Circulación de información sobre medicamentos y otras sustancias para aumentar el rendimiento cognitivo: un estudio de un blog brasileño (2015-2017) / Circulation of information on drugs and other substances to increase cognitive performance: a study of a Brazilian blog (2015-2017)

RESUMEN Al observar los procesos de (bio)medicalización y farmacologización de la sociedad, este artículo aborda los medicamentos que han sido utilizados por individuos sanos para aumentar sus dimensiones cognitivas, como el estado de alerta, la memoria y la concentración. Las llamadas "drogas inteligentes" o "drogas nootrópicas" se han extendido entre los jóvenes a través de Internet. La circulación de información sobre tales drogas se analiza desde un blog brasileño llamado Cérebro Turbinado, sobre el que se realizó una investigación documental basada en el material publicado en el blog entre 2015 y 2017, de acceso público. La investigación adopta marcos teóricos y metodológicos de las ciencias sociales, junto a una perspectiva antropológica. Los resultados muestran que el blog actúa como un medio para la difusión del conocimiento biomédico entre el público lego y muestra la producción de nuevas formas de subjetividad al revelar los significados que se atribuyen a tales sustancias en los procesos de socialización.

ABSTRACT By observing the processes of (bio)medicalization and pharmaceuticalization of society, this article addresses drugs that have been used by healthy individuals to increase cognitive dimensions such as alertness, memory, and concentration. The use of so-called "smart drugs" or "nootropics" has spread among young people, aided by the internet. The circulation of information about such drugs are analyzed using a Brazilian blog called "Cérebro Turbinado," through publications available for public access between 2015 and 2017. The study adopts theoretical and methodological frameworks of the social sciences, including an anthropological perspective. Documental research was conducted on the internet, specifically with scientific dissemination materials and the material available from the aforementioned blog. The results show that the blog acts as a medium for spreading biomedical knowledge among the lay public and indicates the production of new forms of subjectivity by revealing the meanings attributed to these substances in socialization processes.

Attention-deficit/hyperactivity disorder: the impact of methylphenidate on working memory, inhibition capacity and mental flexibility / Transtorno do déficit de atenção/hiperatividade (TDAH): o impacto do metilfenidato na memória operacional, capacidade inibitória e flexibilidade mental

ABSTRACT Objective To compare children with attention-deficit/hyperactivity disorder (ADHD), before and after the use of methylphenidate, and a control group, using tests of working memory, inhibition capacity and mental flexibility. Methods Neuropsychological tests were administrated to 53 boys, 9–12 years old: the WISC-III digit span backward, and arithmetic; Stroop Color; and Trail Making Tests. The case group included 23 boys with ADHD, who were combined type, treatment-naive, and with normal intelligence without comorbidities. The control group (n = 30) were age and gender matched. After three months on methylphenidate, the ADHD children were retested. The control group was also retested after three months. Results Before treatment, ADHD children had lower scores than the control group on the tests (p ≤ 0.001) and after methylphenidate had fewer test errors than before (p ≤ 0.001) Conclusion Methylphenidate treatment improves the working memory, inhibitory control and mental flexibility of ADHD boys.

RESUMO Objetivo Comparar crianças com transtorno de déficit de atenção/hiperatividade (TDAH) com controles, utilizando testes de memória de trabalho, capacidade inibitória e flexibilidade mental, em meninos de 9 a 12 anos. Métodos Testes neuropsicológicos administrados: teste de ordem inversa dos dígitos, teste aritmético (WISC-III), Teste Stroop e Teste de Trilhas. Grupo experimental meninos (n=23), com TDAH combinado, virgens de tratamento, inteligência normal sem comorbidades. Grupo controle (n = 30) com as mesmas características do grupo experimental em termos de idade e sexo. Após três meses com metilfenidato, os grupos TDAH e controle foram novamente testadas. Resultados Antes do tratamento, as crianças com TDAH apresentaram menor pontuação do que o grupo controle nos testes analisados (p≤ 0.001) e o grupo com TDAH apresentou menos erros nos testes após metilfenidato (p ≤ 0.001). Conclusão O tratamento com metilfenidato melhora a memória de trabalho, controle inibitório e flexibilidade mental de meninos com TDAH.

