285 resultados para antidepressants
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The prescription information (summary of product characteristics, SPC) is compiled by the pharmaceutical industry as required by the national regulatory authorities. They vary in their content about the properties of drugs and about the usefulness of therapeutic drug monitoring (TDM) in the blood of patients. Based on a previous study carried out in Germany, the degree of agreement of French SPC for 59 psychotropic drugs with the existing medico-scientific evidence in the area of TDM was examined using a recently developed instrument. A summary score of SPC content (SPCC) related to TDM (SPCC(TDM)) has been calculated and compared with the level of recommendation of TDM of the AGNP-TDM expert group consensus guidelines for TDM in psychiatry [AGNP: Arbeitsgemeinschaft für Neuropsychopharmakologie und Pharmakopsychiatrie (Association for neuropsychopharmacology and pharmacopsychiatry)]. Among the antidepressants, antipsychotics, tranquillizers/hypnotic agents and mood stabilizers, the highest SPCC(TDM) scores in the French SPC were reached for imipramine (16), haloperidol (6), clonazepam (8) and lithium (23), respectively. Results were similar to those obtained from the analysis of German SPC, and considerable disagreement was found between the information on TDM in SPC and existing medico-scientific evidence, albeit less in the case of mood stabilizers. Taking into account the recommendations of the AGNP-TDM expert group guidelines, there is a deficit in the French SPC concerning TDM-relevant information. An amelioration of this situation could help to improve the clinical practice of TDM of psychotropic drugs, as the SPC is a widely used tool.
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Adherence to antidepressant treatment has been shown to range from 30 to 70%. The aim of this study was to compare the patient's self-report of adherence with the doctors' estimation of adherence and therapeutic alliance in 104 outpatients with mood and/or anxiety disorder treated with antidepressants. The adherence scores estimated by the patients and the doctors were significantly different, the doctors underestimating adherence in 29% of cases and overestimating it in 31% of cases compared to the patients' evaluation. Adherence measured by drug plasma concentration, despite being higher than expected from previously published reports, was in line with the patients' self-reported score but not the doctors' estimation. Finally, the patients' and the doctors' Helping Alliance scores were not related to adherence self-report.
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BACKGROUND: Anecdotal reports suggests that most clinicians treat medications as belonging to a class with regard to all therapeutic indications; this means that the whole 'class' of drugs is considered to possesses a specific therapeutic action. The present article explores the possible existence of a true 'class effect' for agents available for the treatment of bipolar disorder. METHODS: We reviewed the available treatment data from randomized controlled trials (RCTs) and explored 16 'agent class'/'treatment issue' cases for bipolar disorder. Four classes of agents were examined: first-generation antipsychotics (FGAs), second-generation antipsychotics (SGAs), antiepileptics and antidepressants, with respect to their efficacy on four treatment issues of bipolar disorder (BD) (acute mania, acute bipolar depression, maintenance against mania, maintenance against depression). RESULTS: From the 16 'agent class'/' treatment issue' cases, only 3 possible class effects were detected, and they all concerned acute mania and antipsychotics. Four effect cases have not been adequately studied (FGAs against acute bipolar depression and in maintenance protection from depression, and antidepressants against acute mania and protection from mania) and they all concern treatment cases with a high risk of switching to the opposite pole, thus research in these areas is poor. There is no 'class effect' at all concerning antiepileptics. CONCLUSIONS: The available data suggest that a 'class effect' is the exception rather than the rule in the treatment of BD. However, the possible presence of a 'class effect' concept discourages clinicians from continued scientific training and reading. Focused educational intervention might be necessary to change this attitude.
