An Investigation of Instability in Dried Blood Spot Samples for Pharmacokinetic Sampling in Phase 3 Trials of Verubecestat.

In-clinic dried blood spot (DBS) pharmacokinetic (PK) sampling was incorporated into two phase 3 studies of verubecestat for Alzheimer's disease (EPOCH [NCT01739348] and APECS [NCT01953601]), as a potential alternative to plasma PK sampling for improved logistical feasibility and decreased blood volume burden. However, an interim PK analysis revealed verubecestat concentrations in DBS samples declined with time to assay in both trials. An investigation revealed wide variation in implementation practices for DBS sample handling procedures resulting in insufficient desiccation which caused verubecestat instability. High-resolution mass spectrometry evaluations of stressed and aged verubecestat DBS samples revealed the presence of two hydrolysis degradants. To minimize instability, new DBS handling procedures were implemented that provided additional desiccant and minimized the time to analysis. Both verubecestat hydrolysis products were previously discovered and synthesized during active pharmaceutical ingredient stability characterization. A liquid chromatography-mass spectrometry assay to quantitate the dominant verubecestat degradant in DBS samples was developed and validated. The application of this method to stressed and aged verubecestat DBS samples confirmed that degradant concentrations accounted for the observed decreases in the verubecestat concentration. Furthermore, after increasing desiccant amounts, degradant concentrations accounted for approximately 7% of the verubecestat concentration in DBS clinical samples, indicating that issues with sample handling were minimized with new storage and shipping conditions. This case study illustrates the challenges with employing new sampling techniques in large, global trials, and the importance of anticipating and mitigating implementation risks.

The post 16 gap: how do young people conceptualise PE? An exploration of the barriers to participation in physical education, physical activity and sport in senior school pupils.

Previous studies have identified several key barriers to Physical Education, Physical activity and Sport (PEPAS). However, there is a paucity of qualitative evidence investigating why young people do and do not participate in PA and the relationship between their levels of participation at different stages of life. This study builds on a previous study and aims to investigate the barriers to PEPAS in adolescents at transition stage. The extant literature highlights that instilling regular PA throughout life strongly relies on developing physical literacy through participation in high quality physical education. Despite the understanding of the importance of high quality physical education, there is an over emphasis on the short term outcomes of physical education (PE) sessions which have been noted to overemphasise immediate physical activity rather than focus on educational outcomes important to physical literacy. Anecdotally, the recent Covid 19 Global pandemic and subsequent lockdown has resulted in a digitalisation of PE in schools and a subsequent reliance of PA programmes based on adult fitness classes, which may not necessarily be categorised as PE in its true sense. Twenty-four respondents aged 16-19 were divided into five focus groups. Data were analysed verbatim using NVivo following the guidelines by Braun and Clark (2006) on thematic analysis. The findings indicated that most respondents equated PE with team sports. Findings suggest that Physical Educators need to acknowledge how past and present experience of PE impacts young people's future motivation to continue PA beyond school. Delivery of traditional PE lessons, prioritising sporting ability, can act as a participation barrier to pupils who consider themselves "non-sporty". Accordingly, a shift towards inclusive pedagogical models with an emphasis on a holistic approach, may best promote the physical literacy necessary for the competence and confidence to continue movement in a lifelong capacity.

Absorption, metabolism and excretion of [14C]omarigliptin, a once-weekly DPP-4 inhibitor, in humans.

1. Omarigliptin (MARIZEV®) is a once-weekly DPP-4 inhibitor approved in Japan for the treatment of type 2 diabetes. The objective of this study was to investigate the absorption, metabolism and excretion of omarigliptin in humans. 2. Six healthy subjects received a single oral dose of 25 mg (2.1 µCi) [14 C]omarigliptin. Blood, plasma, urine and fecal samples were collected at various intervals for up to 20 days post-dose. Radioactivity levels in excreta and plasma/blood samples were determined by accelerator mass spectrometry (AMS). 3. [14 C]Omarigliptin was rapidly absorbed, with peak plasma concentrations observed at 0.5-2 h post-dose. The majority of the radioactivity was recovered in urine (∼74.4% of the dose), with less recovered in feces (∼3.4%), suggesting the compound was well absorbed. 4. Omarigliptin was the major component in urine (∼89% of the urinary radioactivity), indicating renal excretion of the unchanged drug as the primary clearance mechanism. Omarigliptin accounted for almost all the circulating radioactivity in plasma, with no major metabolites detected. 5. The predominantly renal elimination pathway, combined with the fact that omarigliptin is not a substrate of key drug transporters, suggest omarigliptin is unlikely to be subject to pharmacokinetic drug-drug interactions with other commonly prescribed agents.

