Effectiveness of Nifurtimox Eflornithine Combination Therapy (NECT) in T. b. gambiense second stage sleeping sickness patients in the Democratic Republic of Congo: Report from a field study.

BACKGROUND: Nifurtimox-eflornithine combination therapy (NECT) for the treatment of second stage gambiense human African trypanosomiasis (HAT) was added to the World Health Organization's Essential Medicines List in 2009 after demonstration of its non-inferior efficacy compared to eflornithine therapy. A study of NECT use in the field showed acceptable safety and high efficacy until hospital discharge in a wide population, including children, pregnant and breastfeeding women, and patients with a HAT treatment history. We present here the effectiveness results after the 24-month follow-up visit. METHODOLOGY/PRINCIPAL FINDINGS: In a multicenter, open label, single arm phase IIIb study, second stage gambiense HAT patients were treated with NECT in the Democratic Republic of Congo. Clinical cure was defined 24 months after treatment as survival without clinical and/or parasitological signs of HAT. Of the 629 included patients, 619 (98.4%) were discharged alive after treatment and were examined for the presence of trypanosomes, white blood cell count in cerebro-spinal fluid, and disease symptoms. The clinical cure rate of 94.1% was comparable for all subpopulations analyzed at the 24-month follow-up visit. Self-reported adverse events during follow-up were few and concerned mainly nervous system disorders, infections, and gastro-intestinal disorders. Overall, 28 patients (4.3%) died during the course of the trial. The death of 16 of the 18 patients who died during the follow-up period was assessed as unlikely or not related to NECT. Within 24 months, eight patients (1.3%) relapsed and received rescue treatment. Sixteen patients were completely lost to follow-up. CONCLUSIONS/SIGNIFICANCE: NECT treatment administered under field conditions was effective and sufficiently well tolerated, no major concern arose for children or pregnant or breastfeeding women. Patients with a previous HAT treatment history had the same response as those who were naïve. In conclusion, NECT was confirmed as effective and appropriate for use in a broad population, including vulnerable subpopulations. TRIAL REGISTRATION: The trial is registered at ClinicalTrials.gov, number NCT00906880.

Serological response to nifurtimox in adult patients with chronic Chagas disease: An observational comparative study in Argentina.

Nifurtimox is indicated in Chagas disease but determining its effectiveness in chronic disease is hindered by the length of time needed to demonstrate negative serological conversion. We manually reviewed long-term follow-up data from hospital records of patients with chronic Chagas disease (N = 1,497) in Argentina diagnosed during 1967-1980. All patients were aged ≥18 years at diagnosis and were either treated with nifurtimox (n = 968) or received no antitrypanosomal treatment (n = 529). The primary endpoint was negative seroconversion (the "event"), defined as a change from positive to negative in the serological or parasitological laboratory test used at diagnosis. Time to event was from baseline visit to date of endpoint event or censoring. The effectiveness of nifurtimox versus no treatment was estimated with Cox proportional hazard regression using propensity scores with overlap weights to calculate the hazard ratio and 95% confidence interval. The nifurtimox group was younger than the untreated group (mean, 32.4 vs. 40.3 years), with proportionally fewer females (47.9% vs. 60.1%), and proportionally more of the nifurtimox group than the untreated group had clinical signs and symptoms of Chagas disease at diagnosis (28.9% vs. 14.0%). Median maximum daily dose of nifurtimox was 8.0 mg/kg/day (interquartile range [IQR]: 8.0-9.0) and median treatment duration was 44 days (IQR: 1-90). Median time to event was 2.1 years (IQR: 1.0-4.5) for nifurtimox-treated and 2.4 years (IQR: 1.0-4.2) for untreated patients. Accounting for potential confounders, the estimated hazard ratio (95% confidence interval) for negative seroconversion was 2.22 (1.61-3.07) favoring nifurtimox. Variable treatment regimens and follow-up duration, and an uncommonly high rate of spontaneous negative seroconversion, complicate interpretation of this epidemiological study, but with the longest follow-up and largest cohort analyzed to date it lends weight to the benefit of nifurtimox in adults with chronic Chagas disease. Trial registration: The study protocol was registered at ClinicalTrials.gov: NCT03784391.

Biopharmaceutical Characteristics of Nifurtimox Tablets for Age- and Body Weight-Adjusted Dosing in Patients With Chagas Disease.

