O presente trabalho visa desenvolver micropartículas na forma farmacêutica pó inalatório contendo levodopa, um fármaco empregado no tratamento da doença de Parkinson. As micropartículas foram preparadas pela técnica de secagem por aspersão utilizando os polímeros ácido hialurônico, quitosana e hidroxipropilmetilcelulose. Desenvolveu-se método analítico indicativo de estabilidade por cromatografia líquida de alta eficiência (CLAE) para o controle de qualidade da formulação, bem como, estudos preliminares de estabilidade e determinação da cinética de fotodegradação. Utilizou-se coluna analítica ACE® RP-18 com tampão fosfato monobásico 0,01 M, ajustado a pH 3,0 como fase móvel, com vazão de 1,0 mL/min e detecção em 280 nm. A linearidade foi obtida na faixa de concentração de 10-60 μg/mL (r2=0,9999) (α=5%). Os limites de quantificação e detecção foram 208 ng/mL e 46,8 ng/mL, respectivamente. Os excipientes e produtos de degradação não apresentaram interferência na eluição da levodopa. Resultados adequados foram encontrados para repetibilidade, precisão intermediária (<2% DPR), exatidão e robustez. Os resultados de recuperação estiveram na faixa de 100,01% a 100,93%. A cinética de fotodegradação em solução frente à luz UVC indicou reação de segunda ordem. A caracterização da formulação demonstrou resultados satisfatórios em relação ao teor, diâmetro aerodinâmico, densidade, teor de umidade e morfologia. A formulação apresentou tamanho de partícula inferior a 16,2 μm e formato arredondado com estrutura oca. A densidade de compactação mostrou valores entre 0,06-0,08 g/cm3 e diâmetro aerodinâmico abaixo de 5 μm, sugerindo que os pós são apropriados para a deposição nas regiões mais profundas do pulmão. Além disso, realizou-se estudo de citotoxicidade pulmonar in vivo, o qual demostrou que a administração intratraqueal das micropartículas não induziu aumentos significativos dos indicadores de toxicidade pulmonar, em comparação ao grupo controle-positivo. Portanto, a avaliação da toxicidade aguda sugere que a liberação pulmonar de levodopa pode ser uma nova e promissora via de administração para este fármaco. / The aim of this study was to develop microparticles containing levodopa for pulmonary delivery, a drug used in the treatment of Parkinson´s disease. The microparticles were prepared by spray-drying using the polymers hyaluronic acid, chitosan and hydroxypropyl methylcellulose. A stability-indicating method was developed and validated for quality control by high performance liquid chromatography (HPLC), as well as, stability studies and photodegradation kinetics. The analytical column ACE® RP-18 was operated with 0.01 M monobasic potassium phosphate, adjusted to a pH value 3.0 as mobile phase, at a flow rate of 1.0 mL/min with detection wavelength at 280 nm. Linearity was obtained over the concentration range of 10-60 μg/mL (r2=0.9999) (α=5%). The quantification limit and detection limit were 208 ng/mL and 46.8 ng/mL, respectively. Excipient ingredients and resulting degradation products had no interference in the levodopa elution. Adequate results were found for repeatability, inter-day precision (<2% RSD), accuracy and robustness. The recovery results were in the range of 100.01% to 100.93%. The photodegradation kinetics in solution front to UVC light indicated the second-order reaction. The formulation showed satisfactory results for drug content, aerodynamic diameter, density, water content and morphology. The formulation presented particle size below 16.2 μm and spherical shape presenting a hollow structure. The tapped density ranged from 0.06-0.08 g/cm3 and an aerodynamic diameter smaller than 5 μm, suggesting that the powders are appropriated for deep lung deposition. Besides that, a cytotoxicity study in vivo was performed which showed that microparticles intratracheal administration did not induce significant increases of lung toxicity indicators compared with the positive control. Therefore, the acute lung toxicity evaluation suggests that pulmonary levodopa delivery could be a new and promising administration route for this drug.

