Utilização de lactonas macrocíclicas sob diferentes doses e vias de administração em equinos
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Data
2020-12-11
Autores
Camargo, Samara Arão
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Universidade Estadual Paulista (Unesp)
Resumo
Os nematóides gastrintestinais são economicamente os parasitas mais importantes de equinos. Tendo como principal forma para o controle dessas parasitoses o uso de lactonas macrocíclicas, sendo encontradas no mercado apenas em apresentação oral para esta espécie. Formulações diferentes podem causar alterações na atuação e eficácia dos princípios ativos, o que tornam imprescindíveis estudos farmacológicos mais profundos sobre os mesmos. Sendo assim, objetivou-se avaliar a eficácia e a toxicidade de três lactonas macrocíclicas sob duas vias de administração (enteral e parenteral), avaliando-se a presença de reação local na administração injetável por meio de imagens ultrassonográficas e termográficas. O experimento foi realizado no período de setembro a novembro de 2019, com a utilização de 70 equinos, da raça Quarto de Milha, sendo os mesmos divididos em 7 grupos inteiramente casualizados. As drogas utilizadas foram a abamectina (0,2 mg/kg), moxidectina (0,2 e 0,4mg/kg) e a ivermectina (0,2mg/kg) pelas vias intramuscular e oral. Foram realizadas coletas de fezes para contagem de ovos por grama de fezes (OPG) e coprocultura para posterior identificação de larvas infectantes nos dias 0, 3, 7, 14, 21, 28, 42, 56 e 70. Os resultados foram analisados para se obter o percentual da redução do número de ovos por grama de fezes (R- OPG), utilizando o programa estatístico RESO. Também foram coletadas amostras de sangue nos dias 0, 3 e 7 para análise da toxicidade, por meio de marcadores bioquímicos AST, Ureia, Creatinina, CK e LDH. Para a análise de uma possível lesão tecidual pós-aplicação do antihelmintico por via intramuscular foram utilizados métodos de imagem como termografia e ultrassonografia nos dias 0 (antes da aplicação), 3 e 7 (pós-aplicação). Os dados foram submetidos à ANOVA e, quando significativos, as médias foram agrupadas por meio do teste de Tukey a um nível de significância 5%. As drogas administradas por via oral mostraram uma eficácia de 100%, porém os anti-helmínticos utilizados de maneira injetável não se mostrou eficaz em nenhum momento do experimento atingindo reduções entre 83 e 34%. Apesar da eficácia observada na administração oral dos fármacos, houve PRO precoce, indicando uma possibilidade de resistência. As imagens ultrassonográficas mostraram que a aplicação intramuscular das lactonas macrocíclicas causaram uma lesão no local na aplicação, principalmente na moxidectina utilizada em dose duplicada (70% dos animais), o que não pode ser observado nas termografia. Os parâmetros bioquímicos observados mostraram que não houve dano muscular, nem sobrecarga hepática. Portanto, os resultados desse estudo permitem inferir que os anti-helmínticos administrados por via oral promoveu controle eficaz contra nematódeos gastrointestinais, enquanto o tratamento parenteral além de não ser eficaz, promoveu lesão muscular aguda.
Gastrointestinal nematodes are economically the most important parasites of horses. The main way to control these parasites is the use of macrocyclic lactones, which are found on the market only in oral presentation for this species. Different formulations can cause changes in the performance and efficacy of the active ingredients, which make deeper pharmacological studies on them essential. Thus, the objective was to evaluate the efficacy and toxicity of three macrocyclic lactones under two routes of administration (enteral and parenteral), evaluating the presence of a local reaction in the injectable administration through ultrasound and thermographic images. The experiment was carried out from September to November 2019, with the use of 70 Quarter Horse horses, divided into 7 completely randomized groups. The drugs used were abamectin (0.2 mg / kg), moxidectin (0.2 and 0.4 mg / kg) and ivermectin (0.2 mg / kg) by intramuscular and oral routes. Stool collections were performed to count eggs per gram of feces (OPG) and co-culture for later identification of infective larvae on days 0, 3, 7, 14, 21, 28, 42, 56 and 70. The results were analyzed to obtain the percentage of reduction in the number of eggs per gram of feces (R-OPG), using the statistical program RESO. Blood samples were also collected on days 0, 3 and 7 for toxicity analysis, using biochemical markers AST, Urea, Creatinine, CK and LDH. For the analysis of a possible tissue injury after application of the anti-helminthic intramuscularly, imaging methods such as thermography and ultrasound were used on days 0 (before application), 3 and 7 (post-application). The data were submitted to ANOVA and, when significant, the means were grouped using the Tukey test at a 5% significance level. Drugs administered orally showed 100% efficacy, but anthelmintics used injectable were not effective at any time during the experiment, reaching reductions between 83 and 34%. Despite the efficacy observed in the oral administration of drugs, there was early PRO, indicating a possibility of resistance. The ultrasound images showed that the intramuscular application of the macrocyclic lactones caused a lesion in the application site, mainly in the moxidectin used in duplicate dose (70% of the animals), which cannot be observed in thermography. The observed biochemical parameters showed that there was no muscle damage or liver overload. Therefore, the results of this study allow us to infer that oral anthelmintics promoted effective control against gastrointestinal nematodes, while parenteral treatment, besides not being effective, promoted acute muscle damage.
Gastrointestinal nematodes are economically the most important parasites of horses. The main way to control these parasites is the use of macrocyclic lactones, which are found on the market only in oral presentation for this species. Different formulations can cause changes in the performance and efficacy of the active ingredients, which make deeper pharmacological studies on them essential. Thus, the objective was to evaluate the efficacy and toxicity of three macrocyclic lactones under two routes of administration (enteral and parenteral), evaluating the presence of a local reaction in the injectable administration through ultrasound and thermographic images. The experiment was carried out from September to November 2019, with the use of 70 Quarter Horse horses, divided into 7 completely randomized groups. The drugs used were abamectin (0.2 mg / kg), moxidectin (0.2 and 0.4 mg / kg) and ivermectin (0.2 mg / kg) by intramuscular and oral routes. Stool collections were performed to count eggs per gram of feces (OPG) and co-culture for later identification of infective larvae on days 0, 3, 7, 14, 21, 28, 42, 56 and 70. The results were analyzed to obtain the percentage of reduction in the number of eggs per gram of feces (R-OPG), using the statistical program RESO. Blood samples were also collected on days 0, 3 and 7 for toxicity analysis, using biochemical markers AST, Urea, Creatinine, CK and LDH. For the analysis of a possible tissue injury after application of the anti-helminthic intramuscularly, imaging methods such as thermography and ultrasound were used on days 0 (before application), 3 and 7 (post-application). The data were submitted to ANOVA and, when significant, the means were grouped using the Tukey test at a 5% significance level. Drugs administered orally showed 100% efficacy, but anthelmintics used injectable were not effective at any time during the experiment, reaching reductions between 83 and 34%. Despite the efficacy observed in the oral administration of drugs, there was early PRO, indicating a possibility of resistance. The ultrasound images showed that the intramuscular application of the macrocyclic lactones caused a lesion in the application site, mainly in the moxidectin used in duplicate dose (70% of the animals), which cannot be observed in thermography. The observed biochemical parameters showed that there was no muscle damage or liver overload. Therefore, the results of this study allow us to infer that oral anthelmintics promoted effective control against gastrointestinal nematodes, while parenteral treatment, besides not being effective, promoted acute muscle damage.
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Palavras-chave
Anti-helmíntico, Eficácia, Reação local, Toxicidade, Anthelmintic, Efficacy, Local reaction, Toxicity