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Carbamazepine and oxcarbazepine: reflections after an oxcarbazepine-induced Stevens-Johnson syndrome/toxic epidermal necrolysis overlap.Poletti Jabbour, Jamil, Wiegering Rospigliosi, Andrés, Pereyra Elías, Reneé, Elías Barrera, Carmen Cecilia 29 April 2016 (has links)
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Letters to editor
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Effects of epilepsy and antiepileptic medication on reproductive functionLöfgren, E. (Eeva) 12 December 2007 (has links)
Abstract
Epilepsy is associated with reproductive disorders and decreased fertility. The role of antiepileptic medication and type of epilepsy in development of these disorders has been widely debated. The effects of oxcarbazepine on reproductive function in women and the effects of antiepileptic medication on male fertility have not been previously studied, and only a few studies have evaluated fertility in subjects with epilepsy in a population based setting.
This study aimed to analyze predictors of reproductive disorders and the effects of oxcarbazepine on reproductive function in women. Moreover, the effects of antiepileptic medication on male reproductive health were also evaluated, and finally, the reproductive health of patients with epilepsy and the normal population was compared in a population based setting.
The study was conducted in the Departments of Neurology, Gynecology and Obstetrics and Public Health Science and General Practice in the University of Oulu. Studies I–III were cross-sectional studies consisting of 249 subjects with epilepsy and 247 control subjects. Study IV was a retrospective study; the data was based on Northern Finland Birth Cohort 1966(NFBC1966), consisting of 12,058 subjects, of which 222 had epilepsy. In studies I–III all subjects were interviewed, clinical examinations were done, blood samples were analyzed and ovarian ultrasound examination or testicular ultrasound examination and sperm samples were studied. In study IV all subjects with epilepsy were identified from NFBC1966 and patient files were reviewed. Fertility analyses were based on information obtained from the Finnish Population Center and Finnish Birth Register.
Reproductive disorders were more common in women with idiopathic generalized epilepsy and in women taking valproate. Also young age increased the risk of these disorders. Oxcarbazepine was associated with reproductive disorders in women with epilepsy. In men all antiepileptic drugs studied were associated with sperm abnormalities, and sperm abnormalities in men taking valproate were associated with decreased testicular volume. In a population based setting active epilepsy and antiepileptic medication during adulthood decreased fertility.
The reproductive endocrine effects of AEDs should be taken into consideration when prescribed to fertile aged men and women, especially, if the anticipated duration of treatment is long.
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Desenvolvimento e validaÃÃo de mÃtodos bioanalÃticos para quantificaÃÃo da amoxicilina, norfloxacino e oxcarbazepina em estudos farmacocinÃticos. / Development and validation of bioanalytical methods for quantification of amoxicillin, norfloxacin and oxcarbazepine in pharmacokinetic studies.Ismael Leite Martins 29 July 2009 (has links)
FundaÃÃo de Amparo à Pesquisa do Estado do Cearà / Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Foram desenvolvidos e validados trÃs mÃtodos robustos para a determinaÃÃo de amoxicilina, norfloxacino, oxcarbazepina (OXC) e 10,11-dihidro-10-hidroxicarbamazepina (MHD) em plasma, utilizando cromatografia lÃquida de alta eficiÃncia em fase reversa (RP-HPLC) com detecÃÃo ultravioleta, fluorescÃncia e espectrometria de massa, respectivamente. Os mÃtodos envolveram extraÃÃo lÃquido-lÃquido, com diclorometano (amoxicilina), acetonitrila (amoxicilina e norfloxacino), Ãter etÃlico-diclorometano (60:40 v/v, oxcarbazepina), utilizando cefadroxil, ciprofloxacino e d10-carbamazepina como padrÃes interno (PI). SeparaÃÃes cromatogrÃficas foram realizadas utilizando colunas Gemini C18 5 Âm (150 X 4,6 mm), Synergi RP-MAX 4 Âm (150 X 4,6 mm) e Luna C18 Âm (150 X 4,6 mm), com sistemas de eluiÃÃo constituÃdos por mistura de tampÃo fosfato de 0,01 M (pH 3,5)/acetonitrila (95:5 v/v), acetonitrila-tampÃo fosfato (85:15, v/v) e acetonitrila-Ãgua (50:50 v/v) + 20 mM Ãcido acÃtico, respectivamente. As curvas de calibraÃÃo foram lineares, nas faixas de 0,5 a 40 Âg/mL, 30 a 3500 ng/mL, 20 a 5250 ng/ml e 40 a 10500 ng/ml. As recuperaÃÃes nas concentraÃÃes de 1,5, 15 e 30 Âg/ml foram de 59,4%, 60,5% e 67,1% para amoxicilina; 90, 1400 e 2800 ng/mL foram de 103,5%, 100,2% e 100,2% para norfloxacino, 60, 2000 e 4000 ng/ml foram de 105,4, 89,2 e 92,8% para OXC e 120, 4000 e 8000 ng/ml foram de 88,4, 88,7 e 90,6% para MHD, respectivamente. Os mÃtodos validados incluÃram avaliaÃÃo de precisÃo e exatidÃo intra e