O presente trabalho visa desenvolver micropartículas na forma farmacêutica pó inalatório contendo levodopa, um fármaco empregado no tratamento da doença de Parkinson. As micropartículas foram preparadas pela técnica de secagem por aspersão utilizando os polímeros ácido hialurônico, quitosana e hidroxipropilmetilcelulose. Desenvolveu-se método analítico indicativo de estabilidade por cromatografia líquida de alta eficiência (CLAE) para o controle de qualidade da formulação, bem como, estudos preliminares de estabilidade e determinação da cinética de fotodegradação. Utilizou-se coluna analítica ACE® RP-18 com tampão fosfato monobásico 0,01 M, ajustado a pH 3,0 como fase móvel, com vazão de 1,0 mL/min e detecção em 280 nm. A linearidade foi obtida na faixa de concentração de 10-60 μg/mL (r2=0,9999) (α=5%). Os limites de quantificação e detecção foram 208 ng/mL e 46,8 ng/mL, respectivamente. Os excipientes e produtos de degradação não apresentaram interferência na eluição da levodopa. Resultados adequados foram encontrados para repetibilidade, precisão intermediária (<2% DPR), exatidão e robustez. Os resultados de recuperação estiveram na faixa de 100,01% a 100,93%. A cinética de fotodegradação em solução frente à luz UVC indicou reação de segunda ordem. A caracterização da formulação demonstrou resultados satisfatórios em relação ao teor, diâmetro aerodinâmico, densidade, teor de umidade e morfologia. A formulação apresentou tamanho de partícula inferior a 16,2 μm e formato arredondado com estrutura oca. A densidade de compactação mostrou valores entre 0,06-0,08 g/cm3 e diâmetro aerodinâmico abaixo de 5 μm, sugerindo que os pós são apropriados para a deposição nas regiões mais profundas do pulmão. Além disso, realizou-se estudo de citotoxicidade pulmonar in vivo, o qual demostrou que a administração intratraqueal das micropartículas não induziu aumentos significativos dos indicadores de toxicidade pulmonar, em comparação ao grupo controle-positivo. Portanto, a avaliação da toxicidade aguda sugere que a liberação pulmonar de levodopa pode ser uma nova e promissora via de administração para este fármaco. / The aim of this study was to develop microparticles containing levodopa for pulmonary delivery, a drug used in the treatment of Parkinson´s disease. The microparticles were prepared by spray-drying using the polymers hyaluronic acid, chitosan and hydroxypropyl methylcellulose. A stability-indicating method was developed and validated for quality control by high performance liquid chromatography (HPLC), as well as, stability studies and photodegradation kinetics. The analytical column ACE® RP-18 was operated with 0.01 M monobasic potassium phosphate, adjusted to a pH value 3.0 as mobile phase, at a flow rate of 1.0 mL/min with detection wavelength at 280 nm. Linearity was obtained over the concentration range of 10-60 μg/mL (r2=0.9999) (α=5%). The quantification limit and detection limit were 208 ng/mL and 46.8 ng/mL, respectively. Excipient ingredients and resulting degradation products had no interference in the levodopa elution. Adequate results were found for repeatability, inter-day precision (<2% RSD), accuracy and robustness. The recovery results were in the range of 100.01% to 100.93%. The photodegradation kinetics in solution front to UVC light indicated the second-order reaction. The formulation showed satisfactory results for drug content, aerodynamic diameter, density, water content and morphology. The formulation presented particle size below 16.2 μm and spherical shape presenting a hollow structure. The tapped density ranged from 0.06-0.08 g/cm3 and an aerodynamic diameter smaller than 5 μm, suggesting that the powders are appropriated for deep lung deposition. Besides that, a cytotoxicity study in vivo was performed which showed that microparticles intratracheal administration did not induce significant increases of lung toxicity indicators compared with the positive control. Therefore, the acute lung toxicity evaluation suggests that pulmonary levodopa delivery could be a new and promising administration route for this drug.

