Resumo:Os bloqueios regionais são utilizados na medicina veterinária como parte do protocolo de uma anestesia balanceada, junto à anestesia geral inalatória. A eficácia, contudo, é variável frente à dificuldade de realização devido às referências anatômicas vagas ou inexperiência do executor. O bloqueio peribulbar possui indicação para procedimentos oftálmicos em geral, porém a realização da técnica requer cuidado pela proximidade da agulha ao bulbo ocular o que, caso ocorra erro, pode propiciar a perfuração do mesmo. O acompanhamento com a imagem ultrassonográfica pode se constituir em excelente ferramenta na execução de técnicas locais, principalmente as de acesso delicado e com risco de lesões como o bloqueio peribulbar. Com o objetivo de padronizar a técnica de bloqueio peribulbar guiado por ultrassonografia em cães, este trabalho foi executado com se segue: na primeira fase, quatro cães recém-eutanasiados foram submetidos à injeção peribulbar guiada pelo ultrassom com a administração de azul de metileno 1%, para a identificação das estruturas orbitárias e oculares atingidas pela solução. A segunda fase ocorreu na forma de estudo comparativa da duração do bloqueio sensitivo, motor e das intercorrências oftálmicas observadas durante a avaliação da técnica convencional de bloqueio peribulbar e da técnica guiada por ultrassom, com ropivacaína a 1% em 15 cães sadios. Os resultados obtidos demonstraram acinesia, bloqueio sensitivo e motor equivalentes, com ocorrência e intensidade das intercorrências oftálmicas semelhantes, salvo a hemorragia conjuntival que teve maior repercussão nos bulbos bloqueados de maneira tradicional. Concluiu-se que a padronização da técnica do bloqueio peribulbar, com punção única inferior, guiado por ultrassom apresenta aplicabilidade na espécie canina, com a vantagem de promover a confirmação visual da exatidão...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract:he regional blocks are used in veterinary medicine as part of a balanced anesthesia protocol, next to inhalational anesthesia. The effectiveness, however, is variable front due to the difficulty of achieving anatomical references vague or inexperience of the performer. The peribulbar has indicated for ophthalmic procedures in general, but the technique requires care by the proximity of the needle to the eyeball that if an error occurs, can lead to perforation of the same. The monitoring with ultrasound image may be a great tool in the implementation of local techniques, especially the delicate and access-threatening injuries as peribulbar block. Aiming to standardize the technique of peribulbar guided by ultrasound in dogs, this work was performed with the following: in the first phase, four dogs euthanized recently underwent peribulbar injection guided by ultrasound with the administration of methylene blue 1% for identification of the structures affected by ocular and orbital solution. The second phase occurred in the form of comparative study of the duration of sensory block, motor and ophthalmic complications observed during the assessment of the conventional peribulbar and ultrasound-guided technique with 1% ropivacaine in 15 healthy dogs. The results showed akinesia, motor and sensory block equivalents, with the occurrence and severity of ophthalmic complications similar, except the conjunctival haemorrhage had major repercussions in the way traditional bulbs blocked. It was concluded that the standardization of the peribulbar technique with lower single puncture guided by ultrasound has applicability in dogs, with the advantage of promoting visual confirmation of the accuracy of the technique and the correct deposition of the anesthetic agent in the proper place, concomitantly the preservation of eye structures, with satisfactory quality and duration / Orientador:Valéria Nobre Leal de Souza Oliva / Banca:Maria Gisela Laranjeira / Banca:Paulo do Nascimento Junior / Mestre

Made available in DSpace on 2016-12-08T16:24:03Z (GMT). No. of bitstreams: 1 PGCV07MA020.pdf: 443765 bytes, checksum: d530474b1e56085bd807f9be2a864e05 (MD5) Previous issue date: 2007-09-05 / The musculoskeletal lesions that involve the joints of horses are still the major cause of fall in performance of athletic horses. Thus, the use of intraarticular anesthesia is an easy method of relieving articular pain. The promotion of an intra-synovial analgesia to the patient accelerates its recovery period at the hospital, promoting a comfort period mainly after arthroscopic surgeries, as well as controls pain coming from joint diseases. Purpose: The purpose of this study was to compare the intraarticular analgesic effects and systemic effects of ropivacaine and morphine in horses submitted to experimentally induced synovitis. Methods: Twelve healthy horses, without specific breed, males and females, between 8 and 15 years were used in this study; each animal was used twice with an interval period of 30 days, totalizing 24 treatments. The synovitis was induced using 0.5ng/joint of LPS from E. coli 055:B5 on the left radio-carpal joint. Six hours after LPS injection it was given 