interlote, assegurando que estes estavam dentro de limites admissÃveis. Os mÃtodos foram entÃo aplicados com sucesso em estudos de bioequivalÃncia, administrando 500 mg ou 400 mg das formulaÃÃes referÃncia/teste de amoxicilina e norfloxacino, e em estudos farmacocinÃticos com formulaÃÃo de oxcarbazepina suspensÃo (6%), em voluntÃrios sadios. / A robust method for the determination of amoxicillin, norfloxacin, oxcarbazepine (OXC) and its active metabolite, 10,11-dihydro-10-hydroxycarbamazepine (MHD) in human plasma, using reversed-phase high-performance liquid chromatography (RP-HPLC) with ultraviolet, fluorescence and mass spectrometry detection, respectively, have been developed and valited. The methods involve precipitation of plasma protein with dichloromethane (amoxicillin), acetonitrile (amoxicillin and norfloxacin) and diethyl etherâdiclhoromethane (60:40 v/v, oxcarbazepine), using cefadroxil, ciprofloxacin and deuterade carbamazepine (d10-carbamazepine) as internal standard (IS). Chromatographic separations were performed on a column Gemini C18 5 Âm (150 X 4.6 mm), Synergi MAX-RP 4 Âm (150 X 4.6 mm) and Luna C18 5 Âm (150mm X 4.6 mm) with an elution system consisting of a mixture of 0.01 M buffer phosphate (pH 3.5)/acetonitrile (95:05 v/v), phosphate bufferâacetonitrile (85:15, v/v) and acetonitrile/water (50:50 v/v) + 20mM acetic acid, respectively. The calibration curve was linear, in the range of 0.5 to 40 Âg/mL, 30 to 3500 ng/mL, 20 to 5250 ng/mL and 40 to 10,500 ng/mL. The recoveries at concentrations of 1.5, 15 and 30 Âg/mL were foram 59.4%, 60.5% and 67.1% for amoxicillin; 90, 1400 and 2800 ng/mL were 103.5%, 100.2% and 100.2% for norfloxacin, 60, 2000 and 4000 ng/mL were 105.4, 89.2 and 92.8% for OXC and 120, 4000 and 8000 ng/mL were 88.4, 88.7 and 90.6% for MHD, respectively. The statistical evaluation of the developed method was conducted by examining within-batch and between-batch precision data, which were within the required limits. The methods were successfully applied in bioequivalence studies given 500 or 400-mg of the reference formulation / test amoxicillin and norfloxacin, and pharmacokinetic studies with formulation of oxcarbazepine suspension (6%) in healthy volunteers.
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Influência do verapamil na farmacocinética e na perfusão cerebral da oxcarbazepina e dos enantiômeros do metabólito 10-hidroxicarbazepina em voluntários sadios / Influence of verapamil on the pharmacokinetics and cerebral perfusion of oxcarbazepine and the enantiomers of its metabolite 10- hydroxycarbazepine in healthy volunteersAntunes, Natalicia de Jesus 25 November 2014 (has links)
A oxcarbazepina (OXC) é indicada como terapia adjuvante ou monoterapia no tratamento de crises epilépticas parciais ou crises tônico-clônicas generalizadas em adultos e crianças. A OXC sofre rápida eliminação pré-sistêmica com formação do metabólito ativo 10-hidroxicarbazepina (MHD), o qual possui como enantiômeros o R-(-)- e o S-(+)-MHD. A OXC e o MHD são substratos da glicoproteína-P (P-gp), que pode ser inibida pelo verapamil. O presente estudo avalia a influência do verapamil na farmacocinética e perfusão cerebral da OXC e dos enantiômeros do MHD em voluntários sadios. Os voluntários sadios (n=12) receberam em uma ocasião doses de 300 mg/12h de OXC e em outra ocasião doses de 300 mg/12h de OXC associadas com 80 mg/8h de verapamil. As amostras de sangue foram coletadas no estado de equilíbrio durante 12 horas e a avaliação da perfusão cerebral realizada utilizando a tomografia computadorizada por emissão de fóton único (SPECT) antes do início do tratamento e nos tempos 4, 6 ou 12h após a administração da OXC. As concentrações plasmáticas total e livre da OXC e dos enantiômeros do MHD foram avaliadas por LC-MS/MS. A análise farmacocinética não compartimental foi realizada com o programa WinNonlin e a farmacocinética populacional foi desenvolvida utilizando a modelagem não-linear de efeitos mistos com o programa NONMEM. Os limites de quantificação obtidos foram de 12,5 ng OXC/mL de plasma e 31,25 ng de cada enantiômero MHD/mL de plasma para a análise da concentração total, enquanto foi de 4,0 ng de OXC/mL de plasma e de 20,0 ng de cada enantiômero do MHD/mL de plasma para a determinação da concentração livre. Os coeficientes de variação obtidos nos estudos de precisão e a porcentagem de inexatidão inter e intra-ensaios foram inferiores a 15%, assegurando a reprodutibilidade e repetibilidade dos resultados. A análise farmacocinética não compartimental da OXC em monoterapia resultou nos seguintes parâmetros: concentração plasmática máxima (Cmax) de 1,35 ?g/mL como valor total e 0,32 ?g/mL como concentração livre em 1,0 h, área sob a curva concentração plasmática versus tempo (AUC0-12) de 3,98 ?g.h/mL e meia-vida de eliminação de 2,45 h, volume de distribuição aparente (Vss/F) de 352,17 L e clearance aparente (CLss/F) de 75,58 L/h. A disposição cinética do MHD é enantiosseletiva, com