Treatment of Chagas disease with nifurtimox requires age- and body weight-adjusted dosing, resulting in complex dosing instructions. Appropriate formulations are needed for precise and compliant dosing, especially in pediatric patients. We characterized the biopharmaceutical features of a standard nifurtimox 120-mg tablet and a 30-mg tablet developed to improve dose accuracy. Two open-label, randomized crossover studies were conducted in adult outpatients with Chagas disease. One study investigated whether 4 × 30-mg tablets and 1 × 120-mg tablet were bioequivalent and whether tablets can be administered as an aqueous slurry without affecting bioavailability. The second study investigated the effect of a high-calorie/high-fat diet versus fasting on the absorption of nifurtimox after a single 4 × 30-mg dose. Interventions were equivalent if the 90% confidence interval (CI) of their least-squares (LS) mean ratios for both AUC0-tlast and Cmax were in the range of 80%-125%. The 4 × 30-mg and 1 × 120-mg tablet doses were bioequivalent (AUC0-tlast : LS mean ratio, 104.7%; 90%CI, 99.1%-110.7%; Cmax : LS mean ratio, 101.7%; 90%CI, 89.4%-115.6%; n = 24). Exposure when giving the 4 × 30-mg dose as a slurry or as tablets was comparable, with an AUC0-tlast ratio of 93.2% (84.2%-103.1%; n = 12) and a slightly decreased Cmax ratio for the slurry of 76.5% (68.8%-85.1%). Food improved the bioavailability of nifurtimox substantially (AUC0-tlast ratiofed/fasted , 172%; 90%CI, 154%-192%; Cmax ratiofed/fasted , 168%; 90%CI, 150%-187%). The data indicate that the 30- and 120-mg tablets are suitable for dosing adult and pediatric patients accurately; nifurtimox should be administered under fed conditions.

New WHO guidelines for treatment of gambiense human African trypanosomiasis including fexinidazole: substantial changes for clinical practice

Human African trypanosomiasis caused by Trypanosoma brucei gambiense is a parasitic infection that usually progresses to coma and death unless treated. WHO has updated its guidelines for the treatment of this infection on the basis of independent literature reviews and using the Grading of Recommendations Assessment, Development and Evaluation methodology. The first-line treatment options, pentamidine and nifurtimox­eflornithine combination therapy, have been expanded to include fexinidazole, an oral monotherapy given a positive opinion from the European Medicines Agency. Fexinidazole is recommended for individuals who are aged 6 years and older with a bodyweight of 20 kg or more, who have first-stage or second-stage gambiense human African trypanosomiasis and a cerebrospinal fluid leucocyte count less than 100 per µL. Nifurtimox­eflornithine combination therapy remains recommended for patients with 100 leucocytes per µL or more. Without clinical suspicion of severe second-stage disease, lumbar puncture can be avoided and fexinidazole can be given. Fexinidazole should only be administered under supervision of trained health staff. Because these recommendations are expected to change clinical practice considerably, health professionals should consult the detailed WHO guidelines. These guidelines will be updated as evidence accrues.

Prescription of concomitant medications in patients treated with Nifurtimox Eflornithine Combination Therapy (NECT) for T.b. gambiense second stage sleeping sickness in the Democratic Republic of the Congo.

BACKGROUND: Nifurtimox eflornithine combination therapy (NECT) to treat human African trypanosomiasis (HAT), commonly called sleeping sickness, was added to the World Health Organisation's (WHO) Essential Medicines List in 2009 and to the Paediatric List in 2012. NECT was further tested and documented in a phase IIIb clinical trial in the Democratic Republic of Congo (DRC) assessing the safety, effectiveness, and feasibility of implementation under field conditions (NECT-FIELD study). This trial brought a unique possibility to examine concomitant drug management. METHODOLOGY/PRINCIPAL FINDINGS: This is a secondary analysis of the NECT-FIELD study where 629 second stage gambiense HAT patients were treated with NECT, including children and pregnant and breastfeeding women in six general reference hospitals located in two provinces. Concomitant drugs were prescribed by the local investigators as needed. Patients underwent daily evaluations, including vital signs, physical examination, and adverse event monitoring. Concomitant medication was documented from admission to discharge. Patients' clinical profiles on admission and safety profile during specific HAT treatment were similar to previously published reports. Prescribed concomitant medications administered during the hospitalization period, before, during, and immediately after NECT treatment, were mainly analgesics/antipyretics, anthelmintics, antimalarials, antiemetics, and sedatives. Use of antibiotics was reasonable and antibiotics were often prescribed to treat cellulitis and respiratory tract infections. Prevention and treatment of neurological conditions such as convulsions, loss of consciousness, and coma was used in approximately 5% of patients. CONCLUSIONS/SIGNIFICANCE: The prescription of concomitant treatments was coherent with the clinical and safety profile of the patients. However, some prescription habits would need to be adapted in the future to the evolving available pharmacopoeia. A list of minimal essential medication that should be available at no cost to patients in treatment wards is proposed to help the different actors to plan, manage, and adequately fund drug supplies for advanced HAT infected patients. TRIAL REGISTRATION NUMBER: The initial study was registered at ClinicalTrials.gov, number NCT00906880.

