RESUMO
Se presenta un caso de enfermedad de Chagas en fase aguda en un paciente masculino de 40 años, proce-dente de la Vereda Buenos Aires, Municipio de Miraflores, Departamento del Guaviare. El paciente acudió a urgencias con fiebre, cefalea, astenia, adinamia y disuria. Se realizó un frotis de sangre y un análisis de orina, con resultados positivos para infección urinaria sintomática, pero negativos para malaria. Cinco días más tarde se confirmó el diagnóstico de enfermedad de Chagas en fase aguda tras recibir un resultado positivo para Trypanosoma cruzi. El paciente recibió tratamiento con nifurtimox y benznidazol, y se llevó a cabo una investigación de contactos y zonas de riesgo, búsqueda activa comunitaria e institucional, entomológica y de reservorios, y una vigilancia de laboratorio para detectar posibles casos de infección en la comunidad. Se identificaron cinco casos con síntomas similares, pero las pruebas parasitológicas fueron negativas. Se aplic-aron medidas de educación sanitaria para prevenir la propagación de la enfermedad.
Assuntos
Humanos , MasculinoRESUMO
La enfermedad de Chagas, tripanosomiasis americana o simplemente Chagas, es una infección parasitaria que afecta a más de 8 millones de personas a nivel mundial. La Organización Mundial de la Salud ha incluido a esta patología dentro de la categoría de enfermedades tropicales desatendidas (junto a la malaria, leishmaniasis y dengue, entre otras), ya que afecta mayoritariamente a grupos vulnerables de la sociedad sin acceso a condiciones adecuadas de sanidad ni tratamientos médicos, y en contacto continuo con los vectores de contagio. La terapia actual incluye fármacos utilizados desde hace ya más de 50 años que, si bien son efectivos en la fase inicial de la enfermedad, fallan en la erradicación total del parásito, a la vez que generan graves efectos adversos. En vista de este panorama, surge la necesidad de nuevas estrategias de bajo costo para optimizar la terapia. Una posible alternativa para mejorar el tratamiento, diagnóstico y prevención surge desde la nanotecnología: el presente artículo revisa el estado actual de la investigación de nanomedicinas para tratar la enfermedad de Chagas. Cabe mencionar que, si bien se ha avanzado enormemente en dirección a una terapia que disminuya los efectos adversos de la droga, aún no se ha logrado diseñar y producir un nanovehículo farmacéutico óptimo contra el agente etiológico de la enfermedad.
Chagas disease, American trypanosomiasis or Chagas disease, is a parasitic infection that affects more than 8 million people worldwide. This pathology was included by the World Health Organization within the category of neglected tropical diseases (along with malaria, leishmaniasis and dengue, among others), since it mainly affects vulnerable groups in society without access to adequate health conditions nor medical treatments, and in continuous contact with the transmission vectors. Current therapy includes drugs used for more than 50 years that, although effective in the initial phase of the disease, fail in the total eradication of the parasite, while generating serious adverse effects. In light of this situation, new low-cost approach strategies are necessary to optimize therapy. A possible alternative to improve treatment, diagnosis and prevention arises from nanotechnology: this article reviews the current state of research in nanomedicines to treat Chagas disease. It is worth mentioning that, although great progress has been made towards a therapy that reduces the adverse effects of the drug, it has not yet been possible to design and produce an optimal pharmaceutical nanovehicle against the etiologic agent of the disease.
Assuntos
Veículos Farmacêuticos , Doença , Doença de Chagas , NanomedicinaRESUMO
Trypanothione (T(SH)2) is the main antioxidant metabolite for peroxide reduction in Trypanosoma cruzi; therefore, its metabolism has attracted attention for therapeutic intervention against Chagas disease. To validate drug targets within the T(SH)2 metabolism, the strategies and methods of Metabolic Control Analysis and kinetic modeling of the metabolic pathway were used here, to identify the steps that mainly control the pathway fluxes and which could be appropriate sites for therapeutic intervention. For that purpose, gamma-glutamylcysteine synthetase (γECS), trypanothione synthetase (TryS), trypanothione reductase (TryR) and the tryparedoxin cytosolic isoform 1 (TXN1) were separately overexpressed to different levels in T. cruzi epimastigotes and their degrees of control on the pathway flux as well as their effect on drug resistance and infectivity determined. Both experimental in vivo as well as in silico analyses indicated that γECS and TryS control T(SH)2 synthesis by 60-74% and 15-31%, respectively. γECS overexpression prompted up to a 3.5-fold increase in T(SH)2 concentration, whereas TryS overexpression did not render an increase in T(SH)2 levels as a consequence of high T(SH)2 degradation. The peroxide reduction flux was controlled for 64-73% by TXN1, 17-20% by TXNPx and 11-16% by TryR. TXN1 and TryR overexpression increased H2O2 resistance, whereas TXN1 overexpression increased resistance to the benznidazole plus buthionine sulfoximine combination. γECS overexpression led to an increase in infectivity capacity whereas that of TXN increased trypomastigote bursting. The present data suggested that inhibition of high controlling enzymes such as γECS and TXN1 in the T(SH)2 antioxidant pathway may compromise the parasite's viability and infectivity.
