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Baloxavir marboxil (BXM) is a cap-dependent nucleic acid endonuclease inhibitor, which exerts its antiviral effects after being metabolized to its active form baloxavir acid (BXA). Ethylenediamine tetra-acetic acid (EDTA) and heparin are the two most used anticoagulants in clinical blood sample collection to estimate drug levels in plasma. However, compared to heparin plasma, there is a lack of clinical pharmacokinetic data of BXA using EDTA anticoagulant tubes for blood collection. In the present study, an efficient, rapid, and sensitive ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for simultaneous quantification of BXM and its active metabolite BXA in human plasma with its isotopic baloxavir-d5 (BXA-d5) as internal standard (IS). Plasma samples (50 μL) were undergone using acetonitrile containing 0.1 % formic acid a precipitant. Chromatographic separation was achieved by a Waters XBridge®C8 (2.1 mm × 50 mm, 2.5 µm) column. The gradient mobile phase was 0.1 % formic acid in water (A, pH 2.8) and 0.1 % formic acid in acetonitrile (B) and delivered at a flow rate of 0.6 mL/min for 4.5 min. BXM and BXA were monitored using a positive electrospray triple quadrupole mass spectrometer (TRIPLE QUAD™ 6500+) via multiple reaction monitoring mode. The mass-to-charge ratios (m/z) were 572.2→247.0, 484.2→247.0 and 489.2→252.0 for BXM, BXA, and BXA-d5 (IS). Calibration curves exhibited excellent linearity in the range of 0.1-10 ng/mL for BXM (r 2 > 0.996), and 0.3-300 ng/mL for BXA (r 2 > 0.998). Within-run and between-run precisions in coefficients of variations were less than 11.62 % for BXM and less than 7.47 % for BXA, and accuracies in relative error were determined to be within -7.78 % to 5.70 % for BXM and -6.67 % to 8.56 % for BXA. Extraction recovery efficiency was 92.76 % for BXM, 95.32 % for BXA, and 99.26 % for BXA-d5, respectively. The matrix effect of BXM and BXA was in line with the requirements, where the relative deviation of the accuracy was less than 6.67 % and the precision was less than 6.69 %. The validated efficient and simple UHPLC-MS/MS method was successfully used in the pharmacokinetic study of BXM and BXA in healthy human volunteers with K 2 EDTA and heparin tubes for blood collection. EDTA might compete with BXA for chelating metal ions and thereby decrease the plasma ratio in whole blood, leading to approximately 50 % lower measurement of pharmacokinetic parameters as compared with those obtained from heparin plasma anticoagulant tubes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Purpose: Pemigatinib (INCB054828), a potent and selective oral fibroblast growth factor receptor 1-3 inhibitor, is a Biopharmaceutical Classification System class II compound with good permeability and pH-dependent solubility that is predominantly metabolized by cytochrome P450 (CYP) 3A. Two drug-drug interaction studies, one with acid-reducing agents, esomeprazole (proton pump inhibitor [PPI]) and ranitidine (histamine-2 [H2] antagonist), and the other with potent CYP3A-modulating agents, itraconazole (CYP3A inhibitor) and rifampin (CYP3A inducer), were performed., Methods: Both were open-label, fixed-sequence studies conducted in up to 36 healthy participants each, enrolled into two cohorts (n = 18 each). Pemigatinib plasma concentration was measured, and pharmacokinetic parameters were derived by non-compartmental analysis., Results: There was an 88% and 17% increase in pemigatinib area under the plasma drug concentration-time curve (AUC) and maximum plasma drug concentration (C max ), respectively, with itraconazole, and an 85% and 62% decrease in pemigatinib AUC and C max with rifampin coadministration. There was a 35% and 8% decrease in pemigatinib AUC and C max , respectively, with esomeprazole, and a 2% decrease in C max and 3% increase in AUC with ranitidine coadministration. In both studies, all adverse events reported were grade ≤ 2., Conclusion: Coadministration with itraconazole or rifampin resulted in a clinically significant change in pemigatinib exposure. Therefore, coadministration of strong CYP3A inducers with pemigatinib should be avoided, and the dose of pemigatinib should be reduced if coadministration with strong CYP3A inhibitors cannot be avoided. The effect of PPIs/H2 antagonists on pemigatinib exposure was modest, and pemigatinib can be administered without regard to coadministration of PPIs/H2 antagonists., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Effective antiviral drugs for COVID-19 are still lacking. This study aims to evaluate the clinical outcomes and plasma concentrations of baloxavir acid and favipiravir in COVID-19 patients., Methods: Favipiravir and baloxavir acid were evaluated for their antiviral activity against SARS-CoV-2 in vitro before the trial initiation. We conducted an exploratory trial with 3 arms involving hospitalized adult patients with COVID-19. Patients were randomized assigned in a 1:1:1 ratio into baloxavir marboxil group, favipiravir group, and control group. The primary outcome was the percentage of subjects with viral negative by Day 14 and the time from randomization to clinical improvement. Virus load reduction, blood drug concentration and clinical presentation were also observed. The trial was registered with Chinese Clinical Trial Registry (ChiCTR 2000029544)., Results: Baloxavir acid showed antiviral activity in vitro with the half-maximal effective concentration (EC 50 ) of 5.48 μM comparable to arbidol and lopinavir, but favipiravir didn't demonstrate significant antiviral activity up to 100 μM. Thirty patients were enrolled. The percentage of patients who turned viral negative after 14-day treatment was 70%, 77%, and 100% in the baloxavir marboxil, favipiravir, and control group respectively, with the medians of time from randomization to clinical improvement was 14, 14 and 15 days, respectively. One reason for the lack of virological effect and clinical benefits may be due to insufficient concentrations of these drugs relative to their antiviral activities. One of the limitations of this study is the time from symptom onset to randomization, especially in the baloxavir marboxil and control groups, which is higher than the favipiravir group., Conclusions: Our findings could not prove a benefit of addition of either baloxavir marboxil or favipiravir under the trial dosages to the existing standard treatment., (Copyright © 2020. Published by Elsevier B.V.)

Buparlisib is a selective phosphoinositide 3 kinase inhibitor currently evaluated in clinical trials. We developed and validated an LC-MS/MS coupled with a one-step protein precipitation extraction method for the quantitation of buparlisib in rat plasma. After protein precipitation with acetonitrile, the plasma sample was analyzed using a Cortecs UPLC C 18 column, with acetonitrile-0.1% formic acid as the mobile phase system. Mass spectrometric detection was conducted in positive ionization mode, with target quantitative ion pair of m/z 411.2 → 367.2 for buparlisib. The calibration curve showed good linearity (1.0-3000 ng/ml), with acceptable accuracy (RE ranging from -6.2 to 5.9%) and precision (RSD within 8.2%) values at quality control concentrations. Extraction recovery from plasma was 80.9-88.7% and the matrix effect was negligible (92.6-95.2%). The validated method presented a simple quantification method of buparlisib in detail and utilized it for a pharmacokinetic study at three dose concentrations after oral administration in Wistar rats., (© 2020 John Wiley & Sons, Ltd.)

A sensitive method for quantitation of SK1326 in rat plasma has been established using ultra-performance liquid chromatography-electrospray ionization tandem mass spectrometry (UPLC-ESI/MS/MS). SK1326 and the internal standard (tramadol) in plasma sample were extracted using acetonitrile. A centrifuged upper layer was then evaporated and reconstituted with a mobile phase of 0.5% formic acid-acetonitrile (35:65, v/v). The reconstituted samples were injected into a C 18 reversed-phase column. Using MS/MS in the multiple reaction monitoring mode, SK1326 and tramadol were detected without severe interference from the rat plasma matrix. SK1326 produced a protonated precursor ion ([M + H] + ) at m/z 432.3 and a corresponding product ion at m/z 114.4. The internal standard produced a protonated precursor ion ([M + H] + ) at m/z 264.4 and a corresponding product ion at m/z 58.1. Detection of SK1326 in rat plasma by the UPLC-ESI/MS/MS method was accurate and precise with a quantitation limit of 1.0 ng/mL. The validation, reproducibility, stability and recovery of the method were evaluated. The method has been successfully applied to pharmacokinetic studies of SK1326 in rat plasma. The pharmacokinetic parameters of SK1326 were evaluated after intravenous (at a dose of 10 mg/kg) and oral (at a dose of 20 mg/kg) administration of SK1326 in rats. After oral administration (20 mg/kg) of SK1326, the F (fraction absorbed) value was ~77.1%., (© 2019 John Wiley & Sons, Ltd.)