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[spa]Objetivo: El objetivo de este estudio es el diseño de un parche bucoadhesivo para la administración transbucal de clorhidrato de doxepina utilizando diferentes polímeros así como la caracterización de dichos sistemas en cuanto al análisis calorimétrico y la capacidad de hinchamiento.Materiales y métodos: Se ha utilizado clorhidrato de doxepina y diferentes polímeros, carboximetilcelulosa sódica, hidroxipropilmetilcelulosa y chitosan. La calorimetría diferencial de barrido (DSC) se ha realizado en un dispositivo Mettler FP 80 equipado con un horno FP 85 y la capacidad de hinchamiento utilizando placas de agar.Resultados: Se obtienen termogramas de los parches y las mezclas físicas donde se observan transiciones endotérmicas entre 30 y 120º C y el pico endotérmico del principio activo en las mezclas físicas binarias. La entalpía de deshidratación es similar en los polímeros de carboximetilcelulosa sódica y chitosan (281 J/g) siendo menor en la película de hidroxipropilmetilcelulosa (251 J/g), al igual que el porcentaje de hidratación donde se demuestra que los parches elaborados con hidroxipropilmetilcelulosa presenta menor tendencia a captar agua (55,91 %) frente al 67,04 % y 67,30 % de la carboximetilcelulosa sódica y chitosan, respectivamente.Conclusión: Los resultados obtenidos muestran que existe compatibilidad entre los componentes de la formulación y los datos de entalpía se correlacionan con los datos obtenidos en el ensayo de hinchamiento.[eng]The aim of this study is to design a bucoadhesive patch for the transbuccal administration of doxepin hydrochloride using different polymers as well as the characterization of these systems for calorimetric analysis and the swelling capacity. Materials and methods: Doxepin hydrochloride was used as well as various polymers; carboxymethylcellulose sodium, hydroxypropylmethyl cellulose and chitosan. Differential scanning calorimetry (DSC) was carried out using a Mettler FP 80 device equipped with a FP 85 oven and the swelling capacity using agar plates. Results: Thermograms obtained patches and physical mixtures where there are endothermic transitions between 30 and 120º C and the endothermic peak of the active principle in binary physical mixtures. Dehydration enthalpy is similar in polymers of carboxymethylcellulose sodium and chitosan (281 J/g), the film having less hydroxypropylmethylcellulose (251 J/g), the percentage of moisture shows that the patches prepared with hydroxypropylmethylcellulose have less tendency to collect water (55.91 %) compared to 67.04 % and 67.30 % with sodium carboxymethylcellulose and chitosan, respectively. Conclusion: The results show that there is compatibility between the components of the formulation and the enthalpy data correlate
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Citalopram, a new bicyclic antidepressant, is the most selective serotonin reuptake inhibitor. In a number of double-blind controlled studies, citalopram was compared to placebo and to known tricyclic antidepressants. These studies have shown their efficacy and good safety. The inefficacy of a psychotropic treatment in at least 20% of depressives has led a number of authors to propose original drug combinations and associations, like antidepressant/lithium (Li), antidepressant/sleep deprivation (agrypnia), antidepressant/ECT, or antidepressant/LT3. The aim of this investigation is to evaluate the clinical effectiveness and safety of a combined citalopram/lithium treatment in therapy-resistant patients, taking account of serotonergic functions, as tested by the fenfluramine/prolactin test, and of drug pharmacokinetics and pharmacogenetics of metabolism. DESIGN OF THE STUDY: A washout period of 3 days before initiating the treatment is included. After an open treatment phase of 28 days (D) with citalopram (20 mg D1-D3; 40 mg D4-D14; 40 or 60 mg D15-D28; concomitant medication allowed: chloral, chlorazepate), the nonresponding patients [less than 50% improvement in the total score on the 21 item-Hamilton Depression Rating Scale (HDRS)] are selected and treated with or without Li (randomized in double-blind conditions: citalopram/Li or citalopram/placebo) during the treatment (D29-D35). Thereafter, all patients included in the double-blind phase subsequently receive an open treatment with citalopram/Li for 7 days (D36-D42). The hypothesis of a relationship between serotoninergic functions in patients using the fenfluramine/prolactin test (D1) and the clinical response to citalopram (and Li) is assessed. Moreover, it is evaluated whether the pharmacogenetic status of the patients, as determined by the mephenytoin/dextromethorphan test (D0-D28), is related to the metabolism of fenfluramine and citalopram, and also to the clinical response. CLINICAL ASSESSMENT: Patients with a diagnosis of major depressive disorders according to DSM III are submitted to a clinical assessment of D1, D7, D14, D28, D35, D42: HDRS, CGI (clinical global impression), VAS (visual analog scales for self-rating of depression), HDRS (Hamilton depression rating scale, 21 items), UKU (side effects scale), and to clinical laboratory examens, as well as ECG, control of weight, pulse, blood pressure at D1, D28, D35. Fenfluramine/prolactin test: A butterfly needle is inserted in a forearm vein at 7 h 45 and is kept patent with liquemine. Samples for plasma prolactin, and d- and l-fenfluramine determinations are drawn at 8 h 15 (base line). Patients are given 60 mg fenfluramine (as a racemate) at 8 h 30. Kinetic points are determined at 9 h 30, 10 h 30, 11 h 30, 12 h 30, 13 h 30. Plasma