Assuntos
Antioxidantes/metabolismo , Glutamato-Cisteína Ligase/genética , Glutationa/análogos & derivados , Proteínas de Protozoários/genética , Espermidina/análogos & derivados , Tiorredoxinas/genética , Trypanosoma cruzi/efeitos dos fármacos , Amida Sintases/genética , Amida Sintases/metabolismo , Butionina Sulfoximina/farmacologia , Linhagem Celular , Combinação de Medicamentos , Resistência a Medicamentos/genética , Fibroblastos/parasitologia , Regulação da Expressão Gênica , Glutamato-Cisteína Ligase/metabolismo , Glutationa/antagonistas & inibidores , Glutationa/biossíntese , Humanos , Peróxido de Hidrogênio/farmacologia , NADH NADPH Oxirredutases/genética , NADH NADPH Oxirredutases/metabolismo , Nitroimidazóis/farmacologia , Oxirredução , Estresse Oxidativo , Peroxidases/genética , Peroxidases/metabolismo , Proteínas de Protozoários/metabolismo , Transdução de Sinais , Espermidina/antagonistas & inibidores , Espermidina/biossíntese , Tiorredoxinas/metabolismo , Tripanossomicidas/farmacologia , Trypanosoma cruzi/enzimologia , Trypanosoma cruzi/genéticaRESUMO
La enfermedad de Chagas afecta aproximadamente a 10 millones de personas en Sudamérica y 1,5 millones en la Argentina. La transmisión congénita es la más importante en áreas urbanas. Existen dos drogas aprobadas para el tratamiento: nifurtimox (Laboratorios Bayer) y benznidazol (BNZ) (Laboratorios Roche, LAFEPE y Elea) que fueron desarrolladas hace más de 40 años y cuya farmacología y metabolismo en humanos han sido poco estudiados. La información disponible es virtualmente inexistente en niños y mujeres embarazadas. Se busca aportar estudios sistemáticos hacia una farmacoterapéutica racional en niños ya que empíricamente ha demostrado gran efectividad. Se desarrollaron métodos bioanalíticos aplicables a matrices biológicas como plasma, orina y leche materna para las drogas madres y la identificación de metabolitos en muestras de pacientes bajo terapéutica. La farmacocinética poblacional pediátrica descripta aquí para BNZ es concluyente respecto de sus diferencias con la farmacocinética en adultos. Se identificaron tres compuestos presentados como metabolitos del BNZ. La transferencia de dicho fármaco a la leche materna no supone riesgo para el lactante. Estos resultados brindan información para mejorar los protocolos de tratamiento existentes buscando una farmacoterapéutica adaptada a la edad y un uso más seguro de los fármacos en niños y eventualmente en adultos.
Chagas disease affects approximately 10 million people in South America and 1.5 million in Argentina. Congenital transmission is most important in urban areas. There are two drugs approved for treatment: nifurtimox (Bayer) and benznidazole (BNZ) (Roche, LAFEPE, Elea),developed more than 40 years ago. Their pharmacology and metabolism in humans have been seldom studied. The information available on children and pregnant women is virtually non-existent. The aim of this study is to provide systematic studies towards a rational pharmacotherapeutic sin children, which has been empirically proven to be highly effective. Bioanalytical methods were developed for plasma, urine and breast milk for parent drugs and for the identification of their metabolites in samples of patients under treatment. The pediatric population pharmacokinetics described here for BNZ is conclusive about their differences from adult pharmacokinetics. Three compounds presented as BNZ metabolites were identified. The transfer of this drug to the breast milk does not present a risk to the infant. These evidences offer information to improve the existing treatment protocols, seeking a pharmacotherapy adapted to the age and a safer use of the drugs in children and eventually in adults.
A doença de Chagas afeta aproximadamente 10 milhões de pessoas na América do Sul e 1,5 milhão na Argentina. A transmissão congênita é a mais importante em áreas urbanas. Existem dois medicamentos aprovados para o tratamento: nifurtimox (Laboratórios Bayer) e benznidazol (BNZ) (Laboratórios Roche, LAFEPE e Elea), desenvolvidas há mais de 40 anos, e sua farmacologia e seu metabolismo em humanos têm sido pouco estudados. A informação disponível é praticamente inexistente em crianças e mulheres grávidas. O objetivo é fornecer estudos sistemáticos para uma farmacoterapêutica racional em crianças visto que foram comprovadas empiricamente como sendo altamente eficazes. Métodos bioanalíticos aplicáveis a matrizes biológicas como plasma, urina e leite materno para fármacos-mãe e para a identificação de metabólitos em amostras de pacientes em tratamento terapêutico foram desenvolvidos. A farmacocinética da população pediátrica aqui descrita para BNZ é conclusiva em relação às suas diferenças com a farmacocinética de adultos. Três compostos apresentados como metabólitos do BNZ foram identificados. A transferência do referido medicamento para o leite materno não representa risco para o lactente. Essas evidências oferecem informações para melhorar os protocolos de tratamento existentes, buscando uma farmacoterapia adaptada à idade e um uso mais seguro dos medicamentos em crianças e eventualmente em adultos.
Assuntos
Humanos , Masculino , Feminino , Toxicologia , Doença de Chagas/diagnóstico , Doença de Chagas/tratamento farmacológico , Lactação/efeitos dos fármacos , Doença de Chagas/etiologia , Doença de Chagas/etnologia , Ações Farmacológicas , Efeitos Colaterais Metabólicos de Drogas e SubstânciasRESUMO
BACKGROUND: The immunological and clinical impact of trypanocidal treatment in chronic Chagas' disease (CCD) is unclear. METHODOLOGY AND FINDINGS: Several cytokines were measured in plasma of 66 patients with CCD. Thirty-three patients had been previously treated with benznidazole and 33 had never been treated. The treated group exhibited higher levels of IL-17 (median 142.45×1.22pg/ml, P=0.025), which was the only one significantly associated with Bz treatment, especially after adjusting for time of disease and NYHA class (P=0.024; OR 1.006, 95% CI 1.001-1.010). Compared to untreated patients, the treated group exhibited higher median values of mitral annular E' lateral (13.0×10.0cm/s, P=0.038), S' infero-lateral (8.9×7.6cm/s, P=0.013), S' septal (8.5×7.4cm/s, P=0.034), mean S' (9.0×7.9cm/s, P=0.013) and tricuspid annular S' (13.3×11.1cm/s, P=0.001) and lower values of E/E' septal (7.2×9.5cm/s, P=0.049). After adjustment for time of disease and NYHA class, S' infero-lateral (P=0.031), mean S' (P=0.049) and S' tricuspid (P=0.024) persisted as significantly associated with treatment. CONCLUSION: The present findings suggest that the group of CCD patients treated with Bz displayed increased plasma levels of IL-17 and preserved myocardial function, reinforcing the idea that Bz treatment may be beneficial.