observação de maior proporção para o enantiômero S-(+)-MHD em relação ao R-(-)-MHD (razão AUC0-12 S-(+)/R-(-) de 4,26). A fração livre avaliada no tmax da OXC foi 0,26 para a OXC, 0,42 para o R-(-)-MHD e 0,38 para o S- (+)-MHD, mostrando enantiosseletividade na ligação às proteínas plasmáticas do MHD. O tratamento com o verapamil reduziu o tempo médio de residência (MRT) (4,71 vs 3,83 h) e Cmax como concentração livre (0,32 vs 0,53 ?g/mL) da OXC e aumentou os valores para ambos os enantiômeros do MHD de Cmax como valor total (2,60 vs 3,27 ?g/mL para o R-(-)- e 11,05 vs 11,94 ?g/mL para o S-(+)-MHD), Cmax como concentração livre (3,11 vs 4,14 ?g/mL para o S-(+)-MHD), Cmédia (2,11 vs 2,42 ?g/mL para o R-(-)- e 8,10 vs 9,07 ?g/mL para o S-(+)-MHD) e AUC0-12 (25,36 vs 29,06 ?g.h/mL para o R-(-)- e 97,19 vs 111,37 ?g.h/mL para o S-(+)-MHD). A ii farmacocinética populacional da OXC foi melhor descrita por modelo de dois compartimentos com eliminação de primeira ordem e com um conjunto de três compartimentos de trânsito para descrever o perfil de absorção da OXC. A disposição de ambos os enantiômeros do MHD foi caracterizada por modelo de um compartimento. Os valores de CLss/F estimados na monoterapia foram de 84,9 L/h para a OXC e de 2,0 L/h para ambos enantiômeros do MHD, enquanto os valores de Vss/F foram de 587 L para a OXC, 23,6 L para o R-(-)-MHD e 31,7 L para o S-(+)- MHD. Concluindo, a associação do verapamil aumentou a biodisponibilidade da OXC em 12% (farmacocinética populacional) e aumentou os valores de AUC de ambos os enantiômeros do metabólito MHD (farmacocinética não compartimental), o que está provavelmente relacionado com a inibição da P-gp no trato intestinal. A associação do verapamil aumentou as concentrações cerebrais preditas de ambos os enantiômeros do MHD em maior extensão do que aquelas observadas no plasma. As mudanças no fluxo sanguíneo cerebral (SPECTs realizados 6h após a administração da OXC) associadas à coadministração de verapamil provavelmente foram causadas pelo aumento dos níveis cerebrais de ambos os enantiômeros do MHD. A confirmação dessa observação requer um braço experimental adicional com SPECTs realizados também após a administração do verapamil em monoterapia. / Oxcarbazepine (OXC) is indicated as adjunctive therapy or monotherapy for the treatment of partial or generalized tonic-clonic seizures in adults and children. OXC undergoes rapid pre-systemic reduction with formation of the active metabolite 10- hydroxycarbazepine (MHD), which has the enantiomers R-(-)- and S-(+)-MHD. OXC and MHD are substrates of P-glycoprotein (P-gp), which can be inhibited by verapamil. The present study evaluates the influence of verapamil on the pharmacokinetics and cerebral perfusion of OXC and the MHD enantiomers in healthy volunteers. The healthy volunteers (n=12) received on one occasion doses of 300 mg/12h OXC and on another occasion they received doses of 300 mg/12h OXC associated with 80 mg/8h of verapamil. Blood samples were collected at steady state for 12 hours and the assessment of cerebral perfusion was performed using a single-photon emission computed tomography (SPECT) before the beginning of treatment and at times 4, 6 or 12 hours after OXC administration. The total and free plasma concentrations of OXC and MHD enantiomers were assessed by LC-MS/MS. The non-compartmental pharmacokinetics analysis was performed using the WinNonlin program, and population pharmacokinetics was developed using nonlinear mixed effects modelling with NONMEM.The limits of quantification obtained were 12.5 ng/mL plasma for OXC and 31.25 ng of each MHD enantiomer/mL plasma for total concentration analysis, while it was 4.0 ng OXC/mL plasma and 20.0 ng of each MHD enantiomer/mL plasma for the free concentration determination. The coefficients of variation obtained in studies of accuracy and the percentage of inaccuracy inter and intra-assay were less than 15%, ensuring the result reproducibility and repeatability. The non-compartmental pharmacokinetic analysis of OXC in monotherapy treatment, resulted in the following parameters: maximum plasma concentration (Cmax) of 1.35 ?g/mL as total concentration and 0.32 mg/mL as free concentration in 1.0 h, area under the plasma concentration vs time curve (AUC0-12) was 3.98 ?g.h/mL, half-life of 2.45 h, apparent volume of distribution (Vss/F) of 352.17 L and the apparent clearance (CLSS/F) of 75.58 L/h. The MHD kinetic disposition is enantioselective, with observation of a greater proportion of the S-(+)-MHD enantiomer compared to R-(-)-MHD (ratio AUC0-12 S-(+)/R-(-) of 4.26). The free fraction measured in the tmax of OXC was 0.26 for OXC, 0.42 for R-(-)-MHD and 0.38 for S-(+)-MHD, showing enantioselectivity in the plasma protein binding of MHD. Verapamil treatment reduced the mean residence time (MRT) (4.71 vs 3.83 h) and Cmax (0.26 vs 0.31 ?g/mL) as free concentration for OXC and increased the both MHD enantiomers values of Cmax (2.60 vs 