"It's not as easy as saying, 'just get them to eat more veggies'": Exploring healthy eating in residential care in Australia.

Young people living in residential out-of-home care (henceforth OoHC) are at increased risk of becoming overweight or obese. Currently, recognition of the everyday mechanisms that might be contributing to excess weight for children and young people in this setting is limited. The aim of this study was to better understand the barriers and complexities involved in the provision of a 'healthy' food environment in residential OoHC. Heightening awareness of these factors and how they might compromise a young person's physical health, will inform the development, refinement and evaluation of more sensitive and tailored weight-related interventions for this population. The paper presents a nuanced picture of the complexity of everyday food routines in residential care, and illustrates the ways in which food is 'done' in care; how food can be both symbolic of care but also used to exercise control; the way in which food can be used to create a 'family-like' environment; and the impact of traumatic experiences in childhood on subsequent behaviours and overall functioning in relation to food. It is argued that a health agenda designed for a mainstream population ignores the very complex relationship that children in residential OoHC may have with food. It is recommended that future intervention approaches account for personal food biographies, trauma and children's social backgrounds and how these are implicated in everyday practices and interactions around food.

Health Human Resources Guidelines: Minimum Staffing Standards and Role Descriptions for Canadian Cystic Fibrosis Healthcare Teams.

In cystic fibrosis clinics across Canada, the most common barrier that healthcare workers face when providing care to their patients is having too little time. The Health Human Resources Guidelines were developed to define specifically what amounts of time should be allocated for each discipline of cystic fibrosis clinical care and to provide a description of all the roles involved, reinforcing how these work together to provide comprehensive multidisciplinary care. With involvement from all cystic fibrosis clinics in Canada, through the use of a tailored survey, the Health Human Resources Guidelines are an exclusively Canadian document that has been developed for implementation across the country. The guidelines have been incorporated into a national Accreditation Site Visit program for use in evaluating and improving care across the country and have been distributed to all Canadian cystic fibrosis clinics. The guidelines provide hospital administrators with clear benchmarks for allocating personnel resources to the cystic fibrosis clinics hosted within their institutions.

Disposition and metabolism of the cathepsin K inhibitor odanacatib in humans.

Odanacatib is a selective inhibitor of the cathepsin K enzyme that is expressed in osteoclasts involved in the degradation of bone organic matrix, and is being developed as a novel treatment of osteoporosis. Odanacatib has demonstrated increases in bone mineral density in postmenopausal women and is undergoing a pivotal phase III trial. The absorption, metabolism, and excretion of [(14)C]odanacatib were studied in healthy male volunteers (n = 6) after a single oral dose of 25 mg (100 µCi). Plasma, urine, and fecal samples were collected at intervals up to 34 days postdose. The pharmacokinetics of odanacatib were characterized by slow absorption (mean time to achieve maximum plasma concentration of 14.2 hours) and long apparent elimination half-life (mean t1/2 96.7 hours); 74.5% of the dose was recovered in feces and 16.9% in urine, resulting in a total recovery of 91.4%. Seven metabolites were identified in urine; the major pathway (methyl hydroxylation producing M8 and its derivatives) was largely dependent on CYP3A. Metabolites and odanacatib accounted for 77% and 23% of urinary radioactivity, respectively. In fecal extracts, the only radioactive components identified were odanacatib (60.9%) and M8 (9.5%). The fraction of odanacatib in feces derived from absorbed drug was estimated using a bioavailability value obtained from the results of a separate intravenous study. Collectively, the data indicate that odanacatib has a long t1/2 on account of its low metabolic intrinsic clearance, and that metabolism (principally mediated by CYP3A) and excretion of intact parent compound account for ∼70% and ∼30% of the clearance of odanacatib in humans.

The preclinical efficacy, selectivity and pharmacologic profile of MK-5932, an insulin-sparing selective glucocorticoid receptor modulator.

