Development of an ionic liquid-based dispersive liquid-liquid microextraction method for the determination of nifurtimox and benznidazole in human plasma

Dispersive ionic liquid-liquid microextraction combined with liquid chromatography and UV detection was used for the determination of two antichagasic drugs in human plasma: nifurtimox and benznidazole. The effects of experimental parameters on extraction efficiency - the type and volume of ionic liquid and disperser solvent, pH, nature and concentration of salt, and the time for centrifugation and extraction - were investigated and optimized. Matrix effects were detected and thus the standard addition method was used for quantification. This microextraction procedure yielded significant improvements over those previously reported in the literature and has several advantages, including high inter-day reproducibility (relative standard deviation=1.02% and 3.66% for nifurtimox and benznidazole, respectively), extremely low detection limits (15.7 ng mL-1 and 26.5 ng mL-1 for nifurtimox and benznidazole, respectively), and minimal amounts of sample and extraction solvent required. Recoveries were high (98.0% and 79.8% for nifurtimox and benznidazole, respectively). The proposed methodology offers the advantage of highly satisfactory performance in addition to being inexpensive, simple, and fast in the extraction and preconcentration of these antichagasic drugs from human-plasma samples, with these characteristics being consistent with the practicability requirements in current clinical research or within the context of therapeutic monitoring. © 2013 Elsevier B.V

Publication of abstracts presented at the National Pediatric Research Meetings of the Argentine Society of Pediatrics: Related factors

Objectives: To estimate the proportion of abstracts presented at National Pediatric Research Meetings that are fully-published and describe their design and factors that influence nonpublication. Methods: Descriptive and analytical study including all abstracts presented at National Pediatric Research Meetings (1998-2011). One author per study was identified and asked to complete a survey on its design, publication and factors associated with non-publication. Results: Out of 746 abstracts that were submitted, the authors of 522 (70%) completed the survey. Among these, 84.3% were observational studies and 15.7%, experimental; 34% had received funding. Two hundred and seventeen abstracts were published subsequently (41.5%, 95% confidence interval [CI]: 37.3-45.9). Funded studies had better chances of being published (odds ratio [OR]: 2, 95% CI: 1.4-2.9, p \u3c 0.001). Lack of time, insufficient sample size, and problems with funding were referred as the most common reasons for failure to publish. Conclusion: Among all abstracts presented at National Pediatric Research Meetings, 41.5% were fully published. Lack of time was the most common reason for unpublished studies

Population pharmacokinetic study of benznidazole in pediatric chagas disease suggests efficacy despite lower plasma concentrations than in adults

Introduction: Chagas disease, caused by the parasite Trypanosoma cruzi, can lead to long term cardiac morbidity. Treatment of children with benznidazole is effective, but no pediatric pharmacokinetics data are available and clinical pharmacology information on the drug is scarce. Patients and Methods: Prospective population pharmacokinetic (PK) cohort study in children 2-12 years old with Chagas disease treated with oral benznidazole 5-8 mg/kg/day BID for 60 days. (clinicaltrials.gov #NCT00699387). Results: Forty children were enrolled in the study. Mean age was 7.3 years. A total of 117 samples were obtained from 38 patients for PK analysis. A one compartment model best fit the data. Weight-corrected clearance rate (CL/F) showed a good correlation with age, with younger patients having a significantly higher CL/F than older children and adults. Simulated median steady-state benznidazole concentrations, based on model parameters, were lower for children in our study than for adults and lowest for children under 7 years of age. Treatment was efficacious in the 37 patients who completed the treatment course, and well tolerated, with few, and mild, adverse drug reactions (ADRs). Discussion: Observed benznidazole plasma concentrations in children were markedly lower than those previously reported in adults (treated with comparable mg/kg doses), possibly due to a higher CL/F in smaller children. These lower blood concentrations were nevertheless associated to a high therapeutic response in our cohort. Unlike adults, children have few adverse reactions to the drug, suggesting that there may be a direct correlation between drug concentrations and incidence of ADRs. Our results suggest that studies with lower doses in adults may be warranted. Trial Registration: ClinicalTrails.gov NCT00699387.Facultad de Ciencias Exacta