0.01 ml/kg of saline (control group/n=6); 0.1mg/kg of ropivacaine 1% (ROP group/n=6); 0.1 mg/kg of morphine 1% group (MORF group/n=6) and 0.05 of ropivacaine 1% added to 0.05 mg/kg of morphine (ROP+MORF/n=6). The intraarticular anesthesia was subjectively measured using a lameness score evaluation, numerical rating scale (NRS) and a single descriptive scale (SDS), and by the range of motion of the affected joint. The hematological and sinovial variables were analyzed right before LPS injection (M0), 6h after LPS injection (M6) and at the end of the evaluation period (M1440). Clinical variables were analyzed on the following intervals: just before LPS injection; 360 minutes after LPS injection or at the moment where treatments were injected (M0); 30 minutes after treatment (M30); 90 minutes (M90); 150 minutes (M150); 210 minutes (M210); 360 minutes (M360); 720 minutes (M720) and 1440 minutes (M1440). Results: Ropivacaine injection promoted an analgesic effect with fast onset of action. Its effects lasted for approximately 150 minutes in inflamed tissue. Morphine, despite of a slower onset of action showed a longer analgesic effect than ropivacaine. When used together promoted an additive analgesia, with fast onset of action and analgesia covering the whole post-injection period (24hours). There was a significant decrease on TNC in all groups when comparing to placebo (G-SAL) at M1440. Conclusions: Intraarticular morphine and ropivacaine is an analgesic complementary treatment option and represent a good pain relief on primary synovitis. The absence of side effects by this rout of administration suggests that opioids, like morphine can be a new and promise class of agents administered intraarticularly in joint diseases and that can take us to the development of a new generation of analgesic drugs with possible anti-inflammatory effects. / As lesões músculo esqueléticas que envolvem as articulações podais dos cavalos permanecem sendo a maior causa da queda na performance atlética de cavalos de corrida. Desta forma, o uso intra-articular de analgésicos é um meio útil e efetivo de aliviar os estímulos nociceptivos causados pelas patologias articulares ou ainda causadas no póscirúrgico. Objetivos: Comparar os efeitos analgésicos e reações sistêmicas do cloridrato de ropivacaína e do sulfato de morfina pela via intra-articular em eqüinos submetidos à sinovite experimentalmente induzida. Métodos: Foram utilizados doze (12) eqüinos hígidos, sem padrão racial, machos ou fêmeas, com idade entre 8 a 15 anos; cada animal foi utilizado 2 vezes com intervalos de 30 dias, totalizando 24 animais. A sinovite foi induzida através da administração intra-articular (articulação rádio-cárpica) de 0,5 ng de lipopolissacarídeo (LPS) de Escherichia coli 055:B5. Decorridos 360 minutos da administração de LPS foram administrados 0,01 mL/kg de solução salina 0,9% (grupo controle) constituindo o grupo SAL (n=06); 0,1 mg/kg de cloridrato de ropivacaína (1%) no grupo ROPI (n=06); 0,1 mg/kg de sulfato de morfina (1%) no grupo MORF (n=06) e 0,05 mg/kg de ropivacaína (0,2%) associado à 0,05 mg/kg de morfina (1%) no grupo RM (n=06). A avaliação da analgesia intraarticular foi descrita através da visualização do grau de claudicação (1-5), utilizando-se a escala visual numérica (EVN), bem como a escala descritiva de dor (ED). Os parâmetros hematológicos e sinoviais foram analisados imediatamente antes da administração do LPS (M0), 6h após a injeção do LPS (M6) e ao final das avaliações (M1440). Os parâmetros clínicos foram avaliados nos seguintes intervalos de tempo: imediatamente antes da administração de LPS (T-360); 6h após a administração de LPS (M0), 30 minutos após a administração da solução salina ou ropivacaína e/ou morfina (M30), 90 minutos (M90), 150 minutos (M150), 210 minutos (M210), 360 minutos (M360), 720 minutos (M720), 1440 minutos (M1440) após a administração da solução salina ou ropivacaína e/ou morfina. Resultados: A aplicação da ropivacaína promoveu analgesia com rápido inicio de ação, cujos efeitos perduram em média por 150 minutos em tecidos inflamados. A morfina apesar de um início de ação mais lento mostrou um prolongamento dos efeitos analgésicos quando comparado a ropivacaína. Quando em combinação com a ropivacaína promoveu uma analgesia intra-articular aditiva, com rápido inicio de ação e analgesia de até 24h em cavalos submetidos à sinovite experimental. Houve uma diminuição significativa dos valores de células nucleadas totais (CNT) dos grupos em estudo quando comparados ao G-SAL ao final das avaliações (M1440). Conclusões: A administração concomitante da ropivacaína e da morfina pela via intra-articular é uma opção complementar de tratamento analgésico, e representam uma opção viável no alívio da dor proveniente das sinovites agudas. A ausência de efeitos colaterais por esta via sugere que os opióides, como a morfina, podem ser uma nova e promissora classe de agentes aplicados pela via intra-articular em doenças articulares e que podem nos levar ao desenvolvimento de uma nova geração de drogas analgésicas com possíveis potenciais antiinflamatórios.