Negligible exposure to nifurtimox through breast milk during maternal treatment for Chagas Disease.

BACKGROUND: Treatment with nifurtimox (NF) for Chagas disease is discouraged during breast-feeding because no information on NF transfer into breast milk is available. NF is safe and effective for paediatric and adult Chagas disease. We evaluated the degree of NF transfer into breast milk in lactating women with Chagas disease. PATIENTS AND METHODS: Prospective study of a cohort of lactating women with Chagas disease. Patients were treated with NF for 1 month. NF was measured in plasma and milk by high performance liquid chromatography (HPLC). Breastfed infants were evaluated at admission, 7th and 30th day of treatment (and monthly thereafter, for 6 months). RESULTS: Lactating women with chronic Chagas disease (N = 10) were enrolled (median age 28 years, range 17-36). Median NF dose was 9.75 mg/kg/day three times a day (TID). Six mothers had mild adverse drug reactions (ADRs), but no ADRs were observed in any of the breastfed infants. No interruption of breastfeeding was observed. Median NF concentrations were 2.15 mg/L (Inter quartil range (IQR) 1.32-4.55) in milk and 0.30 mg/L (IQR 0.20-0.95) in plasma. Median NF milk/plasma ratio was 16 (range 8.75-30.25). Median relative infant NF dose (assuming a daily breastmilk intake of 150 mL/kg/day) was 6.7% of the maternal dose/kg/day (IQR 2.35-7.19%). CONCLUSIONS: The low concentrations of NF in breast milk and the normal clinical evaluation of the breastfed babies imply that maternal NF treatment for Chagas disease during breastfeeding is unlikely to lead to clinically relevant exposures in the breastfed infants. TRIAL REGISTRATION: Clinical trial registry name and registration number: ClinicalTrials.gov NCT01744405.

Detection of Trypanosoma cruzi by PCR in adults with chronic Chagas disease treated with nifurtimox.

Chagas disease, a vector-borne parasitosis caused by Trypanosoma cruzi, is endemic to Latin America and has spread to other countries due to immigration of infected persons. It is estimated that 160,000 people are infected in Chile, most of them in the chronic phase and without etiological treatment. The infection is confirmed by conventional serological methods while molecular methods have become in valuable tools to evaluate parasitemia in treated and non-treated chronic Chagas disease patients. The objective of this study was to determine, by conventional Polymerase Chain Reaction, the presence of T. cruzi kinetoplastid DNA in peripheral blood samples from 114 adult individuals with confirmed chronic Chagas disease, before and 6.6 years (average) after treatment with nifurtimox. The samples were received and preserved in guanidine-EDTA until DNA purification. Conventional PCR assays were performed in triplicate with T. cruzi kinetoplastid DNA primers 121 and 122. The amplified products were fractionated by electrophoresis in 2% agarose gels. A 330 bp product represented a positive assay. 84.2% (96 cases) and 6.1% (7 cases) of the samples taken before and after the treatment, respectively, were positive. The McNemar test showed a statistically significant difference between the groups of samples (p<0.001). Since serological negativization (the current cure criterion) delay many years after therapy and positive parasitological results represent a treatment failure, the conversion of pre-therapy positive conventional PCR is a qualitative and complementary tool that could be included in protocols of prolonged follow-up.

Nanocarriers for effective delivery of benznidazole and nifurtimox in the treatment of chagas disease: A review.