levels of d- and l-fenfluramine are determined by gas chromatography and prolactin by IRNA. Mephenytoin/dextromethorphan test: Patients empty their bladders before the test; they are then given 25 mg dextropethorphan and 100 mg mephenytoin (as a racemate) at 8 h 00. They collect all urines during the following 8 hours. The metabolic ratio is determined by gas chromatography (metabolic ratio dextromethorphan/dextrorphan greater than 0.3 = PM (poor metabolizer); mephenytoin/4-OH-mephenytoin greater than 5.6, or mephenytoin S/R greater than 0.8 = PM). Citalopram plasma levels: Plasma levels of citalopram, desmethylcitalopram and didesmethylcitalopram are determined by gas chromatography--mass spectrometry. RESULTS OF THE PILOT STUDY. The investigation has been preceded by a pilot study including 14 patients, using the abovementioned protocol, except that all nonresponders were medicated with citalopram/Li on D28 to D42. The mean total score (n = 14) on the 21 item Hamilton scale was significantly reduced after the treatment, ie from 26.93 +/- 5.80 on D1 to 8.57 +/- 6.90 on D35 (p less than 0.001). A similar patCitalopram, a new bicyclic antidepressant, is the most selective serotonin reu
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Background: Paroxetine (Paxil,) is an SSRI, used for thetreatment of depression, obsessive compulsive disorder,anxiety disorders and premenstrual dysphoria. Untilrecently, no studies had associated SSRIs as a group withan increased risk for major malformations above the 1%-3% baseline rate. However, in the past year, several studiesnoted specifically, an increase risk of cardiovascular defectsassociated with paroxetine, compared to other antidepressantswithin its class.Objectives: To determine whether paroxetine increases therisk of cardiovascular defects in infants of women exposedduring the first trimester of pregnancy.Methods: We collected prospectively ascertained cases ofinfants from Teratogen Information Services throughout theworld, exposed to paroxetine in the first trimester of pregnancyand compared them to a non-exposed Motheriskcohort.We also contacted the authors of data base studies thathad been published on antidepressants as a class, to determinehow many of these women had been exposed to paroxetineand the rates of cardiovascular defects in their infants.Results: We were able to ascertain the outcomes of 1177infants from 9 services. The rate of heart defects in the paroxetineparoxetinegroup was 0.8% versus 0.7% non-exposed group.The combined rate in the data base studies was 1.5%.Conclusions: Paroxetine does not appear to be associated withan increase risk for cardiovascular defects following use inpregnancy, as the incidence in more than 3000 infants was wellwithin the population incidence of approximately 1%.
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Introduction The population of elderly persons is increasing andnegative outcomes due to polymedication are frequent. Discrepanciesin information about medication are frequent when older persons aretransitioning from hospital to home, increasing the risk of hospitalreadmission. The aims of this study were a) to determine discrepanciesin medical regimen indicated in two official discharge documents(DS = discharge summary, DP=discharge prescription); b) to characterizethe pharmacotherapy prescribed in older patients dischargedfrom a geriatric service.Materials & Methods Elderly patients (N=230) discharged from thegeriatric service (CHUV, Lausanne) over a 6-month period (January toJune 2009) were selected. Community pharmacists compared DS andDP to identify discrepancies including (a) drugs' name; (b) schedule ofadministration, dosage, frequency, prn prescription, treatment durationand galenic formulation. Beers' criteria were applied to identifypotentially inappropriate drugs and a descriptive analysis of drug costs,prescription profiles and generics were also performed.Results On average, patients were 82 ± 7 years old and stayed23.0 ± 11.6 days in the geriatric service. The delay between the datesof patient's discharge with the DP and the sending of the DS to hisgeneral physician averaged 14.0 ± 7.5 days (range 1-55). The DPhad an average of 10.0 ± 3.3 drugs (range 2-19). 77% of patients hadat least one discrepancy. A drug was missing on the DS in 57.8% ofpatients and 19.6% had a missing prn prescription. Among the 2312drugs prescribed, 3% belonged to Beers' list. They were prescribed to61 patients (26.5%), with 6 patients cumulating two Beers' potentiallyinappropriate drugs in their treatment. Analgesics (85% of thepatients), anticoagulants (80%), mineral supplements (77%), laxatives(52%) and antihypertensives (46%) were the drug classes most frequentlyprescribed. Mean costs of treatment as per DP was160.4 ± 179.4 Euros. Generic prescription represented more than 5%of the costs for 3 therapeutic classes (cholesterol-lowering agents(64%), antihypertensives (50%) and antidepressants (47%)).Discussion & Conclusion The high discrepancy rate between medicationlisted in the DP and the DS highlights a need for safetyimprovement. Potential benefits are expected from reinforced pharmacist-physician collaboration in transition from hospital to primarycare. In addition, even though Beers' criteria are questionable, thedrugs prescribed in this already fragile population, and the potentialopportunities of economical optimizations, are advocating thedevelopment and the scientific evaluation of a structured advancedcollaborative pharmacy practice service. This foresees improvedeffectiveness, safety and efficiency in the medication management ofelderly persons.