As controvérsias sócio-históricas das práticas farmacológicas com o metilfenidato / Las controversias socio-históricas de las prácticas farmacológicas con metilfenidato / The socio-historical controversies in pharmacological practices with methylphenidate

Resumo O metilfenidato, principal substância utilizada no tratamento farmacológico do Transtorno do Défict de Atenção e Hiperatividade (TDAH), é atualmente o psicoestimulante mais consumido no mundo e assunto constante na mídia e nas produções científicas em Psicologia e Psiquiatria. Neste artigo, discutimos alguns elementos do discurso científico sobre esse medicamento, nos servindo de elementos históricos, ricos em controvérsias, para propor sua emergência como problema, conforme indica Foucault. Assim, analisamos a diversidade de sentidos e práticas que envolvem o tema, desde a síntese das primeiras anfetaminas em laboratório, no início do século XX, até o momento atual, em que o metilfenidato é reconhecido como principal via de tratamento do TDAH, alcançando altíssimas taxas de consumo ao redor do planeta. Por fim, são apontadas algumas questões pertinentes ao contexto brasileiro, principalmente no que se refere às políticas públicas de saúde.

Resumen El metilfenidato, la principal sustancia usada en el tratamiento farmacológico del Trastorno de Déficit de Atención e Hiperactividad (TDAH), es actualmente el psicoestimulante más consumido en el mundo y tema constante en los medios de comunicación y en la producción científica de psicología y psiquiatría. En este artículo, se discuten algunos elementos del discurso científico sobre este producto, utilizándose elementos históricos, ricos en controversia, para proponer su emergencia como un problema, como indicado por Foucault. De este modo, se analiza la diversidad de significados y prácticas que implican el tema, desde la síntesis de las primeras anfetaminas en laboratorio, a principios del siglo XX, hasta el momento presente, donde el metilfenidato es reconocido como el principal medio de tratamiento del TDAH, alcanzando tasas de consumo extremadamente altas en todo el mundo. Por último, señalamos algunas cuestiones relacionadas con el contexto brasileño, especialmente con respecto a las políticas de salud pública.

Abstract Methylphenidate, the main substance used in the pharmacological treatment of Attention Deficit Hyperactivity Disorder (ADHD), is currently the most consumed psychostimulant in the world and a constant matter in media and scientific production in psychology and psychiatry studies. In this article, we discuss some scientific discourse elements about this medicine by using historical elements that are rich in controversies, in order to propose their emergence as a problem, as Foucault indicates. Thus, we have analysed the diversity of meanings and practices involving this issue, from the production of the first amphetamines in laboratory in the early twentieth century to the present days, in which methylphenidate is recognized as the first choice of treatment for ADHD, reaching extremely high consumption rates around the planet. Finally, some relevant questions about the Brazilian context are pointed out, especially concerning public health policies.

Effect of repeated oral therapeutic doses of methylphenidate on food intake and growth rate in rats

Central nervous system stimulants are known to produce anorexia. Previous data suggest that methylphenidate can have variable effects on caloric intake and growth rate. A dose-response study was performed to monitor caloric intake, liquid intake and growth rate in rats following repeated administration of human oral therapeutic doses 2 mg/kg/day, 5mg/kg/day and 8mg/kg/day of methylphenidate. We found that food intake and water intake, increased in all weeks and at all doses used in the study. Growth rate increased more at higher dose [8mg/kg/day] and at low dose [2mg/kg/day] of methylphenidate in 1st and 2nd week whereas more decreased by the above doses in 3rd week, suggesting that food stimulation leads to initial increase in growth rate but long term administration of methylphenidate attenuate growth rate that is not due to modulation of appetite but may be due to anxiety and increased activity produce by stimulants. A possible role of DA, 5HT receptors in modulation of appetite and anxiety is discussed

Changes of Heart Rate Variability during Methylphenidate Treatment in Attention-Deficit Hyperactivity Disorder Children: A 12-Week Prospective Study