Orientador: Eneida de Paula / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-21T20:38:17Z (GMT). No. of bitstreams: 1 Vieira_AnaLaisNascimento_M.pdf: 1761666 bytes, checksum: 7180ab65e3505754f86cafe1a14f9b0d (MD5) Previous issue date: 2012 / Resumo: Os anestésicos locais (AL) são fármacos utilizados para o tratamento, alívio ou eliminação da dor crônica ou aguda. Muitas pesquisas têm sido desenvolvidas com a finalidade de prolongar sua duração de ação e reduzir sua toxicidade sistêmica, através do uso de diferentes carreadores, como lipossomas e ciclodextrinas. Essas novas formulações possibilitam a liberação sustentada do ativo no local de ação, prolongando o efeito anestésico, além de evitar picos de concentração plasmática, reduzindo sua toxicidade. A ropivacaína (RVC) é um AL de longa duração de ação, que é sintetizado na forma do estereoisômero S, de menor toxicidade para o sistema nervoso central e cardíaco. Estudos anteriores de nosso laboratório demonstraram a complexação da RVC em hidroxipropil-betaciclodextrina (HP-?CD) (de Araujo et al., 2008b). Neste trabalho objetivamos: i) desenvolver uma formulação contendo complexo de inclusão de RVC em HP-?CD na razão molar de 1:1 e posteriormente, encapsulado em lipossomas de fosfatidilcolina de ovo (EPC) contendo 1 mol%de ?-tocoferol, ii) caracterizar esta nova formulação anestésica, comparando-a com as preparações comerciais deste fármaco, quanto à estabilidade e liberação sustentada do anestésico. Os lipossomas unilamelares grandes (LUV) compostos por fosfatidilcolina de ovo e ?- tocoferol (1,0: 0,01 - razão molar) foram preparados por extrusão, em pH 7,0. A formulação lipossomal foi caracterizada quanto à eficiência de encapsulação com a obtenção de valores de porcentagem de encapsulação da RVC de 33,0±2,4 % e coeficiente de partição de 102,1. Ensaios de Ressonância Magnética Nuclear com variação de campo magnético (diffusion ordered spectroscopy, DOSY) demonstraram a interação molecular da RVC tanto com a ciclodextrina (constante de associação, Ka RVC: HP-?CD = 128 M-1) quanto com os lipossomas (Ka LUV: RVC = 22 M-1). No sistema de duplo carreamento (LUV: RVC: HP-?CD) a constante de associação foi maior que nos sistemas binários RVC: HP-?CD e LUV: RVC (2,6 e 1,7 vezes, respectivamente) indicando que este novo sistema de liberação sustentada é capaz de aumentar ainda mais a quantidade de ropivacaína carreada. O tamanho dos lipossomas (220,2±20,3 nm) e o potencial zeta (-31,7±1,4 Mv) não se alteraram com a adição do anestésico. As formulações foram acompanhadas por 60 dias, em termos de peroxidação lipídico e tamanho das vesículas: os níveis de peroxidação mostraram-se baixos (menor que 1% do total de lipídios da formulação) e as vesículas tiveram um comportamento estável em relação ao tamanho por até 30 dias de armazenamento a 4oC. Ensaios de liberação in vitro, demonstraram menor velocidade de liberação da RVC quando na forma de complexo de inclusão em ciclodextrinas e encapsulada nos lipossomas, em relação à RVC livre. Testes de toxicidade in vitro, em culturas de células de fibroblastos 3T3 revelaram que a RVC livre induz morte celular de maneira concentração dependente; efeito este que foi parcialmente revertido com incubação das células com o sistema de duplo carreamento LUV: RVC: HP-?CD, indicando menor potencial tóxico para a formulação proposta. Ensaios de bloqueio sensorial in vivo (teste de pressão na pata, em camundongo) mostraram uma ação analgésica prolongada da RVC encapsulada no sistema de duplo carreamento (até 300 min. para 0,25% LUV: RVC: HP-?CD), quando comparado ao fármaco livre (180 min.) e sistema binário LUV: RVC (240 min.). Em geral, o efeito da analgesia para o sistema de duplo carreamento proposto foi cerca de 1,6 vezes maior em relação ao fármaco livre e 1,3 vezes maior em relação ao sistema lipossomal binário. Os resultados obtidos contribuem com a investigação, pesquisa e caracterização de formas farmacêuticas de liberação sustentada e demonstram regulação da cinética de liberação da RVC quando do uso conjugado desses dois carreadores (lipossoma de EPC e HP-?CD) em sistema de liberação sustentada de anestésico local, abrindo perspectivas para justificar o uso clínico / Abstract: Local anesthetics (LA) are medicines used for the treatment, alleviation or elimination of acute or chronic pain. Many studies have been carried out aiming to prolong LA duration of action and to reduce their systemic toxicity by the use of carrier systems such as liposomes and cyclodextrins. Such formulations allow the sustained release of the LA at the site of action, prolonging the anesthetic effect and avoiding peak plasma concentrations, thus reducing LA toxicity. Ropivacaine (RVC) is a long acting LA, synthesized in the S enantiomer form which is less toxic to the Central nervous and cardiac systems. Previous work from our lab has shown the complexation of RVC in hydroxipropyl-beta-cyclodextrin (HP-?CD) (de Araujo et al., 2008b). The present work aimed: i) the development of a formulation containing RVC in HP-?CD inclusion complex in a 1:1 mole % ratio and subsequently encapsulated into egg phosphatidylcholine plus 1 mol% ?-tocopherol liposomes; ii) the characterization of that formulation, comparing it with commercial preparations of RVC, regarding the stability and sustained release of the anesthetic. Large unilamellar liposomes (LUV) composed of egg phosphatidylcholine and ?