapid method to detect and direct readout of drugs in human urine has been developed using dynamic surface-enhanced Raman spectroscopy (D-SERS) with portable Raman spectrometer on gold nanorods (GNRs) and a classification algorithm called support vector machines (SVM). The high-performance GNRs can generate gigantic enhancement and the SERS signals obtained using D-SERS on it have high reproducibility. On the basis of this feature of D-SERS, we have obtained SERS spectra of urine and urine containing methamphetamine (MAMP). SVM model was built using these data for fast identified and visual results. This general method was successfully applied to the detection of 3, 4-methylenedioxy methamphetamine (MDMA) in human urine. To verify the accuracy of the model, drug addicts' urine containing MAMP were detected and identified correctly and rapidly with accuracy more than 90%. The detection results were displayed directly without analysis of their SERS spectra manually. Compared with the conventional method in lab, the method only needs a 2 μL sample volume and takes no more than 2 min on the portable Raman spectrometer. It is anticipated that this method will enable rapid, convenient detection of drugs on site for the police.

Fentanyl and its analogs, such as acetylfentanyl, have become a concern for potential abuse. Fentanyl compliance monitoring and urine drug testing are becoming increasingly necessary; however, a limited number of fentanyl immunoassays have been validated for clinical use. The purpose of this study was to validate the use of the DRI® fentanyl immunoassay, determine the potential cross-reactivity of acetylfentanyl and other pharmaceuticals, and investigate acetylfentanyl use in San Francisco. All urine toxicology samples from patients presenting to the emergency department were analyzed using the fentanyl immunoassay for 4 months. Positive samples were analyzed qualitatively using liquid chromatography-high resolution mass spectrometry (LC-HRMS) for fentanyl, fentanyl metabolites, fentanyl analogs and greater than 200 common drugs and metabolites. Subsequently, quantitative analysis was performed using LC-tandem mass spectrometry (LC-MS-MS). Acetylfentanyl, risperidone and 9-hydroxyrisperidone were found to cross-react with the fentanyl immunoassay. No acetylfentanyl was detected in our emergency department patient population. The fentanyl immunoassay demonstrated 100% diagnostic sensitivity in a subset of urines tested; however, the specificity was only 86% due to seven false-positive samples observed. Five of the seven samples were positive for risperidone and 9-hydroxyrisperidone. The DRI® fentanyl immunoassay can be used to screen for fentanyl or acetylfentanyl; however, confirmatory testing should be performed for all samples that screen positive., (© The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

1. The absorption, distribution, metabolism and excretion of a novel dipeptidyl peptidase IV inhibitor, gemigliptin, were examined following single oral administration of (14)C-labeled gemigliptin to rats. 2. The (14)C-labeled gemigliptin was rapidly absorbed after oral administration, and its bioavailability was 95.2% (by total radioactivity). Distribution to specific tissues other than the digestive organs was not observed. Within 7 days after oral administration, 43.6% of the administered dose was excreted via urine and 41.2% was excreted via feces. Biliary excretion of the radioactivity was about 17.7% for the first 24 h. After oral administration of gemigliptin to rats, the in vivo metabolism of gemigliptin was investigated with bile, urine, feces, plasma and liver samples. 3. The major metabolic pathway was hydroxylation, and the major circulating metabolites were a dehydrated metabolite (LC15-0516) and hydroxylated metabolites (LC15-0635 and LC15-0636).

Bipolar disorder (BD) is a common and debilitating mental disorder. However, there are no biomarkers available to aid in the diagnosis of this disorder. Here, we used a gas chromatography-mass spectrometry (GC-MS) based metabonomic method to characterize the urinary metabolic profiling of BD subjects and healthy controls to identify and validate urinary metabolite biomarkers for BD. Multivariate statistical analysis was used to visualize group discrimination and identify differentially expressed urinary metabolites in BD subjects relative to the healthy controls. Multivariate statistical analysis showed that the BD group was significantly distinguishable from the healthy control. Totally, 37 urinary metabolites responsible for discriminating BD subjects from healthy controls were identified. Interestingly, of 37 differential metabolites, 2,4-dihydroxypyrimidine was identified as an effective diagnostic biomarker for BD, yielding an area under the receiver operating characteristic curve (AUC) of 0.889 in the training samples (45 BD subjects and 61 healthy controls) and 0.805 in the test samples (26 BD subjects and 33 healthy controls). Our findings suggest that 2,4-dihydroxypyrimidine is a promising candidate urinary biomarker for BD, which may facilitate development of a urine-based diagnostic test for BD.