3.27 ?g/mL for R-(-)- and 11.94 vs 11.05 ?g/mL for S-(+)-MHD) as total concentration, Cmax (3.11 vs 4,14 ?g/mL for S- (+)-MHD) as free concentration, Cavg (2.11 vs 2.42 ?g/mL for R-(-)- and 8.10 vs 9.07 ?g/mL for S-(+)-MHD) and AUC0-12 (25.36 vs 29.06 ?g.h/mL for R-(-)- and 97.19 vs 111.37 ?g.h/mL for S-(+)-MHD). The population pharmacokinetics of oxcarbazepine was best described by a two-compartment model with first-order elimination and a iv set of three transit compartments to describe the absorption profile of the parent compound. The disposition of both MHD enantiomers was characterised by onecompartment model. The CLss/F estimates in monotherapy were 84.9 L/h for OXC and 2.0 L/h for both MHD enantiomers, whereas the values of Vss/F were 587 L for OXC, 23.6 L for R-(-)-MHD and 31.7 L for S-(+)-MHD. In conclusion, verapamil coadministration increased the OXC bioavailability in 12% (population pharmacokinetics) and increased the AUC of both metabolite MHD enantiomers (non-compartmental pharmacokinetics), which is probably related to the inhibition of P-gp in the intestinal tract. Verapamil co-administration increased the predicted brain concentrations of both MHD enantiomers in a greater extent than those observed in plasma. Changes in cerebral blood flow (SPECTs performed 6h after administration of OXC) associated with co-administration of verapamil were probably caused by an increase in brain levels of both MHD enantiomers. Confirmation of this observation requires additional experimental arm with SPECTs also performed after administration of verapamil in monotherapy.
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Determina??o de Verapamil e Oxcarbazepina em amostras de urina e formula??es farmac?uticas por amperometria pulsada em FIALima, Amanda Barbosa January 2016 (has links)
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Previous issue date: 2016 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Verapamil (VP) e Oxcarbazepina (OX) s?o f?rmacos de baixo ?ndice terap?utico que necessitam de rigoroso controle de qualidade em formula??es farmac?uticas, bem como de an?lises em fluidos biol?gicos para estudos farmacol?gicos de elimina??o dessas drogas. Neste sentido, o desenvolvimento de m?todos simples, r?pidos e de baixo custo ? de extrema import?ncia para quantifica??o desses f?rmacos nessas amostras. Deste modo, o presente trabalho apresenta um m?todo eletroanal?tico em fluxo para determinar VP e OX tanto em formula??es farmac?uticas, quanto em amostras de urina. A t?cnica eletroqu?mica utilizada para quantifica??o foi a Amperometria de M?ltiplos Pulsos (MPA) acoplada a um sistema de an?lise por inje??o em fluxo (FIA), utilizando o diamante dopado com boro (BDD). Foram aplicados tr?s pulsos de potencial pela MPA para determina??o do VP em meio de ?cido sulf?rico 0,1 mol L-1, sendo +1,6 V para a oxida??o e, posteriormente, +0,2 V para redu??o do produto gerado do VP e +0,1 V para a limpeza do eletrodo de BDD. Para a determina??o de OX, tamb?m foram otimizados tr?s pulsos de potencial em meio de tamp?o acetato 0,1 mol L-1 (pH 4,0), sendo + 1,7 V para a oxida??o da OX e gera??o do produto que foi reduzido em -1,1 V e -1,3 V para a limpeza do eletrodo de BDD. Em ambos os casos, apenas o sinal obtido nos pulsos de potencial de redu??o foram utilizados para quantifica??o dos f?rmacos. As faixas lineares de trabalho obtidas para quantifica??o do VP e da OX foram de 0,8 a 40,0 ?mol L-1 (R= 0,9976) e 2,0 a 80,0 ?mol L-1 (R= 0,9989), respectivamente. Os limites de detec??o foram calculados em 0,16 ?mol L-1 para VP e 0,42 ?mol L-1 para OX. Uma boa repetibilidade foi obtida para 10 an?lises consecutivas desses f?rmacos, com desvio padr?o relativo de 2,2% para VP e 0,94 % para OX. Os estudos de adi??o e recupera??o do VP e OX em amostras farmac?uticas e urina apresentaram resultados pr?ximos a 100% e o doseamento do VP foi validado pela metodologia oficial. Altas frequ?ncias anal?ticas foram alcan?adas pelo sistema FIA com 45 e 65 determina??es por hora de VP e OX, respectivamente, usando al?as de amostragem inferiores a 200 ?L e vaz?es de 3,5 mLmin-1. An?lises desses f?rmacos em amostras de urina mostraram que ? poss?vel determin?-los mesmo na presen?a de altas concentra??es de ?cido asc?rbico e ?cido ?rico. Portanto, o m?todo proposto mostrou-se como alternativa simples e r?pida para quantifica??o desses f?rmacos em formula??es farmac?uticas e urina. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, [2016]. / Verapamil (VP) and Oxcarbazepine (OX) are drugs of narrow therapeutic index that require strict quality control in pharmaceutical formulations and analysis in biological fluids for pharmacological studies of elimination of these drugs. In this sense, the development of simple, fast and low-cost methods is very important to quantify these drugs in pharmaceutical samples. Therefore, this work presents a electroanalytical method in flow for determining VP and OX in pharmaceutical formulations and human urine samples. The electrochemical technique used for quantification was performed by multiple pulses amperometry (MPA) coupled to a flow injection analysis system (FIA), using boron-doped diamond (BDD) as working electrode. Were applied three potential pulses by MPA for the determination of VP in sulfuric acid 0.1 mol L-1: (1) +1.6 V for oxidation of VP, (2) +0.2 V for reduction of the generated product of VP in the fisrt potential pulse, (3) +0.1 V for cleaning of the BDD electrode surface. The determination of OX also was performed by MPA in three potential pulses in 0.1 mol L-1 acetate buffer (pH 4.0): (1) +1.7 V for oxidation of OX and generation of the product that it was reduced at (2) -1.1 V, and (3) -1.3 V for cleaning of the BDD electrode surface. In both cases, only the signal obtained in the reduction potential pulses were used for quantification of drugs. The linear ranges of work obtained for quantitation of VP and OX were 0.8 to 40.0 ?mol L-1 (R = 0.9976) and 2.0 to 80.0 ?mol L-1 (R = 0, 9989), respectively. The detection limits were calculated to be 0.16 ?mol L-1 for VP and 0.42 ?mol L-1 for OX. Good repeatabilities were obtained for 10 consecutives injections of these drugs, with relative standard deviation of 2.2% for VP and 0.94% for OX. The addition and recovery studies for VP and OX in pharmaceutical and urine samples were close to 100% and determination of VP was validated by the official methodology. High analytical frequencies were achieved by FIA system of 45 and 65 determinations per hour for VP and OX, respectively, using sampling handles less than 200 ?L and flow rate of 3.5 mLmin-1. The analysis of these drugs in urine showed that it is possible to determine this sample even in the presence of high concentrations of ascorbic acid and uric acid. Therefore, the present method by MPA-FIA proved to be a quick and easy alternative to quantify VP and OX in pharmaceutical formulations and urine.
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Influência do verapamil na farmacocinética e na perfusão cerebral da oxcarbazepina e dos enantiômeros do metabólito 10-hidroxicarbazepina em voluntários sadios / Influence of verapamil on the pharmacokinetics and cerebral perfusion of oxcarbazepine and the enantiomers of its metabolite 10- hydroxycarbazepine in healthy volunteersNatalicia de Jesus Antunes 25 November 2014 (has links)
A oxcarbazepina (OXC) é indicada como terapia adjuvante ou monoterapia no tratamento de crises epilépticas parciais ou crises tônico-clônicas generalizadas em adultos e crianças. A OXC sofre rápida eliminação pré-sistêmica com formação do metabólito ativo 10-hidroxicarbazepina (MHD), o qual possui como enantiômeros o R-(-)- e o S-(+)-MHD. A OXC e o MHD são substratos da glicoproteína-P (P-gp), que pode ser inibida pelo verapamil. O presente estudo avalia a influência do verapamil na farmacocinética e perfusão cerebral da OXC e dos enantiômeros do MHD em voluntários sadios. Os voluntários sadios (n=12) receberam em uma ocasião doses de 300 mg/12h de OXC e em outra ocasião doses de 300 mg/12h de OXC associadas com 80 mg/8h de verapamil. As amostras de sangue foram coletadas no estado de equilíbrio durante 12 horas e a avaliação da perfusão cerebral realizada utilizando a tomografia computadorizada por emissão de fóton único (SPECT) antes do início do tratamento e nos tempos 4, 6 ou 12h após a administração da OXC. As concentrações plasmáticas total e livre da OXC e dos enantiômeros do MHD foram avaliadas por LC-MS/MS. A análise farmacocinética não compartimental foi realizada com o programa WinNonlin e a farmacocinética populacional foi desenvolvida utilizando a modelagem não-linear de efeitos mistos com o programa NONMEM. Os limites de quantificação obtidos foram de 12,5 ng OXC/mL de plasma e 31,25 ng de cada enantiômero MHD/mL de plasma para a análise da concentração total, enquanto foi de 4,0 ng de OXC/mL de plasma e de 20,0 ng de cada enantiômero do MHD/mL de plasma para a determinação da concentração livre. Os coeficientes de variação obtidos nos estudos de precisão e a porcentagem de inexatidão inter e intra-ensaios foram inferiores a 15%, assegurando a reprodutibilidade e repetibilidade dos resultados. A análise farmacocinética não compartimental da OXC em monoterapia resultou nos seguintes parâmetros: concentração plasmática máxima (Cmax) de 1,35 ?g/mL como valor total e 0,32 ?g/mL como concentração livre em 1,0 h, área sob a curva concentração plasmática versus tempo (AUC0-12) de 3,98 ?g.h/mL e meia-vida de eliminação de 2,45 h, volume de distribuição aparente (Vss/F) de 352,17 L e clearance aparente (CLss/F) de 75,58 L/h. A disposição cinética do MHD é enantiosseletiva, com observação de maior proporção para o enantiômero S-(+)-MHD em relação ao R-(-)-MHD (razão AUC0-12 S-(+)/R-(-) de 4,26). A fração livre avaliada no tmax da OXC foi 0,26 para a OXC, 0,42 para o R-(-)-MHD e 0,38 para o S- (+)-MHD, mostrando enantiosseletividade