PURPOSE: The aim of this study was to clarify the relationship between the autonomic nervous system and attention deficit hyperactivity disorder (ADHD) rating scales and to evaluate the usefulness of heart rate variability (HRV) as a psychophysiological biomarker for ADHD. MATERIALS AND METHODS: Subjects were recruited from outpatients in the Department of Child and Adolescent Psychiatry at the Korea University Medical Center from August 2007 to December 2010. Subjects received methylphenidate. Time- and frequency-domain analyses of HRV, the Korean ADHD rating scale (K-ARS), and computerized ADHD diagnostic system were evaluated before treatment. After a 12-week period of medication administration, we repeated the HRV measurements and K-ARS rating. RESULTS: Eighty-six subjects were initially enrolled and 37 participants completed the 12-week treatment and HRV measurements subsequent to the treatment. Significant correlations were found between the K-ARS inattention score and some HRV parameters. All of the HRV parameters, except the standard deviations of the normal-to-normal interval, very low frequency, and low frequency to high frequency, showed a significant positive correlation between baseline and endpoint measures in completers. High frequency (HF) and the square root of the mean squared differences of successive normal-to-normal intervals (RMSSD), which are related to parasympathetic vagal tone, showed significant decreases from baseline to endpoint. CONCLUSION: The HRV test was shown to be reproducible. The decrease in HF and RMSSD suggests that parasympathetic dominance in ADHD can be altered by methylphenidate treatment. It also shows the possibility that HRV parameters can be used as psychophysiological markers in the treatment of ADHD.

A experiência do uso de metilfenidato em adultos diagnosticados com TDAH / The experience of using methylphenidate in adults diagnosed with ADHD / La experiencia del uso de metilfenidato en adultos diagnosticados con TDAH

O Transtorno de Déficit de Atenção e Hiperatividade (TDAH) é visto pelas autoridades médicas internacionais como um problema de ordem pública. O TDAH é envolto em questões que fazem urgir o debate acerca dos efeitos do diagnóstico e sua crescente difusão, entre as quais se destacam a recente expansão do diagnóstico para incluir o adulto e o vertiginoso aumento do consumo do metilfenidato. Como o fornecimento público do metilfenidato é contemplado pela Assistência Farmacêutica do Espírito Santo, a presente pesquisa tem por objetivo analisar os efeitos da Política Estadual de Assistência Farmacêutica referente ao TDAH na produção de subjetividade dos sujeitos que solicitam o metilfenidato. Busca-se abordar as experiências dos usuários no curso de seu tratamento medicamentoso. Foram realizadas entrevistas com solicitantes do metilfenidato maiores de 19 anos residentes em Vitória. Como resultado, percebeu-se que os efeitos advindos do diagnóstico e do uso do medicamento são mais diversos do que os comumente relatados e quase sempre experienciados de forma conflituosa e ambivalente. Ao mesmo tempo, tanto a Ritalina quanto o TDAH parecem funcionar como tecnologias subjetivas que, em sua relação com os sujeitos diagnosticados, transformam suas vidas em graus diversos, indicando a necessidade de acompanhamento dos seus efeitos.

Attention Deficit Hyperactivity Disorder (ADHD) is seen by the international medical authorities as a matter of public order. ADHD is surrounded by issues that stress the importance of debating about the effects of the diagnosis and its growing dissemination. Among them, we highlight recent expansion of the diagnosis to include adults and the skyrocketing consumption of methylphenidate, the main drug indicated for its treatment. Given that Espirito Santo Pharmaceutical Care provides methylphenidate publicly, this article aims to analyze the usage experience of it by adults diagnosed with ADHD, as well as the impact of such a diagnosis in their lives. Therefore, interviews were conducted with methylphenidate users, who were over 19 years old and living in Vitoria. Diagnosis and methylphenidate usage effects found were much more diverse than is commonly reported, and they are often experienced as conflicting and ambivalent. At the same time, as Ritalin as ADHD seem to work as subjective technologies that transform diagnosed people lives to different degrees, pointing to the need to of monitoring its effects.