Tofacitinib is a novel, oral Janus kinase inhibitor. The objectives of this study were to summarize the pharmacokinetics and metabolism of tofacitinib in humans, including clearance mechanisms. Following administration of a single 50-mg (14)C-labeled tofacitinib dose to healthy male subjects, the mean (standard deviation) total percentage of administered radioactive dose recovered was 93.9% (±3.6), with 80.1% (±3.6) in the urine (28.8% parent), and 13.8% (±1.9) in feces (0.9% parent). Tofacitinib was rapidly absorbed, with plasma concentrations and total radioactivity peaking at around 1 hour after oral administration. The mean terminal phase half-life was approximately 3.2 hours for both parent drug and total radioactivity. Most (69.4%) circulating radioactivity in plasma was parent drug, with all metabolites representing less than 10% each of total circulating radioactivity. Hepatic clearance made up around 70% of total clearance, while renal clearance made up the remaining 30%. The predominant metabolic pathways of tofacitinib included oxidation of the pyrrolopyrimidine and piperidine rings, oxidation of the piperidine ring side-chain, N-demethylation and glucuronidation. Cytochrome P450 (P450) profiling indicated that tofacitinib was mainly metabolized by CYP3A4, with a smaller contribution from CYP2C19. This pharmacokinetic characterization of tofacitinib has been consistent with its clinical experience in drug-drug interaction studies.

Purpose: To explore, in a microdose (phase-0) study, the pharmacokinetics, bioavailability and concentrations in key compartments of the lung, of AR-709, a novel diaminopyrimidine antibiotic for the treatment of respiratory infection., Methods: Four healthy men each received two single, 100 μg microdoses of ¹⁴C-AR-709, 7 days apart: the first was administered intravenously (IV), the second orally. Plasma pharmacokinetics of ¹⁴C and unchanged AR-709 were obtained by high-performance liquid chromatography and accelerator mass spectrometry (AMS). Next, 15 healthy men received a single, 100 μg microdose of ¹⁴C-AR-709 IV. Plasma, bronchoalveolar lavage fluid, alveolar macrophages and bronchial mucosal biopsy samples were analysed by AMS., Results: After IV administration, clearance of AR-709 was 496 mL/min, volume of distribution was 1,700 L and the absolute oral bioavailability was 2.5 %. Excretion in urine was negligible. At 8-12 h after IV dosing, ¹⁴C concentrations in lung samples were 15- (bronchial mucosa) to 200- (alveolar macrophages) fold higher than in plasma. In alveolar macrophages, ¹⁴C was still mostly associated with AR-709 at 12 h after dosing., Conclusions: The results of this microdose study indicate that AR-709 attains concentrations appreciably higher within the lung than in plasma. Its low oral bioavailability however, precludes oral administration. Although IV administration would appear to be an effective route of administration, this would limit the use of AR-709 to a clinical setting and would therefore be economically unsustainable. If further clinical development were to be undertaken, therefore, an alternative route of administration would be necessary.

We reported one non fatal case (42 month old boy) of intoxication with diazinon following accidental ingestion. Diazinon and three of its metabolites (2 common metabolites with other organophosphate pesticides: diethylphosphate and diethylthiophosphate; one specific metabolite: 2-isopropyl-4-methyl-6-hydroxypyrimidine) were determined in serum and in urine, respectively, using three liquid chromatography-tandem mass spectrometry methods. Diazinon was detected in serum while its metabolites were detected in urine. The concentrations of diazinon and its common metabolites were compared to concentrations previously described in literature in the same intoxication context and were discussed. The concentration of the specific metabolite was compared to concentrations highlighted in occupational exposure, because to the best of our knowledge, we reported here the first urinary concentration of this metabolite in an acute intoxication context., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Gallic acid (GA) and its metabolites are polyphenolic compounds present in daily diets and herbal medicines. To understand the GA effects on the endogenous metabolism of mammals, we systematically analyzed the metabonomic responses of rat plasma, liver, urine, and feces to a single GA dosage of 120 and 600 mg/kg, which were below the no-obvious-adverse-effect-level of 1 g/kg for rats. Clinical chemistry and histopathological assessments were conducted to provide complementary information. Our results showed that GA intake induced significant metabonomic changes in multiple rat biological matrices. Such changes were more outstanding in liver than in the other matrices and clearly showed dose- and time-dependence. The results suggested GA-induced promotion of oxidative stress as the major effect. High-dose GA caused significant metabolic changes involving glycogenolysis, glycolysis, TCA cycle, and metabolism of amino acids, purines, and pyrimidines, together with gut microbiota functions. Low-dose GA only caused some urinary metabonomic changes and to a much less degree. The GA-induced liver metabonomic changes were not completely recoverable within a week, although such recovery completed in plasma, urine, and feces within 80 h. These findings provided new essential information on the effects of dietary polyphenols and demonstrated the great potential of this nutrimetabonomics approach.