Assuntos
Doença de Chagas/tratamento farmacológico , Ecocardiografia , Interleucina-17/sangue , Miocárdio/metabolismo , Nitroimidazóis/farmacologia , Doença de Chagas/sangue , Doença Crônica , Estudos Transversais , Citocinas/sangue , Feminino , Coração/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Valva Mitral/efeitos dos fármacosRESUMO
The discovery that trypanosomatids, unicellular organisms of the order Kinetoplastida, are capable of synthesizing prostaglandins raised questions about the role of these molecules during parasitic infections. Multiple studies indicate that prostaglandins could be related to the infection processes and pathogenesis in trypanosomatids. This work aimed to unveil the role of the prostaglandin F2α synthase TcOYE in the establishment of Trypanosoma cruzi infection, the causative agent of Chagas disease. This chronic disease affects several million people in Latin America causing high morbidity and mortality. Here, we propose a prokaryotic evolutionary origin for TcOYE, and then we used in vitro and in vivo experiments to show that T. cruzi prostaglandin F2α synthase plays an important role in modulating the infection process. TcOYE overexpressing parasites were less able to complete the infective cycle in cell culture infections and increased cardiac tissue parasitic load in infected mice. Additionally, parasites overexpressing the enzyme increased PGF2α synthesis from arachidonic acid. Finally, an increase in benznidazole and nifurtimox susceptibility in TcOYE overexpressing parasites showed its participation in activating the currently anti-chagasic drugs, which added to its observed ability to confer resistance to hydrogen peroxide, highlights the relevance of this enzyme in multiple events including host-parasite interaction.
Assuntos
Doença de Chagas/imunologia , NADPH Desidrogenase/imunologia , Prostaglandina-Endoperóxido Sintases/imunologia , Proteínas de Protozoários/imunologia , Trypanosoma cruzi/imunologia , Animais , Doença de Chagas/genética , Doença de Chagas/patologia , Chlorocebus aethiops , Células HeLa , Humanos , NADPH Desidrogenase/genética , Proteínas de Protozoários/genética , Trypanosoma cruzi/genética , Células VeroRESUMO
Several polymers have been investigated for producing cationic nanocarriers due to their ability to cross biological barriers. Polycations such as copolymers of polymethylmethacrylate are highlighted due to their biocompatibility and low toxicity. The purpose of this study was to produce small and narrow-sized cationic nanoparticles able to overcome cell membranes and improve the biological activity of benznidazole (BNZ) in normal and cancer cells. The effect of composition and procedure parameters of the used emulsification-solvent evaporation method were controlled for this purpose. The experimental approach included particle size, polydispersity index, zeta potential, atomic force microscopy (AFM), attenuated total reflectance Fourier transforms infrared spectroscopy (ATR- FTIR), drug loading efficiency, and physical stability assays. Spherical and stable (over six weeks) sub 150nm cationic nanoparticles were optimized, with the encapsulation efficiency >80%. The used drug/copolymer ratio modulated the slow drug release, which was adjusted by the parabolic diffusion mathematical model. In addition, the ability of the cationic nanoparticles improve the BNZ uptake in the normal kidney cells (HEK 293) and the human colorectal cancer cells (HT 29) demonstrate that this novel BNZ-loaded cationic has great potential as a chemotherapeutic application of benznidazole.
Assuntos
Nanopartículas , Portadores de Fármacos , Liberação Controlada de Fármacos , Células HEK293 , Humanos , Nitroimidazóis , Tamanho da PartículaRESUMO
Los tratamientos de primera línea para la enfermedad de Chagas generan importantes efectos adversos que acentúan el deterioro de la salud en los pacientes. La necesidad de generar fármacos alternativos ha permitido desarrollar estudios donde se emplean parásitos capaces de expresar una proteína fluorescente, a fin de correlacionar fluorescencia con población de protozoarios. En este sentido, ideamos una metodología para el seguimiento de la proliferación de Trypanosoma cruzi-GFP (Green Fluorescent Protein) en modelos in vitro e in vivo, empleando el equipo iBox- UVP. Los ensayos in vitro se iniciaron con una curva de calibración usando concentraciones entre 5x105 y 5x107 parásitos/mL. Seguidamente, con una curva de proliferación evidenciamos a través de la fluorescencia la susceptibilidad de los parásitos frente a la droga comercial Benznidazol (IC50= 5,3±1,3 μM). En el ensayo in vivo se corroboró cualitativamente el efecto quimioterapéutico del Benznidazol (100 mg/kg/día) en ratones C57BL/6, partiendo de un inóculo de 2,5x105 parásitos, haciendo captura de imágenes de fluorescencia cada dos días a partir del día 1, e inicio del tratamiento por vía oral el sexto día. El coeficiente de correlación cercano a 1 obtenido en la curva de calibración habla de un método de cuantificación parasitario sencillo y robusto; también los ensayos en modelos in vitro e in vivo permitieron monitorear el efecto dosis-dependiente de Benznidazol sobre T. cruzi-GFP. En síntesis, elaboramos una metodología novedosa, rápida, no invasiva y que sigue en tiempo real la respuesta quimioterapéutica de drogas anti-T. cruzi.