Para avaliar a influencia em curto prazo da reposição dopaminérgica na flutuação da atenção em pacientes com DP, a latência média e o desvio-padrão da latência do tempo de reação simples e com escolha foram estabelecidos em 15 pacientes com DP antes e 90 minutos depois da administração da dose habitual matutina de levodopa e em 15 controles normais. Verificou-se , além de efeitos motores, maior sincronia nas latências de testes de tempo de reação complexos, mas não nos simples, sugerindo efeitos da dopamina em mecanismos atencionais e/ou de controle executivo que envolvam flexibilidade na identificação do estímulo e/ou na escolha da resposta / To evaluate short time effects of dopaminergic medication on fluctuation of attention in PD patients, simple and choice reaction latency and latency standard deviation was determined in 15 PD patients before and 90 min. after usual early morning levodopa dose and in 15 normal controls. Besides motor improvement, improved synchrony on complex but not on simple reaction time tests was observed, suggesting dopamine attention and executive control modulation, probably thru stimulus identification and action selection flexibility

Background: The valuation of risks and the speed with which decisions are made and acted upon are important characteristics of everyone’s personality. These characteristics exist along a continuum that ranges from weak to strong expressions of impulsivity. In certain situations it is crucial to decide and react quickly. Yet these qualities can prove disadvantageous if they are expressed excessively and persistently. Self-reports, such as the Barratt Impulsiveness Scale, inquire long-term patterns of behavior to assess the level of trait impulsivity. Experimental paradigms, on the other hand, quantify specific impulsive facets, which depend rather on the current environment and state of the individual. These paradigms include decision-making tasks that capture impulsive facets such as the attitudes towards delays, risks and losses. Research indicates that these attitudes are governed by a valuation network of cortical and subcortical brain regions along with several neurotransmitters. Within this intricate network, frontostriatal circuits innervated by dopamine were identified as an important locus of control. Although a wealth of studies have subsequently examined the influence of the dopaminergic system on impulsive choice, the regulatory mechanisms remain largely unclear. This may originate from the interrelations within the valuation network but also from the complexity of the dopaminergic system itself. Seminal investigations have shown that this complicated interplay may be partly explained by an underlying inverted U-shaped function, which describes an optimal level of dopamine, flanked by increasing impulsivity in the context of sub- and supraoptimal signaling. Research Question: This work aimed to shed more light on the inverted-U theory by characterizing the contribution of dopaminergic signaling to trait and decisional impulsivity, and by clarifying whether the manipulation of decisional impulsivity through boosting striatal dopamine via L-DOPA depends on baseline signaling. We hypothesized that individuals with optimal striatal dopaminergic signaling as measured by [18F]DOPA positron emission tomography would feature low trait impulsivity as assessed with the Barratt Impulsiveness Scale. By contrast, individuals with suboptimal signaling were hypothesized to exhibit stronger trait impulsivity corresponding to higher scores on the Barratt Impulsiveness Scale. Assuming an inverted U-shaped function, we predicted that the dopamine precursor L-DOPA would reduce impulsive decisions in the latter but overdose individuals with an already optimal signaling and thus make their choice behavior more impulsive. Materials and Methods: The present studies combined trait and choice measures of impulsivity with the investigation of the dopaminergic system by positron emission tomography and a pharmacological manipulation. In a double-blind, randomized, placebo-controlled, counter-balanced, repeated