Neglected tropical diseases (NTDs) constitute a group of infectious diseases prevalent in countries with tropical and subtropical climate that affect the poorest individuals and produce high chronic disability associated with serious problems for the health system and socioeconomic development. Chagas disease or American trypanosomiasis is included on the NTDs list. However, even though this disease affects more than 10 million people, mostly in Latin America, causing the death of over 10,000 people every year, only two drugs are approved for its treatment, benznidazole and nifurtimox. These antiparasitic agents were developed almost half a century ago and present several biopharmaceutical disadvantages such as low aqueous solubility and permeability limiting their bioavailability. In addition, both therapeutic agents are available only as tablets and a liquid pediatric formulation is still lacking. Therefore, novel pharmaceutical strategies to optimize the pharmacotherapy of Chagas disease are urgently required. In this regard, nanotechnological approaches may be a crucial alternative for the delivery of both drugs ensuring an effective pharmacotherapy although the successful bench-to-bedside translation remains a major challenge. The present work reviews in detail the formulation and in-vitro/in-vivo analysis of different nanoformulations of nifurtimox and benznidazole in order to enhance their solubility, dissolution, bioavailability and trypanocidal activity.

Quantification of Immunoglobulin G against Trypanosoma cruzi in Individuals with Chronic Chagas Disease Treated with Nifurtimox and Evaluated in Prolonged Follow-Up.

In the indeterminate chronic period of Chagas disease (ChD) the treatment has not been conclusive, because the serological negativization requires many years. This study aims to evaluate the efficacy of nifurtimox (NF) in the treatment of chronic ChD in prolonged follow-up by serological techniques of indirect immunofluorescence assay (IFA) and enzyme-linked immunosorbent assay (ELISA) IgG comparing 2 groups of patients, treated and non treated. Mann-Whitney test was performed for ELISA and IFA, with significant difference between the groups (P < 0.05). IgG levels were lower in individuals treated compared with untreated patients, indicating chemotherapeutic efficacy in prolonged follow-up.

Chagas disease: An underrecognized diagnosis.

Chagas disease is a parasite infection primarily transmitted to humans via the bite of triatomine insect vectors. Up to 8 million people are estimated to be infected with Chagas disease in the Americas. Patients who do not receive treatment can develop severe cardiac debility, gastrointestinal organ dysfunction, and may die. The changing demographics of the United States, a consequence of changing immigration patterns, means that healthcare providers are more likely to encounter patients with Chagas disease, and must understand its cause, pathogenesis, diagnosis, and treatment.

Mortality trends and risk factors in advanced stage-2 Human African Trypanosomiasis: A critical appraisal of 23 years of experience in the Democratic Republic of Congo.

We conducted a retrospective study on mortality trends and risk factors in 781 naïve cases of advanced stage-2 sleeping sickness admitted between 1989 and 2012 at the National Reference Center for Human African Trypanosomiasis (HAT), Department of Neurology, Kinshasa University, Democratic Republic of Congo (DRC). Death was the outcome variable whereas age, gender, duration of disease, location of trypanosomes in body fluids, cytorachy, protidorachy, clinical status (assessed on a syndromic and functional basis) on admission, and treatment regimen were predictors in logistic regression models run at the 0.05 significance level. Death proportions were 17.2% in the standard melarsoprol schedule (3-series of intravenous melarsoprol on 3 successive days at 3.6 mg/kg/d, with a one-week interval between the series, ARS 9); 12.1% in the short schedule melarsoprol (10 consecutive days of intravenous melarsoprol at 2.2 mg/kg/d, ARS 10), 5.4% in the first-line eflornithine (14 days of eflornithine at 400 mg/kg/d in 4 infusions a day DFMO B), 9.1% in the NECT treatment regimen (eflornithine for 7 days at 400, mg/kg/d in 2 infusions a day combined with oral nifurtimox for 10 days at 15 mg/kg/d in 3 doses a day); and high (36%) in the group with select severely affected patients given eflornithine because of their clinical status on admission, at the time when this expensive drug was kept for treatment of relapses (14 days at 400 mg/kg/d in 4 infusions a day, DFMO A). After adjusting for treatment, death odds ratios were as follows: 10.40 [(95% CI: 6.55-16.51); p = .000] for clinical dysfunction (severely impaired clinical status) on admission, 2.14 [(95% CI: 1.35-3.39); p = .001] for high protidorachy, 1.99 [(95% CI: 1.18-3.37); p = .010] for the presence of parasites in the CSF and 1.70 [(95% CI: 1.03-2.81); p = .038] for high cytorachy. A multivariable analysis within treatment groups retained clinical status on admission (in ARS 9, ARS 10 and DFMO B groups) and high protidorachy (in ARS 10 and DFMO B groups) as significant predictors of death. The algorithm for initial clinical status assessment used in the present study may serve as the basis for further development of standardized assessment tools relevant to the clinical management of HAT and information exchange in epidemiological reports.