-tocopherol (1,0:0,01 mol %) was prepared by extrusion, at pH 7.0. The liposomal formulation was characterized with respect to encapsulation efficiency (33.0±2.4%) corresponding to partition coefficient of 102.1. Nuclear magnetic resonance (diffusion ordered spectroscopy, DOSY) experiments clearly demonstrated the molecular interaction between RVC and the HP-?CD (association constant, Ka RVC:HP-?CD = 128 M-1) and liposomes (Ka LUV:RVC = 22 M-1). In the ternary system LUV:RVC:HP-?CD) a stronger association was detected (Ka = 2.6 and 1.7 x higher than in the binary RVC:HP-?CD e LUV:RVC systems, respectively), pointing out the increased RVC loading capacity of the new drug-delivery system. The size of the vesicles (220.2± 20.3 nm), and zeta potential of the liposomes (-31.7±1.4 Mv) were not changed by the incorporation of the anesthetic. The formulations were followed by 60 days in terms of lipid peroxidation and size of vesicles: peroxidation were shown to be low (less than 1% of total lipids in the formulation) and the vesicles remained stable in relation to their size up to 30 days of storage at 4°C. Release kinetics experiments revealed a decrease in the release of RVC when in the inclusion complex with HP-?CD and when encapsulated into the liposomes, relatively to free RVC, Citotoxicity assays in vitro, over cultures of 3T3 fibroblast cells showed that RVC was able to induce cell death in a concentration dependent manner and that this effect was partially reverted if cells were incubated with double-loading LUV:RVC:HP-?CD system. In vivo sensory block experiments (paw withdraw threshold to pressure in rats) showed a prolonged anesthetic effect for RVC in the ternary system (300 min) in comparison to free RVC (180min) and binary system LUV:RVC (240min). In general, pain relief effect of the double-loading system was longed about 1.6 times than that of free RVC and 1.3 times when compared to the liposomal binary system. The results obtained were important in the research, study and characterization of controlled release dosage forms and show changes on the release kinetics of RVC following the combined use of two carriers (EPC liposomes and HP-?CD) in a delivery system among its future use in clinical practice / Mestrado / Bioquimica / Mestre em Biologia Funcional e Molecular

Orientador: Artur Udelsmann / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-20T06:58:04Z (GMT). No. of bitstreams: 1 Bonfim_MatheusRodrigues_D.pdf: 1120826 bytes, checksum: eaeb23285e6e03692af7bbc927746618 (MD5) Previous issue date: 2012 / Resumo: Introdução: os anestésicos locais são drogas que bloqueiam de maneira reversível a condução de impulsos ao longo das fibras nervosas. São amplamente utilizados em anestesias locorregionais e no tratamento da dor, entretanto seu uso não é isento de riscos. A cardiotoxicidade é a mais preocupante das complicações nos casos de injeção intravascular acidental de grandes doses e até pouco tempo sem tratamento específico. A bupivacaína é o anestésico local mais utilizado, mas depois de editorial na revista Anesthesiology em 1979 sobre seus graves efeitos cardiovasculares em caso de intoxicação, esforços foram empreendidos para encontrar agentes menos tóxicos. Surgiu então a ropivacaína, que embora reconhecidamente menos tóxica, ainda não é totalmente isenta de riscos e logo tornou-se necessário encontrar um tratamento específico para os casos de intoxicações por anestésicos locais. Em 1998 foi demonstrado que as emulsões lipídicas eram eficientes para combater a cardiotoxicidade dos anestésicos locais e desde então esses agentes vêm sendo utilizados com sucesso. Alguns autores encontraram um melhor resultado com emulsões lipídicas contendo na sua formulação triglicérides de cadeia longa comparativamente às com triglicérides de cadeia média, enquanto outros não. Objetivo: comparar as alterações hemodinâmicas da intoxicação com ropivacaína em suínos e os resultados do tratamento com emulsões lipídicas com triglicérides de cadeia longa e com aquelas contendo 1:1 de triglicérides de cadeia longa e de cadeia média, comparando os resultados com os obtidos com uma solução neutra. Método: suínos da raça Large-White foram anestesiados com tiopental, realizada intubação traqueal e mantidos em ventilação mecânica sob isoflurano. As variáveis hemodinâmicas foram registradas por meio de pressão invasiva e cateterização da artéria pulmonar (cateter de Swan-Ganz). Após período de 30 minutos de repouso, 7 mg/kg de ropivacaína foram injetados por via endovenosa e novas medidas hemodinâmicas foram realizadas decorrido 1 minuto. Os animais foram então aleatoriamente distribuídos em três grupos e receberam 4 ml/kg de solução salina, ou 4 ml/kg da emulsão lipídica a 20% com triglicérides de cadeia longa, ou 4 ml/kg da emulsão lipídica a 20% com triglicérides de cadeia longa e cadeia média. As alterações hemodinâmicas foram reavaliadas aos 5, 10, 15, 20 e 30 minutos.Resultados: a intoxicação pela ropivacaína causou diminuição da pressão arterial e do índice cardíaco principalmente, sem importantes alterações das resistências vasculares. A terapia com as duas emulsões lipídicas foi capaz de restaurar a pressão arterial através, principalmente, do aumento das resistências vasculares uma vez que o índice cardíaco não apresentou melhora expressiva neste estudo. A emulsão lipídica com triglicérides de cadeia média causou aumento superior das resistências vasculares, sobretudo pulmonares. Os resultados hemodinâmicos com o uso das duas emulsões na intoxicação pela ropivacaína foram melhores que no grupo controle. Conclusão: nos grupos que receberam emulsões lipídicas os resultados hemodinâmicos foram melhores que no grupo controle, porém não foram observadas diferenças da pressão arterial sistêmica e do índice cardíaco entre os animais que receberam a solução com triglicérides de cadeia longa e a mistura de triglicérides de cadeia média e longa / Abstract: Introduction: local anesthetics are drugs that reversibly block the conduction of impulses along nerve fibers. These agents are widely used in local and regional anesthesia and pain management, despite their potential inherent risks. Cardiovascular toxicity is the most worrisome complication in case of inadvertent intravascular injection of high doses of local anesthetics. Until recently, there was no specific treatment for this type of complication. Bupivacaine is the most commonly used local anesthetic. However, since the publication of severe cardiovascular effects of bupivacaine toxicity in the editorial column of the Anesthesiology journal (1979), efforts have been made to find less toxic agents. This led to the discovery of ropivacaine. Although ropivacaine is known to be less toxic, its use is still not devoid of potential risks. Soon it became imperative to find a specific treatment for cases of local anesthetic toxicity. In 1998, it was demonstrated that lipid emulsions were effective in combating cardiovascular toxicity induced by local anesthetics. Since then these agents have been successfully used. Some authors have found better results using lipid emulsions containing long-chain triglycerides in its formulation compared to medium-chain triglycerides, in contrast to other authors. Objective: to compare hemodynamic alterations of ropivacaine toxicity in pigs