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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Pharmacokinetics of Voriconazole in horses and alpacas

Chan, Hui Min, Ravis, William R., January 2008 (has links) (PDF)
Thesis (Ph. D.)--Auburn University, 2008. / Abstract. Vita. Includes bibliographical references (p. 227-228).
2

Comparison of Characteristics of Patients who Received Posaconazole or Voriconazole for the Treatment of Coccidioidomycosis

Hackman, Christine, Hardy, Dory, Matthias, Kathryn January 2013 (has links)
Class of 2013 Abstract / Specific Aims: To describe the characteristics of patients who were switched to or prescribed posaconazole or voriconazole for the treatment of coccidioidomycosis including duration of previous anti-fungal treatment and rationale for changing from the first-line agents to posaconazole or voriconazole. Methods: This was a retrospective medical chart review of all patients admitted to an academic medical center with a diagnosis of coccidioidomycosis and prescribed posaconazole or voriconazole between January 2008 and December 2011. Subjects for the study were identified by ICD-9 codes for coccidioidomycosis (114.0-114.9) and through the pharmacy system for orders for posaconazole or voriconazole. Data collected included demographic information, antifungal prescription data, and outcome of fungal infection, if available. Main Results: A total of 41 subjects were identified as being prescribed either voriconazole or posaconazole for a diagnosis for coccidioidomycosis. The majority of subjects were prescribed voriconazole (93%) rather than posaconazole. While the majority of subjects were diagnosed with only pulmonary disease, 44% of subjects’ coccidioidomycosis diagnoses were classified as disseminated and 46% were admitted to an intensive care unit. The median (range) duration of first-line antifungal therapy was 3 (2-10) days for the posaconazole group and 3 (0-25) days for the voriconazole group. Overall, the reason(s) for switching antifungal therapy was listed as: failure of first-line therapy (26%), adverse drug event (4.3%), other (35%), and unknown (35%). Conclusion: There was no significant difference in baseline or disease characteristics between patients who were prescribed voriconazole or posaconazole for coccidioidomycosis. The main limitation of this retrospective evaluation is that the reason for use of voriconazole or posaconazole rather than first-line agents was often not easily determined based on the documentation in the medical records.
3

Evaluation of Prophylactic Voriconazole and Posaconazole Concentration Monitoring and Dose Changes in Liquid and Solid Transplant Patients

Nguyen, Jill, Workinger, Sarah, Matthias, Kathryn January 2012 (has links)
Class of 2012 Abstract / Specific Aims: The primary aim of this study was to determine the incidence of posaconazole and voriconazole concentration monitoring that occurs in transplant patients receiving antifungal prophylaxis therapy. The secondary aim was to determine whether voriconazole and posaconazole serum concentrations were used for dose adjustments. Methods: Patients status post either a liquid or solid organ transplant over the age of 1 year who received invasive fungal infection prophylaxis with either posaconazole or voriconazole between the dates of February 1, 2010 through January 31, 2011 while admitted to academic medical center were included in this descriptive retrospective study. This study has been approved by the Institutional Review Board. Data collected on each subject included demographic information, type of transplant, posaconazole or voriconazole concentrations, and duration and dosage adjustments. Main Results: 54 subjects were identified who received either voriconazole or posaconazole for fungal prophylaxis after transplant. For subjects who were prescribed posaconazole (N = 8), concentration monitoring was performed in 50% of subjects and 0% of posaconazole dose adjustments were based on concentrations. For subjects who were prescribed voriconazole, concentration monitoring and dose adjustments based on voriconazole concentrations were performed in 20% and 78% of subjects respectively. Adverse outcomes associated with the use of antifungal therapy were reported in 0% of the posaconazole therapy group and 17% of the voriconazole therapy group. Conclusions: Both posaconazole and voriconazole concentrations were obtained from patients who were receiving antifungal therapy for invasive fungal infection prophylaxis. Adjustments of prophylactic doses are not well characterized.
4