A multicentre, randomised, non-inferiority clinical trial comparing a nifurtimox-eflornithine combination to standard eflornithine monotherapy for late stage Trypanosoma brucei gambiense human African trypanosomiasis in Uganda.

BACKGROUND: While the combination of nifurtimox and eflornithine (NECT) is currently recommended for the treatment of the late stage human African trypansomiasis (HAT), single-agent eflornithine was still the treatment of choice when this trial commenced. This study intended to provide supportive evidence to complement previous trials. METHODS: A multi-centre randomised, open-label, non-inferiority trial was carried out in the Trypanosoma brucei gambiense endemic districts of North-Western Uganda to compare the efficacy and safety of NECT (200 mg/kg eflornithine infusions every 12 h for 7 days and 8 hourly oral nifurtimox at 5 mg/kg for 10 days) to the standard eflornithine regimen (6 hourly at 100 mg/kg for 14 days). The primary endpoint was the cure rate, determined as the proportion of patients alive and without laboratory signs of infection at 18 months post-treatment, with no demonstrated trypanosomes in the cerebrospinal fluid (CSF), blood or lymph node aspirates, and CSF white blood cell count < 20 /µl. The non-inferiority margin was set at 10%. RESULTS: One hundred and nine patients were enrolled; all contributed to the intent-to-treat (ITT), modified intent-to-treat (mITT) and safety populations, while 105 constituted the per-protocol population (PP). The cure rate was 90.9% for NECT and 88.9% for eflornithine in the ITT and mITT populations; the same was 90.6 and 88.5%, respectively in the PP population. Non-inferiority was demonstrated for NECT in all populations: differences in cure rates were 0.02 (95% CI: -0.07-0.11) and 0.02 (95% CI: -0.08-0.12) respectively. Two patients died while on treatment (1 in each arm), and 3 more during follow-up in the NECT arm. No difference was found between the two arms for the secondary efficacy and safety parameters. A meta-analysis involving several studies demonstrated non-inferiority of NECT to eflornithine monotherapy. CONCLUSIONS: These results confirm findings of earlier trials and support implementation of NECT as first-line treatment for late stage T. b. gambiense HAT. The overall risk difference for cure between NECT and eflornithine between this and two previous randomised controlled trials is 0.03 (95% CI: -0.02-0.08). The NECT regimen is simpler, safer, shorter and less expensive than single-agent DFMO. TRIAL REGISTRATION: ISRCTN ISRCTN03148609 (registered 18 April 2008).

Human African Trypanosomiasis in Emigrant Returning to China from Gabon, 2017.

Human African trypanosomiasis is endemic to parts of sub-Saharan Africa and should be considered in the differential diagnosis of patients who have visited or lived in Africa. We report a 2017 case of stage 2 Trypanosoma brucei gambiense disease in an emigrant who returned to China from Gabon.

Terapia de Resgate com Nifurtimox e Dipiridamol na Miocardite Chagásica Aguda Grave com Insuficiência Cardíaca em Camundongos NMRI / Rescue Therapy with Nifurtimox and Dipyridamole for Severe Acute Chagas Myocarditis with Congestive Heart Failure in NMRI Albino Mice

Fundamento: A doença de Chagas é um problema de saúde global, sendo necessário o desenvolvimento de novos protocolos terapêuticos. Nosso grupo demonstrou recentemente que o nifurtimox associado ao dipiridamol tem efeitos curativos em camundongos com doença de Chagas aguda. Neste estudo, avaliamos o efeito deste protocolo terapêutico em camundongos chagásicos com insuficiência cardíaca. Objetivo: Avaliar se o nifurtimox e o dipiridamol são úteis no tratamento de resgate em camundongos com miocardite chagásica aguda com insuficiência cardíaca. Métodos: Foram divididos em três grupos 42 camundongos com miocardite chagásica aguda e insuficiência cardíaca congestiva: Controle Chagas (n = 11); Nif-Dip, tratados com nifurtimox e dipiridamol (n = 14); e Nif-Dip-Insuficiência Cardíaca, tratados com nifurtimox e dipiridamol, associados com digoxina, furosemida e captopril (n = 17). As doses de nifurtimox e dipiridamol foram de 40 e 30mg/kg/dia, respectivamente, durante 6 semanas. Os camundongos foram submetidos a avaliações clínicas, eletrocardiográficas, hemoparasitológicas e histopatológicas. Resultados: Observou-se menor mortalidade no Grupo Nif-Dip (n = 4; 28,57%) em relação ao Controle Chagas (n = 6; 54,54%) e ao Nif-Dip-Insuficiência Cardíaca (n = 9; 52,9%). Clinicamente, os camundongos tratados com nifurtimox e dipiridamol aumentaram o peso corporal e melhoraram a insuficiência cardíaca, sem mostrar esplenomegalia. Nestes grupos, foram erradicadas as parasitemias e os parasitas teciduais; a fibrose, a miocitólise, o infiltrado de células inflamatórias e os mastócitos diminuíram. Os distúrbios de repolarização, os intervalos QRS e o QT prolongados, o aumento da amplitude da onda S e a dissociação atrioventricular foram revertidos pelo tratamento. Conclusão: O tratamento com nifurtimox e dipiridamol pode ser usado no resgate em camundongos com doença chagásica aguda grave, já que o nifurtimox teve atividade tripanocida, e o dipiridamole potenciou seu efeito. O dipiridamol seria útil na insuficiência cardíaca chagásica