measures design, 87 healthy adults completed a computerized decision-making test battery. The battery includes four tasks, each of which captures one distinct dimension of impulsive choice: a delay discounting task quantifies delay discounting, a probability discounting for gains task quantifies risk-seeking for gains, a probability discounting for losses task quantifies risk-seeking for losses and a mixed gambles task quantifies loss aversion. In order to test for baseline-dependent L-DOPA effects on these dimensions, we controlled for trait impulsivity (a suggested proxy for central dopamine) as assessed with the Barratt Impulsiveness Scale (N = 87) and striatal dopamine as measured by [18F]DOPA positron emission tomography (in 60 of the 87 participants). Results: Our findings highlight the complex role of dopamine in impulsivity and the heterogeneity of its underlying biology. Participants who scored relatively high on the Barratt Impulsiveness Scale appeared to benefit from L-DOPA, indicated by a decrease in delay discounting, risk-seeking for gains and loss aversion. Participants with low levels of impulsive personality traits as assessed with the Barratt Impulsiveness Scale, on the other hand, exhibited opposite changes in choice preference. Bearing in mind that trait impulsivity may be a behavioral expression of central dopamine, our results suggest an inverted U-shaped function in which impulsive decision-making arises from both sub- and supraoptimal dopaminergic activity. We found further support for an inverted U-shaped function when accounting for baseline dopamine as measured by [18F]DOPA positron emission tomography. Participants who had higher values on the Barratt Impulsiveness Scale featured low, presumably suboptimal, striatal dopamine signaling. After enhancing and possibly optimizing the basal signaling with L-DOPA, they discounted delays less and tended to less risk-seeking for gains and loss aversion. By contrast, participants with low trait impulsivity as assessed with the Barratt Impulsiveness Scale exhibited higher striatal dopamine, probably corresponding to optimal baseline activity as L-DOPA shifted their choice behavior in the opposite direction, thus indicating a dopamine overdose. The intake of L-DOPA had no influence on risk-seeking for losses, even when differences in trait impulsivity and basal levels of striatal dopamine were considered. Performance on tasks of the decision-making battery produced only few, weak intercorrelations, which implies that delay discounting, risk-seeking for gains, risk-seeking for losses and loss aversion represent dissociable aspects of choice. Conclusions: Our results endorse and extend previous findings that indicated an inverted U-shaped influence of dopamine on delay discounting and decisions under risk. Utilizing a battery of largely independent choice tasks, we were able to disentangle the effect of gains and losses on risky decisions. Whereas risk-seeking for gains seemed to depend on baseline dopamine signaling, we found no evidence for dopaminergic neurotransmission affecting risk-seeking for losses. Consistent with the literature, our data shows that self-reported trait impulsivity and experimentally measured decision-making dimensions are distinct phenomena within the multidimensional construct of impulsivity. Our analyses further revealed that choice measures were differentially related to dopaminergic activity, which suggests that they represent not merely descriptive distinctions but separable psychobiological decision-making processes. Since the regulation of choice probably spreads across neurotransmitter systems, more research on these systems is warranted. After identifying the precise mechanisms within each system, comprehensive studies of their interplay may ultimately uncover how impulsive decisions arise. Considering a series of studies that related steep delay discounting and excessive risk-seeking to poor health and mental illness, the acquired knowledge may also inform translational research on impulsivity-related maladies. / Hintergrund: Die Bewertung von Risiken und die