Background: A LC-MS/MS method was validated for the quantification of SUVN-G3031, a novel H3 receptor inverse agonist in clinical development for the treatment of patients with narcolepsy, with and without cataplexy. Methodology: SUVN-G3031 was extracted from plasma following acetonitrile protein precipitation, separated by Ultra HPLC and quantified using positive ESI-MS/MS. Results: The method was linear across the range of 0.1-100 ng ml -1 in plasma. Results for intra and inter-day accuracy were from 99.8 to 104% and precision (%CV) was ≤10.6%. Conclusion: The method was applied to a first-in-human study in healthy volunteers. The method is precise, accurate and highly selective for the quantification of SUVN-G3031 in human plasma.

Background: SPH3127 is a novel direct renin inhibitor designed as an oral drug for the regulation of blood pressure and body fluid homeostasis via the renin-angiotensin-aldosterone system (RAAS). This candidate is now being evaluated in a phase I clinical trial in China., Objectives: The purpose of this study is to investigate detailed nonclinical pharmacokinetic data, and to predict human pharmacokinetic parameters., Methods: In vivo pharmacokinetic studies of SPH3127 were performed to investigate the exposure, absorption, clearance, distribution and metabolism after intravenous and oral administration in rats, beagle dogs and cynomolgus monkeys. The cynomolgus monkey pharmacokinetics/pharmacodynamics study was conducted to investigate the effect-concentration relationship of SPH3127. Its human pharmacokinetic properties were predicted employing an allometric scaling approach based on non-clinical species data. In vitro studies were also employed in a cytochrome P450 (CYP) enzyme phenotyping study, an inhibition and induction study, and a Caco-2 cell permeation and metabolites profile analysis., Results: After a single intravenous administration of SPH3127 in rats and monkeys, high clearance and volume of distribution and a short terminal elimination half-life were seen for both species. The oral bioavailability of SPH3127 to rats and monkeys was about 11.5-24.5% and 3.3-11.3%, respectively, with the short peak time, T max , ranging from 0.25 to 1.3 h. SPH3127 shows low permeability across Caco-2 cell membranes, and as the substrate of p-gp with apparent efflux characteristics. SPH3127 is mainly distributed in the gastrointestine, liver, kidney, pancreas and lung after oral dose in rats, and which decreased quickly to a 1% peak concentration during 12 h. The plasma protein binding ratio of SPH3127 is low as 11.7-14.8% for all species. Excretion studies in rats suggested that fecal, urine and bile excretion represented about 15% of the intake dose, indicating that SPH3127 undergoes extensive metabolism after oral dosing. Phenotyping data revealed that CYP3A4 was the most active enzyme catalyzing the metabolism of SPH3127. The key metabolites were likely N-hydroxylation (M8-7), mono-oxidation-dehydrogenation (M7-4) and mono-oxidation (M8-1, M8-2), both for in vitro liver microsome incubation of all species and in vivo results in rats. The in vitro CYP inhibition study only found very weak action for CYP3A4 (midazolam 1'-hydroxylation) and CYP3A4 (midazolam 6β-hydroxylation) with IC 50 of 56.8 µM and 41.1 µM, respectively. Monkey pharmacokinetic/pharmacodynamic data showed favorable safety margins when compared with the exposure of the effect dose and that of the monkey NOAEL level. Simple four-species allometric scaling led to predicted human plasma clearance and volume of distribution, and then simulated the oral human plasma concentration-time profile, which are both in good consistency with phase I clinical trial pharmacokinetic data., Conclusions: SPH 3127 has appropriate pharmacokinetic properties for further clinical exploration.

The prevalence of new psychoactive substances (NPS) on the illicit drug market continues to grow, with new analogs being routinely synthesized. Routes of administration for these compounds are also diversifying, and recent research has shown an increase in the incorporation of NPS into vaping liquids. Among the most commonly encountered NPS are the cathinone and fentanyl analogs. Fentanyl analogs in particular have been implicated in a significant number of deaths, usually in combination with other prescription and illicit drugs. We report the case of a 44-year-old male with a history of polysubstance abuse found deceased at his home address. Items located within the vicinity of the deceased were found to contain furanylfentanyl and 2-methyl-4'-(methylthio)-2-morpholinopropiophenone (MMMP also known as MTMP, MMTMP, Irgacure 907 and Caccure 907). Both of these compounds were detected in the post-mortem peripheral blood of the deceased: furanylfentanyl at 1.6 ng/mL and MMMP at 6.7 ng/mL. MMMP is an unrestricted, commercially available photo-initiator used in the printing and polymer industry, which structurally can be classed as a highly modified cathinone. Although MMMP has been found previously in drug seizures, this is the first fatality in which MMMP has been detected. A number of other prescription and illicit drugs were also detected in the blood. MMMP was not detected in the post-mortem urine; however three metabolites, beta-hydroxy-MMMP, beta-hydroxy-MMMP-sulfoxide and beta-hydroxy-MMMP-sulfone, were presumptively identified. The significance of MMMP to the cause of death is uncertain as its pharmacological and toxicological profile is unclear., (© The Author(s) 2018. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

In this open-label study (NCT02142920), we investigated the distribution, pharmacokinetics, and metabolism of the pan-class-I isoform phosphatidylinositol 3-kinase/mammalian target of rapamycin inhibitor gedatolisib (PF-05212384), following a single intravenous administration in healthy male subjects. A single, 89-mg, intravenous dose of gedatolisib was associated with a favorable safety profile in the 6 healthy subjects evaluated. Peak plasma concentrations for unchanged gedatolisib and total radioactivity were observed at the end of the 30-minute infusion. The only observed drug-related material in plasma was the parent drug, gedatolisib. Terminal half-life for plasma gedatolisib was ∼37 hours. Following the dose, 66%-73% of drug-related material was recovered in the feces. Metabolism of gedatolisib was trace; only 1 oxidative metabolite, M5, was identified in feces (<1% of total dose). Identification of gedatolisib in feces suggests that biliary and/or intestinal secretion of unchanged parent drug significantly contributes to gedatolisib clearance., (© 2018, The American College of Clinical Pharmacology.)

Imarikiren hydrochloride (TAK-272/ SCO-272) is a novel direct renin inhibitor. This randomized, double-blind, phase I study evaluated the safety and pharmacokinetics/pharmacodynamics of multiple oral administrations of imarikiren in healthy nonelderly (aged 20-45 years) and elderly (aged 65-85 years) Japanese male subjects. Subjects were randomized within 1 of 3 cohorts to receive imarikiren or placebo: Cohort 1 (imarikiren 80 mg; nonelderly), Cohort 2 (imarikiren 160 mg; nonelderly), or Cohort 3 (imarikiren 80 mg; elderly). Imarikiren or placebo was administered orally, once daily, for 7 days. Accumulation of imarikiren did not occur during the 7-day treatment period. Area under the plasma-concentration time curve and maximum plasma concentration of imarikiren were higher in elderly than in nonelderly subjects (52% and 39% higher, respectively). Inhibition of plasma renin activity was observed for 7 days and was maintained for at least 71 hours after the last imarikiren administration at the 80-mg (nonelderly and elderly) and 160-mg (nonelderly) doses. Plasma active renin concentration increased in nonelderly and elderly subjects; peak concentrations were higher on day 7 than on day 1. Increase from baseline in plasma active renin concentration was smaller in elderly than in nonelderly subjects during the 7-day treatment period and until 71 hours after last imarikiren administration. Treatment-emergent adverse events were reported in 33.3% (elderly) and 22.2% (nonelderly) of imarikiren subjects. Multiple oral administrations of imarikiren for 7 days were safe and well tolerated with no drug accumulation and strong and sustained suppression of plasma renin activity., (© 2018, The Authors. The Journal of Clinical Pharmacology published by Wiley Periodicals, Inc. on behalf of American College of Clinical Pharmacology.)