Background: Chagas disease is a global health problem; therefore, the development of new therapeutic protocols is necessary. Our group recently demonstrated that nifurtimox associated with dipyridamole has curative effects in mice with acute Chagas disease. In this study, we assess the effect of this therapeutic protocol in chagasic mice with heart failure. Objective: To evaluate whether nifurtimox and dipyridamole are useful to rescue mice with severe acute chagasic myocarditis with heart failure. Methods: 42 mice with acute chagasic myocarditis and congestive heart failure were divided into three groups: control chagas (n = 11), Nif-Dip treated with nifurtimox and dipyridamole (n = 14) and Nif-Dip-heart failure treated with nifurtimox and dipyridamole associated with digoxin, furosemide, and captopril (n = 17). Nifurtimox and dipyridamole doses were 40 and 30 mg/kg/day, respectively, for 6 weeks. Mice underwent clinical, electrocardiographic, hemoparasitological and histopathological assessments. Results: Lower mortality in Nif-Dip (28.57%; n = 4) compared to control chagas (54.54%; n = 6) and Nif-Dip-heart failure (52.9%; n = 9) was observed. Clinically, nifurtimox and dipyridamole-treated mice increased body weight and improved heart failure without splenomegaly. In these groups, parasitemia and tissue parasites were eradicated; fibrosis, myocytolysis, inflammatory cell infiltrate and mast cells decreased. Repolarization disorders, prolonged QRS and QT intervals, increase of S wave amplitude and atrioventricular dissociation were reversed by the treatment. Conclusion: Nifurtimox with dipyridamole can rescue NMRI mice from severe acute chagas disease, as nifurtimox showed trypanocidal activity and dipyridamole potentiated its effect. Dipyridamole would be useful in chagasic heart failure

Planejamento de fármacos anti-T. cruzi: Síntese de compostos nitrofurânicos, avaliação da atividade biológica in vitro e estudos de relações estrutura-atividade / Design of anti-T. cruzi compounds: Synthesis of 5-nitrofuran derivatives, in vitro biological activity and study of structure-activity relationships

