PK/PD Analysis of Marbofloxacin by Monte Carlo Simulation against Mycoplasma agalactiae in Plasma and Milk of Lactating Goats after IV, SC and SC-Long Acting Formulations Administration

This project has been funded by Ministerio de Economia y Competividad (AGL201676568-R) of Spain. Ana Garcia-Galan Perez is beneficiary of a research fellowship (State Subprogram Training of the State Program for the Promotion of Talent and its Employability, BES-2017-080186).Thanks are due to J. Carrizosa (IMIDA) and the Caprine Veterinary Farm of the University of Murcia for their assistance with the experiments.In some countries like Spain and France, contagious agalactia (CA) is a highly relevant issue. CA is a mycoplasmosis affecting small ruminants and it is associated with a relevant economic impact on dairy. The poor efficacy of vaccines and their inability to prevent disease transmission is conducive to the use of antibiotics to control CA. However, only a few groups of antimicrobial agents are effective against these species, and selecting an adequate antimicrobial agent following the categorization of antibiotics made by the different international organisms (European Medicine Agency, World Health Organization) in veterinary medicine becomes a difficult task. The PK/PD approach is a useful tool to guide veterinarians on the appropriate targets through a rational selection of the best dose regimen of antimicrobial agents. In this study, marbofloxacin pharmacokinetics was studied after three routes of administration with two long-acting formulations. The minimum inhibitory concentrations (MIC) values of Mycoplasma agalactia isolated from goats affected by CA in Spain were calculated. The results show that systemic exposure achieved in lactating goats following these formulations provides rate of drug release that could be adequate to maintain effective plasma concentrations against M. agalactiae. The PK/PD analysis by Monte Carlo simulation showed that a dosage regimen from 8.47 to 11.57 mg/kg every 24 h could effectively treat goats affected by CA. Contagious agalactia is a mycoplasmosis affecting small ruminants that have become an important issue in many countries. However, PK/PD studies of antibiotics to treat this problem in lactating goats affected by Mycoplasma (M.) agalactiae, the main CA-causing mycoplasma are almost non-existent. The aims of this study were to evaluate the plasma and milk disposition of marbofloxacin in lactating goats after intravenous (IV), subcutaneous (SC) and subcutaneous poloxamer P407 formulations with and without carboxy-methylcellulose (SC-P407-CMC and SC-P407) administration. Marbofloxacin concentrations were analysed by the High Performance Liquid Chromatography (HPLC) method. Minimum inhibitory concentrations (MIC) of M. agalactiae field isolates from mastitic goat's milk were used to calculate surrogate markers of efficacy. Terminal half-lives of marbofloxacin after IV, SC, SC-P407 and SC-P407-CMC administration were 7.12, 6.57, 13.92 and 12.19 h in plasma, and the half-lives of elimination of marbofloxacin in milk were 7.22, 7.16, 9.30 and 7.74 h after IV, SC, SC-P407 and SC-P407-CMC administration, respectively. Marbofloxacin penetration from the blood into the milk was extensive, with Area Under the Curve (AUC(milk)/AUC(plasma)) ratios ranged 1.04-1.23, and maximum concentrations (Cmax-milk/Cmax-plasma) ratios ranged 0.72-1.20. The PK/PD surrogate markers of efficacy fAUC24/MIC and the Monte Carlo simulation show that marbofloxacin ratio (fAUC(24)/MIC > 125) using a 90% of target attainment rate (TAR) need a dose regimen between 8.4 mg/kg (SC) and 11.57 mg/kg (P407CMC) and should be adequate to treat contagious agalactia in lactating goats.Ministerio de Economia y Competividad of Spain AGL201676568-RResearch fellowship (State Subprogram Training of the State Program for the Promotion of Talent and its Employability) BES-2017-08018

Pharmacokinetics of praziquantel and pyrantel pamoate combination following oral administration in cats