Statins are a class of drugs mostly used for treating hyperlipidemia, and rosuvastatin is the newest drug in the market belonging to this class. In this present work, a method was developed based on the molecular fluorescence technique, with the objective to quantify rosuvastatin in urine samples. For this purpose, the study of several parameters was made to achieve the maximum analytical signal (under reaction with sulfuric acid during 40 min). Also, a previous step to avoid matrix interference was carried out (liquid-liquid extraction). The limit of detection (LOD) and the limit of quantification (LOQ) were 0.38 and 1.28 mg L(-1), respectively. Linear relationship between rosuvastatin concentration and it's fluorescence intensity was found until 5.0 mg L(-1). The proposed method was tested in several samples spiked with rosuvastatin and recovery was found in the range of 90 ± 10%.

Macitentan is a tissue-targeting, dual endothelin receptor antagonist, currently under phase 3 investigation in pulmonary arterial hypertension. In this study the disposition and metabolism of macitentan were investigated following administration of a single oral 10 mg dose of (14)C-macitentan to six healthy male subjects. The total radioactivity in matrices was determined using liquid scintillation counting. The proposed structure of metabolites was based on mass spectrometry characteristics and, when available, confirmed by comparison with reference compounds. Mean (± SD) cumulative recovery of radioactivity from faeces and urine was 73.6% (± 6.2%) of the administered radioactive dose, with 49.7% (± 3.9%) cumulative recovery from urine, and 23.9% (± 4.8%) from faeces. In plasma, in addition to parent macitentan, ACT-132577, a pharmacologically active metabolite elicited by oxidative depropylation and the carboxylic acid metabolite ACT-373898 were identified. In urine, four entities were identified, with the hydrolysis product of ACT-373898 as the most abundant one. In faeces, five entities were identified, with the hydrolysis product of macitentan and ACT-132577 as the most abundant one. Concentrations of total radioactivity in whole blood were lower compared to plasma, which indicates that macitentan and its metabolites poorly bind to or penetrate into erythrocytes.

Aim: Fimasartan is a selective angiotensin II receptor blocker. Hydrochlorothiazide (HCTZ), which is used to treat hypertension and edematous conditions, is coadministered with many antihypertensive agents., Methods: An open-label, randomized, multiple-dosing, 2-arm, 1-sequence, 2-period study was conducted to assess the effects of fimasartan (240 mg) on HCTZ (25 mg) or vice versa in 18 and 14 healthy male volunteers, respectively. During each drug administration period, drugs were given once daily for 7 days, with a 7-day washout period between the 2 administration periods., Results: The respective geometric mean ratios of fimasartan for AUC τ,ss and C max,ss with HCTZ were 1.30 [90% confidence interval (CI), 0.84-2.01] and 1.17 (90% CI, 0.93-1.47) compared with fimasartan alone. The respective geometric mean ratios of HCTZ for AUC τ,ss and C max,ss with fimasartan were 0.94 (90% CI, 0.84-1.04) and 0.88 (90% CI, 0.80-0.97) compared with HCTZ alone. Plasma renin activity indicated no significant differences between fimasartan monotherapy and coadministered treatment., Conclusions: Fimasartan administered alone or in combination with HCTZ was well tolerated at the described dosages. Coadministration of fimasartan increased the urinary excretion of HCTZ and urine volume, but these observations are unlikely to have any clinical relevance.

A series of 1,6-dihydropyrimidine-2-amine derivatives and 1,6-dihydropyrimidine-2-thiol derivatives were synthesized by the reaction of substituted 1,3-diphenylprop-2-en-1-one (chalcones) with guanidine hydrochloride and thiourea, respectively. All the synthesized compounds were in good agreement with elemental and spectral data. The synthesized compounds were screened in vivo for diuretic activity. The four compounds 2d, 2e, 3d and 3e, which showed moderate to good diuretic activity, were evaluated for their toxicity studies and none of the compounds showed any toxicity of the liver as compared with control. However, compounds 3e and 3d showed diuretic properties more than that of standard (acetazolamide) and were long acting. Overall, compound 3e, 6-(2,6-dichlorophenyl)-4-(pyridin-2-yl)-1,6-dihydropyrimidine-2-thiol, was found to be the most promising candidate of the series.