A doença de Chagas afeta cerca de 6 a 7 millhões de pessoas no mundo, principalmente América Latina. A busca de alternativas terapêuticas para esta enfermidade tem grande relevância para a sociedade, já que as opções atuais são limitadas, sendo disponível apenas o benznidazol (BZD) e nifurtimox. Os derivados nitroheterocíclicos são considerados compostos bioativos com número crescente de estudos na comunidade científica contra seu agente etiológico, o Trypanosoma cruzi. Neste sentido, o presente trabalho tem por objetivo a identificação de derivados do 5-nitrofurano com atividade frente a diferentes cepas do T. cruzi, assim como estudar possíveis modo de ação desta classe de compostos. Esta investigação envolve estudos computacionais com o propósito de construir modelos quantitativos de relações estrutura-atividade (QSAR multivariado) que possam auxiliar na previsão de novas estruturas com perfil farmacológico otimizado. No presente trabalho foram realizadas as etapas de planejamento, síntese e identificação de 36 compostos com resultados satisfatórios quanto à identificação estrutural, pureza e rendimento, que foi da ordem de 70%. A determinação da atividade anti-T. cruzi in vitro dos compostos obtidos foi realizada frente às cepas Silvio X10 cl1, Y, Bug 2149 cl10 e Colombiana na forma epimastigota do parasito. A maioria dos compostos analisados apresentou maior capacidade de inibição de crescimento do parasito, comparado ao BZD: Silvio X10 cl1 - IC50 = 29,16 ±2,90 µM, Y - IC50 = 40,40 ±3,37µM, Bug 2149 cl10 - IC50 = 30,63 ±3,21 µM, Colombiana - IC50 = 47,91 ±4,96 µM. O composto mais ativo (BSF-35) apresentou os seguintes valores: Silvio X10 cl1 - IC50 = 3,17 ±0,32 µM, Y - IC50 = 1,17 ±0,12 µM, Bug 2149 cl10 - IC50 = 1,81 ±0,18 µM e Colombiana - IC50 = 3,06 ±0,23 µM. Foram realizados cálculos de propriedades moleculares das estruturas tridimensionais dos compostos, seguido pela análise exploratória de dados por análise de agrupamentos hierárquicos (HCA) e análise de componentes principais (PCA), possibilitando o reconhecimento de padrões do conjunto. Considerando esta análise prévia, foram obtidos modelos QSAR com abordagem multivariada, aplicando algorítmo OPS e método de regressão por quadrados mínimos parciais, PLS. Os melhores modelos gerados foram obtidos considerando os compostos benzenos substituídos para as quatro cepas estudadas. Os descritores que mais influenciaram na análise foram o ClogP (coeficiente de partição) e cargas CHELPG. Considerando as informações obtidas, foram planejados e sintetizados quatro novos compostos com objetivo de obter compostos mais ativos e validar os modelos QSAR. Estes compostos apresentaram alta atividade frente a forma epimastigota das quatro cepas estudadas. Os compostos mais ativos foram avaliados quanto a citotoxicidade frente células LLC-MK2 e apresentaram seletividade até 25 vezes superior ao BZD. Estudos in vitro frente a forma amastigota da cepa Y em células U2OS foram realizados com metodologia fenotípica de análise de alto conteúdo (HCA') e os compostos apresentaram atividade até 64 vezes superior ao BZD e com seletividade de até 50 vezes superior a este fármaco. Quanto à determinação da atividade dos compostos frente às enzimas tripanotiona redutase (TcTR) e glutationa redutase (GR), os compostos analisados não apresentaram atividade relevante, indicando não ser este o mecanismo desta classe de compostos. Com finalidade de explorar outro possível mecanismo de ação dos compostos 5-nitrofurânicos, foi realizada a análise de potencial de redução da membrana mitocondrial, porém a morte parasitária não foi atribuída à despolarização da membrana em estudos simultâneos com iodeto de propídio

Chagas disease affects approximately 6-7 millions people worldwide, especially Latin America. The search for therapeutic alternatives for this disease is of great relevance to society, as current options are limited and there are only two available drugs: benznidazole (BZD) and nifurtimox. The nitroheterocyclic derivatives are considered bioactive compounds with increasing number of studies in the scientific community against its etiologic agent, Trypanosoma cruzi. In this sense, this work aims to identify derivatives of 5-nitrofuran with activity against different strains of T. cruzi, and to study possible mode of action of this compounds. This research involves computational studies to obtain models of quantitative structure-activity relationships (QSAR multivariate) that can help predict new structures with optimized pharmacological profile. In this work were carried out the design, synthesis and identification of 36 compounds with satisfactory results regarding the structural identification, purity and yield (approximately 70%). The determination of anti-T. cruzi activity in vitro of the compounds obtained was carried out with Silvio X10 cl1, Y, Bug 2149 CL10 and Colombiana strains of epimastigote form of the parasite. Most of the compounds examined showed greater capacity of growth inhibition of the parasite compared to the BZD (Silvio X10 CL1 - IC 50 = 29.16 ± 2.90 µM, Y - IC50 = 40.40 ± 3,37µM, 2149 CL10 Bug - IC 50 = 30.63 ± 3.21 µM, Colombiana - IC 50 = 47.91 ± 4.96 µM). The most active compound (BSF-35) showed the following values: Silvio X10 cl1 - IC 50 = 3.17 ± 0.32 uM, Y - IC 50 = 1.17 ± 0.12 µM, Bug 2149 CL10 - IC50 = 1, 81 ± 0.18 µM and Colombiana - IC 50 = 3.06 ± 0.23 µM. Calculations were performed for the molecular properties of three-dimensional structures of the compounds, followed by exploratory data analysis by hierarchical cluster analysis (HCA) and principal component analysis (PCA), allowing the recognition of the set. Considering this preliminary analysis were obtained QSAR models with multivariate approach, using OPS algorithm and regression method of partial least squares, PLS. The best generated models were obtained considering the benzyl substituted compounds for the four strains. The descriptors that most influenced the analysis were ClogP (partition coefficient) and CHELPG charges. Considering the information obtained, four new compounds were designed and synthesized to obtain more active compounds and validate QSAR models. These compounds showed high activity against epimastigote form of the four strains studied. The most active compounds were evaluated for cytotoxicity against LLC-MK2 cells and the compounds selectivity values were up to 25 times higher than BZD. In vitro studies against amastigote form of the Y strain in U2OS cells were performed with phenotypic method of high content analysis (HCA') and the compounds showed activity to 64 times higher than BZD and selectivity of up to 50 times. The activity of the compounds against trypanothione reductase enzymes (TcTR) and glutathione reductase (GR) showed no significant activity, indicating that this is not the mechanism of this class of compounds. In order to exploit another possible mechanism of action of 5-nitrofuran derivatives, analysis reduction of mitochondrial membrane potential was held, however the cell death was not attributed to membrane depolarization in simultaneous studies with propidium iodide