The mTOR signaling pathway has emerged as a possible therapeutic target for epilepsy. Clinical trials have shown that mTOR inhibitors such as everolimus reduce seizures in tuberous sclerosis complex patients with intractable epilepsy. Furthermore, accumulating preclinical data suggest that mTOR inhibitors may have anti-seizure or anti-epileptogenic actions in other types of epilepsy. However, the chronic use of rapalogs such as everolimus is limited by poor tolerability, particularly by immunosuppression, poor brain penetration and induction of feedback loops which might contribute to their limited therapeutic efficacy. Here we describe two novel, brain-permeable and well tolerated small molecule 1,3,5-triazine derivatives, the catalytic mTORC1/C2 inhibitor PQR620 and the dual pan-PI3K/mTOR inhibitor PQR530. These derivatives were compared with the mTORC1 inhibitors rapamycin and everolimus as well as the anti-seizure drugs phenobarbital and levetiracetam. The anti-seizure potential of these compounds was determined by evaluating the electroconvulsive seizure threshold in normal and epileptic mice. Rapamycin and everolimus only poorly penetrated into the brain (brain:plasma ratio 0.0057 for rapamycin and 0.016 for everolimus). In contrast, the novel compounds rapidly entered the brain, reaching brain:plasma ratios of ∼1.6. Furthermore, they significantly decreased phosphorylation of S6 ribosomal protein in the hippocampus of normal and epileptic mice, demonstrating effective mTOR inhibition. PQR620 and PQR530 significantly increased seizure threshold at tolerable doses. The effect of PQR620 was more marked in epileptic vs. nonepileptic mice, matching the efficacy of levetiracetam. Overall, the novel compounds described here have the potential to overcome the disadvantages of rapalogs for treatment of epilepsy and mTORopathies directly connected to mutations in the mTOR signaling cascade., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Open-label single- and double-blind repeat-dose studies in healthy female volunteers were conducted to investigate the pharmacokinetics (PK) and safety/tolerability of epelsiban total daily doses ranging from 600 to 900 mg. In 1 study (n = 12), epelsiban was dosed at 300 or 450 mg twice daily (every 12 hours) for a single day. In the repeat-dose double-blind study, epelsiban and placebo were administered to 31 subjects as 200 mg 3 times daily, 300 mg 3 times daily (TID), or 450 mg twice daily (BID) for 14 days. After both single and 14 daily repeat doses, the PK profiles for epelsiban and its metabolite, GSK2395448, remained linear at all administered doses. The exposures at a given total daily dose were also similar between BID and TID dosing regimens. Exposure (AUC 0-τ ), based on dosing intervals, for both epelsiban and GSK2395448 was similar. However, compared with morning dosing, C max was lower after evening dosing, possibly because of a food effect. The highest accumulation of epelsiban and GSK2395448 exposures (AUC 0-τ ) was approximately 34% for each after repeat dosing, consistent with the short half-life. At total daily doses of 600 and 900 mg, epelsiban was generally well tolerated, and there were no significant safety concerns identified., (© 2017, The American College of Clinical Pharmacology.)

Background and Purpose: AZD8055 is a potent orally available mTOR kinase inhibitor with in vitro and in vivo antitumour activity against a range of tumour types. Preclinical studies showed that AZD8055 induced a dose-dependent pharmacodynamic effect in xenograft models in vivo, but a lack of understanding of the relative contributions of the maximum inhibition of the biomarkers and the duration of inhibition to the antitumour effect, limited the rational design of experiments to optimize the dose and schedules of treatment., Experimental Approach: In this study, a mathematical modelling approach was developed to relate pharmacodynamics and antitumour activity using preclinical data generated in mice bearing U87-MG xenografts., Key Results: Refinement and validation of the model was carried out in a panel of additional human tumour xenograft models with different growth rates and different sensitivity to AZD8055 (from partial growth inhibition to regression). Finally, the model was applied to accurately predict the efficacy of high, intermittent dosing schedules of AZD8055., Conclusions and Implications: Overall, this new model linking pharmacokinetics, pharmacodynamic biomarkers and efficacy across several tumour xenografts with different sensitivity to AZD8055 was able to identify the optimal dose and route of administration to maximize the antitumour efficacy in preclinical models and its potential for translation into man., (© 2017 The British Pharmacological Society.)

Pholcodine is an opiate derivative drug which is widely used in pediatric medicine. In this study, a chemiluminescence (CL) method is described that determines pholcodine in human plasma and syrup samples. This method is based on the fact that pholcodine can greatly enhance the weak CL emission of reaction between tris(1,10 phenanthroline)ruthenium(II), Ru(phen) 3 2+ , and acidic Ce(IV). The CL mechanism is described in detail using UV-vis light, fluorescence and CL spectra. Effects of chemical variables were investigated and under optimum conditions, CL intensity was proportional to the pholcodine concentration over the range 4.0 × 10 -8 to 8.0 × 10 -6  mol  L -1 . The limit of detection (LOD) (S/N = 3) was 2.5 × 10 -8  mol  L -1 . Percent of relative standard deviations (%RSD) for 3.0 × 10 -7 and 3.0 × 10 -6  mol  L -1 of pholcodine was 2.9 and 4.0%, respectively. Effects of common ingredients were investigated and the method was applied successfully to the determination of pholcodine in syrup samples and human plasma., (Copyright © 2016 John Wiley & Sons, Ltd.)

Hydrogen sulfide (H 2 S) is involved in blood pressure regulation. We evaluated hemodynamic effects of Na 2 S and morpholin-4-ium (4-methoxyphenyl)(morpholino)phosphinodithioate (GYY4137), H 2 S donors. GYY4137 is the most widely studied slow-releasing H 2 S donor, however, its ability to release H 2 S under physiological conditions is unclear. Hemodynamics were recorded in anaesthetized Wistar-Kyoto rats at baseline and after intravenous (IV) or intraperitoneal (IP) administration of either a vehicle (20% dimethyl sulfoxide), GYY4137 or Na 2 S. The stability of GYY4137 in buffers and in plasma was evaluated with nuclear magnetic resonance. The vehicle, as well as GYY4137, given IV did not affect mean arterial blood pressure (MABP), whereas Na 2 S produced a significant decrease in MABP. Similarly, IP given Na 2 S, but not GYY4137, lowered MABP. In the buffers at pH of 7.4 and 5.5 and in rat plasma no reaction of GYY4137 was found during 18 hours of observation. In contrast, rapid decomposition of GYY4137 occurred in buffers at pH 2.0. In conclusion, parenteral GYY4137 does not exert a hemodynamic effect in Wistar-Kyoto rats. This seems to be due to the high stability of GYY4137 at physiological pH. Therefore, it is likely that widely reported biological effects of GYY4137 are not H 2 S-dependent but may depend on GYY4137 itself. However, the H 2 S-dependent biological effects of GYY4137 may be expected in tissues characterized by low pH.

We evaluated the effects of ACEA (selective cannabinoid (CB) 1 receptor agonist), WIN 55,212-2 mesylate (WIN; non-selective CB 1 and CB 2 receptor agonist) and N-palmitoylethanolamine (PEA; an endogenous fatty acid of ethanolamide) in DBA/2 mice, a genetic model of reflex audiogenic epilepsy. PEA, ACEA or WIN intraperitoneal (i.p.) administration decreased the severity of tonic-clonic seizures. We also studied the effects of PEA, WIN or ACEA after co-administration with NIDA-41020 (CB 1 receptor antagonist) or GW6471 (PPAR-α antagonist) and compared the effects of WIN, ACEA and PEA in order to clarify their mechanisms of action. PEA has anticonvulsant features in DBA/2 mice mainly through PPAR-α and likely indirectly on CB 1 receptors, whereas ACEA and WIN act through CB 1 receptors. The co-administration of ineffective doses of ACEA, PEA and WIN with some antiepileptic drugs (AEDs) was examined in order to identify potential pharmacological interactions in DBA/2 mice. We found that PEA, ACEA and WIN co-administration potentiated the efficacy of carbamazepine, diazepam, felbamate, gabapentin, phenobarbital, topiramate and valproate and PEA only also that of oxcarbazepine and lamotrigine whereas, their co-administration with levetiracetam and phenytoin did not have effects. PEA, ACEA or WIN administration did not significantly influence the total plasma and brain levels of AEDs; therefore, it can be concluded that the observed potentiation was only of pharmacodynamic nature. In conclusion, PEA, ACEA and WIN show anticonvulsant effects in DBA/2 mice and potentiate the effects several AEDs suggesting a possible therapeutic relevance of these drugs and their mechanisms of action., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Objective The clinical part of this study aimed to investigate whether the racemate of delmopinol [(±)-delmopinol] is equivalent to its two enantiomers [(+)-delmopinol and (-)-delmopinol] with respect to efficiency and to determine and compare their pharmacokinetic properties. The purpose of the pre-clinical part was to elucidate possible differences in antimicrobial efficiency. Materials and methods The compounds were tested clinically in a double-blind, randomized, cross-over study comprising three treatment periods of 4 days each. The antimicrobial efficacy of the enantiomers was compared in vitro with respect to planktonic and biofilm bacteria of different species. Results No statistically significant differences in prevention of plaque formation were observed. Except for a somewhat higher systemic exposure in terms of AUC and Cmax indicated for (-)-delmopinol compared to (+)-delmopinol, the pharmacokinetic properties were similar. The most common adverse event was a transient anaesthetic feeling in the mouth. This event was reported with the same frequency for all three test solutions. The enantiomers showed similar antimicrobial effects on planktonic bacteria and their biofilms. Conclusions The enantiomers were found to be equally effective with respect to inhibition of plaque development and only minor differences were observed with respect to their pharmacokinetic properties. No differences could be observed in the adverse events reports. There is, therefore, no reason to use one of the enantiomers of delmopinol instead of the racemate. This was further supported by the antimicrobial tests. It is suggested that the combined action of cationic and neutral delmopinol is important for its effect on biofilms.