Schnelligkeit mit der Entscheidungen getroffen und umgesetzt werden, sind wichtige Persönlichkeitsmerkmale eines jeden Menschen. Diese Merkmale existieren entlang eines Kontinuums, das von schwachen bis zu starken Ausprägungen von Impulsivität reicht. In bestimmten Situationen ist es entscheidend, schnell zu entscheiden und zu reagieren. Diese Eigenschaften können sich jedoch als nachteilig erweisen, wenn sie übermäßig und beharrlich zum Ausdruck gebracht werden. Selbstauskunftsberichte wie die Barratt-Impulsivitätsskala fragen nach überdauernden Verhaltensmustern, um den Grad impulsiver Persönlichkeit zu beurteilen. Experimentelle Paradigmen hingegen quantifizieren spezifische impulsive Facetten, die eher von der aktuellen Umwelt und Verfassung des Individuums abhängen. Zu diesen Paradigmen gehören Entscheidungsaufgaben, die impulsive Facetten wie die Einstellungen zu Verzögerungen, Risiken und Verlusten erfassen. Forschungsarbeiten legen nahe, dass diese Einstellungen von einem Bewertungsnetzwerk aus kortikalen und subkortikalen Hirnregionen zusammen mit mehreren Neurotransmittern gesteuert werden. Innerhalb dieses komplizierten Netzwerks wurden durch Dopamin innervierte frontostriatale Schaltkreise als wichtige Kontrollpunkte identifiziert. Obwohl nachfolgend eine Fülle von Studien den Einfluss des dopaminergen Systems auf impulsive Entscheidungen untersucht hat, bleiben die Regulationsmechanismen weitgehend unklar. Dies mag von den Wechselbeziehungen innerhalb des Bewertungsnetzwerks, aber auch von der Komplexität des dopaminergen Systems selbst herrühren. Bahnbrechende Untersuchungen haben gezeigt, dass dieses komplizierte Zusammenspiel teilweise durch eine zugrundeliegende umgekehrte U-Funktion erklärt werden könnte, die einen optimalen Dopamin-Spiegel flankiert von zunehmender Impulsivität bei sub- und supraoptimaler Signalgebung beschreibt. Fragestellung: Diese Arbeit zielte darauf ab, die umgekehrte U-Hypothese näher zu beleuchten, indem sie den Beitrag der dopaminergen Signalgebung zu Persönlichkeits- und Entscheidungsimpulsivität charakterisiert und klärt, ob die Manipulation der Entscheidungsimpulsivität durch Erhöhung des striatalen Dopamins mittels L-DOPA vom Baseline-Signal abhängt. Wir nahmen an, dass Individuen mit optimaler striataler dopaminerger Signalgebung, gemessen mit der 18F-DOPA Positronen-Emissions-Tomographie, eine geringe Persönlichkeitsimpulsivität aufweisen würden, die mit der Barratt-Impulsivitätsskala bewertet wurde. Bei Individuen mit suboptimaler Signalgebung vermuteten wir hingegen eine impulsivere Persönlichkeit, die höheren Werten auf der Barratt-Impulsivitätsskala entspricht. Unter Annahme einer umgekehrten U-Funktion prognostizierten wir, dass der Dopamin-Vorläufer L-DOPA bei letzteren impulsive Entscheidungen reduzieren würde, aber Individuen mit bereits optimaler Signalgebung überdosieren und somit deren Entscheidungsverhalten impulsiver machen würde. Material und Methoden: Die hier präsentierten Studien kombinierten Maße von Persönlichkeits- und Entscheidungsimpulsivität mit der Untersuchung des dopaminergen Systems mittels Positronen-Emissions-Tomographie und einer pharmakologischen Manipulation. In einem doppelblinden, randomisierten, placebokontrollierten, balancierten Messwiederholungsdesign absolvierten 87 gesunde Erwachsene eine computerbasierte Testbatterie zum Entscheidungsverhalten. Die Batterie umfasst vier Aufgaben, von denen jede eine bestimmte Dimension impulsiver Entscheidungsfindung erfasst: „Delay Discounting“ quantifiziert die Fähigkeit zum Belohnungsaufschub, „Probability Discounting for Gains“ quantifiziert das Risikoverhalten bei Gewinnen, „Probability Discounting for Losses“ quantifiziert das Risikoverhalten bei Verlusten und „Mixed Gambles“ quantifiziert die Verlustaversion. Um auf baseline-abhängige L-DOPA-Effekte bei diesen Dimensionen zu testen, kontrollierten wir für Persönlichkeitsimpulsivität (ein vorgeschlagener Proxy für zentrales Dopamin), die mit der Barratt-Impulsivitätsskala (N = 87) bewertet wurde, und für striatales Dopamin, das mit der 18F-DOPA Positronen-Emissions-Tomographie