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OBJECTIVE: Depersonalization is a fascinating clinical phenomenon referring to a self-consciousness disorder, characterized by emotional detachment from one's own feelings, thoughts, or actions. This article intends to summarize the current literature in this area. METHOD: Using the Medline data base, we reviewed literature addressing the clinical, etiology, nosology, physiopathology, and treatment of depersonalization. CONCLUSIONS: Derealization means that perception of the world and of external reality are altered. These 2 phenomena are often associated. They are not specific to any psychiatric entity and are reported in many different psychiatric syndromes. Many factors, including use of different substances, are involved in their onset. The physiopathology is still little known. However, some conceptual models suggest partial amygdala inhibition combined with activation of other amygdaloid structures. A serotoninergic functioning impairment is indicated in different pharmacologic studies. Different psychotropic drugs, especially serotoninergic antidepressants, have been proposed for pharmacotherapy; however, there are no conclusive randomized studies, and the contribution of psychotherapy in treating these patients is still questioned
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Five selective serotonin reuptake inhibitors (SSRIs) have been introduced recently: citalopram, fluoxetine, fluvoxamine, paroxetine and sertraline. Although no therapeutic window has been defined for SSRIs, in contrast to tricyclic antidepressants, analytical methods for therapeutic drug monitoring of SSRIs are useful in several instances. SSRIs differ widely in their chemical structure and in their metabolism. The fact that some of them have N-demethylated metabolites, which are also SSRIs, requires that methods be available which allow therapeutic drug monitoring of the parent compounds and of these active metabolites. most procedures are based on prepurification of the SSRIs by liquid-liquid extraction before they are submitted to separation by chromatographic procedures (high-performance liquid chromatography, gas chromatography, thin layer chromatography) and detection by various detectors (UV, fluorescence, electrochemical detector, nitrogen-phosphorus detector, mass spectrometry). This literature review shows that most methods allow quantitative determination of SSRIs in plasma, in the lower ng/ml range, and that they are, therefore, suitable for therapeutic drug monitoring purposes of this category of drugs.
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In 2008 there is no major breakthrough in the field of psychopharmacology. Paliperidone, (Invega), or 9-hydroxyrisperidone, the main hydroxylated metabolite of risperidone, is now available in Switzerland. It has the same pharmacodynamic profile and a different pharmacokinetic profile, linked to an extended release preparation. Bupropion, an antidepressant with noradrenergic and dopaminergic activity, is now accepted on the Swiss market for the treatment of depression under the name of Wellbutrin. Until now, its indication was limited to tobacco withdrawal (under the name of Zyban). The article also includes new data issued from the STAR*D study (concerning the efficacy of cognitive behavioural therapy) and a few remarks about the recent debate in the media about the efficacy of antidepressants.