Chronic treatment with the monoamine releaser d-amphetamine has been consistently shown to decrease cocaine self-administration in laboratory studies and clinical trials. However, the abuse potential of d-amphetamine is an obstacle to widespread clinical use. Approaches are needed that exploit the efficacy of the agonist approach but avoid the abuse potential associated with dopamine releasers. The present study assessed the effectiveness of chronic oral administration of phendimetrazine (PDM), a pro-drug for the monoamine releaser phenmetrazine (PM), to decrease cocaine self-administration in four rhesus monkeys. Each day, monkeys pressed a lever to receive food pellets under a 50-response fixed-ratio (FR) schedule of reinforcement and self-administered cocaine (0.003-0.56 mg/kg per injection, i.v.) under a progressive-ratio (PR) schedule in the evening. After completing a cocaine self-administration dose-response curve, sessions were suspended and PDM was administered (1.0-9.0 mg/kg, p.o., b.i.d.). Cocaine self-administration was assessed using the PR schedule once every 7 days while food-maintained responding was studied daily. When a persistent decrease in self-administration was observed, the cocaine dose-effect curve was re-determined. Daily PDM treatment decreased cocaine self-administration by 30-90% across monkeys for at least 4 weeks. In two monkeys, effects were completely selective for cocaine. Tolerance developed to initial decreases in food-maintained responding in the third monkey and in the fourth subject, fluctuations were observed that were lower in magnitude than effects on cocaine self-administration. Cocaine dose-effect curves were shifted down and/or rightward in three monkeys. These data provide further support for the use of agonist medications for cocaine abuse, and indicate that the promising effects of d-amphetamine extend to a more clinically viable pharmacotherapy., (Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.)

Background: Many HIV infected individuals with suppressed viral loads experience chronic immune activation frequently developing neurological impairment designated as HIV associated neurocognitive disorder (HAND). Adjunctive therapies may reduce HIV associated inflammation and therefore decrease the occurrence of HAND., Methods: We have conducted in vitro, animal and clinical studies of the neurokinin 1 receptor (NK1R) antagonist aprepitant in HIV/SIV infection., Results: Aprepitant inhibits HIV infection of human macrophages ex vivo with an ED50 ~ 5 µM. When administered at 125 mg once daily for 12 months to SIV-infected rhesus macaques, aprepitant reduced viral load by approximately tenfold and produced anti-anxiolytic effects. The anti-viral and anti-anxiolytic effects occur at approximately the third month of dosing; and the effects are sustained throughout the duration of drug administration. Protein binding experiments in culture media and animal and human plasma indicate that the free fraction of aprepitant is lower than previously reported supporting usage of higher doses in vivo. The analysis of blood samples from HIV positive individuals treated for 2 weeks with aprepitant at doses up to 375 mg demonstrated reduced levels of pro-inflammatory cytokines including G-CSF, IL-6, IL-8 and TNFα. Decreased pro-inflammatory cytokines may reduce HIV comorbidities associated with chronic inflammation., Conclusions: Our results provide evidence for a unique combination of antiretroviral, anti-inflammatory and behavioral modulation properties of aprepitant in vitro and in vivo. These results provide robust support for a clinical exposure target above that recommended for chemotherapy-induced nausea and vomiting. Doses up to 375 mg once daily in HIV-infected patients still elicit sub-therapeutic exposure of aprepitant though effective plasma concentrations can be achievable by proper dose modulation.

Over the years there has been a growing interest in the therapeutic potential for central nervous system pathologies of sigma receptor modulators. The widely studied PRE-084 and our compounds RC-33 and RC-34 are very potent and selective sigma 1 receptor agonists that could represent promising drug candidates for Amyotrophic Lateral Sclerosis (ALS). Herein, we develop and validate robust and easy-to-use reverse-phase chromatographic methods suitable for detecting and quantifying PRE-084, RC-33 and RC-34 in mouse blood, brain and spinal cord. An HPLC/UV/ESI-MS system was employed for analyzing PRE-084 and an HPLC/UV-PDA system for determining RC-33 and RC-34. Chromatographic separations were achieved on Waters Symmetry RP18 column (150 × 3.9 mm, 5 µm), eluting with water and acetonitrile (both containing 0.1% formic acid) in gradient conditions. The recovery of PRE-084, RC-33 and RC-34 was >95% in all the considered matrices. Their limits of quantitation and detection were also determined. Validation proved the methods be suitable for separating tested compounds from endogenous interferences, being characterized by good sensitivity, linearity, precision and accuracy. A preliminary central nervous system distribution study showed a high distribution of RC-33 in brain and spinal cord, with concentration values well above the determined limit of quantitation. The proposed methods will be used in future preclinical investigations., (Copyright © 2015 John Wiley & Sons, Ltd.)

The pharmacokinetics (PK) and safety of single-dose buparlisib (30 mg) were assessed in subjects with mild to severe hepatic impairment (n = 6 each) relative to healthy controls (n = 13). Blood samples were collected until 336 hours postdose and evaluated by liquid chromatography tandem mass spectrometry. PK parameters (including area under the curve [AUC∞ ] and Cmax ) were derived using noncompartmental analysis. Buparlisib was rapidly absorbed in all groups (median Tmax 1.0-1.3 h). Buparlisib exposure (AUC∞ ) was moderately increased in subjects with mild (geometric mean ratio [GMR] 1.16; 90%CI 0.81, 1.65), moderate (GMR 1.14; 90%CI 0.80, 1.63), or severe (GMR 1.20; 90%CI 0.84, 1.72) hepatic impairment, relative to healthy controls. Apparent oral clearance was similar across groups. Due to a higher unbound fraction in the severe group (0.21) than all other groups (0.17), subjects with severe hepatic impairment had greater exposure to unbound buparlisib (GMR relative to healthy controls: AUC∞ 1.52; 90%CI 1.09, 2.13; Cmax 1.83; 90%CI 1.42, 2.36). The results indicate that a buparlisib dose adjustment may not be necessary for patients with mild to moderate hepatic impairment. The safety and therapeutic indices should be considered before determining if a dose adjustment is appropriate for patients with severe hepatic impairment., (© 2015 The Authors. The Journal of Clinical Pharmacology Published by Wiley Periodicals, Inc. on behalf of American College of Clinical Pharmacology.)

The objective of this study was to describe the population pharmacokinetics (PK) of mosapride under fasting and fed conditions. A single 5-mg oral dose of mosapride was administered to fasted (n = 15) and fed (n = 12) beagle dogs. Plasma concentrations of mosapride were subsequently measured by liquid chromatography-tandem mass spectrometry. Data were analyzed using modeling approaches with the NONMEM 7.2 software. A one-compartment open PK model utilizing model event time (MTIME) with first-order absorption and first-order elimination was found to be more appropriate than all other PK models tested. The absorption rate constants of mosapride were significantly decreased under fed conditions, compared to fasting conditions. The observed bootstrap medians of PK parameters were generally consistent with the corresponding population mean estimates. Furthermore, with the exception of some mosapride concentrations, most of observed data fell into the range of the 5th and 95th percentiles of the simulated values. Overall, the final model was able to describe the observed mosapride concentrations reasonably well. These findings suggest that food intake affects both the rate and extent of absorption of mosapride and that the pharmacological effect of mosapride can differ significantly depending on food intake., (© 2015 John Wiley & Sons Ltd.)