The pharmacodynamics of antifungal agents against Aspergillus

Jeans, Adam Rupert January 2013 (has links)
Background: Voriconazole is a first line agent for the treatment for invasive pulmonary aspergillosis. There are increasing reports of Aspergillus fumigatus isolates with reduced susceptibility to voriconazole. I investigated the pharmacodynamics of voriconazole against drug susceptible and drug resistant strains of Aspergillus fumigatus through the development of a novel dynamic in vitro model of the human alveolus. I then investigated whether combination therapy with voriconazole and anidulafungin would be beneficial in the treatment of infection with these isolates. Methods: An in vitro dynamic model of IPA was developed that enabled simulation of human-like voriconazole pharmacokinetics. Galactomannan was used as a biomarker. The pharmacodynamics of voriconazole against wild-type and three resistant strains of A. fumigatus were defined. The results were bridged to humans to provide decision support for setting breakpoints for voriconazole using Clinical Laboratory Standards Institute (CLSI) and European Committee of Antimicrobial Susceptibility Testing (EUCAST) methodology. The interaction of voriconazole and anidulafungin in an in vitro static model was described using the Greco model. Results: Isolates with higher MICs required higher area under the concentration time curve (AUCs) to achieve suppression of galactomannan. An AUC:MIC using CLSI and EUCAST methodology that achieved suppression of galactomannan was 55 and 32.1, respectively. A trough concentration:MIC using CLSI and EUCAST methodology that achieved suppression of galactomannan was 1.68 and 1, respectively. Potential CLSI breakpoints for voriconazole are: susceptible ≤ 0.5 mg/L; resistant > 1 mg/L. Potential EUCAST breakpoints for voriconazole are: susceptible ≤ 1 mg/L; resistant > 2 mg/L. Galactomannan concentrations were only marginally reduced by anidulafungin monotherapy in the static model. An additive effect between voriconazole and anidulafungin was apparent. Conclusions: Voriconazole resistance mechanisms can be overcome with higher drug exposures, but this may require concentrations likely to cause toxicity in humans. The addition of anidulafungin does not markedly alter the exposure-response relationship of voriconazole. A rise in serum galactomannan during combination therapy with voriconazole and anidulafungin should be interpreted as treatment failure and not attributed to a paradoxical reaction related to echinocandin treatment. The dynamic in vitro model is a useful tool to address many remaining questions related to treatment of invasive fungal infection.
5

Pulmonary delivery of aqueous voriconazole solution

Tolman, Justin Andrew 13 August 2012 (has links)
Invasive Pulmonary Apsergillosis (IPA) is caused by inhalation of fungal conidia to the deep lung followed by germination and invasive hyphal growth in heavily immunosuppressed patients (e.g. those with hematologic malignancies, hematopoietic stem cell transplant recipients, and those undergoing solid organ transplantation). Hyphal growth into pulmonary capillaries often leads to dissemination of the infection and high mortality rates despite current treatment and prophylactic modalities. In addition, systemic antifungal therapy is often limited by drug toxicities, low and variable bioavailability, erratic pharmacokinetics, and drug interactions. Although targeted drug delivery to the lungs has been investigated to reduce adverse events and promote drug efficacy, inconsistent pharmacokinetic properties following inhalation of poorly water soluble antifungals has prompted variable drug efficacy. In this dissertation, inhaled voriconazole was investigated through in vitro and in vivo testing to evaluate pharmacokinetic properties, characterize drug safety and, determine drug efficacy as prophylaxis against IPA. In Chapter 2, the in vitro evaluation of solution properties and aerosol characterization of aqueous voriconazole was evaluated. Subsequent in vivo single and multiple dose pharmacokinetic studies demonstrated high drug concentrations were achieved in lung tissue and plasma following inhalation in contrast to previous reports of inhaled antifungals. Inhaled voriconazole was then administered twice daily (BID, at 08:00 and 16:00) in a murine model of IPA as described in Chapter 3 with significant improvements in animal survival over 12 days compared to both positive and negative control groups. As described in Chapter 4, voriconazole was then chronically administered BID at a high and low dose to rats over 21 days with a 7 day recovery period to assess dose tolerability through laboratory tests and histopathological changes to lung, liver, kidney, and spleen tissues. Inhaled voriconazole was well tolerated through all assessments but with signs of mild acute histiocytosis in lung tissue without other signs of inflammation. Chapter 5 expanded the single inhaled dose pharmacokinetic profile in lung tissue and plasma with determination of additional pharmacokinetic parameters through compartmental modeling. Peak and trough voriconazole concentrations were also evaluated in mice as well as rats following multiple doses administered over 12 hours (Q12H) as opposed to BID. / text
6