and treatment outcome using lipid emulsions with long-chain triglycerides compared to those containing 1:1 long-chain and medium-chain triglycerides, in relation to the results obtained by using a neutral solution. Methods: Large-White pigs anesthetized with thiopental, underwent endotracheal intubation and mechanical ventilation. Isoflurane was used for anesthesia maintenance. Hemodynamic variables were recorded by invasive monitoring with arterial line and pulmonary artery catheterization (Swan-Ganz catheter). After a 30-minute resting period, 7 mg/kg of ropivacaine were intravenously injected and new hemodynamic measurements were performed within 1 minute. The animals were then randomly distributed into three groups, receiving 4 ml/kg of a saline solution, or 4 ml/kg of a 20% long-chain triglyceride lipid emulsion, or 4 ml/kg of a 20% lipid emulsion containing mixtures of long-chain triglycerides and medium-chain triglycerides. Hemodynamic alterations were reassessed at 5, 10, 15, 20 and 30 minutes. Results: ropivacaine toxicity caused a decrease mainly in arterial blood pressure and cardiac index, without important alterations in vascular resistance. Therapy with both lipid emulsions was capable of restoring arterial blood pressure, especially by increasing vascular resistance, since cardiac index did not improve significantly in this study. Lipid emulsions with medium-chain triglycerides caused a higher increase in vascular resistance, especially in pulmonary artery resistance. Better hemodynamic results were observed when both emulsions were used for ropivacaine toxicity than in the control group. Conclusion: in the groups receiving lipid emulsions, the hemodynamic results were better than in the control group. However, there were no differences in arterial blood pressure and cardiac index between animals given solutions containing long-chain triglycerides and solutions containing mixtures of long-chain triglycerides and medium-chain triglycerides / Doutorado / Fisiopatologia Cirúrgica / Doutor em Ciências Médicas

No description available.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of the present study was to determine the duration and efficacy of local analgesia produced by bupivacaine, lidocaine and ropivacaine used to block the palmar digital (PD) nerve. Nine adult horses underwent a thorough physical examination and evaluation using wireless motion sensors to determine the absence of signs of lameness. Galvanized steel clamps were used to induce lameness. The horses were randomly allocated in a crossover design (bupivacaine 7,5 mg/ml, lidocaine 30 mg, ropivacaine 11,25 mg). The objective lameness evaluations were recorded immediately before administration of the anesthetic on the digital palmar nerve, and then at 5, 10, 15, 30, 60, 90,120, 150, 180, 210, 240 and 300 minutes after the block. The evaluation of mean improvement in lameness after the block was performed using the Wilcoxon test (P> 0.05). The relative lameness severity (RLS) observed after the induction of lameness was 2,4 times the threshold (6mm) and the intensity of the induced lameness was similar between horses (coefficient of variance = 55,26%). Bupivacaine, lidocaine and ropivacaine were effective in blocking at least 75% of the lameness induced by clamps, 5 minutes after the block, the tested drugs improved more than 60% of the lameness. With 7.5 mg bupivacaine improved lameness in more than 90% between 10 and 60 minutes after blocking. Lidocaine (30 mg), resulted in maximal analgesia between 10 and 30 minutes after blocking and the lameness improvement was higher than 69%. Administration of 11.25 mg ropivacaine was able to improve lameness more than 86% between 10 and 180 minutes. The doses of bupivacaine and ropivacaine used in this study were effective in blocking lameness induced by clamps. The dose of 30 mg of lidocaine was not able to completely reverse the lameness. At 5 minutes of blocking, the local anesthetics tested had produced a significant improvement in lameness. Objective analysis of lameness showed a longer analgesic effect on the PD nerve block using ropivacaine than bupivacaine and lidocaine. / O objetivo deste estudo foi avaliar o início, a duração e a eficácia da analgesia local produzida pela lidocaína, bupivacaína e ropivacaína no bloqueio do nervo digital palmar. Foram selecionados nove cavalos adultos submetidos a exame físico e avaliação utilizando sensores inerciais para avaliar a ausência de sinais de claudicação. Braçadeiras de aço galvanizado foram utilizadas para induzir claudicação. Os cavalos foram alocados aleatoriamente em um modelo crossover (bupivacaína 7,5 mg, lidocaína 30 mg, ropivacaína 11,35 mg). As análises objetivas de claudicação foram registradas antes da administração perineural dos fármacos no nervo digital palmar e em seguida aos 5, 10, 15, 30, 60, 90,120, 150, 180, 210, 240 e 300 minutos após o bloqueio. A avaliação das médias de estimativa de melhora da claudicação após o bloqueio foi realizada através do teste de Wilcoxon (P>0,05). A severidade da claudicação relativa (SCR) observada após a indução de claudicação foi 2,4 vezes o limiar (6 mm) e a intensidade da claudicação induzida foi semelhante entre os cavalos (coeficiente de variação = 55,26%). Bupivacaína, lidocaína e ropivacaína foram eficientes em bloquear acima de 75% da claudicação induzida experimentalmente, 5 minutos após o bloqueio todas as drogas testadas apresentavam melhora na claudicação superior a 60%. Utilizando 7,5 mg de bupivacaína a estimativa de melhora na claudicação foi superior a 90% entre 10 e 60 minutos após o bloqueio. Com 30 mg de lidocaína a analgesia máxima ocorreu entre 10 e 30 minutos após o bloqueio e a estimativa de melhora na claudicação foi superior a 69%. A administração de 11,25 mg de ropivacaína bloqueou a claudicação em mais de 86%, entre 10 e 180 minutos após o bloqueio. As doses de bupivacaína e ropivacaína utilizadas neste estudo foram eficientes em bloquear a claudicação induzida por braçadeiras. A dose de 30 mg de lidocaína não foi eficiente em bloquear totalmente a claudicação. Cinco minutos após o bloqueio todos os anestésicos locais apresentavam melhora na estimativa de claudicação. As análises objetivas de claudicação mostraram efeito analgésico mais longo no bloqueio do nervo digital palmar da ropivacaína do que da bupivacaína e lidocaína.