El Trastorno por Déficit de Atención con Hiperactividad (TDAH) es visto por las autoridades médicas internacionales como un problema de orden público. El TDAH está envuelto en asuntos que hacen urgir el debate sobre los efectos del diagnóstico y su creciente difusión. Entre ellos, cabe destacar la reciente expansión del diagnóstico para incluir al adulto y al vertiginoso aumento del consumo del metilfenidato. Teniendo en cuenta que la provisión pública del metilfenidato es contemplada por la Atención Farmacéutica de Espírito Santo, esta investigación tiene como objetivo analizar los efectos de la Política Estatal de Atención Farmacéutica, dirigida para el TDAH, en la producción de subjetividad de los sujetos que solicitan el metilfenidato. Se busca abarcar las experiencias de los usuarios en el transcurso de su tratamiento medicamentoso. Fueron realizadas entrevistas con los solicitantes del metilfenidato con más de 19 años residentes en Vitória. Como resultado, se encontró que los efectos derivados del diagnóstico y del uso del medicamento son más distintos de los que comúnmente relatados, casi siempre experimentados de modo conflictivo y ambivalente. Al mismo tiempo, tanto la Ritalina como el TDAH parecen funcionar como tecnologías subjetivas que, en su relación con los sujetos diagnosticados, transforman sus vidas en diferentes grados, señalando para la necesidad de acompañamiento de sus efectos.

El dilema del metilfenidato en el TDAH: estudio de caso / The dilema of methylphenidate in the ADHD: case of study

El Trastorno por Déficit de Atención con Hiperactividad (TDAH), es una de las alteraciones del neurodesarrollo de mayor prevalencia; su trinomio sintomático de desatención, hiperactividad e impulsividad, genera significativas dificultades en distintos contextos en donde se desenvuelve el niño. Este trabajo presenta el estudio de caso de un niño de 11 años, diagnosticado con TDAH con predominio de déficit de atención (TDAH-DA), medicado con metilfenidato (MFD) a 36 mg. Se buscó analizar y comparar las diferencias en el desempeño de atención y funciones ejecutivas, evaluadas a través de la batería neuropsicológica Monitoreo Cognitivo Computarizado, en relación a la presencia o ausencia de medicación. Los resultados permiten evidenciar como la suspensión de la mediación en este caso afectó el sistema pre-atencional, la atención sostenida y la flexibilidad cognitiva, y no así la atención selectiva, la fluencia de lectura, la capacidad de nominación y el output motor, en especial de la mano izquierda, los cuales incluso obtuvieron un mejor desempeño al suspenderla. Este estudio plantea los beneficios del MFD en el sistema pre-atencional y atención sostenida más que en la atención selectiva y su influencia en el detrimento de la velocidad de procesamiento.

The Attention Deficit Hyperactivity Disorder (ADHD) is one of the most common neurodevelopmental disorders. Its symptomatic trinomial of inattention, hyperactivity and impulsiveness generates significant difficulties within several contexts in which the child evolves. This work shows a case study of an 11-yearoldboy, diagnosed with ADHD subtype: inattentive, medicated with methylphenidate (MPH) 36mg. The aim of this study was to analyze and compare the differences regarding the development of attention and executive functions, assessed through the neuropsychological battery Cognitive Computerized Monitoring related with the presence or absence of medication. In this case, the results show how withdrawing the medication affects the pre-attentional system, sustained attention and cognitive flexibility. On the other hand, the results demonstrate that the cessation of medication does not affect selective attention, Reading fluency, naming capacity and motor output, especially the right hand’s motor output that even showed better performance when suspending medication. This study confirms the benefits of MPH in the pre-attentional system and sustained attention, more than selective attention and its influence in the detriment of processing speed.

Uma análise da dispensa pública do metilfenidato no Brasil: o caso do Espírito Santo / An analysis of public dispensing of methylphenidate in Brazil: the case of Espirito Santo state

A expansão do transtorno do déficit de atenção e hiperatividade (TDAH) e o crescimento global do consumo do psicoestimulante metilfenidato, indicado para seu tratamento, são desafios atuais de saúde pública em várias partes do mundo. Esta pesquisa visou investigar a dispensa pública do cloridrato de metilfenidato pelo Sistema Único de Saúde brasileiro (SUS), com ênfase no Estado do Espírito Santo (ES). Realizou-se um mapeamento das políticas de assistência farmacêutica das unidades federativas do país, através de contatos telefônicos e consultas nos seus sites oficiais. Verificou-se que entre as Assistências Farmacêuticas estaduais do Brasil, apenas quatro possuem listas padronizadas de dispensa de medicamentos que incluem o metilfenidato, estando entre elas a do ES. As características e variações da demanda e consumo do metilfenidato, registradas nas Farmácias Cidadãs do ES entre os anos de 2009 e 2011, foram analisadas em conjunto com informações colhidas em três entrevistas semiestruturadas com profissionais da Gerência de Assistência Farmacêutica. Constatou-se expressivo aumento no consumo do medicamento via SUS no período analisado, com distribuição assimétrica entre as oito Farmácias Cidadãs do estado. Tais dados destacam a necessidade de uma análise cuidadosa, atenta aos múltiplos aspectos que interferem tanto na constituição do diagnóstico quanto na demanda por seu tratamento, principalmente no que tange ao acompanhamento da dispensa pública do metilfenidato. O estudo se faz fundamental a fim de embasar a formulação de políticas e o funcionamento de serviços voltados para o TDAH, no contexto da saúde pública.