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Résumé pour large public Unité de Biochimie et Psychopharmacologie Clinique, Centre de neurosciences Psychiatrique, Département de Psychiatrie Adulte, Faculté de Biologie et de Médecine, Université de Lausanne Lors de la prise d'un médicament, celui-ci va passer par différentes étapes que sont l'absorption, la distribution, le métabolisme et enfin l'élimination. Ces quatre étapes sont regroupées sous le nom de pharmacocinétique. A noter que ces quatre paramètres sont dynamiques et en constante évolution. Durant cette thèse, nous avons investigué différents aspects de la pharmacocinétique, tout d'abord par une revue de la littérature sur la glycoprotéine-P (Pgp). Récemment découverte, cette protéine de membrane est située aux endroits stratégiques de l'organisme comme la barrière hématoencéphalée, le placenta ou les intestins où elle influencera l'entrée de différentes substances, en particulier les médicaments. La Pgp serait impliquée dans les phénomènes de résistances aux agents thérapeutiques en oncologie. La Pgp influence donc l'absorption des médicaments, et son impact en clinique, en termes d'efficacité de traitement et de toxicité prend chaque jour plus d'importance. Ensuite nous avons mis au point une méthode d'analyse quantitative d'un antidépresseur d'une nouvelle génération : la mirtazapine (Remeron®). La nouveauté réside dans la façon dont la mirtazapine interagit avec les neurotransmetteurs impliqués dans la dépression que sont la sérotonine et la noradrénaline. Cette méthode utilise la chromatographie liquide pour séparer la mirtazapine de ses principaux métabolites dans le sang. La spectrométrie de masse est utilisée pour les détecter et les quantifier. Les métabolites sont des substances issues de réactions chimiques entre la substance mère, la mirtazapine, et généralement des enzymes hépatiques, dans le but de rendre cette substance plus soluble en vue de son élimination. Cette méthode permet de quantifier la mirtazapine et ses métabolites dans le sang de patients traités et de déterminer la variation des taux plasmatiques chez ces patients. Puis nous avons étudié le métabolisme d'un autre antidépresseur, le citalopram, qui a un métabolisme complexe. Le citalopram est un racémate, c'est-à-dire qu'il existe sous forme de deux entités chimiques (R-(-) et S-(+) citalopram) qui ont le même nombre d'éléments mais arrangés différemment dans l'espace. La voie métabolique cérébrale du citalopram est sous le contrôle d'une enzyme, la monoamine oxydase (MAO), conduisant à une forme acide du citalopram (l'acide propionique du citalopram). La MAO existe sous deux formes : MAO-A et MAO-B. Nous avons utilisé des souris déficientes d'un gène, celui de la MAO-A, pour mieux en comprendre le métabolisme en les comparants à des souris sauvages (sans déficience de ce gène). Nous avons utilisé le citalopram et deux de ses métabolites (le déméthylcitaloprarn et le didéméthyícitalopram) comme substrats pour tester la formation in vitro de l'acide propionique du citalopram. Nos résultats montrent que la MAO-A favorise la formation de l'entité R-(-) et présente une plus grande affinité pour le citalopram, tandis que la MAO-B métabolise préférentiellement l'entité S-(+) et a une plus grande affinité pour les deux métabolites déméthylés. De plus, la déficience en MAO-A est partiellement compensée parla MAO-B chez les souris déficientes du gène de la MAO-A. Enfin, nous avons étudié une deuxième voie métabolique du citalopram qui s'est avérée toxique chez le chien Beagle. Celle-ci est catalysée par une autre famille d'enzymes, les cytochromes P-450, et mène aux métabolites déméthylés et didéméthylés du citalopram. Nous avons utilisé des tissus hépatiques de chiens Beagle. Plusieurs cytochromes P-450 sont impliqués dans le métabolisme du citalopram menant à sa forme déméthylée, ceci tant chez l'homme que chez le chien. Par contre, dans le métabolisme de la forme déméthylée menant à 1a forme didéméthylée, un seul cytochrome P-450 serait impliqué chez l'Homme, tandis qu'ils seraient plusieurs chez le chien. L'activité enzymatique produisant la forme didéméthylée est beaucoup plus importante chez le chien comparé à l'homme. Cette observation soutien l'hypothèse que des taux élevés de la forme didéméthylée participent à la toxicité spécifique du citalopram chez le chien. Nous pouvons conclure que plusieurs famille d'enzymes sont impliquées tant au niveau cérébral qu'hépatique dans la métabolisation de médicaments psychotropes. Sachant que les enzymes peuvent être stimulées ou inhibées, il importe de pouvoir suivre au plus prés les taux plasmatiques des différents psychotropes et de leurs métabolites. Résumé Unité de Biochimie et Psychopharmacologie Clinique, Centre de neurosciences Psychiatrique, Département de Psychiatrie Adulte, Faculté