na ligação às proteínas plasmáticas do MHD. O tratamento com o verapamil reduziu o tempo médio de residência (MRT) (4,71 vs 3,83 h) e Cmax como concentração livre (0,32 vs 0,53 ?g/mL) da OXC e aumentou os valores para ambos os enantiômeros do MHD de Cmax como valor total (2,60 vs 3,27 ?g/mL para o R-(-)- e 11,05 vs 11,94 ?g/mL para o S-(+)-MHD), Cmax como concentração livre (3,11 vs 4,14 ?g/mL para o S-(+)-MHD), Cmédia (2,11 vs 2,42 ?g/mL para o R-(-)- e 8,10 vs 9,07 ?g/mL para o S-(+)-MHD) e AUC0-12 (25,36 vs 29,06 ?g.h/mL para o R-(-)- e 97,19 vs 111,37 ?g.h/mL para o S-(+)-MHD). A ii farmacocinética populacional da OXC foi melhor descrita por modelo de dois compartimentos com eliminação de primeira ordem e com um conjunto de três compartimentos de trânsito para descrever o perfil de absorção da OXC. A disposição de ambos os enantiômeros do MHD foi caracterizada por modelo de um compartimento. Os valores de CLss/F estimados na monoterapia foram de 84,9 L/h para a OXC e de 2,0 L/h para ambos enantiômeros do MHD, enquanto os valores de Vss/F foram de 587 L para a OXC, 23,6 L para o R-(-)-MHD e 31,7 L para o S-(+)- MHD. Concluindo, a associação do verapamil aumentou a biodisponibilidade da OXC em 12% (farmacocinética populacional) e aumentou os valores de AUC de ambos os enantiômeros do metabólito MHD (farmacocinética não compartimental), o que está provavelmente relacionado com a inibição da P-gp no trato intestinal. A associação do verapamil aumentou as concentrações cerebrais preditas de ambos os enantiômeros do MHD em maior extensão do que aquelas observadas no plasma. As mudanças no fluxo sanguíneo cerebral (SPECTs realizados 6h após a administração da OXC) associadas à coadministração de verapamil provavelmente foram causadas pelo aumento dos níveis cerebrais de ambos os enantiômeros do MHD. A confirmação dessa observação requer um braço experimental adicional com SPECTs realizados também após a administração do verapamil em monoterapia. / Oxcarbazepine (OXC) is indicated as adjunctive therapy or monotherapy for the treatment of partial or generalized tonic-clonic seizures in adults and children. OXC undergoes rapid pre-systemic reduction with formation of the active metabolite 10- hydroxycarbazepine (MHD), which has the enantiomers R-(-)- and S-(+)-MHD. OXC and MHD are substrates of P-glycoprotein (P-gp), which can be inhibited by verapamil. The present study evaluates the influence of verapamil on the pharmacokinetics and cerebral perfusion of OXC and the MHD enantiomers in healthy volunteers. The healthy volunteers (n=12) received on one occasion doses of 300 mg/12h OXC and on another occasion they received doses of 300 mg/12h OXC associated with 80 mg/8h of verapamil. Blood samples were collected at steady state for 12 hours and the assessment of cerebral perfusion was performed using a single-photon emission computed tomography (SPECT) before the beginning of treatment and at times 4, 6 or 12 hours after OXC administration. The total and free plasma concentrations of OXC and MHD enantiomers were assessed by LC-MS/MS. The non-compartmental pharmacokinetics analysis was performed using the WinNonlin program, and population pharmacokinetics was developed using nonlinear mixed effects modelling with NONMEM.The limits of quantification obtained were 12.5 ng/mL plasma for OXC and 31.25 ng of each MHD enantiomer/mL plasma for total concentration analysis, while it was 4.0 ng OXC/mL plasma and 20.0 ng of each MHD enantiomer/mL plasma for the free concentration determination. The coefficients of variation obtained in studies of accuracy and the percentage of inaccuracy inter and intra-assay were less than 15%, ensuring the result reproducibility and repeatability. The non-compartmental pharmacokinetic analysis of OXC in monotherapy treatment, resulted in the following parameters: maximum plasma concentration (Cmax) of 1.35 ?g/mL as total concentration and 0.32 mg/mL as free concentration in 1.0 h, area under the plasma concentration vs time curve (AUC0-12) was 3.98 ?g.h/mL, half-life of 2.45 h, apparent volume of distribution (Vss/F) of 352.17 L and the apparent clearance (CLSS/F) of 75.58 L/h. The MHD kinetic disposition is enantioselective, with observation of a greater proportion of the S-(+)-MHD enantiomer compared to R-(-)-MHD (ratio AUC0-12 S-(+)/R-(-) of 4.26). The free fraction measured in the tmax of OXC was 0.26 for OXC, 0.42 for R-(-)-MHD and 0.38 for S-(+)-MHD, showing enantioselectivity in the plasma protein binding of MHD. Verapamil treatment reduced the mean residence time (MRT) (4.71 vs 3.83 h) and Cmax (0.26 vs 0.31 ?g/mL) as free concentration for OXC and increased the both MHD enantiomers values of Cmax (2.60 vs 3.27 ?g/mL for R-(-)- and 11.94 vs 11.05 ?g/mL for S-(+)-MHD) as total concentration, Cmax (3.11 vs 4,14 ?g/mL for S- (+)-MHD) as free concentration, Cavg (2.11 vs 2.42 ?g/mL for R-(-)- and 8.10 vs 9.07 ?g/mL for S-(+)-MHD) and AUC0-12 (25.36 vs 29.06 ?g.h/mL for