The Role Of The Cross Pathway Control Protein In The Stress Response And Adaptation Of Aspergillus Species To Antifungals

Amarsaikhan, Nansalmaa 01 August 2010 (has links) (PDF)
In this study, the adaptation and response of Aspergillus nidulans and Aspergillus fumigatus wild type and cpcA strains to antifungal compounds were studied using cultural, genetic and proteomic methods. CpcA is the fungal cross pathway control protein which may also have a role in the development of resistance to antifungal that has become a major problem in human and plant fungal diseases and many studies are devoted to address the drug resistance mechanisms. Cell adapts itself to stress when it is subjected to a stress repeatedly. The ancestor of CpcA, ATF4 (CREB2) has recently been found to be important in the survival of tumor cells after starvation and nutrient limitation and these findings are expected to open new insights into the future antifungal therapy. Fungal cross pathway control system conserves similar mechanism with the stress response pathway in humans as a response to amino acid starvation. Fungal adaptation to antifungal agents was studied using the genetic model A. nidulans with the experimentally induced adaptation setup. It was concluded that A. nidulans cells are able to adapt to antifungal. In order to understand how cell becomes resistant to a previously susceptible agent, it is important to investigate the process when the cell encounters the agent for the first time. Fungal cellular response to antifungal drugs was studied using the human opportunistic pathogen A. fumigatus at the protein level. This is the first proteomic study directed to investigate the A. fumigatus response to voriconazole (VRC). The recently developed two dimensional gel electrophoresis approach, Fluorescence 2-D Differential Gel Electrophoresis (DIGE) method was applied to visualize differentially expressed proteins. It was concluded that, about 150 proteins were differentially regulated as a response to stress exerted by azole group antifungal drugs. cpcA strains of A. nidulans and A. fumigatus were compared to wild type strains in terms of susceptibility to various stresses, adaptation potential also at the proteome level. The results obtained in this study showed that CpcA was important in the response of Aspergillus to oxidative, heat stress and in the adaptation of cells to VRC and that its absence drastically changed the cellular response to VRC at the protein level by changing the expression of about 80 proteins. Thus, this protein is a good candidate in future as a potential drug resistance mediator and further characterization is needed to elucidate its mechanism of action on drug resistance.
7

Impact of oral voriconazole during chemotherapy for acute myeloid leukemia and myelodysplastic syndrome: a Japanese nationwide retrospective cohort study / 急性骨髄性白血病および骨髄異形成症候群の化学療法における経口ボリコナゾールの影響:国内後ろ向きコホート研究

Tsutsumi, Ikuyo 23 January 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(社会健康医学) / 甲第22152号 / 社医博第100号 / 新制||社医||10(附属図書館) / 京都大学大学院医学研究科社会健康医学系専攻 / (主査)教授 川上 浩司, 教授 武藤 学, 教授 髙折 晃史 / 学位規則第4条第1項該当 / Doctor of Public Health / Kyoto University / DFAM
8

Typage moléculaire du complexe d'espèces Fusarium solani et détermination de son mécanisme de résistance au voriconazole / Molecular typing of Fusarium solani species complex and determination of its resistance mechanism to voriconazole