Glucocorticoids are used widely in the treatment of inflammatory diseases, but use is accompanied by a significant burden of adverse effects. It has been hypothesized that gene- and cell-specific regulation of the glucocorticoid receptor by small molecule ligands could be translated into a therapeutic with an improved risk-benefit profile. MK-5932 is a highly selective glucocorticoid receptor modulator that is anti-inflammatory in vivo with an improved profile on glucose metabolism: Bungard et al. (2011). Bioorg. Med. Chem. 19, 7374-7386. Here we describe the full biological profile of MK-5932. Cytokine production following lipopolysaccharide (LPS) challenge was blocked by MK-5932 in both rat and human whole blood. Oral administration reduced inflammatory cytokine levels in the serum of rats challenged with LPS. MK-5932 was anti-inflammatory in a rat contact dermatitis model, but was differentiated from 6-methylprednisolone by a lack of elevation of fasting insulin or glucose levels after 7 days of dosing, even at high exposure levels. In fact, animals in the vehicle group were consistently hyperglycemic at the end of the study, and MK-5932 normalized glucose levels in a dose-dependent manner. MK-5932 was also anti-inflammatory in the rat collagen-induced arthritis and adjuvant-induced arthritis models. In healthy dogs, oral administration of MK-5932 exerted acute pharmacodynamic effects with potency comparable to prednisone, but with important differences on neutrophil counts, again suggestive of a dissociated profile. Important gaps in our understanding of mechanism of action remain, but MK-5932 will be a useful tool in dissecting the mechanisms of glucose dysregulation by therapeutic glucocortiocids.

Pharmacokinetics and metabolism in rats, dogs, and monkeys of the cathepsin k inhibitor odanacatib: demethylation of a methylsulfonyl moiety as a major metabolic pathway.

Odanacatib is a potent cathespin K inhibitor that is being developed as a novel therapy for osteoporosis. The disposition and metabolism of odanacatib were evaluated in rats, dogs, and rhesus monkeys after intravenous and oral administration of [¹4C]odanacatib. Odanacatib was characterized by low systemic clearance in all species and by a long plasma half-life in monkeys (18 h) and dogs (64 h). The oral bioavailability was dependent on the vehicle used and ranged from 18% (monkey) to ~100% (dog) at doses of 1 to 5 mg/kg, using nonaqueous vehicles. After intravenous and oral administration to intact rats and monkeys > 90% of the dose was recovered, mainly in the feces. Studies in bile duct-cannulated animals indicated that biliary secretion was the major mode of elimination of radioactivity; odanacatib also underwent some intestinal secretion. In monkeys, odanacatib was almost completely eliminated by metabolism; metabolism also played a major role in the clearance of odanacatib in rats and dogs. The major metabolic pathways were methyl hydroxylation (formation of M8 and its derivatives), methyl sulfone demethylation (formation of M4 and its derivative M5), and glutathione conjugation (formation of the cyclized cysteinylglycine adduct M6 after addition of glutathione to the nitrile group of odanacatib). The major metabolites in rats [M4 (parent-14 Da) and M5 (oxygenated derivative of M4)] were determined to arise from a novel pathway that involved oxidative demethylation of the methylsulfonyl moiety of odanacatib. Overall, odanacatib displayed species-dependent metabolism, which explains, at least in part, the divergent plasma half-life observed.

Fractional mass filtering as a means to assess circulating metabolites in early human clinical studies.

Recent changes in the regulatory environment have led to a need for new methods to assess circulating human drug metabolites in early clinical studies with respect to their potential toxicological impact. The specific goals of such studies are to determine if the metabolites present in human plasma following administration of a drug candidate also are observed in plasma from the animal studies employed for preclinical toxicological evaluation, and to estimate corresponding exposure margins (animal:human) for the major metabolites. Until recently, the accepted best practice for the characterization of circulating drug metabolites utilized liquid chromatography/tandem mass spectrometry (LC/MS/MS)-based methodologies, in conjunction with authentic chemical standards, for the detection and quantitative analyses of metabolites predicted from both animal studies and experiments with human liver preparations in vitro. While this approach is satisfactory for anticipated biotransformation products, metabolites that were not expected to circulate in human plasma frequently escape detection. Current accurate mass instruments enable the use of the technique of fractional mass filtering to detect both expected and unexpected metabolites in a rapid, less resource-intensive and more robust manner. Application of this technology to several clinical development programs at Merck Research Laboratories has demonstrated the value of fractional mass filtering in the assessment of circulating drug metabolites in early clinical trials.

Metabolism and disposition in humans of raltegravir (MK-0518), an anti-AIDS drug targeting the human immunodeficiency virus 1 integrase enzyme.