Objectives The pharmacokinetics of praziquantel and pyrantel pamoate has never been reported in cats. The present study was designed to establish the plasma concentration-time profile and to derive pharmacokinetic data for a combined formulation of praziquantel and pyrantel in cats, after a single, oral administration. Methods Twenty-two clinically healthy adult cats were used, each receiving a single oral dose of praziquantel (8.5 mg/kg) and pyrantel (100 mg/kg). Blood samples were collected at regular time points up to 48 h post-dosing. Plasma concentrations of praziquantel and pyrantel were measured using a liquid chromatography-mass spectrometry-high-throughput screening method. Results Clinical examination of all cats did not reveal any side effects after oral administration of these medications. The terminal half-life for praziquantel and pyrantel was 1.07 and 1.36 h, respectively. Praziquantel peak concentration (Cmax) was 1140 μg/ml, reached at 1.22 h. The plasma concentrations of pyrantel after oral administration were low with a mean Cmax of 0.11 μg/ml, reached at a Tmax of 1.91 h. Pyrantel showed a very limited absorption as pamoate salt, suggesting permanence and efficacy inside the gastrointestinal tract, where the adult stages of most parasitic nematodes reside. Conclusions and relevance Pyrantel showed a very limited absorption as pamoate salt. Praziquantel was rapidly absorbed following oral administration and the concentrations achieved suggest that praziquantel could be an effective and safe medication in cats. Although some resistance problems are arising as a result of their long use, these anthelminthic products can still play a major role in parasitic control, especially in geographical areas where the high cost of newer treatments or necessity of parenteral administration could decrease the number of treated animals

Population pharmacokinetics and pharmacokinetic/pharmacodynamic evaluation of marbofloxacin against Coagulase-negative staphylococci, Staphylococcus aureus and Mycoplasma agalactiae pathogens in goats

Marbofloxacin is a broad-spectrum fluoroquinolone, and an extra-label use has been reported in horse, sheep and goat. However, extrapolation of dosage regimens from cattle to horse and small ruminants could lead to incorrect dosing due to pharmacokinetic differences among species, increasing the risk of antimicrobial resistance or toxicity. Pharmacokinetic properties of marbofloxacin, including PK/PD analysis, have been studied by intravenous, intramuscular and subcutaneous administration in lactating and non-lactating goats. A population pharmacokinetic model of marbofloxacin in goats was built using 10 pharmacokinetic studies after intravenous, intramuscular, and subcutaneous administration at a dose of 2, 5 and 10 mg/kg. Serum or plasma and milk concentration-time profiles were simultaneously fitted with a non-linear mixed effect model with Monolix software. Level of milk production (lactating and non-lactating) and health status (healthy and un-healthy) were retained as covariates on volume of distribution and clearance. Marbofloxacin concentrations were well described in plasma/serum and milk by the population model. Simulated dose regimens of marbofloxacin administered at 2, 5 and 10 mg/kg by intramuscular route for five days were evaluated (n = 5000 per group). Steady-state fAUCs for each dose regimen were obtained. Probability of target attainment of fAUC/MIC ratios were determined and PK/PDco values (highest MIC for which 90% of individuals can achieve a prior numerical value of the fAUC/MIC index) were established using Monte Carlo simulations (n = 50,000). MIC values for wild type isolates of Staphylococcus aureus, coagulase negative staphylococci, and Mycoplasma agalactiae were determined and tentative epidemiological cutoff (TECOFF) were obtained at 1.0, 0.5 and 0.5 mg/L, respectively. The PK/PDco for the dose regimen of 2 mg/kg/24 h and 5 mg/kg/24 h (0.125 and 0.25 mg/L) were lower than TECOFF (0.5 and 1 mg/L). The dosage regimen of 10 mg/kg/24 h was adequate for intermediate MIC values of 0.125–0.50 mg/L and could be effective for a population with a target fAUC/MIC ratio ˂ 48 for Coagulase negative staphylococci and Mycoplasma agalactiae, but not for Staphylococcus aureus. Results obtained in thi

Pharmacokinetics of Metformin in Combination With Sitagliptin in Adult Horses After Enteral Administration

© 2019. Elsevier. This document is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0 This document is the accepted version of a published work that appeared in final form in Journal of Equine Veterinary Science (JEVS) To access the final work, see DOI: https://doi.org/10.1016/j.jevs.2018.10.017Insulin dysregulation (ID) is a common metabolic disorder in horses. Recently, incretin hormone release has been suggested to be involved in ID in horses. In human medicine, metformin and sitagliptin are commonly used in combination for metabolic syndrome. This combination could be useful in treating ID in horses. However, no pharmacokinetics data have been reported in this species. The objective of the present study was to establish the plasma concentration–time profile and to derive pharmacokinetics data for a combination of metformin and sitagliptin in horses after enteral administration. Six healthy adult Purebred Spanish horses were used. A metformin (15 mg/kg) plus sitagliptin (1.5 mg/kg) preparation was administered by intragastric route (IG) as an enteral solution. Blood samples were collected from 0 to 48 hours after IG drug administration. Plasma concentrations of metformin and sitagliptin were measured using HPLC methods. The t½λz for metformin was 2.9 hours and for sitagliptin 21 hours. The Cmax was 442 ± 84 mg/L within 0.9 hours for metformin and 94 ± 14 mg/L within 1.3 hours for sitagliptin. No adverse effects were observed, and the combination of metformin and sitagliptin was well tolerated. Therefore, these results suggest that metformin plus sitagliptin might be a combination to consider in horses with ID. Additional studies are needed to establish the effectiveness and tolerance in equids affected by endocrine disorders