Debourgogne, Anne 29 March 2013 (has links)
Le complexe d'espèces Fusarium solani regroupe des champignons phytopathogènes également impliqués en pathologie humaine dans des infections parfois profondes et souvent de mauvais pronostic. Dans un premier temps, une méthode de MLST, s'appuyant sur 5 gènes de ménage a donc été développée. Validée sur 51 isolats épidémiologiquement distincts, cette méthode stable et reproductible présente un pouvoir discriminant de 99,1 %. Après comparaison à la technique de référence utilisée en phylogénie, un schéma consensus à 8 loci a été proposé. Dans un second temps, une étude de la sensibilité de ce pathogène à l'amphotéricine B et au voriconazole a été menée par deux techniques d'évaluation des CMI : microdilution CLSI M38-A2 et bandelettes E-test. Devant le paradoxe entre une sensibilité diminuée in vitro au voriconazole et la recommandation de cette molécule pour le traitement curatif de la fusariose humaine, des mécanismes de résistance ont été exploré. L'hypothèse d'un phénomène d'efflux n'a pas été retenue alors que celle d'une modification de la cible, la 14 alpha stérol déméthylase, peut être envisagée après la description de différentes mutations pour les isoformes CYP51A, B et C / Fusarium solani species complex includes phytopathogenic fungi also involved in human infections with poor prognosis. Firstly, MLST method, based on five housekeeping genes has been developed. This method has been validated on 51 isolates epidemiologically distinct, and has been shown to be stable and reproducible and provides a discriminating power of 99.1%. After comparison with the reference technique used in phylogeny, a consensus method with 8 loci has been proposed. Secondly, a study of the susceptibility to amphotericin B and voriconazole has been conducted with two MIC determination methods : CLSI M38-A2 microdilution and E-test. The paradox between decreased susceptibility to voriconazole in vitro and recommendation of this molecule for the curative treatment of Fusarium infections has lead to the exploration of resistance mechanisms. The hypothesis of an efflux phenomenon has not been retained whereas a change in the target, the sterol 14 alpha demethylase may be considered following the description of different mutations on proteins CYP51A, B and C
9

Contribution à l'étude de nouveaux agents antiamibiens dans un modèle expérimental de kératite à Acanthamoeba chez le rat / Contribution to the study of new antiamoebic agents in an experimental model of Acanthamoeba keratitis in rats