Raltegravir is a potent human immunodeficiency virus 1 (HIV-1) integrase strand transfer inhibitor that is being developed as a novel anti-AIDS drug. The absorption, metabolism, and excretion of raltegravir were studied in healthy volunteers after a single oral dose of 200 mg (200 microCi) of [(14)C]raltegravir. Plasma, urine, and fecal samples were collected at specified intervals up to 240 h postdose, and the samples were analyzed for total radioactivity, parent compound, and metabolites. Radioactivity was eliminated in substantial amounts in both urine (32%) and feces (51%). The elimination of radioactivity was rapid, since the majority of the recovered dose was attributable to samples collected through 24 h. In extracts of urine, two components were detected and were identified as raltegravir and the glucuronide of raltegravir (M2), and each accounted for 9% and 23% of the dose recovered in urine, respectively. Only a single radioactive peak, which was identified as raltegravir, was detected in fecal extracts; raltegravir in feces is believed to be derived, at least in part, from the hydrolysis of M2 secreted in bile, as demonstrated in rats. The major entity in plasma was raltegravir, which represented 70% of the total radioactivity, with the remaining radioactivity accounted for by M2. Studies using cDNA-expressed UDP-glucuronosyltransferases (UGTs), form-selective chemical inhibitors, and correlation analysis indicated that UGT1A1 was the main UGT isoform responsible for the formation of M2. Collectively, the data indicate that the major mechanism of clearance of raltegravir in humans is UGT1A1-mediated glucuronidation.

Zafirlukast metabolism by cytochrome P450 3A4 produces an electrophilic alpha,beta-unsaturated iminium species that results in the selective mechanism-based inactivation of the enzyme.

Zafirlukast is a leukotriene antagonist indicated for the treatment of mild to moderate asthma, but the drug has been associated with occasional idiosyncratic hepatotoxicity. Structurally, zafirlukast is similar to 3-methylindole because it contains an N-methylindole moiety that has a 3-alkyl substituent on the indole ring. The results presented here describe the metabolic activation of zafirlukast via a similar mechanism to that described for 3-methylindole. NADP(H)-dependent biotransformation of zafirlukast by hepatic microsomes from rats and humans afforded a reactive metabolite, which was detected as its GSH adduct. Mass spectrometry and NMR data indicated that the GSH adduct was formed by the addition of GSH to the methylene carbon between the indole- and methoxy-substituted phenyl rings of zafirlukast. The formation of this reactive metabolite in human liver microsomes was shown to be exclusively catalyzed by CYP3A enzymes. Evidence for in vivo metabolic activation of zafirlukast was obtained when the same GSH adduct was detected in bile of rats given an iv or oral dose of the drug. On the basis of results with model peroxidases and of the structures of product alcohols from incubations containing H2(18)O, it appeared that zafirlukast underwent dehydrogenation by two sequential one-electron oxidations. In addition, zafirlukast proved to be a mechanism-based inhibitor of CYP3A4 activity in human liver microsomes and in microsomes containing cDNA-expressed CYP3A4. The enzyme inhibitory property of zafirlukast was selective for this enzyme among all of the P450 enzymes that were tested in human liver microsomes. The inactivation was characterized by a K(I) of 13.4 microM and k(inact) of 0.026 min(-1). In summary, zafirlukast dehydrogenation to an electrophilic alpha,beta-unsaturated iminium intermediate may be associated with idiosyncratic hepatotoxicity and/or cause drug-drug interactions through inactivation of CYP3A4.

[Survey of attitudes to air travel after terrorist events of September 2001]. / Informe sobre actitudes hacia viajar en avión posteriores a los atentados terroristas del 11 de septiembre de 2001.

An opportunistic questionnaire study of peoples attitudes to, commercial flying and their behavioural responses after the events of September 11 2001 in the USA. Cohorts drawn from people attending a series of educational lectures, a specific leisure time activity and a travel health clinic 6 months after the disasters. More people appeared to worry about air travel 6 months after Sept 11 2001 than in reports prior to this date and the worried seem to experience a greater intensity of anxiety.

Informe sobre actitudes hacia viajar en avión posteriores a los atentados terroristas del 11 de septiembre de 2001 / [Survey of attitudes to air travel after terrorist events of September 2001]

An opportunistic questionnaire study of peoples attitudes to, commercial flying and their behavioural responses after the events of September 11 2001 in the USA. Cohorts drawn from people attending a series of educational lectures, a specific leisure time activity and a travel health clinic 6 months after the disasters. More people appeared to worry about air travel 6 months after Sept 11 2001 than in reports prior to this date and the worried seem to experience a greater intensity of anxiety.

Informe sobre actitudes hacia viajar en avión posteriores a los atentados terroristas del 11 de septiembre de 2001. / [Survey of attitudes to air travel after terrorist events of September 2001]

An opportunistic questionnaire study of peoples attitudes to, commercial flying and their behavioural responses after the events of September 11 2001 in the USA. Cohorts drawn from people attending a series of educational lectures, a specific leisure time activity and a travel health clinic 6 months after the disasters. More people appeared to worry about air travel 6 months after Sept 11 2001 than in reports prior to this date and the worried seem to experience a greater intensity of anxiety.