The first-line treatments for Chagas disease generate significant adverse effects that accentuate the health deterioration in patients. The need to generate alternative drugs has led to the development of studies in which parasites will express a fluorescent protein, and correlate this expression with protozoan population. We devised a methodology for monitoring the proliferation of Trypanosoma cruzi- GFP (Green Fluorescent Protein) in models in vitro and in vivo, using the equipment iBox-UVP. In vitro assays were initiated with a calibration curve using concentrations between 5x105 and 5x107 parasites/mL. Subsequently, with a proliferation curve, through fluorescence we determined the susceptibility of the parasites against the commercial drug Benznidazol (IC50= 5,3±1,3 μM). In vivo assays corroborated qualitatively the chemotherapeutic effect of Benznidazol (100 mg/kg/day) in C57BL/6 mice, starting from an inoculum of 2.5x105 parasites, making capture of fluorescence imaging every two days from day 1, and starting oral treatment on the sixth day. The correlation coefficient close to 1 obtained in the calibration curve showed that this quantification method of parasites is simple and robust; assays in vitro and in vivo allowed monitoring dose-dependent effects of Benznidazol agains T. cruzi-GFP. We have produced an innovative, rapid, non-invasive method that monitors in real time the chemotherapeutic response of anti-T. cruzi drugs.
RESUMO
One of the most significant health problems in the American continent in terms of human health, and socioeconomic impact is Chagas disease, caused by the protozoan parasite Trypanosoma cruzi. Infection was originally transmitted by reduviid insects, congenitally from mother to fetus, and by oral ingestion in sylvatic/rural environments, but blood transfusions, organ transplants, laboratory accidents, and sharing of contaminated syringes also contribute to modern day transmission. Likewise, Chagas disease used to be endemic from Northern Mexico to Argentina, but migrations have earned it global. The parasite has a complex life cycle, infecting different species, and invading a variety of cells - including muscle and nerve cells of the heart and gastrointestinal tract - in the mammalian host. Human infection outcome is a potentially fatal cardiomyopathy, and gastrointestinal tract lesions. In absence of a vaccine, vector control and treatment of patients are the only tools to control the disease. Unfortunately, the only drugs now available for Chagas' disease, Nifurtimox and Benznidazole, are relatively toxic for adult patients, and require prolonged administration. Benznidazole is the first choice for Chagas disease treatment due to its lower side effects than Nifurtimox. However, different strategies are being sought to overcome Benznidazole's toxicity including shorter or intermittent administration schedules-either alone or in combination with other drugs. In addition, a long list of compounds has shown trypanocidal activity, ranging from natural products to specially designed molecules, re-purposing drugs commercialized to treat other maladies, and homeopathy. In the present review, we will briefly summarize the upturns of current treatment of Chagas disease, discuss the increment on research and scientific publications about this topic, and give an overview of the state-of-the-art research aiming to produce an alternative medication to treat T. cruzi infection.
Assuntos
Doença de Chagas/epidemiologia , Nifurtimox/uso terapêutico , Nitroimidazóis/uso terapêutico , Tripanossomicidas/uso terapêutico , América/epidemiologia , Doença de Chagas/tratamento farmacológico , Humanos , Estágios do Ciclo de Vida/efeitos dos fármacos , Nifurtimox/farmacologia , Nitroimidazóis/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacosRESUMO
OBJECTIVE: To develop an extemporaneous 1% benznidazole (BNZ) suspension, with masked taste and adequate stability starting from available commercial tablets. The quality of compounding was evaluated through content uniformity measurement and physical and microbiological stability evaluation, under different storage conditions during 90 days. METHODS: Six batches of 1% BNZ suspension were prepared using safe excipients currently available in a galenic area of Hospital Pharmacy and then stored at 5 and 25 °C for 90 days. The BNZ content was determined by UV spectrophotometry. Physical stability was defined as the absence of colour, odour and/or flavour changes and the re-suspension of solid phase by a reasonable amount of simple 15-s shaking. The compliance with microbiological attributes of non-sterile pharmaceutical products was also evaluated. RESULTS: An oral liquid suspension, containing 1% of BNZ, was developed from commercially available BNZ tablets. The formulations stored for 90 days were easily re-dispersed after a simple 15-s shaking, ensuring the pouring of a liquid volume containing the desired dose of BNZ. All samples were within the acceptable range of BNZ concentration with minimal standard deviations. There were no detectable changes in colour, odour, viscosity, pH and microbial growth, complying with official quality requirements. The quality attributes were not affected by storage, room or refrigeration conditions or by the frequent opening or closing of the multidose containers. CONCLUSION: Paediatric oral liquid suspension containing 1.0% of BNZ was easily prepared starting from commercial tablets, being an interesting alternative for optimising the paediatric treatment of Chagas disease.