Gueudry, Julie 16 October 2018 (has links)
La kératite à Acanthamoeba (KA) est une kératite infectieuse rare et grave,potentiellement cécitante. L'infection est causée par Acanthamoeba spp., unprotozoaire ubiquitaire présent dans le sol, l'air et l'eau. Jusqu'à 85% des cas de KAsont associés au port de lentilles cornéennes, et plus rarement suite à untraumatisme.Actuellement, aucune molécule n’a d’autorisation de mise sur le marché danscette indication dans l'Union européenne et aux États-Unis. Ces dernières années,des combinaisons d'agents anti-amibiens tels que les biguanides et les diamidinesont été utilisées comme traitement de référence. Cependant, les schémasthérapeutiques et les concentrations d'agents actifs reposent sur des donnéesempiriques. Récemment, le voriconazole, antifongique triazolé, a été utilisé avecsuccès pour traiter des KA humaines. Malgré cela, la communauté ophtalmologiquese heurte le plus souvent dans les formes sévères à de grandes difficultés de prise encharge et se retrouve parfois en situation d’impasse thérapeutique. La pertefonctionnelle et anatomique de l’oeil est encore possible.A partir d’un modèle de KA chez le rat, plusieurs molécules et voiesd’administration ont été testées. Dans une première partie, en lien avec projeteuropéen ODAK (Orphan drug for Acanthamoeba Keratitis), nos travaux ont suggéréqu’une concentration de collyre PHMB supérieure ou égale à 0,04% devait êtrepréférée. Dans une deuxième partie, nous avons pu montrer la supériorité duvoriconazole en collyre par rapport à la voie orale. Enfin, l’étude de lapharmacocinétique du voriconazole et du posaconazole après injections directesintracornéennes, démontre leur faible utilité en clinique humaine du fait de lafréquence nécessaire de réinjection, bien que des analyses complémentairesconcernant le posaconazole en collyre pour confirmer son intérêt soient nécessaires.L'ensemble de ces travaux pourrait permettre d’adapter les protocolesthérapeutiques de la KA. / Acanthamoeba keratitis (AK) is a rare and severe form of infectious keratitis,which is potentially sight-threatening. The infection is caused by Acanthamoeba spp.a common protozoan present in soil, air and water. Up to 85% of AK cases areassociated with contact lens wearing, more rarely after corneal injury.Currently, there are no agents approved for the treatment of AK in theEuropean Union or in the United States of America. In recent years, combinations ofunlicensed anti-amoebic agents such as biguanides and diamidines have been usedas the reference treatment. Treatment regimens and concentrations of active agentsare based on empirical data. Recently, voriconazole, a mono-triazole, wassuccessfully used to treat cases of human AK. Despite this, the ophthalmologicalcommunity is most often faced with severe forms of the disease with severemanagement difficulties and sometimes with a situation of therapeutic impasse. Thefunctional and anatomical loss of an eye can occur.Several agents and routes of administration have been tested in a rat model ofAK. First, as part of the European ODAK project (Orphan drug for AcanthamoebaKeratitis), our work suggested that a concentration of PHMB eye drops greater thanor equal to 0.04% should be preferred. Second, we were able to show the superiorityof voriconazole in eye drops compared to the oral route. Finally, our study on thepharmacokinetics of voriconazole and posaconazole after intrastromal injections,demonstrates their low utility in human because of the need for frequent reinjection.Nevertheless, additional analyses are necessary to confirm the interest ofposaconazole eye drops. All of this work could make it possible to adapt thetherapeutic protocols of AK.
10

Desenvolvimento de formulações contendo voriconazol encapsulado em nanopartículas lipídicas e promotores químicos de absorção para aplicação tópica na unha / Development of formulations containing voriconazole encapsulated in lipid nanoparticles and chemical absorption promoters for topical nail application