gemessen wurde (bei 60 der 87 Probanden und Probandinnen). Ergebnisse: Unsere Ergebnisse unterstreichen Dopamins komplexe Rolle in der Impulsivität und die Heterogenität der dieser zugrundeliegenden Biologie. Probanden und Probandinnen, die auf der Barratt-Impulsivitätsskala relativ hoch punkteten, schienen von L-DOPA zu profitieren, was sich in einer Abnahme der Abwertung von verzögerten Belohnungen, der Risikobereitschaft bei Gewinnen und der Verlustaversion zeigte. Probanden und Probandinnen mit einem geringen Grad an impulsiven Persönlichkeitszügen (bewertet mit der Barratt Impulsivitätsskala) zeigten dagegen entgegengesetzte Veränderungen in der Entscheidungspräferenz. In dem Bewusstsein, dass Persönlichkeitsimpulsivität ein Verhaltensausdruck zentralen Dopamins sein mag, suggerieren unsere Ergebnisse eine umgekehrte U-Funktion, bei der impulsives Entscheidungsverhalten sowohl aus sub- als auch supraoptimaler dopaminerger Aktivität erwächst. Wir fanden weiteren Anhalt für eine umgekehrte U-Funktion nach Berücksichtigung des Baseline-Dopamins, gemessen mit der 18F-DOPA Positronen-Emissions-Tomographie. Teilnehmer und Teilnehmerinnen mit höheren Werten auf der Barratt-Impulsivitätsskala wiesen eine niedrige, vermutlich suboptimale, striatale Dopamin-Signalgebung auf. Nach Erhöhung und möglicherweise Optimierung der basalen Signalgebung mittels L-DOPA werteten diese Verzögerungen weniger ab und neigten zu weniger Risikobereitschaft bei Gewinnen und Verlustaversion. Im Gegensatz dazu wiesen Teilnehmer und Teilnehmerinnen mit geringer Persönlichkeitsimpulsivität (bestimmt mit der Barratt-Impulsivitätsskala) ein höheres striatales Dopamin auf. Dies entsprach wahrscheinlich einer optimalen Baseline-Aktivität, da L-DOPA deren Entscheidungsverhalten in die entgegengesetzte Richtung verlagerte, hinweisend auf eine Dopamin-Überdosierung. Die Einnahme von L-DOPA hatte keinen Einfluss auf das Risikoverhalten bei Verlusten, selbst wenn Unterschiede in der Persönlichkeitsimpulsivität und den Basalspiegeln von striatalem Dopamin berücksichtigt wurden. Die Performanz in den Aufgaben der Entscheidungsbatterie war nur wenig und schwach untereinander korreliert, was impliziert, dass „Delay Discounting“, „Probability Discounting for Gains“, „Probability Discounting for Losses“ und „Mixed Gambles“ separate Entscheidungsaspekte repräsentieren. Schlussfolgerungen: Unsere Ergebnisse bestätigen und erweitern bisherige Erkenntnisse, die nahelegten, dass der Belohnungsaufschub und Entscheidungen unter Risiken unter einem umgekehrt U-förmigen Einfluss Dopamins stehen. Mit einer Batterie von weitgehend unabhängigen Entscheidungsaufgaben konnten wir die Effekte von Gewinnen und Verlusten auf riskante Entscheidungen auftrennen. Während das Risikoverhalten bei Gewinnen vom Baseline-Dopamin-Signal abhängig zu sein schien, fanden wir keine Hinweise dafür, dass sich die dopaminerge Neurotransmission auf das Risikoverhalten bei Verlusten auswirkt. Übereinstimmend mit der Literatur zeigen unsere Daten, dass selbstberichtete Persönlichkeitsimpulsivität und experimentell gemessene Entscheidungsdimensionen unterschiedliche Phänomene innerhalb des mehrdimensionalen Konstrukts der Impulsivität sind. Unsere Analysen ergaben ferner, dass Entscheidungsmaße in unterschiedlicher Beziehung zu dopaminerger Aktivität standen. Dies legt nahe, dass diese nicht nur beschreibende Unterscheidungen, sondern separate psychobiologische Entscheidungsprozesse darstellen. Da die Regulierung von Entscheidungen wahrscheinlich mehrere Neurotransmittersysteme umfasst, ist die weitere Erforschung dieser Systeme gerechtfertigt. Nach Identifizierung der genauen Mechanismen innerhalb jedes Systems könnten umfassende Studien zu deren Zusammenwirken letztlich aufdecken, wie impulsive Entscheidungen entstehen. Angesichts einer Reihe von Studien, die eine geringe Fähigkeit zum Belohnungsaufschub und eine übermäßige Risikobereitschaft mit schlechter Gesundheit und psychischen Erkrankungen in Verbindung brachten, könnte das erworbene Wissen auch in die translationale Erforschung impulsivitätsassoziierter Krankheiten einfließen.