Assuntos
Doença de Chagas/tratamento farmacológico , Estabilidade de Medicamentos , Nitroimidazóis/administração & dosagem , Paladar , Administração Oral , Criança , Composição de Medicamentos/métodos , Armazenamento de Medicamentos , Humanos , Nitroimidazóis/uso terapêutico , Pediatria , Espectrofotometria Ultravioleta , Suspensões , ComprimidosRESUMO
La quimioterapia de la enfermedad de Chagas cuenta en la actualidad con el empleo de dos fármacos solamente: Nifurtimox y Benznidazol. Nifurtimox es un nitrofurano y Benznidazol es un compuesto nitroimidazólico. El uso de estas drogas para tratar la fase aguda de la enfermedad se acepta ampliamente. Sin embargo, su utilización en el tratamiento de la fase crónica no está exenta de cuestionamientos serios. Los efectos colaterales de ambas son un inconveniente mayor en su uso, y frecuentemente fuerza a los médicos a detener el tratamiento. Los estudios de toxicidad experimentales con Nifurtimox evidenciaron neurotoxicidad, daño testicular, toxicidad ovárica y efectos deletéreos en corazón, tejido mamario, adrenales, colon y esófago. Para el Benznidazol, se observaron efectos deletéreos en adrenales, colon y esófago. También inhibe el metabolismo de varios xenobióticos transformados por el sistema del citocromo P450 y sus metabolitos reaccionan con los componentes fetales in vivo. Ambas drogas exhibieron efectos mutagénicos significativos y se demostró en algunos estudios que eran carcinogénicas o tumorigénicas. Los efectos tóxicos de ambos fármacos dependen de la reducción enzimática de su grupo nitro. En este trabajo se resume la actividad de este laboratorio en el esfuerzo por comprender los mecanismos de la acción tóxica de estos fármacos.(AU)
Chemotherapy of Chagas disease is currently performed by the use of only two drugs: Nifurtimox and Benznidazole. Nifurtimox is a nitrofurane and Benznidazole is a nitroimidazole compound. The use of these drugs to treat the acute phase of the disease is now widely accepted. However, their use in the treatment of the chronic phase is not without serious consequences. The side effects of both drugs are a major drawback in their use and often force physicians to stop treatment. In the case of Nifurtimox, experimental toxicity studies showed neurotoxicity, testicular damage, ovarian toxicity and deleterious effects in heart, breast tissue, adrenals, colon and esophagus. Benznidazole deleterious effects were observed in adrenals, colon and esophagus. It also inhibits the metabolism of various xenobiotics transformed by cytochrome P450 and its metabolites react with fetal components in vivo. Both drugs exhibited significant mutagenic effects and in some studies, they demonstrated to be carcinogenic or tumorigenic. Toxic effects of both drugs are dependent on the enzymatic reduction of the nitro group. This paper summarizes this laboratory’s activity in an effort to understand the mechanisms of these drugs’ toxic action.(AU)
A quimioterapia da doenþa de Chagas tem atualmente com o uso de apenas dois medicamentos: nifurtimox e benzonidazol. Nifurtimox é um nitrofuran e benzonidazol é um composto nitroimidazólico. A utilizaþÒo destes fármacos para o tratamento da fase aguda da doenþa é agora amplamente aceite. No entanto, a sua utilizaþÒo no tratamento da fase crónica nÒo é sem dúvida graves. Os efeitos colaterais de ambas sÒo uma grande desvantagem na sua utilizaþÒo, e frequentemente médicos forþa para interromper o tratamento. Estudos experimentais com Nifurtimox mostraram neurotoxicidade, lesÒo testicular, toxicidade ovariana e efeitos deletérios no coraþÒo, tecido mamário, adrenal, cólon e es¶fago. Para benzonidazole efeitos deletérios foram observadas em supra-renal, cólon e esofágica. Também inibe o metabolismo de vários xenobióticos transformadas pelo citocromo P450 e seus metabolitos reagem com componentes fetal in vivo. Ambos os fármacos apresentaram efeitos mutagÛnicos significativos demonstrado em alguns estudos que eram cancerígenas ou tumorigenic. Os efeitos tóxicos de ambas as drogas sÒo dependentes da reduþÒo enzimática do grupo nitro. Neste trabalho a atividade do nosso laboratório no esforþo para compreender os mecanismos de aþÒo tóxica dessas drogas é resumida.(AU)
RESUMO
En las normas actuales de tratamiento etiológico de la fase crónica tardía de la enfermedad de Chagasen Argentina, Brasil y la Organización Mundial de la Salud, se recomienda controlar la eficaciaterapéutica con pruebas serológicas y parasitológicas convencionales. Sin embargo las primerassuelen continuar positivas 10 años o más luego del tratamiento, y las segundas son, en general, debaja sensibilidad en esta etapa de la enfermedad. La Reacción en Cadena de la Polimerasa (PCR)al ser más sensible que los exámenes parasitológicos convencionales, podría informar con unacobertura mayor si hubo falla terapéutica. Hemos ofrecido tratamiento con benznidazol (5 mg/kg/día, por 60 días) a 138 pacientes de 16 a 35 años de edad, infectados crónicamente con Trypanosomacruzi. La eficacia terapéutica se controló con PCR periódicas, hemocultivo y serología convencionalen dos grupos de pacientes: uno (GT, 57 pacientes) que aceptó y cumplió el tratamiento y otro(GNT, 37 pacientes) que lo rechazó. Antes de la administración de benznidazol la PCR mostró unasensibilidad diagnóstica de 41 por ciento (57/138 pacientes) y el hemocultivo 7,2 por ciento (10/138). Sesenta mesespostratamiento el grupo GT mostró una positividad de PCR acumulada de 28,1 por ciento (16/57) y el grupoGNT 54,1 por ciento (20/37; p=0.0016). A pesar de que la sensibilidad diagnóstica de PCR es limitada, lanegatividad de pruebas repetidas con método normatizado podría evidenciar disminución de laparasitemia o probable curación en 71,9 por ciento de los pacientes tratados, lo que habría que confirmar conel seguimiento serológico...