de Biologie et de Médecine, Université de Lausanne La plupart des médicaments subissent une transformation enzymatique dans l'organisme. Les substances issues de cette métabolisation ne sont pas toujours dotées d'une activité pharmacologique. Il s'est avéré par conséquent indispensable de suivre les taux plasmatiques d'une substance et de ses métabolites et d'établir ou non l'existence d'une relation avec l'effet clinique observé. Ce concept nommé « therapeutic drag monitoring » (TDM) est particulièrement utile en psychiatrie ou un manque de compliance des patients est fréquemment observé. Les médicaments psychotropes ont un métabolisme principalement hépatique (cytochromes P-450) et parfois cérébral (monoamines oxydases), comme pour le citalopram par exemple. Une méthode stéréosélective de chromatographie liquide couplée à la spectrométrie de masse a été développée pour analyser les énantiomères R-(-) et S-(+) d'un antidépresseur agissant sur les récepteurs noradrénergiques et sérotoninergiques, la mirtazapine et de ses métabolites déméthylmirtazapine et 8-hydroxymirtazapine. Les données préliminaires obtenues dans les plasmas dosés suggèrent que les concentrations de R-(-)-mirtazapine sont plus élevées que celles de S-(+)-mirtazapine, à l'exception des patients qui auraient comme co-médication des inhibiteurs du CYP2D6, telle que la fluoxétine ou la thioridazine. Il y a une enantiosélectivité du métabolisme de la mirtazapine. En particulier pour la 8-hydroxymirtazapine qui est glucuroconjuguée et pour laquelle le ratio S/R varie considérablement. Cette méthode analytique présente l'avantage d'être utilisable pour le dosage stéréosélectif de la mirtazapine et de ses métabolites dans le plasma de patients ayant d'autres substances en co-médication. La glycoprotéine P fonctionne comme une pompe transmembranaire transportant les xénobiotiques depuis le milieu intracellulaire vers le milieu extracellulaire. Son induction et son inhibition, bien que moins étudiées que pour les cytochromes P-450, ont des implications cliniques importantes en termes d'efficacité de traitement et de toxicité. Cette glycoprotéine P a fait l'objet d'une recherche bibliographique. Nous avons étudié le métabolisme du citalopram, un antidépresseur de la classe des inhibiteurs spécifiques de la recapture de la sérotonine chez la souris et chez le chien. Cette substance subit un métabolisme complexe. La voie de métabolisation conduisant à la formation de l'acide propionique du citalopram, catalysée par les monoamines oxydases, a été étudiée in vitro dans les mitochondries cérébrales chez la souris déficiente du gène de la MAO-A (Tg8). La monoamine oxydase A catalyse la formation de l'énantiomère R-(-) et présente une plus grande affinité pour les amines tertiaires, tandis que la monoamine oxydase B favorise la formation de la forme S-(+) et a une affinité plus marquée pour les amines secondaires et primaires. L'étude du citalopram chez la souris Tg8 adulte a montré que la monoamine oxydase B compense la déficience de la monoamine oxydase A chez ces souris génétiquement modifiées. Une autre voie de métabolisation du citalopram conduisant à la formation de didéméthylcitalopram, catalysée par les cytochromes P-450, a été étudiée in vitro dans des microsomes hépatiques de chiens Beagle. Nos études ont montré que les cinétiques de N-déméthylation du citalopram sont biphasiques chez le chien. Les orthologues canins impliqués dans la première N-déméthylation semblent être identiques aux cytochromes P-450 humains. Par contre, dans la deuxième Ndéméthylation, un seul cytochrome P-450 semble être impliqué chez l'homme (CYP2D6), tandis qu'on retrouve jusqu'à cinq orthologues chez le chien. Le CYP2D15, orthologue canin du CYP2D6, est majoritairement impliqué. De plus, l'activité enzymatique, reflétée par les clairances intrinsèques, dans la première N-déméthylation est jusqu'à 45 fois plus élevée chez le chien comparé à l'homme. Ces différentes observations soutiennent l'hypothèse que des taux élevés de didéméthylcitalopram sont responsables de la toxicité du citalopram chez le chien. Nous pouvons conclure que plusieurs famille d'enzymes sont impliquées tant au niveau cérébral qu'hépatique dans la métabolisation de médicaments psychotropes. Sachant -que les enzymes peuvent être induits ou inhibés, il importe de pouvoir suivre au plus près les taux plasmatiques des différents psychotropes et de leurs métabolites. Summary Most of the drugs are metabolized in the organism. Substances issued from this metabolic activity do not always show a pharmacological activity. Therefore, it is necessary to monitor plasmatic levels of drugs and their metabolites, and establish the relationship with the clinical effect. This concept named therapeutic drug monitoring is very useful in psychiatry where lack of compliance is commonly