R-(-)- and 97.19 vs 111.37 ?g.h/mL for S-(+)-MHD). The population pharmacokinetics of oxcarbazepine was best described by a two-compartment model with first-order elimination and a iv set of three transit compartments to describe the absorption profile of the parent compound. The disposition of both MHD enantiomers was characterised by onecompartment model. The CLss/F estimates in monotherapy were 84.9 L/h for OXC and 2.0 L/h for both MHD enantiomers, whereas the values of Vss/F were 587 L for OXC, 23.6 L for R-(-)-MHD and 31.7 L for S-(+)-MHD. In conclusion, verapamil coadministration increased the OXC bioavailability in 12% (population pharmacokinetics) and increased the AUC of both metabolite MHD enantiomers (non-compartmental pharmacokinetics), which is probably related to the inhibition of P-gp in the intestinal tract. Verapamil co-administration increased the predicted brain concentrations of both MHD enantiomers in a greater extent than those observed in plasma. Changes in cerebral blood flow (SPECTs performed 6h after administration of OXC) associated with co-administration of verapamil were probably caused by an increase in brain levels of both MHD enantiomers. Confirmation of this observation requires additional experimental arm with SPECTs also performed after administration of verapamil in monotherapy.
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Devenir photochimique de la carbamazépine et sous-produits dans des eaux naturelles et écotoxicologie à doses environnementales / Photochemical fate of carbamazepine and transformation products in waterbodies and ecotoxicology at low dosesDesbiolles, Fanny 29 June 2018 (has links)
La carbamazépine (CBZ) est un antiépileptique largement consommé, peu dégradé dans les stations de traitement des eaux usées et donc rejeté dans les eaux de surface. Cette thèse vise à étudier le devenir de CBZ et de deux métabolites, l'oxcarbazépine (OxCBZ) et l'acide 9-carboxylique acridine (9-CAA), sous irradiation par la lumière solaire dans des eaux naturelles douces et salées. Les suivis cinétiques ont permis de mettre en évidence des comportements différents en fonction des composés mais aussi des types d’eaux et impliquant des mécanismes de phototransformation directe et induite mais aussi des réactions d’atténuation naturelle. Pour approfondir ces résultats, la spectrophotométrie d’absorption résolue en temps et l’utilisation d’une sonde chimique ont souligné la formation d’espèces réactives (radicaux hydroxyles, carbonates et halogénés) et des réactions de compétition ont permis de mesurer leur réactivité avec les composés étudiés.La formation de dérivés issus de processus d’hydroxylation, d’oxydation, de perte de la fonction latérale, d’ouverture et/ou contraction de cycle aromatique (etc.) et de sous-produits halogénés dans les eaux salées ont été identifiés lors de la photodégradation de CBZ, OxCBZ et 9-CAA. Enfin, l’écotoxicité aiguë et chronique de CBZ, OxCBZ et 9-CAA a été évaluée individuellement et en mélange à dose environnementales sur 3 espèces vivantes de différents niveaux trophiques en mesurant les paramètres suivants : luminescence sur la bactérie Vibrio fischeri, phytométabolites sur la lentille d'eau Lemna minor et altération aux niveaux population, cellulaire et moléculaire sur le cnidaire Hydra circumcincta. / Carbamazepine (CBZ) is a widely consumed anti-epileptic pharmaceutical drug, inefficiently removed in activated sludge secondary treatment process. Consequently, it is almost completely rejected in its original form into surface waters. Hence, this thesis aimed to study the fate of CBZ and two of its known bio-metabolites, i.e. oxcarbazepine (OxCBZ) and 9-carboxylic acridine acid (9-CAA), under solar light irradiation in fresh and salty waters. Kinetic monitoring revealed different behaviours both compounds and water types dependent implying photolysis, induced photodegradation but also natural attenuation reactions. To deeper understand these results, laser flash photolysis experiments and the use of a chemical probe highlighted the formation of reactive species (hydroxyl, carbonate and halogenated radicals). By implementing competition reactions, the rate constants of each compound with each chemical radical species were determined.The formation of derivatives from hydroxylation, oxidation, ring contraction, loss of side function, aromatic ring opening (etc.) and also halogenated by-products in salty waters were identified throughout CBZ, OxCBZ and 9-CAA phototransformations.Finally, acute and chronic ecotoxicity of CBZ, OxCBZ and 9-CAA individually and in mixture at environmental concentration levels were investigated on 3 living species from different trophic levels. The following endpoints were monitored: luminescence on the bacteria Vibrio fischeri, growth and development and phytometabolites on the duckweed Lemna minor and alterations at the population, cellular and molecular levels on the cnidarian Hydra circumcincta.