Current norms for the etiological treatment of chronic Chagas disease, recommended by WHOor currently in force for Argentina and Brazil, advise the control of therapeutic efficacy usingconventional serological and parasitological tests. However, serology usually remains positive 10 ormore years after treatment and parasitological tests are insensitive in the chronic stage. PolymeraseChain Reaction (PCR) is more sensitive than parasitological tests and could provide earlier evidenceof therapeutic failure. We offered benznidazole treatment (5 mg/kg/day, 60 days) to 138 patients(age=16 to 35 years old), chronically infected with Trypanosoma cruzi. Therapeutic efficacy waschecked with periodic PCR, haemoculture and conventional serology in two groups of patients: One(TG) accepting and complying with treatment and the other (NTG) rejecting it. Before benznidazoleadministration, PCR displayed a diagnostic sensitivity of 41.3 percent (57/138) and haemoculture 7.2 percent(10/138). Sixty months after treatment, TG displayed a cumulated PCR positivity of 28.1 percent (16/57)and NTG 54.1 percent (20/37; p=0.0166). Even though the sensitivity of PCR is limited, repeated negativeresults of a standardized method may reveal lower parasitaemia or probable cure, in 71.9 percent of treatedpatients, to be confirmed with serological follow up...
Assuntos
Humanos , Antiparasitários , Doença de Chagas/diagnóstico , Trypanosoma cruzi , Ensaio de Imunoadsorção Enzimática , Reação em Cadeia da PolimeraseRESUMO
INTRODUCCIÓN: En Argentina se emplea el benznidazolcomo terapéutica de primera línea para el tratamiento etiológico del Chagas. Desde su lanzamiento (hace más de 40 años), sólo se dispone de comprimidos convencionales de 100 mg; no se han desarrollado nuevas formas farmacéuticas que aumenten la eficacia y seguridad, ni alternativas con dosis pediátricas. OBJETIVOS: Desarrollar formas farmacéuticas de benznidazol que ofrezcan ventajas farmacoterapéuticas. MÉTODOS: Preformulación y diseño de nuevas formulaciones de benznidazol, con caracterización físico-química y selección de las formulaciones más favorables. Frente a la discontinuidad de producción del ingrediente activo benznidazol, se desarrolló una metodología de extracción a partir de 8520/8520/nica alternativa comercial disponible. RESULTADOS: Se obtuvieron nuevas formulaciones de comprimidos de 50 y 100 mg debenznidazol, con una rápida disolución del producto de referencia. Además, se obtuvieron formulaciones masticables de 50 mg bajo la forma de hidrogeles azucarados, con un efectivo enmascaramiento del mal sabor. Todas las formulaciones cumplieron los ensayos de evaluación de las propiedades farmacotécnicas y biofarmacéuticas, superando los perfiles de referencia. CONCLUSIONES: Se desarrollaron nuevas alternativas farmacéuticas de benznidazol de rápida disolución, que podrían mejorar el tratamiento etiológico de la enfermedad(especialmente en pediatría) y convertirse en herramientas aptas para su explotación comercial
INTRODUCTION: In Argentina, benznidazole is the drug of choice for the etiological treatment of Chagas disease. Since it was launched (more than 40 years ago), there are only 100 mg tablets available; the development included neither new pharmaceutical forms improving efficacy and safety, nor a pediatric dosage option. OBJECTIVES: To develop pharmaceutical form sof benznidazole with pharmacotherapeutic advantages. METHODS: Preformulation and design of new formulation sof benznidazole, with physicochemical characterization and selection of the most favorable formulations. Due to the discontinuity in the production of the active ingredient benznidazole, a specific methodology was developed in order to obtain it from the only commercially available alternative. RESULTS: New benznidazole tablet formulations were obtained (50 and 100 mg), with a rapid dissolution of the reference product, as well as chewable formulation sof 50 mg as sugar hydrogels featuring an effective taste masking. All formulations passed the evaluation tests for pharmacotechnical and biopharmaceutical properties, out performing the reference profiles. CONCLUSIONS:New fast-dissolving pharmaceutical dosage forms of benznidazole were developed, which could improve the etiological treatment of the disease (especially in the pediatric field) and become a proper tool for its commercial exploitation
Assuntos
Humanos , Administração Oral , Antiparasitários/farmacologia , Antiparasitários/uso terapêutico , Comprimidos/farmacologia , Doença de Chagas/terapia , Géis/farmacologiaRESUMO
INTRODUCCION: En Argentina se emplea el benznidazolcomo terapéutica de primera línea para el tratamiento etiológico del Chagas. Desde su lanzamiento (hace más de 40 años), sólo se dispone de comprimidos convencionales de 100 mg; no se han desarrollado nuevas formas farmacéuticas que aumenten la eficacia y seguridad, ni alternativas con dosis pediátricas. OBJETIVOS: Desarrollar formas farmacéuticas de benznidazol que ofrezcan ventajas farmacoterapéuticas. METODOS: Preformulación y diseño de nuevas formulaciones de benznidazol, con caracterización físico-química y selección de las formulaciones más favorables. Frente a la discontinuidad de producción del ingrediente activo benznidazol, se desarrolló una metodología de extracción a partir de 8520/8520/nica alternativa comercial disponible. RESULTADOS: Se obtuvieron nuevas formulaciones de comprimidos de 50 y 100 mg debenznidazol, con una rápida disolución del producto de referencia. Además, se obtuvieron formulaciones masticables de 50 mg bajo la forma de hidrogeles azucarados, con un efectivo enmascaramiento del mal sabor. Todas las formulaciones cumplieron los ensayos de evaluación de las propiedades farmacotécnicas y biofarmacéuticas, superando los perfiles de referencia. CONCLUSIONES: Se desarrollaron nuevas alternativas farmacéuticas de benznidazol de rápida disolución, que podrían mejorar el tratamiento etiológico de la enfermedad(especialmente en pediatría) y convertirse en herramientas aptas para su explotación comercial (AU)