Norepinephrine, a neurotransmitter in the autonomic sympathetic nervous system, is deaminated by monoamine oxidase to 3,4-dihydroxyphenylglycol (DHPG). Inhibition of the NE transporter (NET) using DHPG as a biomarker was evaluated using atomoxetine, duloxetine, and edivoxetine as probe NET inhibitors. Pharmacokinetic and pharmacodynamic data were obtained from healthy subjects (n = 160) from 5 clinical trials. An indirect response model was used to describe the relationship between drug plasma concentration and DHPG concentration in plasma and cerebrospinal fluid (CSF). The baseline plasma DHPG concentration (1130-1240 ng/mL) and Imax (33%-37%) were similar for the 3 drugs. The unbound plasma drug IC50 (IC50U ) based on plasma DHPG was 0.973 nM for duloxetine, 0.136 nM for atomoxetine, and 0.041 nM for edivoxetine. The baseline CSF DHPG concentration (1850-2260 ng/mL) was similar for the 3 drugs, but unlike plasma DHPG, the Imax for DHPG was 38% for duloxetine, 53% for atomoxetine, and75% for edivoxetine. The IC50U based on CSF DHPG was 2.72 nM for atomoxetine, 1.22 nM for duloxetine, and 0.794 nM for edivoxetine. These modeling results provide insights into the pharmacology of NET inhibitors and the use of DHPG as a biomarker., (© 2015, The American College of Clinical Pharmacology.)

An open-label single- and repeat-dose study was conducted to investigate the pharmacokinetics, safety, and tolerability of ascending doses of epelsiban in healthy female volunteers (n = 48). The pharmacokinetics of the epelsiban metabolite, GSK2395448, were also assessed. Epelsiban was readily absorbed and parent and metabolite readily appeared in plasma. The parent drug's median tmax was approximately 0.5 hours, and the metabolite's median tmax ranged from 0.5 to 1.0 hours post-parent dosing. Both epelsiban and GSK2395448 had rapid elimination half-lives, ranging between 2.66 and 4.85 hours. The metabolite:parent ratios for exposure (AUC and Cmax ) ranged from approximately 70% to greater than 100%, and therefore, GSK2395448 is considered a major metabolite of epelsiban. Mean epelsiban and GSK2395448 AUC values increased in a dose-proportional manner following both single-dose administration from 10 to 200 mg and repeat administration from 10 to 150 mg following twice daily or 4-times-daily dosing. Single-dose epelsiban pharmacokinetics in women was similar to single-dose pharmacokinetics previously observed in men. Epelsiban was generally well tolerated, and no events of clinical concern were observed in volunteers dosed in this study. The safety findings were consistent with the previous study in men, with headache the most commonly reported adverse effect., (© 2015, The American College of Clinical Pharmacology.)

This study was performed to determine the pharmacokinetic profile of mosapride in fasting and fed states. A single 5-mg oral dose of mosapride was administered to fasted (n = 15) and fed (n = 12) beagle dogs, and the plasma concentrations of mosapride were measured by liquid chromatography-tandem mass spectrometry. The resultant data were analyzed by noncompartmental analysis (NCA). Mosapride was absorbed in fasted and fed dogs with similar Tmax . Both Cmax and AUC were significantly higher in the fasting group than in fed dogs, being four times (10.51 μg/mL vs. 2.76 μg/mL) and 3.5 times higher (38.53 h · μg/mL vs. 10.22 h · μg/mL), respectively. These findings suggest that food intake affects the pharmacokinetics of mosapride and that the dosage regimen for this drug need to be reconsidered., (© 2015 John Wiley & Sons Ltd.)

Pharmacokinetic properties of imidazobenzimidazole derivative compound RU-1205 were investigated after subcutaneous administration to rabbits as a substance and a dosage form (lyophilisates for injection) at a dose of 25 mg/kg. The lyophilisate was characterized by high values of the relative bioavailability. In tests, the "hot plate" and "vinegar cramps" the dosage form and the substance exhibited the same analgesic effect.

A high-throughput ultra-performance liquid chromatography coupled to tandem mass spectrometry (LC-ESI-MS-MS) method was developed for the determination of pinaverium bromide in human plasma. Protein precipitation with acetonitrile was used to extract pinaverium and itraconazole (as internal standard) from 500 µL plasma samples. The chromatographic separation was achieved with an Acquity UPLC BEH C18 column (1.7 µm, 2.1 × 100 mm) using a mixture of acetonitrile-5 mM ammonium formate (80:20, v/v) as mobile phase. Isocratic elution at 0.3 mL/min was used. Detection was performed by positive ion electrospray tandem mass spectrometry on a XEVO TQ-S by multiple reaction monitoring mode. The mass transitions monitorized were as follows: m/z 511.2 → 230 for pinaverium bromide, and m/z 705.29 → 392.18 for the itraconazole. The method was validated over a concentration range of 12-12,000 pg/mL. The chromatographic method runtime is 2.5 min and was applied to characterize the pharmacokinetics of pinaverium bromide after the oral administration of 100 mg to healthy Mexican subjects., (© The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: E-52862 is a Sigma-1 receptor antagonist (S1RA) currently under investigation as a potential analgesic medicine. We successfully applied a concentration-effect model retrospectively to a four-way crossover Phase I single ascending dose study and utilized the QTc shortening effects of a meal to demonstrate assay sensitivity by establishing the time course effects from baseline in all four periods, independently from any potential drug effects., Methods: Thirty two healthy male and female subjects were included in four treatment periods to receive single ascending doses of 500 mg, 600 mg or 800 mg of E-52862 or placebo. PK was linear over the dose range investigated and doses up to 600 mg were well tolerated. The baseline electrocardiography (ECG) measurements on Day-1 were time-matched with ECG and pharmacokinetic (PK) samples on Day 1 (dosing day)., Results: In this conventional mean change to time-matched placebo analysis, the largest time-matched difference to placebo QTcI was 1.44 ms (90% CI: -4.04, 6.93 ms) for 500 mg; -0.39 ms (90% CI: -3.91, 3.13 ms) for 600 mg and 1.32 ms (90% CI: -1.89, 4.53 ms) for 800 mg of E-52862, thereby showing the absence of any QTc prolonging effect at the doses tested. In addition concentration-effect models, one based on the placebo corrected change from baseline and one for the change of QTcI from average baseline with time as fixed effect were fitted to the data confirming the results of the time course analysis., Conclusion: The sensitivity of this study to detect small changes in the QTc interval was confirmed by demonstrating a shortening of QTcF of -8.1 (90% CI: -10.4, -5.9) one hour and -7.2 (90% CI: -9.4, -5.0) three hours after a standardised meal., Trial Registration: EU Clinical Trials Register EudraCT 2010 020343 13.

Background: Use of vitamin K antagonists for the prevention of stroke and systemic embolism in dialysis patients with nonvalvular atrial fibrillation is controversial. However, no good alternatives presently are available. The anti-factor Xa antagonist rivaroxaban is contraindicated for lack of pharmacokinetic, pharmacodynamic, and clinical data. This study aims to characterize the pharmacokinetics/pharmacodynamics of rivaroxaban in maintenance hemodialysis patients., Study Design: Pharmacokinetic and pharmacodynamic study., Setting & Participants: 18 maintenance hemodialysis patients without residual kidney function at 2 centers. DRUG ADMINISTRATION, OUTCOMES, & MEASUREMENTS: (1) A single dose of 10mg of rivaroxaban was administered at the end of each of 3 consecutive dialysis sessions and area under the curve (AUC) and the effect on coagulation parameters were measured for 44 hours thereafter. (2) A single dose of 10mg of rivaroxaban was given 6 to 8 hours before a dialysis session and the effect of dialysis on rivaroxaban concentrations was evaluated. (3) To assess potential accumulation, 10mg of rivaroxaban was given once daily and AUC was measured during 24 hours on days 1 and 7., Results: Mean AUC0-44 of rivaroxaban plasma concentrations after a single dose of 10mg was 2,072μg/L/h, mean maximum concentration was 172.6μg/L, and mean terminal elimination half-life was 8.6 hours. Dialysis had no appreciable effect on rivaroxaban plasma concentrations. Mean trough concentration after multiple daily doses of 10mg was 20.2μg/L., Limitations: Higher rivaroxaban doses and patients with substantial residual kidney function were not studied., Conclusions: A 10-mg dose of rivaroxaban in hemodialysis patients without residual kidney function results in drug exposure similar as published for 20mg in healthy volunteers. Rivaroxaban is not eliminated by dialysis. There is no accumulation after multiple daily dosing. The efficacy and safety of rivaroxaban in hemodialysis patients should be the subject of a large randomized trial., (Copyright © 2015 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Objectives: The (+)-isomer of indeloxazine AS1069562 has multiple pharmacological actions, such as serotonin (5-HIT) and norepinephrine (NE) reuptake inhibition and analgesic effects in animal models of neuropathic pain. Here, we investigated the analgesic effects of AS1069562 in rat models of inflammatory and noninflammatory nociceptive pain., Methods: Adjuvant-induced arthritis (AIA) and bradykinin-induced knee joint pain were used as rat models of inflammatory pain. The chronic phase of monoiodoacetate-induced arthritis (MIA) was used as a rat model of noninflammatory pain. Analgesic effects were evaluated by weight-bearing deficit in the AIA and MIA models and by pain response in the bradykinin-induced knee joint pain model., Results: In the AIA model and the bradykinin-induced knee joint pain model, AS1069562 significantly ameliorated the pain-related behavior of weight-bearing deficit and the pain response, respectively. AS1069562 also significantly improved the pain-related behavior of weight-bearing deficit in the chronic phase of the MIA model. Further, following monoiodoacetate injection, repeated administration of AS1069562 or duloxetine significantly improved weight-bearing deficit in the MIA model. Interestingly, the analgesic effect of AS1069562 was sustained for 24 hours after the last administration, although the plasma concentration of AS1069562 was reduced to undetectable levels. In contrast, the analgesic effect of duloxetine did not continue after treatment discontinuation., Discussion: AS1069562 exerts analgesic effects on inflammatory and noninflammatory nociceptive pain in rat models of arthritis pain, and repeated administration of AS1069562 exerts a more persistent analgesic effect on arthritis pain than duloxetine. These findings suggest that AS1069562 has an attractive analgesic profile for the treatment of nociceptive pain.