Azathioprine dose tailoring based on pharmacogenetic information: Insights of clinical implementation

Supplementary data associated with this article can be found in the online version at doi:10.1016/j.biopha.2023.115706Azathioprine is commonly used as an immunosuppressive antimetabolite in the treatment of acute lymphoblastic leukemia, autoimmune disorders (such as Crohn's disease and rheumatoid arthritis), and in patients receiving organ transplants. Thiopurine-S-methyltransferase (TPMT) is a cytoplasmic trans-methylase catalyzing the S-methylation of thiopurines. The active metabolites obtained from thiopurines are hydrolyzed into inactive forms by the Nudix hydrolase 15 (NUDT15). The TPMT*2 (defined by rs1800462), *3A (defined by rs1800460 and rs1142345), *3B (defined by rs1800460), *3C (defined by rs1142345), *6 (defined by rs75543815), and NUDT15 rs116855232 genetic variant have been associated, with the highest level of evidence, with the response to azathioprine, and, the approved drug label for azathioprine and main pharmacogenetic dosing guidelines recommend starting with reduced initial doses in TPMT intermediate metabolizer (IM) patients and considering an alternative treatment in TPMT poor metabolizer (PM) patients. This study aims to assess the clinical impact of azathioprine dose tailoring based on TPMT genotyping studying the azathioprine toxicity and efficacy, treatment starts, and dose adjustments during follow-up, comparing TPMT IM/PM and normal metabolizer (NM) patients. It also studied the association of NUDT15 rs116855232 with response to azathioprine in patients receiving a tailored treatment based on TPMT and characterized the TMPT and NUDT15 studied variants in our population. Results show that azathioprine dose reduction in TPMT IM patients (TPMT*1/*2, *1/*3A, or *1/*3C genotypes) is related to lower toxicity events compared to TPMT NM (TPMT *1/*1 genotype), and lower azathioprine dose adjustments during follow-up without showing differences in the efficacy. The results support the hypothesis of existing other genetic variants affecting azathioprine toxicity

The relationship between gut and nasopharyngeal microbiome composition can predict the severity of COVID-19

Background: Coronavirus disease 2019 (COVID-19) is a respiratory illness caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that displays great variability in clinical phenotype. Many factors have been described to be correlated with its severity but no specific determinants of infection outcome have been identified yet, maybe due the complex pathogenic mechanisms. The microbiota could play a key role in the infection and in the progression and outcome of the disease. Hence, SARS-CoV-2 infection has been associated with nasopharyngeal and gut dysbiosis and higher abundance of opportunistic pathogens. Methods: To identify new prognostic markers for the disease, a multicenter prospective observational cohort study was carried out in COVID-19 patients that were divided in three cohorts according to their symptomatology: mild (n=24), moderate (n=51) and severe/critical (n=31). Faecal and nasopharyngeal samples were taken and the microbiota was analysed. Results: Microbiota composition could be associated with the severity of the symptoms and the linear discriminant analysis identified the genera Mycoplasma and Prevotella as severity biomarkers in nasopharyngeal samples, and Allistipes, Enterococcus and Escherichia in faecal samples. Moreover, M. salivarium was defined as a unique microorganism in COVID-19 patients' nasopharyngeal microbiota while P. bivia and P. timonensis were defined in faecal microbiota. A connection between faecal and nasopharyngeal microbiota in COVID-19 patients was also identified as a strong positive correlation between P. timonensis (faeces) towards P. dentalis and M. salivarium(nasopharyngeal) was found in critically ill patients. Conclusions: This ratio could be used as a novel prognostic biomarker for severe COVID-19 patients.The research project was sup-ported by Government of Andalucia (Spain) (CV20-99908).N

Desarrollo de herramientas metodológicas para incorporar contenidos de ciencia al aula y su valoración económica