The Attention Deficit Hyperactivity Disorder (ADHD) expansion and the growth of the consumption of methylphenidate, commonly indicated for its treatment, are current challenges the public health sector in many parts of the world. This research aimed to investigate the public dispensing of methylphenidate hydrochloride by the Brazilian Unified Health System (SUS), stressing the case of the state of Espirito Santo (ES). A map of pharmaceutical care Policies in the Brazilian Federal Units was made based on telephone calls and consultations at their official websites. It was found that among all state's Pharmaceutical Care Management of the country only 4, including the state of ES, have standardized lists for medicine dispensing in wich methylphenidate is included. The characteristics and variations in demand and consumption of methylphenidate registered in public pharmacies of ES between 2009 and 2011 were analyzed, in conjunction with information gathered in three semi-structured interviews with professionals in the Pharmaceutical Care Management. A significant increase in the consumption of this medicine via SUS was found throughout the analyzed period, with an asymmetric distribution between the eight public pharmacies of ES. These data highlight the need for careful analysis, focusing on the multiple aspects that interfere both in the formation of the diagnosis and in the demand for treatment, mainly in relation to the monitoring of public dispensation of methylphenidate. The study is essential in the public health context in order to support the policies formulation and the functioning of public services for ADHD.

Use of methylphenidate among medical students: a systematic review / Uso de metilfenidato entre estudantes de medicina: revisão sistemática

OBJECTIVE: To review the effects of methylphenidate on cognitive enhancement, memory, and performance in medical students. METHODS: A review of four databases (LILACS, PubMed, ScienceDirect, and SciELO), analyzing the title and of all articles published between 1990 and 2012 in English, Portuguese, and Spanish. Selected articles were read in entirety, including in the review those that met the established criteria. RESULTS: The prevalence of use among medical students reached 16%, with no gender difference. Most students began using the drug after entering the university, and the reasons cited to justify it are related to enhancing academic performance. CONCLUSION: There is no evidence in the literature that the use of methylphenidate is beneficial in terms of memory or learning. The drug simply increases wakefulness and alertness, reducing the time of sleep.

OBJETIVO: Revisar o uso de metilfenidato em estudantes de medicina hígidos, abordando a prevalência, variáveis demográficas, motivos e possível melhora do desempenho acadêmico desta população. MÉTODOS: Realizou-se uma revisão nas bases de dados LILACS, PubMed, ScienceDirect e Sci-ELO, analisando-se o título e resumo de todos os artigos publicados entre 1990 e 2012 nos idiomas inglês, português e espanhol. Os artigos selecionados foram lidos de forma integral, incluindo-se na revisão aqueles que atenderam aos critérios determinados. RESULTADOS: A prevalência do uso em estudantes de medicina chega a 16%, não havendo diferença entre os gêneros. A maioria dos alunos iniciou o uso após ingresso no nível superior e os motivos citados para justificá-lo estão relacionados à melhora do desempenho acadêmico. CONCLUSÃO: Não existe evidência na literatura contemporânea que o uso de metilfenidato é benéfico em relação à memória ou aprendizagem. A droga apenas torna o usuário mais desperto e alerta, reduzindo o tempo de sono.