INTRODUCTION: In Argentina, benznidazole is the drug of choice for the etiological treatment of Chagas disease. Since it was launched (more than 40 years ago), there are only 100 mg tablets available; the development included neither new pharmaceutical forms improving efficacy and safety, nor a pediatric dosage option. OBJECTIVES: To develop pharmaceutical form sof benznidazole with pharmacotherapeutic advantages. METHODS: Preformulation and design of new formulation sof benznidazole, with physicochemical characterization and selection of the most favorable formulations. Due to the discontinuity in the production of the active ingredient benznidazole, a specific methodology was developed in order to obtain it from the only commercially available alternative. RESULTS: New benznidazole tablet formulations were obtained (50 and 100 mg), with a rapid dissolution of the reference product, as well as chewable formulation sof 50 mg as sugar hydrogels featuring an effective taste masking. All formulations passed the evaluation tests for pharmacotechnical and biopharmaceutical properties, out performing the reference profiles. CONCLUSIONS:New fast-dissolving pharmaceutical dosage forms of benznidazole were developed, which could improve the etiological treatment of the disease (especially in the pediatric field) and become a proper tool for its commercial exploitation (AU)
Assuntos
Humanos , Doença de Chagas/terapia , Antiparasitários/farmacologia , Antiparasitários/uso terapêutico , Comprimidos/farmacologia , Géis/farmacologia , Administração OralRESUMO
Descoberta há cem anos, a doença de Chagas afetaa mais de quinze milhões de pessoas em toda aAmérica Latina e, ainda hoje, não há tratamentoeficaz. O fármaco benznidazol, utilizado como únicaopção de tratamento no Brasil, é ineficaz na fasecrônica da doença. Problemas relacionados à biodisponibilidadedo medicamento comercial limitam suaeficácia, principalmente na fase crônica, quando osparasitos estão confinados em tecidos profundos eem lenta replicação. Nesse contexto, pesquisas lideradaspor grupos brasileiros e argentinos vêm sendoconduzidas com o objetivo de desenvolver formulaçõesde benznidazol mais eficientes. Diversas formasfarmacêuticas sólidas e líquidas foram propostas nosúltimos anos com resultados pré-clínicos promissores,sendo descritas melhorias acentuadas nas característicasfarmacocinéticas desse fármaco. Espera-seque as formas inovadoras apresentadas possam seravaliadas em ensaios clínicos e incorporadas à produçãoindustrial em breve.
Discovered about a hundred years ago, Chagas diseasecurrently affects more than fifteen million people in LatinAmerica, and it still remains without any effective treatment.Although benznidazole has been used as the onlypharmacotherapeutic option to treat Chagas disease inBrazil, it is ineffective in the chronic phase of the disease,when the parasites are confined to deep tissue layers andslowly replicate. This happens mainly due to problems related to the bioavailability of the drug, which is currentlyin the market. In this context, Brazilian and Argentineanresearch groups have conducted studies to develop moreefficient benznidazole formulations. Several solid andliquid formulations have been proposed over the last fewyears with promising preclinical results. Improvementsin the pharmacokinetic properties of this drug have beendescribed. Therefore, it is expected, that such innovative drugs and formulations be assessed in clinical trials andsoon incorporated to industrial production.
RESUMO
El Mal de Chagas es una enfermedad parasitaria endémica en América del Sur y Central. Existen dos fármacos disponibles para el tratamiento médico de la enfermedad, el Nifurtimox (Nfx) y el Benznidazol (Bz). No existen protocolos estandarizados, validados y accesibles en laboratorios regionales para determinar niveles de los antichagásicos en sangre. En este trabajo se presenta un método espectrofotométrico para la determinación de Nfx y Bz en sangre. Los metabolitos en sangre se extraen con columnas Extrelut®. Los extractos se evaporan, se redisuelven en mezclas de metanol/agua y se analizan espectrofotométricamente a 400 nm y a 320 nm para Nfx y Bz, respectivamente. Se cuantifica comparando con soluciones estándar de Nfx o Bz en el solvente. La metodología utilizada fue validada entre 0,5 y 50 ug/mL de sangre para Nfx y entre 0,5 y 100 ug/mL de sangre para Bz. La exactitud, precisión, linealidad y robustez del método fueron satisfactorias. Se aplicó el procedimiento determinando concentraciones sanguíneas post administración de ambos fármacos a ratas.
Chagas' Disease is an endemic parasitic disease in South and Central America. There are two drugs available for medical treatment of the disease, Nifurtimox (Nfx) and Benznidazol (Bz). There are no standardized or accessible protocols in regional laboratorios to determine the levels of antichagasic drugs in blood. A spectrophotometric method for Nfx and Bz determination in blood is presented in the present work. Blood metabolites are extracted through Extrelut® columns. Extracts are evaporated, redissolved in metanol/water mixanalysed by spectrophotometry at 400 nm and 320 nm for Nfx and Bz, respectively. They are quantified comparing with standard Nfx or Bz solutions in the solvent. The methodology used was validated between 0.5 and 50 jg/mL of blood for Nfx, and between 0.5 and 100 jg/mL of blood for Bz. The accuracy, precision, lineality and robustness of the method were satisfactory. The procedure was applied determining blood concentrations after administration of both drugs to rats.
O Mal de Chagas é uma doenga parasitaria endémica na América do Sul e Central. Existem dois fármacos disponíveis para o tratamento médico da doença, o Nifurtimox (Nfx) e o Benznidazol (Bz). Não existem protocolos padronizados, validados e acessíveis em laboratorios regionais para determinarem níveis dos antichagásicos em sangue. Neste trabalho se apresenta um método espectrofotométrico para a determinação de Nfx e Bz em sangue. Os metabólitos em sangue são extraídos com colunas Extrelut®. Os extratos se evaporam, são redissolvidos em misturas de metanol/água e se analisam espectrofotometricamente a 400 nm e a 320 nm para Nfx e Bz, respectivamente. São quantificados comparando com soluções padrão de Nfx ou Bz no solvente. A metodologia utilizada foi validada entre 0,5 e 50 μg/mL de sangue para Nfx e entre 0,5 e 100 μg/mL de sangue para Bz. A exatidão, precisao, linearidade e robustez do método foram satisfatórias. Aplicouse o procedimento determinando concentrações sanguíneas pós- administragao de ambos os fármacos em ratos.