Population pharmacokinetic study of benznidazole in pediatric chagas disease suggests efficacy despite lower plasma concentrations than in adults

Introduction: Chagas disease, caused by the parasite Trypanosoma cruzi, can lead to long term cardiac morbidity. Treatment of children with benznidazole is effective, but no pediatric pharmacokinetics data are available and clinical pharmacology information on the drug is scarce. Patients and Methods: Prospective population pharmacokinetic (PK) cohort study in children 2-12 years old with Chagas disease treated with oral benznidazole 5-8 mg/kg/day BID for 60 days. (clinicaltrials.gov #NCT00699387). Results: Forty children were enrolled in the study. Mean age was 7.3 years. A total of 117 samples were obtained from 38 patients for PK analysis. A one compartment model best fit the data. Weight-corrected clearance rate (CL/F) showed a good correlation with age, with younger patients having a significantly higher CL/F than older children and adults. Simulated median steady-state benznidazole concentrations, based on model parameters, were lower for children in our study than for adults and lowest for children under 7 years of age. Treatment was efficacious in the 37 patients who completed the treatment course, and well tolerated, with few, and mild, adverse drug reactions (ADRs). Discussion: Observed benznidazole plasma concentrations in children were markedly lower than those previously reported in adults (treated with comparable mg/kg doses), possibly due to a higher CL/F in smaller children. These lower blood concentrations were nevertheless associated to a high therapeutic response in our cohort. Unlike adults, children have few adverse reactions to the drug, suggesting that there may be a direct correlation between drug concentrations and incidence of ADRs. Our results suggest that studies with lower doses in adults may be warranted. Trial Registration: ClinicalTrails.gov NCT00699387.Facultad de Ciencias Exacta

Hair analysis following chronic smoked-drugs-of-abuse exposure in adults and their toddler: a case report

<p>Abstract</p> <p>Introduction</p> <p>Over the past two decades, the study of chronic cocaine and crack cocaine exposure in the pediatric population has been focused on the potential adverse effects, especially in the prenatal period and early childhood. Non-invasive biological matrices have become an essential tool for the assessment of a long-term history of drug of abuse exposure.</p> <p>Case report</p> <p>We analyze the significance of different biomarker values in hair after chronic crack exposure in a two-year-old Caucasian girl and her parents, who are self-reported crack smokers. The level of benzoylecgonine, the principal metabolite of cocaine, was determined in segmented hair samples (0 cm to 3 cm from the scalp, and > 3 cm from the scalp) following washing to exclude external contamination. Benzoylecgonine was detectable in high concentrations in the child's hair, at 1.9 ng/mg and 7.04 ng/mg, respectively. Benzoylecgonine was also present in the maternal and paternal hair samples at 7.88 ng/mg and 6.39 ng/mg, and 13.06 ng/mg and 12.97 ng/mg, respectively.</p> <p>Conclusion</p> <p>Based on the data from this case and from previously published poisoning cases, as well as on the experience of our research group, we conclude that, using similar matrices for the study of chronic drug exposure, children present with a higher cocaine concentration in hair and they experience more serious deleterious acute effects, probably due to a different and slower cocaine metabolism. Consequently, children must be not exposed to secondhand crack smoke under any circumstance.</p

An ultrafast ultrahigh-performance liquid chromatography coupled with tandem mass spectrometry method for cannabidiol monitoring in pediatric refractory epilepsy