Uso não terapêutico do metilfenidato: uma revisão / Non-medical use of methylphenidate: a review

INTRODUCTION: Methylphenidate is a psychostimulant medication used for the treatment of attention deficit hyperactivity disorder and narcolepsy. However, it has also been used for non-medical purposes, e.g. to produce euphoria, to increase self-esteem, and to achieve the so-called neurocognitive enhancement, decreasing the feeling of tiredness and increasing focus and attention. OBJECTIVE: To describe, from theoretical and contextual points of view, the potential for abuse and non-medical use of methylphenidate. METHOD: The PubMed, SciELO and Cochrane databases were searched using the following keywords in Portuguese: metilfenidato, transtorno do déficit de atenção com hiperatividade, facilitadores dos processos cognitivos or agentes nootrópicos, and abuso de substâncias; and in English: methylphenidate, attention deficit disorder with hyperactivity, cognitive enhancement or nootropic agents, and substance abuse. Studies published between 1990 and 2010 were selected for review. RESULTS: Non-medical use of methylphenidate is a relevant topic that raises important ethical and scientific questions in several areas, e.g. pharmacological and neurobiological characteristics, evidence of methylphenidate use, forms of non-medical use of methylphenidate, mechanisms of action, and therapeutic application of methylphenidate. According to the review, methylphenidate can generally influence performance as a result of its stimulatory effect. Notwithstanding, evidence does not support the conclusion that it can enhance cognitive performance. CONCLUSION: Health professionals need to acquire expert knowledge and inform patients and their families on the methylphenidate potential for abuse when used with non-medical purposes.

INTRODUÇÃO: O metilfenidato é um medicamento psicoestimulante usado no tratamento do transtorno de déficit de atenção e hiperatividade e da narcolepsia. No entanto, a droga também vem sendo utilizada com fins não terapêuticos, por exemplo para produzir euforia, aumentar a autoestima e obter o chamado aprimoramento neurocognitivo, diminuindo a sensação de cansaço e aumentando o foco e a atenção. OBJETIVO: Descrever, sob o ponto de vista teórico e contextual, o potencial de abuso do metilfenidato quando usado com fins não terapêuticos. MÉTODO: Foi realizada uma pesquisa nos bancos de dados PubMed, SciELO e Cochrane, utilizando os seguintes termos em português: metilfenidato, transtorno do déficit de atenção com hiperatividade, facilitadores dos processos cognitivos or agentes nootrópicos e abuso de substâncias; e, em inglês: methylphenidate, attention deficit disorder with hyperactivity, cognitive enhancement or nootropic agents e substance abuse. Foram selecionados estudos publicados entre 1990 e 2010. RESULTADOS: O uso não terapêutico do metilfenidato é um tema relevante e que suscita questões científicas e éticas importantes sob diversos aspectos, por exemplo características farmacológicas e neurobiológicas, evidência de uso da droga, formas não terapêuticas de uso, mecanismos de ação e aplicação terapêutica do metilfenidato. De acordo com a revisão o metilfenidato pode, em geral, influenciar o desempenho como resultado de seu efeito estimulatório. No entanto, independentemente disso, as evidências não apoiam a conclusão de que ele possa promover um melhor desempenho cognitivo. CONCLUSÃO: É importante que profissionais da saúde tenham conhecimento e informem os pacientes e suas famílias sobre o potencial de abuso do metilfenidato quando usado com fins não terapêuticos.

Utilización de resonancia magnética funcional 3T para evaluar los efectos del metilfenidato sobre la función de atención en pacientes con déficit atencional / Using 3T functional magnetic resonance imaging to assess attention in patients with clinically diagnosed attention-deficit disorder before and after methylphenidate administration: assessment of drug effects on attentional function

Our objective was to assess the level of attention in patients with attention-deficit disorder using functional MRI by comparing test results before and after the use of methylphenidate. We studied 6 pediatric patients and 2 adults. All of them were subject to a attention test before and after methylphenidate administration. The pediatric patient population showed a positive difference, with higher levels of attention in the methylphenidate group. In the adult group, improvement in the attentional function was observed in one of them. This method allowed us to physiologically assess if improvement in attentional function occurred after methylphenidate administration. Therefore, this technique is viewed as an important tool for evaluating the usefulness of treatment for attention-deficit.hyperactivity disorder.

El objetivo es evaluar el nivel de atención utilizando resonancia funcional en pacientes con déficit atencional, comparando los resultados entre los test de atención realizados antes y después del uso de metilfenidato. Se estudiaron 6 pacientes pediátricos y 2 adultos. Cada uno realizó un test de atención antes y después de usar metilfenidato. El estudio grupal de los pacientes pediátricos mostró una diferencia positiva con mayor nivel de atención en el grupo con tratamiento con metilfenidato. En el test realizado con medicamento en los adultos se evidenció mejoría en la función de atención en uno de ellos. Este método permite medir fisiológicamente si existe mejoría en la función de atención después de la utilización de metilfenidato, constituyendo una herramienta para evaluar la utilidad del tratamiento del déficit atencional.