Background: Chemotherapy-induced nausea and vomiting (CINV) are significant problems in cancer patients, but a correlation between plasma aprepitant concentration and antiemetic effect has not been reported. This study aimed to characterize the correlation between plasma aprepitant concentration and clinical antiemetic effect in a limited group of Japanese gastric or esophageal cancer patients., Methods: Thirty-three Japanese cancer patients receiving cisplatin-based chemotherapy for the first time following oral aprepitant (125 mg on day 1 and 80 mg on days 2 and 3) were enrolled. The plasma aprepitant concentrations 48 h after the first administration were determined using liquid chromatography-mass spectrometry. Patients were allocated to the high-concentration group (plasma aprepitant concentration was >331.1 ng/ml) or the low-concentration group (plasma aprepitant concentration was ≤ 331.1 ng/ml) to investigate the relationship between plasma aprepitant concentration and antiemetic effects., Results: No significant differences were found between the two groups in terms of percentage of CINV prevention. Of 13 patients who experienced CINV [MASCC Antiemesis Tool (MAT) score >3], those in the high-concentration group showed a significant improvement in CINV following aprepitant administration (days 1-3)., Conclusion: The present study suggests that the antiemetic effect of aprepitant is associated with plasma aprepitant concentration. A plasma aprepitant concentration of 331.1 ng/ml may be a valid threshold for identifying its optimal antiemetic effects in Japanese gastric or esophageal cancer patients.

Context: The clinical introduction of new oral anticoagulants (NOACs) has stimulated the development of tests to quantify the effects of these drugs and manage complications associated with their use. Until recently, the only treatment choices for the prevention of venous thromboembolism in orthopedic surgical patients, as well as for stroke and systemic embolism in patients with atrial fibrillation, were vitamin K antagonists, antiplatelet drugs, and unfractionated and low-molecular-weight heparins. With the approval of NOACs, treatment options and consequent diagnostic challenges have expanded., Objective: To study the utility of thromboelastography (TEG) in monitoring and differentiating between 2 currently approved classes of NOACs, direct thrombin inhibitors (dabigatran) and factor Xa inhibitors (rivaroxaban and apixaban)., Design: Blood samples from healthy volunteers were spiked with each NOAC in both the presence and absence of ecarin, and the effects on TEG were evaluated., Results: Both the kaolin test reaction time (R time) and the time to maximum rate of thrombus generation were prolonged versus control samples and demonstrated a dose response for apixaban (R time within the normal range) and dabigatran. The RapidTEG activated clotting time test allowed the creation of a dose-response curve for all 3 NOACs. In the presence of anti-Xa inhibitors, the ecarin test promoted significant shortening of kaolin R times to the hypercoagulable range, while in the presence of the direct thrombin inhibitor only small and dose-proportional R time shortening was observed., Conclusions: The RapidTEG activated clotting time test and the kaolin test appear to be capable of detecting and monitoring NOACs. The ecarin test may be used to differentiate between Xa inhibitors and direct thrombin inhibitors. Therefore, TEG may be a valuable tool to investigate hemostasis and the effectiveness of reversal strategies for patients receiving NOACs.

Inhibition of norepinephrine (NE) reuptake into noradrenergic nerves is a common therapeutic target in the central nervous system (CNS). In noradrenergic nerves, NE is oxidized by monoamine oxidase to 3,4-dihydroxyphenylglycol (DHPG). In this study, 40 healthy male subjects received the NE transporter (NET) inhibitor edivoxetine (EDX) or atomoxetine (ATX), or placebo. The pharmacokinetic and pharmacodynamic profile of these drugs in plasma and cerebrospinal fluid (CSF) was assessed. In Part A, subjects received EDX once daily (QD) for 14 or 15 days at targeted doses of 6mg or 9mg. In Part B, subjects received 80mg ATX QD for 14 or 15 days. Each subject received a lumbar puncture before receiving drug and after 14 or 15 days of dosing. Plasma and urine were collected at baseline and after 14 days of dosing. Edivoxetine plasma and CSF concentrations increased dose dependently. The time to maximum plasma concentration of EDX was 2h, and the half-life was 9h. At the highest EDX dose of 9mg, DHPG concentrations were reduced from baseline by 51% at 8h postdose in CSF, and steady-state plasma and urine DHPG concentrations decreased by 38% and 26%, respectively. For 80mg ATX, the decrease of plasma, CSF, or urine DHPG was similar to EDX. Herein we provide clinical evidence that EDX and ATX decrease DHPG concentrations in the periphery and CNS, presumably via NET inhibition. EDX and ATX concentrations measured in the CSF confirmed the availability of those drugs in the CNS., (Copyright © 2015 Elsevier B.V. and ECNP. All rights reserved.)

We have studied the pharmacokinetics of drug-marker of cytochrome P450 isoenzyme CYP2C9 (losartan) and its metabolite E-3174 after subchronic oral administration of afobazole in doses 5 and 25 mg/kg in rats. The metabolic ratio (MR) of E-3174/Losartan was calculated. The pharmacokinetic parameters of losartan and its metabolite on the background of 4-day afabazole administration 5 mg/kg dose were not significantly different from analogous values calculated for the control group of rats. Therefore, afobazole in the effective anxiolytic dose did not change the MR value of metabolized P450 isoform. A five-fold dose increase in the afobazole dose led to significant difference in pharmacokinetic parameters, including A UC0-t, Cmax, Kel, t1/2el, MRT, CL/F, and Vd/F of losartan and AUC0-T, Cmax, and Tmax of E-3174. These findings are indicative of the induction of CYP2C9 isoenzyme by afobazole.

As ICH E14 was adopted by the US FDA and the EU CPMC in 2005, thorough QT studies have routinely been analyzed by looking at the time-matched difference between (baseline corrected) QTcF or QTcI under the supra-therapeutic dose and placebo. A study is considered negative, if the two-sided 90% confidence interval for this difference is below 10 ms for all investigated time points. ICH E14 suggests including a positive control, such as moxifloxacin, for assay sensitivity. Concentration-response analysis has been considered a more powerful alternative, but its application to parallel group studies was hampered as a double difference of QTcF per subject cannot be calculated. Recently, a new model based on change from baseline with fixed time and concentration effects has been proposed. It allows for a placebo-corrected prediction of the drug effect with an unbiased standard error, and the estimate of a time effect can be used for assay sensitivity. We demonstrate this approach, utilizing 2 studies reported elsewhere with a crossover design. We compare the results from a conventional concentration-response analysis based on the difference to placebo with results from the novel analysis based on the change from average baseline that includes a fixed time effect., (© 2014, The American College of Clinical Pharmacology.)

Case: We describe two cases in which treatment with aprepitant persistently altered antithrombotic control in patients receiving warfarin. A 60-year-old man received 5 weekly cycles of chemotherapy. Aprepitant was administered as a 3-day regimen from the second cycle of chemotherapy. In each of the chemotherapy cycles that included aprepitant, the therapeutic international normalized ratio (INR) decreased markedly to <1.6, and slowly recovered over several weeks. A 47-year-old woman was treated with 4 weekly cycles of chemotherapy. Aprepitant was administered as a 3-day regimen. On day 8 of the first cycle of chemotherapy, the patient's INR fell markedly to 1.1. Although warfarin dosage was steadily increased over the four subsequent cycles of chemotherapy, therapeutic target range was not recovered. INR gradually returned to normal during the 2 months after the final cycle of chemotherapy., Conclusion: To our knowledge, this is the first case report to document the effects of aprepitant in cancer patients receiving anticoagulation therapy.