Low molecular weight luteinizing hormone (LMWLH) receptor agonists could be of interest as a potential doping substance for athletes. These orally active compounds induce the production of endogenous hormones such as testosterone in a similar way to LH. A method for the detection of these compounds needs to be direct as their effect--the excess production of endogenous hormones--cannot be proven by analysis techniques which test for endogenous hormones. In order to detect a broad range of potential LMWLH receptor agonists, a precursor ion monitoring liquid chromatography tandem mass spectrometry method was developed. The method was tested against a selection of urine samples to ascertain potential problems with background analytes interfering with the compounds of interests. Selected compounds were extracted with an established methodology from urine to determine suitability of implementing into general screening methodologies. The two available LMWLH receptor agonists could be detected at concentrations of 100 ng/ml in urine samples. This establishes a basic precursor ion monitoring method suitable for screening purposes for the detection of LMWLH receptor agonists in urine samples., (Copyright © 2011 John Wiley & Sons, Ltd.)

Background and Objectives: Fimasartan (BR-A-657) is a novel, non-peptide angiotensin II receptor antagonist with a selective type I receptor blockade effect. Two first-in-human studies investigated the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of fimasartan., Methods: Fasted single oral tablet doses of fimasartan 20-480 mg or placebo were administered to 40 healthy male subjects (aged 19-54 years) in a double-blind, randomized, sequential-group design. Subjects receiving fimasartan 240 mg also received the same treatment in the fed state after an interval of 7 days. In another study, oral tablet doses of fimasartan 120 and 360 mg or placebo were given once daily for 7 days to groups of eight fasted healthy male subjects (aged 20-55 years) in a double-blind, randomized, sequential-group design. Safety and tolerability were assessed. The PK and PD of fimasartan were also evaluated and compared for the different doses., Results: Fimasartan was safe and well tolerated, but with an increased incidence of low BP and postural dizziness for the 360 mg dose after repeated administration. Fimasartan produced increases in plasma renin activity, angiotensin I and II, which were not dose dependent. Maximal increases occurred between 6 and 8 hours post-dose, lasting up to 48 hours. Fimasartan was absorbed rapidly after all doses and had a multiphasic distribution. Two peaks in the plasma concentration-time profile were observed in most subjects. Steady state was achieved after three doses, and accumulation was minimal after repeated doses for 7 days (24-30%). The effective half-life ranged from 9.84 to 13.2 hours. The systemic exposure of fimasartan was dose proportional, and no marked food effect was noted after administration of 240 mg in the fed state. Urinary excretion of fimasartan was very low (1.74-2.51%), suggesting non-renal elimination., Conclusion: Fimasartan had a good safety profile and was well tolerated after fasted single oral doses of 20-480 mg, a fed single oral dose of 240 mg, and fasted repeated oral doses of 120 and 360 mg in healthy subjects. In addition, the PK and PD of fimasartan in this population were well characterized. Further studies are needed to evaluate the safety, efficacy, and dose-response relationship of fimasartan in patients with hypertension.