Repeated exposure of adolescent rats to oral methylphenidate does not induce behavioral sensitization or cross-sensitization to nicotine

Several lines of evidence indicate that the use of stimulant drugs, including methylphenidate (MPD), increases tobacco smoking. This has raised concerns that MPD use during adolescence could facilitate nicotine abuse. Preclinical studies have shown that repeated treatment with an addictive drug produces sensitization to that drug and usually cross-sensitization to other drugs. Behavioral sensitization has been implicated in the development of drug addiction. We examined whether repeated oral MPD administration during adolescence could induce behavioral sensitization to MPD and long-lasting cross-sensitization to nicotine. Adolescent male Wistar rats were treated orally with 10 mg/kg MPD or saline (SAL) from postnatal day (PND) 27 to 33. To evaluate behavioral sensitization to MPD in adolescent rats (PND 39), the SAL pretreated group was subdivided into two groups that received intragastric SAL (1.0 mL/kg) or MPD (10 mg/kg); MPD pretreated rats received MPD (10 mg/kg). Cross-sensitization was evaluated on PND 39 or PND 70 (adulthood). To this end, SAL- and MPD-pretreated groups received subcutaneous injections of SAL (1.0 mL/kg) or nicotine (0.4 mg/kg). All groups had 8 animals. Immediately after injections, locomotor activity was determined. The locomotor response to MPD challenge of MPD-pretreated rats was not significantly different from that of the SAL-pretreated group. Moreover, the locomotor response of MPD-pretreated rats to nicotine challenge was not significantly different from that of the SAL-pretreated group. This lack of sensitization and cross-sensitization suggests that MPD treatment during adolescence does not induce short- or long-term neuroadaptation in rats that could increase sensitivity to MPD or nicotine.

Efeito do metilfenidato no processamento auditivo em crianças e adolescentes com transtorno do deficit de atenção/hiperatividade / Effects of methylphenidate in auditory processing evaluation of children and adolescents with attention deficit hyperactivity disorder

OBJETIVO: Comparar o desempenho em teste de avaliação do processamento auditivo (PA) num grupo de crianças e adolescentes com transtorno do déficit de atenção e hiperatividade (TDAH) pré e pós-metilfenidato. MÉTODO: Foram aplicados testes comportamentais padronizados de avaliação do PA em 29 indivíduos com TDAH na faixa etária de 7 a 15 anos, de ambos os sexos. Utilizou-se um grupo de comparação de 29 indivíduos sem déficit de atenção, com e sem transtornos de aprendizado. RESULTADOS: O grupo com TDAH apresentou desempenho nos testes de PA semelhante ao grupo controle sem transtornos do aprendizado sendo seus resultados ainda melhores na ocasião pós-medicação. O grupo sem déficit de atenção e com problemas de aprendizagem apresentou o pior desempenho nos testes de PA e o grupo sem déficit de atenção e sem problemas de aprendizagem foi o que apresentou o melhor desempenho. CONCLUSÃO: O teste de PA não permitiu diferenciar portadores de TDAH de controles pareados; o metilfenidato se associou a melhora do desempenho nos testes de PA nos portadores de TDAH.

PURPOSE: To compare the performance of a group of children and adolescents diagnosed with attention deficit hyperactivity disorder (ADHD) pre and post-methylphenidate use in a behavioral auditory processing test battery (AP). METHOD: Twenty-nine subjects, male and female, ranging from 7 to 15 years old have undergone different behavioral auditory processing tests. A control group composed of 29 subjects with and without learning disabilities was also evaluated. RESULTS: The group with ADHD had a performance similar to the control group without learning disabilities which improved after medication. The group with learning disabilities and without ADHD had the worst performance in tests while the group without learning disabilities and without ADHD exhibited the best ones. CONCLUSION: The AP battery was unable to distinguish ADHD patients from paired controls; the use of methylphenidate improved the performance on AP tests of ADHD group in the post-medication evaluation.