Background: Cannabidiol (CBD) is a nonpsychoactive natural product that has been increasingly used as a promising new drug for the management of neurological conditions such as refractory epilepsy. Development of rapid and sensitive methods to quantitate CBD is essential to evaluate its pharmacokinetics in humans, particularly in children. The objective of this work was to develop and validate an ultrafast ultrahigh-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) method for CBD quantitation that is capable of detecting major CBD and tetrahydrocannabinol (THC) metabolites in the plasma of pediatric refractory epilepsy patients. Methods: Eight-point CBD calibration curves were prepared using 60 µL of plasma from healthy volunteers. Samples were analyzed in a Shimadzu Nexera X2 UHPLC system, which was coupled to a Sciex QTRAP 6500 mass spectrometer. Chromatography was optimized in acetonitrile (ACN)/water with a 70%–90% gradient of ACN in 2 minutes. Multiple reaction monitoring transitions of major CBD and THC metabolites were optimized in patient plasma. Results: The optimized UHPLC-MS/MS method was validated for the linear range (1–300 ng/mL) of CBD (r2 = 0.996). The limit of quantification and limit of detection were 0.26 and 0.86 ng/mL, respectively. Accuracy and precision met the acceptable validation limits. CBD recovery and matrix effects were 83.9 ± 13.9% and 117.4 ± 4.5%, respectively. The method was successfully applied to quantify CBD and detect the major CBD and THC metabolites in clinical samples. 7-COOH-CBD was the most intensely detected metabolite followed by glucuronide conjugates. Conclusions: A simple and sensitive method for rapidly monitoring CBD and identifying relevant metabolites was developed. Its applicability in samples from children treated for epilepsy was demonstrated, making it an excellent alternative for performing pharmacokinetic studies.</p

Treatment of adult chronic indeterminate Chagas disease with benznidazole and three E1224 dosing regimens: a proof-of-concept, randomised, placebo-controlled trial