Safety Profile of Nifurtimox and Treatment Interruption for Chronic Chagas Disease in Colombian Adults.

Nifurtimox (NFX) is one of the approved drugs used to treat Chagas disease. Safety profile studies and models on risk factors for treatment interruption in adults are scarce in Latin America. This study evaluated retrospectively the medical records of adult Chagas disease patients treated with NFX between 2007 and 2012 in Bogotá, Colombia. An accelerated failure time model was used, and associations were expressed as time ratio (TR). In total, 76 adult patients with NFX were included: 60 (79.0%) completed 60 days of treatment, 61 (80.3%) presented adverse drug reactions (ADRs), and 16 (21.0%) required treatment interruption. The predominant symptoms were epigastric pain (23.7%), nauseas (18.4%), sleep disturbances (18.4%), loss of appetite (17.1%), and temporary loss of memory (15.2%). ADRs were classified as mild (64.5%), moderate (30.4%), and severe (5.1%). Time of treatment was significantly longer when presenting ≤ 3 ADRs (TR: 1.78; 95% CI: 1.04-3.03), presence of non-severe ADRs (TR: 6.52; 95% CI: 3.24-13.1), doses of NFX ≤ 8 mg/kg/day (TR: 1.78; 95% CI: 0.90-3.49), and age < 48 years (TR: 1.57; 95% CI: 0.90-2.74). Treatment with NFX in adults caused a high frequency of ADRs, but most of the cases were mild and did not require treatment interruption. Severity and number of ADRs were the main predictors for treatment interruption.

First report of a family outbreak of Chagas disease in French Guiana and posttreatment follow-up.

The outbreak of acute Chagas disease due to oral transmission of the parasite is a well-known phenomenon mainly occurring in the Amazon. Such an event is described here for the first time in French Guiana. Eight patients of the same family, presenting epidemiological and clinical histories compatible with recent Trypanosoma cruzi infection of Chagas disease due to the ingestion of palm Oenocarpus bacaba juice were, rather late after the putative date of infection, underwent four parasitological and two serological specific tests for confirmation of the diagnosis. Real-time PCR results were positive for all the patients; strains were isolated by hemoculture from four patients, PCR identification of TcI DTU was made for six patients, while parasites were not detected in any of the patients by direct microscopic examination. The results of two serologic tests were positive. All patients were treated with benznidazole, and two patients were additionally given nifurtimox. A 6-year follow-up was possible for six patients. Real-time PCR was negative for these patients after 1 year, while the antibody rates decreased slowly and serology results were negative only after several years (1-5 years). Our findings confirm the occurrence of an outbreak of Chagas infection in members of the same family, with the oral mode of infection being the most likely hypothesis to explain this group of cases. Our results show the successful treatment of patients infected by TcI and the usefulness of real-time PCR for the emergency diagnosis of recent Chagas disease cases and in posttreatment follow-up.

Potential new clinical therapies for Chagas disease.

Chagas disease is the highest impact parasitic disease in the Americas but often goes untreated due to the shortcomings of currently available therapeutics. Thus there is an urgent need for new treatment options and growing interest in drug development for the infection. This review summarizes some of the recent advances and failures in this realm, with particular emphasis on recently published studies and unpublished results presented at a recent Chagas Drug Discovery Consortium meeting.