La ciencia y la tecnología juegan un papel fundamental en nuestra sociedad. En este sentido, la ciudadanía parece necesitar unos conocimientos básicos que le permitan responder de manera autónoma a multitud de situaciones, tanto a nivel personal como social (Kolstø et al., 2006). Este requisito, conocido en la literatura como alfabetización científica, lleva siendo uno de los objetivos de la educación en las últimas décadas (Hodson, 2003; Feinstein, 2011). Sin embargo, parece que su consecución presenta algunos problemas. Una de las causas de estas dificultades parece ser la falta de conexión entre los contenidos que se trabajan en las clases y el día a día del ciudadano. Respecto a esto, una solución ampliamente citada en la literatura es contextualizar el aprendizaje, relacionando los contenidos trabajados en clase con escenarios cotidianos y familiares para el alumnado (Clegg & Kolodner, 2014). El proyecto pretendía que nuestros estudiantes llevasen a cabo un análisis de los contextos con contenidos científico-económicos y promovieran su utilización en el aula y en su futuro profesional. Es decir, formar a nuestros profesionales para que pudieran detectar e incorporar entre sus competencias la capacidad de conectar lo aprendido en las asignaturas con las necesidades sociales. En concreto, el proyecto tenía, en base a los problemas detectados en la percepción de la ciencia y en la formación de los ciudadanos, dos grandes tipos de objetivos: Objetivos relacionados con la percepción de los conocimientos científico-tecnológicos y su valoración económica (Ezquerra, Fernández-Sánchez, Cabezas, 2013; Ezquerra, Fernandez-Sanchez, 2014; Ezquerra, Fernandez-Sanchez, Magaña, 2015; 2016; Ezquerra, Fernandez-Sanchez, Magaña & Mingo, 2017): • Identificar en qué situaciones los ciudadanos, en su vida cotidiana, están en presencia de contenidos científicos o tecnológicos. • Determinar de qué modo llegan al ciudadano estos contenidos, con qué intensidad, cómo son propuestos, cómo son percibidos... • Analizar el modo en que podemos otorgar a estos contenidos una valoración económica. Objetivos educativos que se integran dentro de las asignaturas: • Analizar las correspondencias entre los currículos oficiales y los contenidos presentes en el entorno del ciudadano (Ezquerra, Fernandez-Sanchez, Magaña Ramos, 2015; Ezquerra y Magaña, 2016). • Introducir a los estudiantes en una propuesta de aprendizaje basada en la indagación (Rivero et al., 2013; Ezquerra, De Juanas, Martín del Pozo, 2015). • Valorar las estrategias y competencias de los futuros docentes para vincular sus conocimientos con la realidad circundante (De Juanas et al., 2012). • Analizar las actividades que los estudiantes propongan para identificar los contenidos de ciencia y estudiar su valoración económica

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

An in vivo pharmacokinetic study of metformin microparticles as an oral sustained release formulation in rabbits

This research was funded by the Government of the Region de Murcia (Spain) by the Fundacion Seneca (project 20950/PI/18). The Fundacion Seneca had no role in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript.Background: Metformin hydrochloride is a biguanide derivative that has been widely used to treat type 2 diabetes in humans. In veterinary medicine, metformin has shown increasing potential for diabetes treatment in different species, such as equids, dogs, cats and rabbits. It is highly hydrophilic, with incomplete gastrointestinal absorption and very large variability in absolute bioavailability between species, ranging from 4% in equids to 60% in humans. Metformin also shows a short half-life of approximately 2 h in dogs, cats, horses and humans. The objectives of this study were to evaluate a poly (lactic acid) (PLA) metformin microparticle formulation to test in rabbits and conduct a pharmacokinetics study of intravenous ( SIV) and oral solution ( SPO) metformin administration and oral PLA microparticle ( SPLA) administration to rabbits to evaluate the improvement in the metformin pharmacokinetics profile. Results: Metformin-loaded PLA microparticles were characterized by a spherical shape and high encapsulation efficiency. The results from Fourier transform infrared (FTIR) spectroscopy suggested the presence of interactions between metformin and PLA. X-Ray diffraction (XRD) analysis corroborated the results from the differential scanning calorimetry (DSC) studies, showing that metformin is present in an amorphous state within the microparticles. Physicochemical characterization suggested that PLA and metformin hydrochloride interacted within the microparticles via hydrogen bonding interactions. The pharmacokinetic study in rabbits showed sustained-release characteristics from the prepared microparticles with a delay in the time needed to reach the maximum concentration ( Tmax), decreased Cmax and bioavailability, and increased mean residence time (MRT) and half-life compared to the pure drug solution. Conclusions: Metformin-loaded PLA microparticles showed optimal and beneficial properties in terms of their physicochemical characteristics, making them suitable for use in an in vivo pharmacokinetic study. The pharmacokinetic parameters of the metformin microparticles from the in vivo study showed a shorter Tmax, longer MRT and half-life, decreased Cmax and the prolonged/sustained release expected for metformin. However, the unexpected decrease in bioavailability of metformin from the microparticles with respect to the oral solution should be evaluated for microparticle and dose design in future works, especially before being tested in other animal species in veterinary medicine.Government of the Region de Murcia (Spain) by the Fundacion Seneca 20950/PI/1