<p>One of the aims of this thesis was to investigate the involvement of efflux proteins, such as the P-glycoprotein (Pgp), in the drug transport in different regions of the rat and the human intestine. The intestinal extrusion of intracellularly formed CYP3A4 metabolites, including whether this extrusion might be mediated by Pgp, was also studied. The model drugs used were local anaesthetics (LA), which have been evaluated for inflammatory bowel disease, such as ropivacaine, lidocaine and bupivacaine. The intestinal permeability to LAs was found to be high throughout all intestinal regions of the rat and human intestine. Results from the Ussing chamber model indicated only minor efflux involvement as the drug permeability was higher in the serosa to mucosa transport direction than in the opposite direction. However, the involvement of efflux in the absorption of LAs could not be verified using in situ single-pass perfusion of rat jejunum. The extrusion of the ropivacaine metabolite, 2´,6´-pipecoloxylidide (PPX), was polarized to the mucosal reservoir of the Ussing chamber for both rat and human intestinal samples, and was probably not caused by any Pgp involvement. The expression levels of CYP3A4 and efflux transporters were consistent with the enzymes’ activity in human intestine. PPX formation was mediated by CYP3A4 in human intestine, and cyp2c and cyp2d in rat intestine. Species differences were observed, as PPX was formed in rat colon, but not human colon. In conclusion, the permeability of ropivacaine, lidocaine and bupivacaine was not subjected to efflux transport of significance for their intestinal uptake. The transport of ropivacaine metabolites to the mucosal compartment was probably not mediated by Pgp. The Ussing chamber model showed consistent results with those from intestinal microsomes as far as intestinal metabolism is concerned, making it a suitable model for investigations of the interplay of efflux and metabolism. </p>

One of the aims of this thesis was to investigate the involvement of efflux proteins, such as the P-glycoprotein (Pgp), in the drug transport in different regions of the rat and the human intestine. The intestinal extrusion of intracellularly formed CYP3A4 metabolites, including whether this extrusion might be mediated by Pgp, was also studied. The model drugs used were local anaesthetics (LA), which have been evaluated for inflammatory bowel disease, such as ropivacaine, lidocaine and bupivacaine. The intestinal permeability to LAs was found to be high throughout all intestinal regions of the rat and human intestine. Results from the Ussing chamber model indicated only minor efflux involvement as the drug permeability was higher in the serosa to mucosa transport direction than in the opposite direction. However, the involvement of efflux in the absorption of LAs could not be verified using in situ single-pass perfusion of rat jejunum. The extrusion of the ropivacaine metabolite, 2´,6´-pipecoloxylidide (PPX), was polarized to the mucosal reservoir of the Ussing chamber for both rat and human intestinal samples, and was probably not caused by any Pgp involvement. The expression levels of CYP3A4 and efflux transporters were consistent with the enzymes’ activity in human intestine. PPX formation was mediated by CYP3A4 in human intestine, and cyp2c and cyp2d in rat intestine. Species differences were observed, as PPX was formed in rat colon, but not human colon. In conclusion, the permeability of ropivacaine, lidocaine and bupivacaine was not subjected to efflux transport of significance for their intestinal uptake. The transport of ropivacaine metabolites to the mucosal compartment was probably not mediated by Pgp. The Ussing chamber model showed consistent results with those from intestinal microsomes as far as intestinal metabolism is concerned, making it a suitable model for investigations of the interplay of efflux and metabolism.