A pre-column dansylated ultra-performance liquid chromatography-electrospray ionization tandem mass spectrometry (UPLC-MS/MS) method for simultaneous determination of risperidone (RIP), 9-hydroxyrisperidone (9-OH-RIP), monoamine and amino acid neurotransmitters in human urine was developed with the aim of providing data on how neurotransmitters may influence each other or change simultaneously in response to risperidone treatment. MultiSimplex based on the simplex algorithm and the fuzzy set theory was applied to the optimization of chromatographic separation and dansyl derivatization conditions during method development. This method exhibited excellent linearity for all the analytes with regression coefficients higher than 0.997. The lower limit of quantification (LLOQ) values for 9-OH-RIP and RIP were 0.11 and 0.06 ng/ml, respectively, and for neurotrasmitters ranged from 0.31 to 12.8 nM. The mean accuracy ranged from 94.7% to 108.5%. The mean recovery varied between 81.6% and 97.5%. All the RSD of precision and stability were below 9.7%. Finally, the optimized method was applied to analyze the first morning urine samples of schizophrenic patients treated with risperidone and healthy volunteers., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Risperidone is currently one of the most frequently prescribed atypical antipsychotic drugs; its main active metabolite 9-hydroxyrisperidone contributes significantly to the therapeutic effects observed. An original analytical method is presented for the simultaneous analysis of risperidone and the metabolite in plasma, urine and saliva by high-performance liquid chromatography coupled to an original sample pre-treatment procedure based on micro-extraction by packed sorbent (MEPS). The assays were carried out using a C8 reversed-phase column and a mobile phase composed of 73% (v/v) acidic phosphate buffer (30 mM, pH 3.0) containing 0.23% triethylamine and 27% (v/v) acetonitrile. The UV detector was set at 238 nm and diphenhydramine was used as the internal standard. The sample pre-treatment by MEPS was carried out on a C8 sorbent. The extraction yields values were higher than 92% for risperidone and 90% for 9-hydroxyrisperidone, with RSD for precision always lower than 7.9% for both analytes. Limit of quantification values in the different matrices were 4 ng/mL or lower for risperidone and 6 ng/mL or lower for the metabolite. The method was successfully applied to plasma, urine and saliva samples from psychotic patients undergoing therapy with risperidone, with satisfactory accuracy results (recovery>89%) and no interference from other drugs. Thus, the method seems to be suitable for the therapeutic drug monitoring of schizophrenic patients using the three different biological matrices plasma, urine and saliva., (Copyright © 2010 Elsevier B.V. All rights reserved.)

The study of human metabolism of endo-8[bis(2-chlorophenyl)methyl]-3-(2-pyrimidinyl)-8-azabicyclo[3.2.1]octan-3-ol (SCH 486757) after a 200-mg oral dose of the drug to healthy volunteers in the first-in-human study is presented. The structural elucidation of two unique metabolites, which were detected in the process of metabolite characterization in human plasma and urine by liquid chromatography-mass spectrometry (LC-MS), is described. These metabolites (M27 and M34) were initially detected in human plasma at high levels (>35% of the LC-MS response of the parent drug). Additional LC-MS experiments (hydrogen/deuterium exchange and accurate mass measurement) were used to determine structures of metabolites. It was found that both metabolites were formed through a loss of the C-C bridge from the tropane moiety with the conversion into a substituted pyridinium compound. This metabolic process has not been reported previously. Because of the apparent high abundance of metabolites based on the LC-MS response, actual circulating amounts of these metabolites relative to the parent drug were determined semiquantitatively to evaluate their coverage in preclinical species. With the use of reference standards, it was shown that the LC-MS response of M27 and M34 in human plasma was much higher than that of the parent compound. Actual amounts of M27 and M34 metabolites were less than 5% of the level of the parent drug; therefore, additional assessment was not required.

Background: Methylmalonic aciduria combined with homocystinuria (MMA-HC) is the biochemical trait of a metabolic disorder resulting from impaired conversion of dietary cobalamin (cbl, or vitamin B12) to its two metabolically active forms. Effects on urinary purine and pyrimidine levels have not been described for this condition., Methods: Urine samples were collected from three patients with methylmalonic aciduria combined with homocystinuria and from 70 healthy subjects. Urinary purine and pyrimidine levels were quantitated by the use of LC/UV-Vis and LC/ESI/MS., Results: Higher urine levels of pyrimidines were detected with both methods in patients compared to controls., Conclusion: Methylmalonic aciduria with homocystinuria is due to deficiency of the enzyme, cobalamin reductase. The enzyme defect leads to altered hepatic metabolism, which appears to modify circulating pyrimidine levels., (Copyright 2010 Elsevier B.V. All rights reserved.)

Mental retardation (MR) is a common disorder frequently of unknown origin. Because there are few studies regarding MR and inborn errors of metabolism (IEM), we aimed to identify patients with IEM from a cohort of 944 patients with unexplained MR. Biochemical examinations such as determination of creatine (Cr) metabolites, acylcarnitines, purine, and pyrimidines in urine were applied. We found seven patients with IEM [three with cerebral Cr deficiency syndromes (CCDS)], one with adenylosuccinate lyase (ADSL) deficiency, and three, born before the neonatal metabolic screening program in Catalonia, with phenylketonuria (PKU). All told, they represent 0.8% of the whole cohort. All of them had additional symptoms such as epilepsy, movement disorders, autism, and other psychiatric disturbances. In conclusion, in patients with MR, it is essential to perform a thorough appraisal of the associated signs and symptoms, and in most disorders, it is necessary to apply specific analyses. In some cases, it is important to achieve an early diagnosis and therapy, which may reduce the morbimortality, and to offer genetic counselling.