Background: Chagas disease is a major neglected vector-borne disease. In this study, we investigated the safety and efficacy of three oral E1224 (a water-soluble ravuconazole prodrug) regimens and benznidazole versus placebo in adult chronic indeterminate Chagas disease. Method: In this proof-of-concept, double-blind, randomised phase 2 clinical trial, we recruited adults (18–50 years) with confirmed diagnosis of Trypanosoma cruzi infection from two outpatient units in Bolivia. Patients were randomised with a computer-generated randomisation list, which was stratified by centre and used a block size of ten. Patients were randomly assigned (1:1:1:1:1) to five oral treatment groups: high-dose E1224 (duration 8 weeks, total dose 4000 mg), low-dose E1224 (8 weeks, 2000 mg), short-dose E1224 (4 weeks + 4 weeks placebo, 2400 mg), benznidazole (60 days, 5 mg/kg per day), or placebo (8 weeks, E1224-matched tablets). Double-blinding was limited to the E1224 and placebo arms, and assessors were masked to all treatment allocations. The primary efficacy endpoint was parasitological response to E1224 at the end of treatment, assessed by PCR. The secondary efficacy endpoints were parasitological response to benznidazole at end of treatment, assessed by PCR; sustainability of parasitological response until 12 months; parasite clearance and changes in parasite load; incidence of conversion to negative response in conventional and non-conventional (antigen trypomastigote chemiluminescent ELISA [AT CL-ELISA]) serological response; changes in levels of biomarkers; and complete response. The primary analysis population consisted of all randomised patients by their assigned treatment arms. This trial is registered with ClinicalTrials.gov, number NCT01489228. Findings: Between July 19, 2011, and July 26, 2012, we screened 560 participants with confirmed Chagas disease, of whom 231 were enrolled and assigned to high-dose E1224 (n=45), low-dose E1224 (n=48), short-dose E1224 (n=46), benznidazole (n=45), or placebo (n=47). Parasite clearance was observed with E1224 during the treatment phase, but no sustained response was seen with low-dose and short-dose regimens, whereas 13 patients (29%, 95% CI 16·4–44·3) had sustained response with the high-dose regimen compared with four (9%, 2·4–20·4) in the placebo group (p<0·0001). Benznidazole had a rapid and sustained effect on parasite clearance, with 37 patients (82%, 67·9–92·0) with sustained response at 12-month follow-up. After 1 week of treatment, mean quantitative PCR repeated measurements showed a significant reduction in parasite load in all treatment arms versus placebo. Parasite levels in the low-dose and short-dose E1224 groups gradually returned to placebo levels. Both treatments were well tolerated. Reversible, dose-dependent liver enzyme increases were seen with E1224 and benznidazole. 187 (81%) participants developed treatment-emergent adverse events and six (3%) developed treatment-emergent serious adverse events. Treatment-emergent adverse events were headaches, nausea, pruritus, peripheral neuropathy, and hypersensitivity. Interpretation: E1224 is the first new chemical entity developed for Chagas disease in decades. E1224 displayed a transient, suppressive effect on parasite clearance, whereas benznidazole showed early and sustained efficacy until 12 months of follow-up. Despite PCR limitations, our results support increased diagnosis and access to benznidazole standard regimen, and provide a development roadmap for novel benznidazole regimens in monotherapy and in combinations with E1224. Funding: Drugs for Neglected Diseases initiative.Fil: Torrico, Faustino. Universidad Mayor de San Simon Bolivia; Bolivia. Fundación Ceades; BoliviaFil: Gascon, Joaquim. Instituto de Salud Global de Barcelona; EspañaFil: Ortiz, Lourdes. Universidad Autónoma Juan Misael Saracho de Tarija; BoliviaFil: Alonso Vega, Cristina. Drugs For Neglected Diseases Initiative; SuizaFil: Pinazo, María-Jesús. Instituto de Salud Global de Barcelona; EspañaFil: Schijman, Alejandro Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Almeida, Igor C. University of Texas at El Paso; Estados UnidosFil: Alves, Fabiana. Drugs For Neglected Diseases Initiative; SuizaFil: Strub-Wourgaft, Nathalie. Drugs For Neglected Diseases Initiative; SuizaFil: Ribeiro, Isabela. Drugs For Neglected Diseases Initiative; SuizaFil: Santina, Glaucia. Drugs For Neglected Diseases Initiative; SuizaFil: Blum, Bethania. Drugs For Neglected Diseases Initiative; SuizaFil: Correia, Erika. Drugs For Neglected Diseases Initiative; SuizaFil: García Bournissen, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Vaillant, Michel. Competence Center in Methodology and Statistics; LuxemburgoFil: Ramos Morales, Jimena. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Pinto Rocha, Jimy Jose. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Rojas Delgadillo, Gimena. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Magne Anzoleaga, Helmut Ramon. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Mendoza, Nilce. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Quechover, Roxana Challapa. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Caballero, Maria Yurly Escobar. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Lozano Beltran, Daniel Franz. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Zalabar, Albert Mendoza. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Rojas Panozo, Lizeth. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Palacios Lopez, Alejandro. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Torrico Terceros, Dunia. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Fernandez Galvez, Violeta Alejandra. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Cardozo, Letty. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Cuellar, Gabriela. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Vasco Arenas, Rudy Nelson. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Gonzales, Isabel. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Hoyos Delfin, Carlos Florencio. Universidad Juan Misael Saracho; BoliviaFil: Garcia, Lineth. Universidad Mayor de San Simón; BoliviaFil: Parrado, Rudy. Universidad Mayor de San Simón; BoliviaFil: de la Barra, Anabelle. Universidad Mayor de San Simón; BoliviaFil: Montaño, Nair. Universidad Mayor de San Simón; BoliviaFil: Villarroel, Sandro. Universidad Mayor de San Simón; BoliviaFil: Duffy, Tomás. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Bisio, Margarita María Catalina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Ramirez Gomez, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Duncanson, Fred. Eisai; JapónFil: Everson, Michael. Eisai; JapónFil: Daniels, Antonia. Eisai; JapónFil: Asada, Makoto. Eisai; JapónFil: Cox, Eugene. Quantitative Solutions; Países BajosFil: Wesche, David. Quantitative Solutions; Países BajosFil: Diderichsen, Paul Matthias. Quantitative Solutions; Países BajosFil: Marques, Alexandre F. Universidade Federal de Minas Gerais; BrasilFil: Izquierdo, Luis. ISGlobal; EspañaFil: Sender, Silvia Sanz. ISGlobal; EspañaFil: Reverter, Joan Carlos. Hospital Clinic Barcelona; EspañaFil: Morales, Manuel. Hospital Clinic Barcelona; EspañaFil: Jimenez, Wladimiro. Hospital Clinic Barcelona; Españ