Rocha, Kamilla Amaral David 18 August 2015 (has links)
Submitted by Liliane Ferreira (ljuvencia30@gmail.com) on 2018-02-28T14:49:21Z No. of bitstreams: 2 Dissertação - Kamilla Amaral David Rocha - 2015.pdf: 3193387 bytes, checksum: 6cc146ed197535b6a21627e8ffa4891c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-02-28T16:16:32Z (GMT) No. of bitstreams: 2 Dissertação - Kamilla Amaral David Rocha - 2015.pdf: 3193387 bytes, checksum: 6cc146ed197535b6a21627e8ffa4891c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-02-28T16:16:32Z (GMT). No. of bitstreams: 2 Dissertação - Kamilla Amaral David Rocha - 2015.pdf: 3193387 bytes, checksum: 6cc146ed197535b6a21627e8ffa4891c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-08-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The voriconazole (VOR) is an antifungal from the thiazole class, which has a proven action against dermatophytes, main cause of onychomycosis. Topical treatment of pathologies located in the nail is highly desirable, since oral administration of antifungal agents have been shown ineffective. Thus, the goal is the work was the development of nanostructured lipid carriers (NLC) for nail topical administration of the VOR. To quantify VOR in the nail plate, an analytical method was developed and validated by high-performance liquid chromatography (HPLC) with detection in the UV-vis. CLNs were obtained with glyceryl behenate, Miglyol®, polysorbate 80, sorbitan trioleate surfactant, and a cationic cetilpiridíneo chloride (CPC) and different drug loading. Nanoparticles were characterized for medium size, PdI, zeta potential, encapsulation efficiency and recovery, morphology by scanning electron microscopy (SEM), and the stability. Hydration factor of the formulations and permeation enhancers was performed. Analysis of dry and hydrated hooves treated with NLC were achieved by SEM. Release and in vitro permeation studies were performed with unloaded drug (VOR-free) and VOR loaded NLC. The drug quantification method was linear in the concentration range from 0.4 to 40 mg / mL. The limit of quantitation was 400 ng/mL. Furthermore, the method was able to analyze the VOR without suffering interference from components of the nail and NLC. The NLC (n = 3) loaded with drug showed positive surface charge (around +25 mV) and average size of 230 nm. The NLC obtained had 1.75% of drug load, with encapsulation efficiency of 74.52 (+ 2.13)%. Hydration factor studies showed that the formulation with the highest amount of Miglyol was able to hydrate the nail more as well as the urea, which was the best promotor enhancer for nail hydration. NLC developed with and without addition of promoters were stable for a period of 150 days. In vitro release studies showed that the release VOR from the NLC occurs in a controlled manner from the lipid matrix. There was no significant difference in drug penetration when applied CLNs with and without promoter, for the VOR-Free. Although amounts of drug were found more deeply with the use of the CLN in the sample depletion assays, which can facilitate treatment of nail affected by onychomycosis. / O voriconazol (VOR) é um antifúngico da classe tiazol, que possui ação comprovada contra os dermatófitos, principais causadores da onicomicose. O tratamento tópico localizado de patologias na unha é altamente desejado, visto que a administração oral de antifúngicos têm se demonstrado ineficiente. Desta forma, o objetivo deste trabalho consiste no desenvolvimento de carreadores lipídicos nanoestruturados (CLN) para administração tópica do VOR na unha. Para a quantificação do VOR na placa ungueal foi desenvolvido e validado um método analítico por cromatografia líquida de alta eficiência (CLAE) com detecção no UV-vis. Os CLN foram obtidos com behenato de glicerila, Miglyol®, polissorbato 80, trioleato de sorbitano e tensoativo catiônico cloreto de cetilpiridnío (CPC), com diferentes cargas do fármaco. As nanopartículas foram caracterizadas quanto ao tamanho, PdI, potencial zeta, eficiência de encapsulação e recuperação, morfologia por microscopia eletrônica de varredura (MEV), e a estabilidade das mesmas. Avaliação do fator de hidratação das formulações e de promotores de permeação foi realizada. Análises dos cascos secos e hidratados com os CLN foram feitas por MEV. Estudos de liberação e permeação passiva in vitro do VOR livre e encapsulado em CLN foram realizados. O método de quantificação do fármaco mostrou-se linear na faixa de concentração de 0,4 a 40 μg/mL. O limite de quantificação foi de 400 ng/mL. Ainda, o método foi capaz de analisar o VOR sem sofrer interferência dos componentes da unha e dos CLN. Os CLN (n=3) carregados com fármaco apresentaram carga superficial positiva (em torno de +25 mV) e tamanho médio de 230 nm. Obtiveram-se carreadores com 1,75% de carga de fármaco e com eficiência de encapsulação de 74,52 (+ 2,13) %. A avaliação do fator de hidratação mostrou que a formulação com maior quantidade de Miglyol® foi capaz de hidratar mais a unha, assim como o promotor que apresentou melhor resultado foi a uréia (10%). Os CLN desenvolvidos com e sem adição de promotores se mostraram estáveis por um período de 150 dias. Os estudos de liberação in vitro demonstraram que a liberação do VOR a partir dos CLN ocorre de forma controlada a partir da matriz lipídica. Não houve diferença significativa na penetração do fármaco quando aplicado os CLN com e sem promotor, em relação ao VOR-Livre. Embora, quantidades de fármacos foram encontradas mais profundamente com uso dos CLN em ensaios de esgotamento da amostra, o que pode favorecer o tratamento de unhas acometidas pela onicomicose.

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