observed. Antidepressants are mainly metabolized in the liver (cytochrome P-450) and sometimes in the brain (monoamine oxidase) like the citalopram, for exemple. A LC-MS method was developed, which allows the simultaneous analysis of R-(-) and S-(+) enantiomers of mirtazapine, an antidepressant acting specifically on noradrenergic and serotonergic receptors, and its metabolites demethylmirtazapine and 8-hydroxymirtazapine in plasma of mirtazapine treated patients. Preliminary data obtained suggested that R-(-) mirtazapine concentrations were higher than those of S-(+) mirtazapine, except in patients comedicated with CYP2D6 inhibitors such as fluoxetine or thioridazine. There is an enantioselectivity in the metabolism of mirtazapine. In particular for the 8-hydroxymirtazapine, which is glucuroconjugated and S/R ratio varies considerably. Therefore this method seems to be suitable for the stereoselective assay of mirtazapine and its metabolites in plasma of patients comedicated with mirtazapine and other drugs for routine and research purposes. P-glycoprotein is working as an efflux transporter of xenobiotics from intracellular to extracellular environment. Its induction or inhibition, although less studied than cytochrome P-450, has huge clinical implications in terms of treatment efficacy and toxicity. An extensive literature search on P-glycoprotein was performed as part of this thesis. The study of citalopram metabolism, an antidepressant belonging to the class of selective serotonin reuptake inhibitors. This substance undergoes a complex metabolism. First metabolization route leading to citalopram propionic acid, catalyzed by monoamine oxidase was studied in vitro in mice brain mitochondria. Monoamine oxidase A catalyzed the formation of R-(-) enantiomer and showed greater affinity for tertiary amines, whereas monoamine oxidase B triggered the formation of S-(+) enantiomer and demonstrated higher affinity for primary and secondary amines. citalopram evaluation in adult Tg8 mice showed that monoamine oxidase B compensated monoamine oxidase A deficiency in those genetically transformed mice. The second metabolization route of citalopram leading to didemethylcitalopram and catalyzed by cytochrome P-450 was studied in vitro in Beagle dog's livers. Our results showed that citalopram N-demethylation kinetics are biphasic in dogs. Canine orthologs involved in the first N-demethylation seemed to be identical to human cytochromes P-450. However, in the second N-demethylation only one cytochrome P-450 seemed to be involved in human (CYP2D6), whereas up to five canine orthologs were found in dogs. CYP2D15 canine ortholog of CYP2D6 was mainly involved. In addition, enzymatic activity reflected by intrinsic clearance in the first N-demethylation was up to 45 fold higher in dogs compared to humans. Those observations support the assumption that elevated rates of didemethylcitalopram are responsible for citalopram toxicity in dogs. We can conclude that several enzymes groups are involved in the brain, as well as in the liver, in antidepressant metabolization. Knowing that enzymes may be induced or inhibited, it makes sense to closely monitor plasmatic levels of antidepressants and their metabolites.
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A nyone traveling to the United States from countries other than New Zealand will be surprised by the prevalence of health-related advertisements on television, including ads for drugs. Typically, these TV ads follow a pattern: an ad for a burger at only 99 cents, followed by one for a proton-pump inhibitor, then an ad on healthy home-cooked food delivered directly to your home and an ad for a home-based abdominal workout DVD, followed by an ad for a lipid-lowering drug. There are, however, nuances. After 8 pm, the visitor might encounter an ad for the "little blue pill." This sequence sometimes includes an ad featuring antihistamines for allergic rhinitis in spring and one promoting antidepressants in the winter. Such direct-to-consumer advertising (DTCA) of prescription drugs is usual business in the United States and New Zealand but is prohibited in the rest of the world. Why? Because DTCA for prescribing drugs has pros and cons (discussed elsewhere,1-3 including in JGIM4) that are balanced differently in different countries. Constitutional factors-such as the First Amendment protections on speech, including commercial speech, in the United States5 -as well as patient and population safety considerations, which all differ across countries, modulate reactions to DTCA. Additionally, lack of robust data on the impact of DTCA on prescription drug use adds to the confusion. Evidence, though limited, suggests that DTCA increases drug sales. However, whether the increase in sales corrects existing underuse or encourages over/misuse is not clear.