Context: Rivaroxaban is a new oral anticoagulant that functions as a direct anti-Xa inhibitor. Although routine monitoring is not required, measurement of plasma concentrations may be necessary in certain clinical situations. Routine coagulation assays, such as the prothrombin time and, to a lesser degree, activated partial thromboplastin time, correlate with drug concentration, but because of reagent variability, these methods are not reliable for determining rivaroxaban anticoagulation., Objective: To compare different methods and calibrators for measuring rivaroxaban, including the chromogenic anti-Xa assay, which, when calibrated with a rivaroxaban standard, may be more appropriate for determining anticoagulation., Design: We compared measured rivaroxaban concentrations with the same anti-Xa kit but used different calibrators, with different anti-Xa kits but the same calibrators, with antithrombin-supplemented anti-Xa kit versus nonsupplemented kits, and with 2 methods based on rivaroxaban-calibrated, high-phospholipid, dilute Russell viper venom time. Regression and paired t test statistics were used to determine correlation and significant differences among methods and calibrator sources., Results: Although there was strong correlation, statistically significant biases existed among methods that report rivaroxaban levels. A single-source calibrator did not alleviate those differences among methods. High-phospholipid Russell viper venom reagents correlated with rivaroxaban concentration but were not better than chromogenic anti-Xa methods., Conclusions: Rivaroxaban-calibrated, anti-Xa measurements correlate well, but the clinical significance of the variation with rivaroxaban measurements is uncertain. The antithrombin-supplemented, anti-Xa method should be avoided for measuring rivaroxaban.

Background: No data from controlled trials exists regarding the inflammatory response in patients with de novo heart failure (HF) complicating ST-elevation myocardial infarction (STEMI) and a possible role in the recovery of contractile function. We therefore explored the time course and possible associations between levels of inflammatory markers and recovery of impaired left ventricular function as well as levosimendan treatment in STEMI patients in a substudy of the LEvosimendan in Acute heart Failure following myocardial infarction (LEAF) trial., Methods: A total of 61 patients developing HF within 48 hours after a primary PCI-treated STEMI were randomised double-blind to a 25 hours infusion of levosimendan or placebo. Levels of IL-6, CRP, sIL-6R, sgp130, MCP-1, IL-8, MMP-9, sICAM-1, sVCAM-1 and TNF-α were measured at inclusion (median 22 h, interquartile range (IQR) 14, 29 after PCI), on day 1, day 2, day 5 and 6 weeks. Improvement in left ventricular function was evaluated as change in wall motion score index (WMSI) by echocardiography., Results: Only circulating levels of IL-8 at inclusion were associated with change in WMSI from baseline to 6 weeks, r = ÷ 0.41 (p = 0.002). No association, however, was found between IL-8 and WMSI at inclusion or peak troponin T. Furthermore, there was a significant difference in change in WMSI from inclusion to 6 weeks between patients with IL-8 levels below, compared to above median value, ÷ 0.44 (IQR ÷ 0.57, ÷ 0.19) vs. ÷ 0.07 (IQR ÷ 0.27, 0.07), respectively (p < 0.0001). Levosimendan did not affect the levels of inflammary markers compared to control., Conclusion: High levels of IL-8 in STEMI patients complicated with HF were associated with less improvement in left ventricular function during the first 6 weeks after PCI, suggesting a possible role of IL-8 in the reperfusion-related injury of post-ischemic myocardium. Further studies are needed to confirm this hypothesis., Trial Registration: ClinicalTrials.gov NCT00324766.

A sensitive and accurate liquid chromatography method with mass spectrometry detection was developed and validated for the quantification of dabigatran (Pradaxa(®)) and rivaroxaban (Xarelto(®)). (13)C6-dabigatran and (13)C6-rivaroxaban were used as the internal standard. A single-step protein precipitation was used for plasma sample preparation. This method was validated with respect to linearity, selectivity, inter- and intra-day precision and accuracy, limit of quantification and stability. The lower limit of quantification was 2.5ng/mL for both drugs in plasma., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Background: Direct oral anticoagulants (DOACs) are prescribed for systemic anticoagulation. Fixed doses are recommended, but dose individualization may be warranted. Functional coagulation assays may be available, but their use requires knowledge of the drug taken. To provide alternative methodology for guiding dosage, we have developed and validated a liquid chromatography-mass spectrometric assay for apixaban, dabigatran, edoxaban, and rivaroxaban at the concentrations attained during therapy., Methods: Samples, calibrators, and internal quality controls (100 μL) were mixed with internal standard solution (50 μg/L both dabigatran-13C6 and rivaroxaban-13C6 in acetonitrile) and, after centrifugation (16,400g, 4 minutes), supernatant (100 μL) was injected onto a Cyclone-C18-P-XL TurboFlow column. Analytes were focused onto an Accucore PhenylHexyl (2.1 × 100 mm, 2.6 μm) analytical column and eluted using a methanol + acetonitrile (1 + 1):aqueous ammonium acetate (10 mmol/L) gradient. Data were acquired using high-resolution mass spectrometry in full-scan mode (100-2000 m/z) with data-dependent fragmentation to confirm peak identity. Calibration was linear (1-500 μg/L all analytes)., Results: Total analysis time was 6 minutes. Intra-assay imprecision (% RSD) at 1 μg/L was 2.6%, 4.2%, 17.3%, and 9.5% for apixaban, dabigatran, edoxaban, and rivaroxaban, respectively. Mean recovery was 96%-101%. No signal suppression or enhancement was observed. Apixaban, dabigatran, and rivaroxaban were stable over 3 freeze-thaw cycles, after storage at room temperature, and at 2-8°C for up to 2 weeks. Edoxaban was stable over 3 freeze-thaw cycles but showed a mean deterioration of 16% if stored at 2-8°C (2 weeks) and of 18% and 70% (1 day and 2 weeks, respectively) at room temperature., Conclusions: The method is suitable for high-throughput therapeutic drug monitoring of DOACs. The acquisition of full scan data allows for the retrospective identification of metabolites. The method can be used to identify a particular DOAC if information on the drug taken is lacking.

Background: Routine drug monitoring is not required for the two novel direct factor Xa inhibitors apixaban and rivaroxaban. Rapidly available test results might be beneficial in case of bleeding or prior to urgent surgery., Objectives: The aim of this study was to evaluate the applicability of the two rotational thrombelastometry (ROTEM®) -modifications Low-tissue factor activated ROTEM® (LowTF-ROTEM®) and Prothrombinase induced clotting time - activated ROTEM® (PiCT®-ROTEM®) for determination of apixaban and rivaroxaban in vitro and ex vivo., Methods: Blood samples from 20 volunteers were spiked with apixaban / rivaroxaban to yield samples with ascending drug concentrations ranging from 50 - 400ng/mL. LowTF - and PiCT® modified ROTEM® tests and determination of the corresponding antifactor Xa activity were performed in duplicate in 280 samples. LowTF-ROTEM® tests were performed in samples from 20 patients on apixaban or rivaroxaban therapy and 20 controls., Results: There was a strong correlation between apixaban / rivaroxaban plasma concentrations and the LowTF-ROTEM® parameters Clotting time (CT; spearman correlation coefficient (SCC) 0.81 and 0.81, respectively) and Time to maximum velocity (t,MaxVel; SCC: 0.81 and 0.80, resp.) and a low to moderate correlation for the PiCT®-ROTEM® parameters CT (SCC: 0.38 and 0.59, resp.) and t,MaxVel. (0.51 and 0.69, resp.) in the in vitro experiments. LowTF-ROTEM CT was significantly prolonged in patients on apxiaban or rivaroxaban therapy compared to controls., Conclusions: LowTF-ROTEM® could be a valuable diagnostic tool for rapid determination of the effect of apixaban and rivaroxaban at the point of care., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Neurotrophins, such as brain-derived neurotrophic factor (BDNF), are initially expressed in a precursor form (e.g., pro-BDNF) and cleaved to form mature BDNF (mBDNF). After pilocarpine-induced status epilepticus (SE), increases in neurotrophins regulate a wide variety of cell-signaling pathways, including prosurvival and cell-death machinery in a receptor-specific manner. Pro-BDNF preferentially binds to the p75 neurotrophin receptor (p75(NTR) ), whereas mBDNF is the major ligand of the tropomyosin-related kinase receptor. To elucidate a potential role for p75(NTR) in acute stages of epileptogenesis, rats were injected prior to and at onset of SE with LM11A-31, a small-molecule ligand that binds to p75(NTR) to promote survival signaling and inhibit neuronal cell death. Modulation of early p75(NTR) signaling and its effects on electrographic SE, SE-induced neurodegeneration, and subsequent spontaneous seizures were examined after LM11A-31 administration. Despite an established neuroprotective effect of LM11A-31 in several animal models of neurodegenerative disorders (e.g., Alzheimer's disease, traumatic brain injury, and spinal cord injury), high-dose LM11A-31 administration prior to and at onset of SE did not reduce the intensity of electrographic SE, prevent SE-induced neuronal cell injury, or inhibit the progression of epileptogenesis. Further studies are required to understand the role of p75(NTR) activation during epileptogenesis and in seizure-induced cell injury in the hippocampus, among other potential cellular pathologies contributing to the onset of spontaneous seizures. Additional studies utilizing more prolonged treatment with LM11A-31 are required to reach a definite conclusion on its potential neuroprotective role in epilepsy., (© 2014 Wiley Periodicals, Inc.)