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Entwicklung und Validierung eines Enzyme-linked Immunosorbent Assays (ELISA) für die Quantifizierung von Carbamazepin in Abwasser, Oberflächenwasser und TrinkwasserBahlmann, Arnold 17 April 2013 (has links)
Ein kompetitiver ELISA (Enzyme-linked Immunosorbent Assay) für den Nachweis von Carbamazepin (CBZ) mit einer Bestimmungsgrenze von ca. 30 ng/L wurde entwickelt und validiert. Dieser in Gewässern häufig auftretende anthropogene Marker wurde anschließend in einer Vielzahl an Proben aus Abwässern, Oberflächengewässern und Trinkwässern nachgewiesen. Der ELISA zeigte eine exzellente Präzision und erbrachte in allen Matrizes geringfügig höhere Analysenergebnisse als die Referenzmethode HPLC-MS/MS. Die beständige Überbestimmung der CBZ-Konzentration in Höhe von ca. 7 % konnte auf die Präsenz von Cetirizin und geringen Mengen des persistenten Metaboliten 10,11 Epoxy¬carbamazepin (EP-CBZ) zurückgeführt werden. Die Bindungseigenschaften des verwendeten Antikörpers wurden anhand der Kreuz¬reaktivi¬täten von 37 Substanzen eingehend untersucht. Nach Kopplung von Flüssig¬chromato¬graphie und ELISA konnte das strukturell nicht mit CBZ verwandte Anti¬histaminikum Cetirizin als Kreuzreaktand identifiziert werden. Der störende Einfluss dieses Kreuz¬reaktanden auf den CBZ-ELISA konnte nach einer Änderung des pH-Wertes im Proben¬puffer minimiert werden. Die pH-abhängige Selektivitätssteuerung ermöglichte überdies die Entwicklung eines Dual-Analyt-Immunoassays für die parallele Bestimmung von CBZ und Cetirizin. Darüber hinaus wurden die Metaboliten EP-CBZ, DiOH-CBZ, 2-OH-CBZ, 3-OH-CBZ und 10 OH-CBZ in Abwasser, Oberflächenwasser und Trinkwasser quantifiziert. DiOH-CBZ erwies sich als ähnlich persistent wie CBZ und wurde in besonders hohen Konzentrationen gefunden. Außerdem wurden mehrere weitere bislang nicht identifizierte Abbauprodukte von CBZ gefunden. Da weder Probenvorbereitung noch Probenanreicherung erforderlich sind, ist der Test schnell und kostengünstig durchführbar. Die für den Test nötigen Probenvolumen sind mit weniger als 1 mL sehr gering. Diese Eigenschaften erlauben ein Hochdurchsatzscreening und machen die Methode interessant für den Einsatz im Gewässermonitoring. / A competitive ELISA (enzyme-linked immunosorbent assay) for the quantitation of carbamazepine (CBZ) was developed and validated. A limit of quantitation (LOQ) of ca. 30 ng/L allowed for the quantitation of CBZ in many samples from wastewater, surface water and drinking water. The method was found to be excellently precise, but it displayed slightly higher results than obtained by the reference method liquid chromatography-tandem mass spectrometry (LC-MS/MS). The nearly constant overestimation of 7 % could be attributed to the presence of small amounts of cetirizine and the persistent metabolite 10,11 epoxy¬carbamazepine (EP-CBZ). The binding properties of the antibody were studied by determining the cross-reactivities of 37 compounds. Hyphenating liquid chromatography to ELISA led to the discovery of the cross-reactive antihistamine cetirizine that shares no obvious structural similarity with CBZ. The bias caused by cetirizine was eliminated by changing the pH value of the sample buffer. Moreover, the antibody’s pH-dependent selectivity enabled a dual-analyte immunoassay for the parallel determination of CBZ and cetirizine. Furthermore, the metabolites EP-CBZ, DiOH-CBZ, 2-OH-CBZ, 3-OH-CBZ and 10-OH-CBZ were quantified in wastewater, surface water and drinking water. DiOH-CBZ showed the highest concentrations of all analaytes investigated and was found to be equally persistent as CBZ. In addition, several further degradation products of CBZ were found that could not be identified. The ELISA allowed the detection of diurnal and seasonal fluctuations of analyte concentrations in wastewater and surface water. The anthropogenic marker CBZ enabled to trace wastewater from the source to the receiving waters. Since neither sample pretreatment nor enrichment is necessary, the method is very fast and cost-effective. Only a small sample volume (less than 1 mL) is needed making this ELISA an appropriate high-throughput screening tool for environmental monitoring.
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