Orientador: Jose Ranali / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-04T11:51:15Z (GMT). No. of bitstreams: 1 Palma_FabianoRodrigues_D.pdf: 466426 bytes, checksum: abc9540e10df2749efca61cad2ebc0ff (MD5) Previous issue date: 2005 / Resumo: Vários estudos têm demonstrado as vantagens do uso de anestésicos locais de longa duração em cirurgias bucais. O objetivo deste estudo foi avaliar a eficácia anestésica (latência e duração da anestesia pulpar e em tecidos moles) proporcionada pela injeção de 3,6 ml de bupivacaína e ropivacaína na concentração de 0,5% e associadas à epinefrina 1:200.000, no bloqueio do nervo alveolar inferior, para cirurgias de terceiros molares inferiores inclusos, em 30 voluntários sadios. Também foi avaliada a sensibilidade dolorosa ao procedimento anestésico. O estudo foi cruzado e duplo cego, com a seqüência e lado de aplicação das soluções aleatorizados. As avaliações do tempo de latência e duração da anestesia foram feitas através da aplicação de estímulo elétrico ("pulp tester") nos caninos, segundos pré-molares e segundos molares inferiores. A ausência de resposta ao estímulo elétrico máximo do aparelho foi considerada como critério de anestesia pulpar. A Escala Analógica Visual (EAV) foi utilizada para avaliar a sensibilidade dolorosa. Os resultados foram submetidos à análise estatística através do Teste t (p<0,05). Não foram observadas diferenças entre as soluções, com exceção do tempo de latência em tecidos moles, que foi menor com o uso de ropivacaína (p = 0,016). Nas condições deste estudo a bupivacaína e a ropivacaína apresentaram eficácia anestésica semelhante. Assim, a ropivacaína mostra-se um anestésico útil para o bloqueio de longa duração do nervo alveolar inferior e poderia substituir a bupivacaína em cirurgias orais, em função de sua menor toxicidade, demonstrada na literatura / Abstract: The advantages of using long-acting local anesthetics in oral surgery have been demonstrated in a limited number of clinical studies. The purpose of this double-blind and cross-over study, was to evaluate and compare the efficacy of 2 local anesthetics - bupivacaine and ropivacaine - in the concentration of 0.5% containing 1:200,000 epinephrine for inferior alveolar nerve block. Thirty healthy individuals participated in the study on a voluntary basis. All subjects received bupivacaine and ropivacaine injections (3,6 ml), one anesthetic for each side of the mandible, for surgical removal of impacted mandibular third molar teeth, on separate occasions. The onset time and duration of pulpal anesthesia were assessed by electric pulp tester in the inferior canines, second pre-molars and second molars; no response from the subject to the maximum output (80 reading) of the pulp testes was used as the criterion for pulpal anesthesia; the onset time and duration of lip anesthesia were also assessed. Injection discomfort was assessed by Visual Analogue Scale. The results were evaluated by using Student-t test (p<0.05). No differences were found between the solutions, except for a lower onset of lip anesthesia (p=0,016) with the use of ropivacaine. Under the conditions of this study bupivacaine and ropivacaine showed similar anesthetic efficacy. This leads to the conclusion that ropivacaine can be useful as a long acting anesthetic for inferior alveolar nerve block and could replace bupivacaine in oral surgery due to the decreased toxicity related in the literature / Doutorado / Farmacologia, Anestesiologia e Terapeutica / Doutor em Odontologia

Introduction & Objectifs : Pour assurer l’analgésie postopératoire, l’anesthésiste dispose, en plus des différentes classes de médicaments administrés par voie orale ou intraveineuse, de diverses techniques pour bloquer l’influx nerveux douloureux en administrant les anesthésiques locaux (AL) de manière centrale ou périphérique. La ropivacaïne (ROP), un AL à longue durée d’action, est un médicament de première intention partout dans le monde, en raison de sa grande efficacité et de son faible risque de toxicité. Contrairement à certains pays, la ROP n'est toujours pas indiquée au Canada pour la rachianesthésie (bloc central) en raison d'un manque de données probantes. Jusqu'à présent, les efforts de recherche ont essentiellement porté sur la sécurité ainsi que sur la durée d’action du médicament lorsqu’administré par voie spinale. De plus, les doses optimales de ROP pour l’anesthésie régionale périphérique ne sont pas encore précisément connues. La posologie devrait être adaptée au site d’administration ainsi qu’à l’intensité et la durée du stimulus produit par la chirurgie. Ultimement, cela permettrait aux cliniciens d’identifier le régime optimal en fonction des facteurs démographiques qui pourraient affecter la pharmacocinétique (PK) et la pharmacodynamie (PD) de l’AL (objectif global de ces travaux). Validation de la Méthode Analytique Manuscrit 1 : Une méthode analytique spécifique et sensible permettant de déterminer les concentrations plasmatiques de ROP a d’abord été optimisée et validée. Validation du Biomarqueur Manuscrit 2 : Nous avons ensuite mis au point et évalué la fiabilité d’une méthode quantitative basée sur la mesure du seuil de perception sensorielle (CPT) chez le volontaire sain. Ce test nécessite l’application d’un courant électrique transcutané qui augmente graduellement et qui, selon la fréquence choisie, est capable de stimuler spécifiquement les fibres nerveuses impliquées dans le cheminement de l’influx nerveux douloureux. Les résultats obtenus chez les volontaires sains indiquent que la mesure CPT est fiable, reproductible et permet de suivre l’évolution temporelle du bloc sensitif. Études cliniques Manuscrit 3 : Nous avons ensuite caractérisé, pendant plus de 72 h, l’absorption systémique de la ROP lorsqu’administrée pour un bloc du nerf fémoral chez 19 patients subissant une chirurgie du genou. Le modèle PK populationnel utilisé pour analyser nos résultats comporte une