Assuntos
Espectrofotometria , Toxicologia , Sangue , Doença de Chagas , Nifurtimox , Raios Ultravioleta , Metodologia como AssuntoRESUMO
The efficacy of benznidazol on the treatment of chagasic patients from the state of Rio Grande do Sul was evaluated during a three-year follow-up. A cohort of 80 asymptomatic chronic chagasic patients or blood bank donors (49 male and 31 female) was studied. Their ages varied from 17-42 years, with a mean and a median of 30 and 35 years, respectively. The 80 patients presented positive serology, hemoculture and polymerase chain reaction (PCR). They were treated with 5 mg/Kg benznidazol twice a day for 60 days. Serological, parasitological and PCR methods were used to evaluate response. Serology was performed using commercial ELISA and indirect immunofluorescence (IFI) tests, parasitemia was monitored by hemoculture in LIT medium and PCR with primers S35/S36 was used to amplify a Trypanosoma cruzi 330 bp kDNA repetitive sequence. PCR positivity of 240 seropositive individuals was compared using DNA preparations from whole blood/guanidine EDTA (GE), buffy-coat/GE and frozen buffy-coat. Fifty non-chagasic individuals were used as negative controls. PCR positivity was 86.7 percent for the frozen buffy-coat, 71.7 percent for the GE/buffy-coat and 69.2 percent for the GE/whole blood. The hemocultures became negative just after treatment and remained negative during the three years of follow-up. In the third year after treatment, 9/80 (11.3 percent) patients presented negative PCR and, from those, four also presented negative serological tests. Furthermore, a reduction in three serological titers was observed in 27/80 (33.8 percent) of the patients treated. Taken together, the results show that four of the 80 (5.0 percent) chronic chagasic patients from the state of Rio Grande do Sul were cured after treatment with benznidazol.
Assuntos
Adulto , Animais , Feminino , Humanos , Masculino , Adulto Jovem , Doença de Chagas/tratamento farmacológico , Nitroimidazóis/uso terapêutico , Tripanossomicidas/uso terapêutico , Estudos de Casos e Controles , Doença Crônica , Estudos de Coortes , DNA de Cinetoplasto/sangue , Ensaio de Imunoadsorção Enzimática , Técnica Indireta de Fluorescência para Anticorpo , Seguimentos , Reação em Cadeia da Polimerase , Parasitemia/tratamento farmacológico , Resultado do Tratamento , Trypanosoma cruzi/efeitos dos fármacos , Trypanosoma cruzi/genética , Adulto JovemRESUMO
Para determinar el efecto del tratamiento con benznidazol sobre las células T de memoria específica para Trypanosoma cruzi, se seleccionaron 47 pacientes con tres reacciones serológicas positivas para T. cruzi, sin cardiopatía y edades comprendidas entre los 30 y los 50 años. El tratamiento se realizó con benznidazol en dosis de 5 mg/kg/d por 30 días. Se efectuó una evaluación serológica, inmunológica y clínica pretratamiento (tiempo 0) y a los 2, 6 y 12 meses postratamiento. Posteriormente, los controles se hicieron anualmente. La respuesta de linfocitos T frente a un lisado de amastigotas de T. cruzi se evaluó por la técnica de ELISPOT para IFN-ã. La frecuencia de linfocitos T de memoria productores de IFN-ã específicos para T. cruzi disminuyó significativamente en el grupo tratado (n = 33) versus el no tratado (n = 14) 12 meses después del seguimiento. Once de 25 (44%) pacientes que recibieron benznidazol negativizaron la respuesta para IFN-ã. Cuatro de los 11 (36%) pacientes con ELISPOT (+) que negativizaron la respuesta por ELISPOT para IFN-ã también negativizaron la serología convencional a los 2 años postratamiento. Durante el seguimiento no se observaron alteraciones clínicas. Estos hallazgos muestran que el benznidazol es capaz de modular la respuesta celular T de memoria específica para T. cruzi. La medición de la frecuencia de linfocitos T de memoria productores de IFN-ã podría constituir un ensayo más sensible y precoz para determinar el impacto/eficacia del tratamiento específico contra este parásito.
To determine the effect of benznidazol therapy on memory T cells specific for Trypanosoma cruzi, 47 patients between 30 and 50 years old and three positive serological tests for T. cruzi without cardiopathy were selected. Benznidazol was administered in a dose of 5 mg/kg/d during 30 days. Serological, immunological and clinical assessment was performed at basal (time 0) and at 2, 6 and 12 months following treatment, and once a year thereafter. IFN-ã ELISPOT assay was used to evaluate T cell responses against a T. cruzi lysate obtained from amastigotes. The frequency of IFN-ã - producing memory T lymphocytes specific for T. cruzi was significantly lower in the treatment group (n=33) compared to the control group (n=14) 12 months after the therapy. IFN- ã response became negative in 11 patients in the treatment group (44%). Among these 11 patients, conventional serology also became negative in 4 patients (36%) after 2 years of treatment. No clinical manifestations occurred during follow-up. These findings show that benznidazol is capable of modulating T cell responses specific for T. cruzi. Measuring the frequency of memory T lymphocytes producing IFN-ã might become a more sensitive test to determine earlier the impact and/or efficacy of the specific treatment against this parasite.