Resumo:
The objective of this work was to combine the advantages of the dried blood spot (DBS) sampling process with the highly sensitive and selective negative-ion chemical ionization tandem mass spectrometry (NICI-MS-MS) to analyze for recent antidepressants including fluoxetine, norfluoxetine, reboxetine, and paroxetine from micro whole blood samples (i.e., 10 microL). Before analysis, DBS samples were punched out, and antidepressants were simultaneously extracted and derivatized in a single step by use of pentafluoropropionic acid anhydride and 0.02% triethylamine in butyl chloride for 30 min at 60 degrees C under ultrasonication. Derivatives were then separated on a gas chromatograph coupled with a triple-quadrupole mass spectrometer operating in negative selected reaction monitoring mode for a total run time of 5 min. To establish the validity of the method, trueness, precision, and selectivity were determined on the basis of the guidelines of the "Société Française des Sciences et des Techniques Pharmaceutiques" (SFSTP). The assay was found to be linear in the concentration ranges 1 to 500 ng mL(-1) for fluoxetine and norfluoxetine and 20 to 500 ng mL(-1) for reboxetine and paroxetine. Despite the small sampling volume, the limit of detection was estimated at 20 pg mL(-1) for all the analytes. The stability of DBS was also evaluated at -20 degrees C, 4 degrees C, 25 degrees C, and 40 degrees C for up to 30 days. Furthermore, the method was successfully applied to a pharmacokinetic investigation performed on a healthy volunteer after oral administration of a single 40-mg dose of fluoxetine. Thus, this validated DBS method combines an extractive-derivative single step with a fast and sensitive GC-NICI-MS-MS technique. Using microliter blood samples, this procedure offers a patient-friendly tool in many biomedical fields such as checking treatment adherence, therapeutic drug monitoring, toxicological analyses, or pharmacokinetic studies.
Resumo:
Background: Non-adherence to antidepressants generates higher costs for the treatment of depression. Little is known about the cost-effectiveness of pharmacist's interventions aimed at improving adherence to antidepressants. The study aimed to evaluate the cost-effectiveness of a community pharmacist intervention in comparison with usual care in depressed patients initiating treatment with antidepressants in primary care. Methods: Patients were recruited by general practitioners and randomized to community pharmacist intervention (87) that received an educational intervention and usual care (92). Adherence to antidepressants, clinical symptoms, Quality-Adjusted Life-Years (QALYs), use of healthcare services and productivity losses were measured at baseline, 3 and 6 months. Results: There were no significant differences between groups in costs or effects. From a societal perspective, the incremental cost-effectiveness ratio (ICER) for the community pharmacist intervention compared with usual care was 1,866 for extra adherent patient and 9,872 per extra QALY. In terms of remission of depressive symptoms, the usual care dominated the community pharmacist intervention. If willingness to pay (WTP) is 30,000 per extra adherent patient, remission of symptoms or QALYs, the probability of the community pharmacist intervention being cost-effective was 0.71, 0.46 and 0.75, respectively (societal perspective). From a healthcare perspective, the probability of the community pharmacist intervention being cost-effective in terms of adherence, QALYs and remission was of 0.71, 0.76 and 0.46, respectively, if WTP is 30,000. Conclusion: A brief community pharmacist intervention addressed to depressed patients initiating antidepressant treatment showed a probability of being cost-effective of 0.71 and 0.75 in terms of improvement of adherence and QALYs, respectively, when compared to usual care. Regular implementation of the community pharmacist intervention is not recommended.
Resumo:
Major depression is associated with high burden, disability and costs. Non-adherence limits the effectiveness of antidepressants. Community pharmacists (CP) are in a privileged position to help patients cope with antidepressant treatment. The aim of the study was to evaluate the impact of a CP intervention on primary care patients who had initiated antidepressant treatment. Newly diagnosed primary care patients were randomised to usual care (UC) (92) or pharmacist intervention (87). Patients were followed up at 6 months and evaluated three times (Baseline, and at 3 and 6 months). Outcome measurements included clinical severity of depression (PHQ-9), health-related quality of life (HRQOL) (Euroqol-5D) and satisfaction with pharmacy care. Adherence was continuously registered from the computerised pharmacy records. Non-adherence was defined as refilling less than 80% of doses or having a medication-free gap of more than 1 month. Patients in the intervention group were more likely to remain adherent at 3 and 6 months follow-up but the difference was not statistically significant. Patients in the intervention group showed greater statistically significant improvement in HRQOL compared with UC patients both in the main analysis and PP analyses. No statistically significant differences were observed in clinical symptoms or satisfaction with the pharmacy service. The results of our study indicate that a brief intervention in community pharmacies does not improve depressed patients' adherence or clinical symptoms. This intervention helped patients to improve their HRQOL, which is an overall measure of patient status.