Methylphenidate. An update on extended-release formulations

Methylphenidate remains the mainstay of pharmacological management in attention deficit hyperactivity disorder [ADHD]. Despite having been available for over half a century, methylphenidate's original formulation has been modified with the main purpose of extending its duration of action. This article will present a brief review of how these new formulations vary and how these should be selected, considering the evidence available on their effectiveness and on the individual needs of the patient

Methylphenidate increased regional cerebral blood flow in subjects with attention deficit/hyperactivity disorder

The regional cerebral blood flow (rCBF) responses to methylphenidate (MPH) treatment were examined in children with attention deficit/hyperactivity disorder (ADHD). Thirty-two male children, diagnosed with ADHD by the DSM-IV diagnostic criteria, other behavioral assessment scales and neuropsychological battery, were studied using 99mTc-HMPAO-single photon emission computed tomography (SPECT). Subjects were studied before and after MPH treatment. First, using an image subtraction method, we obtained a NDR parametric image of each patient and found increased cerebral blood flow in the frontal lobes, caudate nuclei and thalamic areas after treatment. When the changes in SPECT and clinical response were compared, the matching rate, sensitivity and specificity between them were found to be 77.1, 80.0 and 79.2%, respectively. Second, three transaxial brain slices delineating anatomically defined regions of interest (ROI) at 20, 40, and 60mm above the orbitomeatal line (OML) were used, with the average number of counts for each region of interest normalized to the area of the cerebellar maximal uptake. The left and right prefrontal areas, and caudate and thalamic areas showed significant increases in rCBF after MPH treatment. These findings suggested MPH could affect the function of the fronto-striato-thalamic circuit, which is known as the pathophysiologic site of ADHD and could be used to correct the underlying brain dysfunction of ADHD.

Tratamiento del trastorno por déficit atencional con hiperactividad / Treatment of the attention deficit disorder with hyperactivity

El comportamiento impulsivo, hiperactivo y con poca capacidad de atención en niños se considera un trastorno cuando éste es severo, inapropiado y altera las funciones en el hogar y en el colegio. Actualmente existen dos términos para denominar este trastorno: trastorno de déficit atencional con hiperactividad (TDAH) y trastorno hiperkinético (TH), término ya poco usado. Resulta a veces difícil distinguir el TDAH de otras patologías como por ejemplo: trastorno de conducta, trastornos emocionales, síndrome depresivo, problemas de aprendizaje, ya que éstos suelen asociarse a las características que presentan los niños con TDAH

Observación longitudinal de casos con déficit atencional, hiperactividad motora e inestabilidad emocional en niños provenientes del sector público de salud y educación del Area Norte de la ciudad de Santiago / Longitudinal study of cases with attention deficit, motor hyperactivity and emotional instability in children from health public area and education of nort area from Santiago city

Se analizaron 84 pacientes con las manifestaciones clínicas características del DAHI (Déficit Atencional con Hiperactividad y Excesiva Impulsividad) en un estudio de observación longitudinal a partir de 1983 hasta 1994 en el sector norte de Santiago. Se decidió incluir en el estudio a los pacientes referidos a la clínica ambulatoria de Neurología del Hospital Roberto del Río, durante el mencionado período, desde los Consultorios de Atención Primaria. En casi todos los casos se empleó dextroanfetamina (en casos justificados se empleó metilfenidato), que era entregada a los pacientes si asistían a los controles periódicamente, observándose un adecuado efecto terapéutico, con efectos adversos en pocos casos y sin evidencias de dependencia o aumento de tolerancia. A pesar de ser pacientes complicados desde el punto de vista biológico, económico y social, el plan terapeútico fue satisfactorio en términos generales, siendo los resultados más efectivos y consistentes en quienes la sintomatología del déficit atencional no se acompañaba de alteraciones conductuales, fueron menos favorables cuando hubo manifestaciones de disfunción cerebral orgánica y más problemáticos en la medida que habían evidencias de disfunción psicosocial en el entorno familiar. Los resultados sugieren que la dextroanfetamina puede ser considerada como favorable en una alta proporción de casos independientemente de las condiciones biológicas y del desarrollo psicomotor, pero fueron fundamentales la continuidad y adherencia al plan terapeútico, tanto el manejo ambiental y al uso adecuado del fármaco por parte del paciente y de la familia