Background: This investigation was carried out with already available point-of-care testing (POCT) systems for coagulation parameters to evaluate the qualitative and semiquantitative determination of the time- and concentration-dependent anticoagulant effects of the direct oral anticoagulants rivaroxaban and dabigatran., Methods: The whole blood prothrombin time (PT), activated partial thromboplastin time (aPTT), and activated clotting time (ACT) were determined using the GEM PCL Plus coagulation system. Whole blood PT was also measured on the CoaguCheck XS instrument. In addition, PT and aPTT values were obtained in citrated plasma using the PT reagent Neoplastin Plus and the STA APTT reagent. Drug concentrations of rivaroxaban and dabigatran were determined with a chromogenic anti-Xa assay and the hemoclot assay, which are reported to have good agreement with liquid chromatography coupled with tandem mass spectrometry measurements. POCT was performed in 27 consecutive patients who received rivaroxaban 10, 15, or 20 mg once daily and in 15 patients receiving dabigatran 110 or 150 mg twice daily. Blood samples were collected predose and 2 hours after observed drug intake at steady state., Results: Two hours after observed rivaroxaban administration, the whole blood PT measured on the GEM PCL Plus was prolonged by an average of 64.5% in comparison with predose levels. Less differentiation was observed for rivaroxaban when the PT was measured on the CoaguCheck XS instrument or in plasma (prolongation of 24.1% and 36.8%, respectively). After 2 hours observed dabigatran administration, the whole blood aPTT was comparable with plasma values and was prolonged by 23.5% in comparison with trough values. Significant concentration-dependent prolongations of the activated clotting time were observed to different extents for both direct anticoagulants., Conclusions: Direct oral anticoagulants display variable ex vivo effects on different POCT-assays. POCT for aPTT is sensitive to increased concentrations of dabigatran, whereas the PT-POCT assessed with test systems such as the GEM PCL Plus may be helpful to measure the pharmacodynamic anticoagulant effects of rivaroxaban in emergency clinical situations.

A sensitive and ultra-fast method utilizing the laser diode thermal desorption ion source using atmospheric pressure chemical ionization coupled to tandem mass spectrometry (LDTD-APCI-MS/MS) was developed for the quantitative analysis of BKM120, an investigational anticancer drug in human plasma. Samples originating from protein precipitation (PP) followed by salting-out assisted liquid-liquid extraction (SALLE) were spotted onto the LazWell™ plate prior to their thermal desorption and detection by tandem mass spectrometry in positive mode. The validated method described in this paper presents a high absolute extraction recovery (>90 %) for BKM120 and its internal standard (ISTD) [D8]BKM120, with precision and accuracy meeting the acceptance criteria. Standard curves were linear over the range of 5.00 to 2000 ng mL(-1) with a coefficient of determination (R (2)) >0.995. The method specificity was demonstrated in six different batches of human plasma. Intra- and inter-run precision as well as accuracy within ±20 % at the lower limit of quantification (LLOQ) and ±15 % (other levels) were achieved during a three-run validation for quality control (QC) samples. The post-preparative stability on the LazWell™ plate at room temperature was 72 h and a 200-fold dilution of spiked samples was demonstrated. The method was applied successfully to three clinical studies (n = 847) and cross-checked with the validated LC-ESI-MS/MS reference method. The sample analysis run time was 10 s as compared to 4.5 min for the current validated LC-ESI-MS/MS method. The resultant data were in agreement with the results obtained using the validated reference LC-ESI-MS/MS assay and the same pharmacokinetic (PK) parameters were calculated for both analytical assays. This work demonstrates that LDTD-APCI-MS/MS is a reliable method for the ultra-fast quantitative analysis of BKM120 which can be used to speed-up and support its bioanalysis in the frame of the clinical trials.

Two once-daily rivaroxaban dosing regimens were compared with warfarin for stroke prevention in patients with non-valvular atrial fibrillation in ROCKET AF: 20 mg for patients with normal/mildly impaired renal function and 15 mg for patients with moderate renal impairment. Rivaroxaban population pharmacokinetic (PK)/pharmacodynamic (PD) modeling data from ROCKET AF patients (n = 161) are reported and are used to confirm established rivaroxaban PK and PK/PD models and to re-estimate values of the models' parameters for the current AF population. An oral one-compartment model with first-order absorption adequately described rivaroxaban PK. Age, renal function, and lean body mass influenced the PK model. Prothrombin time and prothrombinase-induced clotting time exhibited a near-linear relationship with rivaroxaban plasma concentration; inhibitory effects were observed through to 24 hours post-dose. Rivaroxaban plasma concentration and factor Xa activity had an inhibitory maximum-effect (Emax ) relationship. Renal function (on prothrombin time; prothrombinase-induced clotting time) and age (on factor Xa activity) had moderate effects on PK/PD models. PK and PK/PD models were shown to be adequate for describing the current dataset. These findings confirm the modeling and empirical results that led to the selection of doses tested against warfarin in ROCKET AF., (© 2014, The American College of Clinical Pharmacology.)

1.  Mosapride citrate (mosapride) is a potent gastroprokinetic agent. The only previous study on mosapride metabolism in human reported one phase I oxidative metabolite, des-p-fluorobenzyl mosapride, in human plasma and urine using HPLC method. Our aim was to identify mosapride phase I and phase II metabolites in human urine, feces and plasma using UPLC-ESI-MS/MS. 2.  A total of 16 metabolites were detected. To the best of our knowledge, 15 metabolites have not been reported previously in human. 3.  Two new metabolites, morpholine ring-opened mosapride (M15) and mosapride N-oxide (M16), alone with one known major metabolite, des-p-fluorobenzyl mosapride (M3), were identified by comparison with the reference standards prepared by our group. The chemical structures of seven phase I and six phase II metabolites of mosapride were elucidated based on UPLC-MS/MS analyses. 4.  There were two major phase I reactions, dealkylation and morpholine ring cleavage. Phase II reactions included glucuronide, glucose and sulfate conjugation. The comprehensive metabolic pathway of mosapride in human was proposed for the first time. 5.  The metabolites in humans were compared with those in rats reported previously. In addition to M10, the other 15 metabolites in humans were also found in rats. This result suggested that there was little qualitative species difference in the metabolism of mosapride between rats and humans. 6.  In all, 16 mosapride metabolites including 15 new metabolites were reported. These results allow a better understanding of mosapride disposition in human.

Background: The determination of rivaroxaban and apixaban from serum samples of patients may be beneficial in specific clinical situations when additional blood sampling for plasma and thus the determination of factor Xa activity is not feasible or results are not plausible., Materials and Methods: The primary aim of this study was to compare the concentrations of rivaroxaban and apixaban in serum with those measured in plasma. Secondary aims were the performance of three different chromogenic methods and concentrations in patients on treatment with rivaroxaban 10 mg od (n = 124) or 20 mg od (n = 94) or apixaban 5 mg bid (n = 52) measured at different time., Results: Concentrations of rivaroxaban and apixaban in serum were about 20-25% higher compared with plasma samples with a high correlation (r = 0·79775-0·94662) using all assays (all P < 0·0001). The intraclass correlation coefficients were about 0·90 for rivaroxaban and 0·55 for apixaban. Mean rivaroxaban concentrations were higher at 2 and 3 h compared with 1 and 12 h after administration measured from plasma and serum samples (all P-values < 0·05) and were not different between 1 vs. 12 h (plasma and serum)., Conclusions: The results indicate that rivaroxaban and apixaban concentrations can be determined specifically from serum samples., (© 2014 The Authors. European Journal of Clinical Investigation published by John Wiley & Sons Ltd on behalf of Stichting European Society for Clinical Investigation Journal Foundation.)