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Summary: What is known and objective: This study developed a population pharmacokinetic (PK) model of levetiracetam (LEV) for treating neonatal seizures (NS) and determined the influence of clinically relevant covariates to explain the interindividual variability and residual error. Methods: Twenty newborns admitted to the Neonatal Intensive Care Unit at the Hospital Central “Dr. Ignacio Morones Prieto” were included. LEV doses were administered by intermittent infusion. Blood samples were drawn 3 times post‐infusion. Levetiracetam was quantified by a chromatographic technique. NONMEM software was used to determine the population PK model of LEV in neonates and the influence of clinical covariates on drug disposition. Results and discussion: The LEV PK in neonates is described by a one‐compartment open model with first‐order elimination. The influence of creatinine clearance (CRCL) and body weight (BW) on clearance (CL[L/h] = 0.47*CRCL), as well as the volume of the distribution (Vd[L] = 0.65*BW) of LEV, were confirmed, considering interindividual variabilities of 36% and 22%, respectively, and a residual error of 13%. What is new and Conclusion: Based on the PK of LEV in neonates and the influence of the final PK model, a priori dosing guidelines are proposed considering CRCL, BW and LEV plasma concentrations between 6 and 20 mg/L for NS treatment. [ABSTRACT FROM AUTHOR]

The aim of this study was to conduct a POP biomonitoring programme for children in high-risk areas. We evaluated 247 serum samples from children between the ages of 6 and 12years old from two zones in Mexico: (1) indigenous zones, which included Cuatlamayan (CUA), Tocoy (TOC), and Santa Maria Picula (SAM); and (2) industrial zones, which included Tercera Chica (TC), Industrial San Luis (IND) and Rincon de San Jose (SJR); Mundo Nuevo (MN); and Alpuyeca (ALP). Our results showed that α-endosulfan was similar to CUA, TOC, SAM, TC and MN (178.6-306.9ng/g lipid). β-Endosulfan levels were higher in ALP (901.5ng/g lipid), followed by CUA (139.9ng/g lipid) and TOC, SAM, TC and MN, which had similar levels (55.4-64.5ng/g lipid). For endosulfan sulfate, the ALP community had the highest concentration levels (1096.4ng/g lipid), whereas CUA and TOC (212.3 and 289ng/g lipid, respectively) had concentrations similar to those found in SAM and TC (99.5 and 119.1ng/g lipid, respectively). DDE levels were found in malaria-endemic areas of SAM, CUA and TOC (1782.2, 1358.3 and 57.0ng/g lipid), followed by MN (35.1ng/g lipid). HCB concentration levels were found to be higher in MN and SJR (691.8 and 575.4ng/g lipid, respectively), followed by CUA and TC (363.9 and 269.1ng/g lipid, respectively), with levels similar to those found in TOC and SAM (191.8 and 181.9ng/g lipid, respectively). Finally, PCB 101 concentration levels were found to be the highest in ALP (1032.7ng/g lipid), followed by similar levels of SJR and IND (567.5 and 327.3ng/g lipid, respectively) and TC and MN, with 109.1 and 144.5ng/g lipid, respectively. The evidence provided by this exploratory study indicates that the evaluation of the health risks posed to children living in contaminated areas is a high priority health issue., (Copyright © 2016 Elsevier B.V. All rights reserved.)

The BCG vaccine induces a Th1 phenotype, which is essential for protection against Mycobacterium tuberculosis. However, the effects of BCG vaccination over time on the T helper subpopulation and the microRNAs involved in adulthood have not been studied. In the present study, we explored the involvement of microRNAs, transcription factors and multifunctional cytokines in BCG vaccination by examining their levels both before and after vaccination of healthy adults. Peripheral blood mononuclear cells were obtained at 0, 2 and 6 months after vaccination. Cells were cultured in the presence or absence of ESAT-6 and CFP-10 or M. tuberculosis filtrate. The expression levels of miRNAs and transcription factors were evaluated using qRT-PCR. Cytokine production in supernatants and serum samples was evaluated using ELISA. Multifunctional CD4+ T cells were analyzed using multiparametric flow cytometry. We observed a decrease in the expression levels of T-BET, GATA3 and FOXP3 at 2 months and miR-146a, miR-326 and miR-155 at 6 months after receiving the vaccine. In the supernatant, the production of IL-17 was increased after 6 months, with both stimuli. In contrast, IL-10, TNF-α and IFN-γ increased at 2 months. In the serum, high levels of IL-10 were found after 2 months compared to time 0 and 6 months. The production of multifunctional cells that expressed the cytokine profiles CD4+TNF-α+IFN-γ-IL-10-, CD4+TNF-α+IL-1IFN-γ-, CD4+IL-10+IFN-γ-TNF-α- and CD4+IL-17+IFN-γ- predominantly increased after 2 months with and without the stimulus. Correlation analysis revealed a negative association between FOXP3 and miR-155 (r=-0.5120, p=0.0176) and between IL-17 and miR-326 (r=-0.5832, p=0.0364). This study is the first to demonstrate roles for microRNAs, transcription factors and cytokines in the T helper differentiation lineage and to describe the possible mechanism by which their expression is modulated by the presence of the BCG vaccine in adulthood. In conclusion, our results suggest that the BCG vaccine induces a modulation in transcription factors and miRNAs with high production of multifunctional cells CD4+TNF-α+IL-10+IFN-γ-., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Setting: In a previous monitoring study of rifampicin (RMP) in tuberculosis (TB) patients treated with a generic formulation of a three-drug fixed-dose combination (3FDC), very low RMP levels were found. This led us to investigate the bioavailability of the product., Objective: To investigate the relative bioavailability of RMP from a generic 3FDC formulation used in the Mexican health care system, in comparison to the reference product, in healthy volunteers., Design: Two-period, two-sequence crossover study., Results: Mean pharmacokinetic parameter values obtained for the test and reference product were respectively 3.13 ± 2.01 μg/ml and 9.95 ± 2.66 μg/ml for peak plasma concentration (C(max)), 15.51 ± 9.77 μg.h/ml and 58.03 ± 16.1 μg.h/ml for area under the concentration (AUC) time curve to the last measurable concentration (AUC(0-12h)) and 17.92 ± 10.66 and 68.43 ± 22.39 μg.h/ml for AUC up to time infinity (AUC(0-∞)). The test/reference ratio of the means (90%CI) was 25.36% (17.33-37.10) for C(max), 21.25% (14.61-30.89) for AUC(0-12h) and 22.08% (15.44-31.56) for AUC(0-∞). These results did not meet the criteria for bioequivalence., Conclusion: The test product displayed delayed absorption and markedly inferior RMP bioavailability in comparison to the reference product. RMP-containing generic formulations should only be used if their bioavailability has been evaluated to ensure interchangeability with the reference product and to avoid the risk of markedly inferior RMP exposure through the use of such a product.