absorption biphasique durant laquelle une fraction de la dose administrée pénètre rapidement (temps d’absorption moyen : 27 min, IC % 19 – 38 min) dans le flux sanguin systémique pendant que l’autre partie, en provenance du site de dépôt, est redistribuée beaucoup plus lentement (demi-vie (T1/2) : 2.6 h, IC % 1.6 – 4.3 h) vers la circulation systémique. Une relation statistiquement significative entre l’âge de nos patients et la redistribution de l’AL suggère que la perméabilité tissulaire est augmentée avec l’âge. Manuscrit 4 : Une analyse PK-PD du comportement sensitif du bloc fémoral (CPT) a été effectuée. Le modèle développé a estimé à 20.2 ± 10.1 mg la quantité de ROP nécessaire au site d’action pour produire 90 % de l’effet maximal (AE90). À 2 X la AE90, le modèle prédit un début d’action de 23.4 ± 12.5 min et une durée de 22.9 ± 5.3 h. Il s’agit de la première étude ayant caractérisé le comportement sensitif d’un bloc nerveux périphérique. Manuscrit 5 : La troisième et dernière étude clinique a été conduite chez les patients qui devaient subir une chirurgie du genou sous rachianesthésie. Tout comme pour le bloc du nerf fémoral, le modèle PK le plus approprié pour nos données suggère que l’absorption systémique de la ROP à partir du liquide céphalo-rachidien est biphasique; c.à.d. une phase initiale (T1/2 : 49 min, IC %: 24 – 77 min) suivie (délai: 18 ± 2 min) d'une phase légèrement plus lente (T1/2 : 66 min, IC %: 36 – 97 min). L’effet maximal a été observé beaucoup plus rapidement, soit aux environs de 12.6 ± 4.9 min, avant de revenir aux valeurs de base 210 ± 55 min suivant l’administration de l’agent. Ces données ont permis d’estimer une AE50 de 7.3 ± 2.3 mg pour l'administration spinale. Conclusion : En somme, ces modèles peuvent être utilisés pour prédire l’évolution temporelle du bloc sensitif de l’anesthésie rachidienne et périphérique (fémorale), et par conséquent, optimiser l’utilisation clinique de la ROP en fonction des besoins des cliniciens, notamment en ce qui a trait à l’âge du patient. / Background & Objectives: To provide postoperative analgesia, the anesthesiologist has at his disposal a panel of different medications and also regional techniques of neural blockade. Loco-regional analgesia (central or peripheral) blocks conduction of painful influx to the central nervous system by the use of local anesthetics (LA). Among these drugs, ropivacaine (ROP), has an enormous potential given is long-acting efficacy and low incidence of toxicity. Currently, ROP is not licensed for use in spinal anesthesia (central block) in all countries due to a lack of data from controlled clinical trials. So far, research efforts on this topic have mainly focused on safety and dose-finding issues. In addition, the most appropriate dose for a peripheral nerve block has never been estimated empirically. Dosing recommendation for LAs should be site-specific and adapted to the intensity of the stimuli produced by a surgery and to the duration of analgesia required. Ultimately, these should guide clinicians in identifying the most appropriate block for the individual patients by taking into account demographic factors that may affect the pharmacokinetics (PK) and pharmacodynamics (PD) of LA overall objective of the current research) Analytical Method Validation Manuscript 1: First, a specific and sensitive assay has been developed and validated for the determination of ROP in human plasma. Biomarker Validation Manuscript 2: Second, the reliability of a neurostimulator measuring current perception threshold (CPT) was assessed in healthy volunteers. The device uses a constant transcutaneous electrical sine wave stimulus at different frequencies specific to pain-conducting fibers. Our results suggest that CPT are reliable and can be applied to characterize, in a quantitative manner, the sensory onset of a peripheral nerve block in a clinical setting. Clinical Studies Manuscript 3: The systemic absorption of ROP after a femoral nerve block in orthopedic patients was then characterized using extended rich PK-sampling, i.e. up to 4 days post-dosing. Our model used for data analysis confirms that, in a similar manner to neuraxial sites of LAs injection, the systemic absorption of ROP from the femoral space is biphasic, i.e. a rapid initial phase (mean absorption time of 25 min, % CI: 19 – 38 min) followed by a much slower phase (half-life (T1/2) of 3.9 h, % CI: 2.9 – 6.0 h). A significant age-related increase in the permeability of the LA was also observed in our elderly patients (n = 19, age = 62.6 ± 7.1 yr). Manuscript 4: A population PK-PD analysis of the sensory anesthesia (CPT) of ROP using our PK model was also performed. The effect-site amount producing 90% of the maximum possible effect (AE90) was estimated as 20.2 ± 10.1 mg. At 2 x AE90, the sigmoid Emax model predicted an onset time of 23.4 ± 12.5 min and a duration of 22.9 ± 5.3 h. To the best of our knowledge, this is the first PK-PD model developed for a peripheral nerve block. Manuscript 5: In the third and last study, a similar approach was used to characterise the PK-PD relationship of intrathecally administered ROP in patients undergoing minor lower limb surgery. The biphasic release of the agent from the intrathecal space was modeled using a rapid initial absorption phase (T1/2 of 49 min, % CI: 24 – 77 min) followed (lag-time of ~ 18 ± 2 min) by a slightly slower input rate (T1/2 of 66 min, % CI: 36 – 97 min). ROP maximal response was observed within 12.6 ± 4.9 min of dosing, with a subsequent return to baseline 210 ± 55 min after the administration of the LA. The effect-site amount producing 50 % of the Emax (AE50) was estimated at 7.3 ± 2.3 mg. Conclusion: Altogether, the proposed models can be used to predict the time-course of sensory blockade after a femoral nerve block and spinal anesthesia using ROP and to optimize dosing regimen according to clinical needs with regard to important cofactors such as age.