This study has developed and validated an assay to quantify metabolites of the carbamate insecticide pirimicarb, whose residues are commonly found on a variety of food products, at levels that might be expected to arise from dietary exposure at or below the acceptable daily intake (ADI, 0.02mg/kg). A novel method for the determination of pirimicarb metabolites in human urine by liquid chromatography with mass spectrometry detection has been developed and validated. It has been used to quantify the elimination kinetics of 2-(dimethylamino)-5,6-dimethylpyrimidin-4-ol (DDHP) and 5,6-dimethyl-2-(methylamino)pyrimidin-4-ol (MDHP) in five volunteers given a single oral dose of pirimicarb at the ADI (0.02mg/kg). MDHP was found to be the major urinary metabolite. However, significant levels of conjugated MDHP and DDHP were released upon hydrolysis. Total MDHP and DDHP recovered over 48h accounted for 74% (range 32-123%) of the administered dose. Both free and conjugated metabolites exhibited similar excretion profiles, characterised by fairly short elimination half-lives (2.8-4.6h). Urinary excretion of MDHP and DDHP was almost complete within 24h. MDHP (either free or total) exhibited the least variability between volunteers. No clinically significant depressions in blood cholinesterases were detected during the dosing study. MDHP is recommended as a sensitive and specific biomarker for pirimicarb exposure, suitable for use in dietary or occupational surveys. We calculate that a 70kg person receiving a dose of pirimicarb at the ADI would be expected to have a 24h sample level of 111-157micromol/mol creatinine total MDHP or 56-95micromol/mol creatinine free MDHP (95% confidence interval)., (Crown Copyright 2009. Published by Elsevier Ireland Ltd. All rights reserved.)

Objective: The effect of trimethoprim, a potent organic cation transport inhibitor, on the pharmacokinetics (PK) of paliperidone extended-release tablets (paliperidone ER), an organic cation mainly eliminated via renal excretion, was assessed., Methods: Open-label, two-period, randomized, crossover study in 30 healthy males. Single dose of paliperidone ER 6 mg was administered either alone on day 1 or day 5 during an 8-day treatment period of trimethoprim 200 mg twice daily. Serial blood and urine samples were collected for PK and plasma protein binding of paliperidone and its enantiomers. The 90% confidence interval (CI) of ratios with/without trimethoprim for PK parameters of paliperidone and its enantiomers calculated., Results: Creatinine clearance decreased from 119 to 102 mL min(-1) with trimethoprim. Addition of trimethoprim increased unbound fraction of paliperidone by 16%, renal clearance by 13%, AUC(infinity) by 9%, and t((1/2)) by 19%. The 90% CIs for ratios with/without trimethoprim were within the 80-125% range for C(max), AUC(last), and renal clearance. For AUC(infinity), 90% CI was 79.37-101.51, marginally below the lower bound of the acceptance range. Paliperidone did not affect steady-state plasma concentrations of trimethoprim., Conclusions: No clinically important drug interactions are expected when paliperidone ER is administered with organic cation transport inhibitors.

Sleep disorders are common conditions that affect about 40 million people in the U.S every year, the most common of which is insomnia, which is characterized by difficulty falling or staying asleep. Zolpidem (Ambien) is a non-benzodiazepine prescription drug that is used to treat insomnia and is often preferred over the commonly used benzodiazepines due to a lesser side effect profile. This is because the non-benzodiazepine binding is more selective to GABA-A receptors versus the non-selective binding of benzodiazepines. With the increasing popularity of non-benzodiazepines, drug abuse and driving-while-impaired cases involving sleep-inducing drugs have risen. Therefore, a highly sensitive and rapid homogeneous immunoassay (EMIT-type assay) has been developed for the detection of zolpidem in urine. The zolpidem antibody is highly specific and does not cross-react with other newer sleep aids such as zopiclone and zaleplon. This assay has a detection limit of 5 ng/mL for zolpidem in urine. Further evaluation of this assay using liquid chromatography-tandem mass spectrometry (LC-MS-MS) analysis of authentic urine samples demonstrated that the accuracy of the assay is greater than 90%. Because this assay is designed to measure the non-conjugated drug in urine, it resulted in simplification for gas chromatography-MS or LC-MS-MS confirmation methods that do not require urine hydrolysis before solid-phase extraction or liquid-liquid extraction.