Kontinuerlig infusion med levodopa/karbidopa gel hos patienter med avancerad Parkinsons sjukdom har visat sig vara en effektiv behandling men innebär även komplikationer. Studiens syfte är att kartlägga vilka behandlingskomplikationer som redovisas i litteraturen. Metoden är en systematisk litteraturstudie där databaserna PubMed, Cochrane, Cinahl och Embase har genomsökts. Resultatet grundar sig på 12 observationsartiklar och en randomiserad kontrollerad studie som visar att behandlingskomplikationer är vanliga, de är varierande i allvarlighetsgrad och kan indelas i fyra grupper beroende på om de är relaterade till kirurgi, det tekniska systemet, den medicinska behandlingen eller inte relaterat alls till behandlingen utifrån dagens kunskap. Slutsats: Det vetenskapliga underlaget är otillräckligt för att sammanställa hur de redovisade behandlingskomplikationerna hör ihop med behandlingen. Därför rekommenderas ytterligare forskning där samband kopplat till baslinjevariabler och socioekonomiska variabler samt samband mellan de olika behandlingskomplikationerna att undersökas ytterligare. / Continuous levodopa/carbidopa intestinal gel is reported to be efficient in the treatment of advanced Parkinson Disease but also associated with adverse events. The aim of this study was to provide an overview of the reported adverse events through a systematic review. The databases PubMed, Cochrane, Cinahl and Embase were searched. The results are based on 12 observational studies and one randomized control trial and shows that adverse events are common and the degree varies. Four categories to which the adverse events can be related were identified; due to the surgery, the device, the medication or not related to the treatment at all. Conclusions: The evidence is considered inadequate to base a statement of how the adverse events are correlated to the treatment why further studies with evaluation of baseline and socioeconomic variables as well as among the different adverse events are recommended.

<p>Pharmacotherapy for Parkinson’s disease (PD) is based on levodopa, the most effective dopaminergic drug. The development of motor complications constitutes the major challenge for new or refined therapies.</p><p>To evaluate the impact of levodopa pharmacokinetics on motor function, an observational study in the patients’ home environment was carried out. A high variability in plasma levodopa levels was found in all patients, irrespective of treatment regimen. The impact of levodopa pharmacokinetics was further studied in a crossover trial comparing sustained-release tablets and continuous daytime intestinal infusion. Infusion produced significantly decreased variability in plasma levels of levodopa, resulting in significantly normalised motor function. A permanent system for long-term levodopa infusion has been developed and 28 patients have been followed for 87 patient-years. Motor response was generally preserved during the long-term observation period, implying that there is no development of tolerance to infusion therapy. Levodopa tablets are normally used in multiples of 50 or 100 mg, thus a rough estimate of individual dosage. A new concept for individualising levodopa/carbidopa doses with microtablets of 5/1.25 mg is under development. An electronic drug-dispensing device for administering the microtablets was tested on patients with PD. All were able to handle the dispenser and most were interested in future use of the concept. Self-assessment of symptoms is accurate in PD, but traditional paper diaries are associated with low compliance. A wireless electronic diary was compared with a corresponding paper diary. The time-stamped and thus completely reliable patient compliance was 88% with the electronic diary.</p><p>To conclude, pharmacokinetics of levodopa is the major determinant for motor fluctuations in PD. Every effort to individualise dosage and to smooth out the fluctuations in levodopa concentrations should be made, e.g. by means of microtablets or enteral infusion. Electronic patient diaries for real-time data capture are suitable for PD studies.</p>

La levodopa (LD) continúa siendo el fármaco más eficaz en la enfermedad de Parkinson (EP), aunque con respuesta clínica heterogénea, pudiendo incrementar los niveles plasmáticos de homocisteína (Hc). Tanto los niveles elevados de Hc como el alelo E4 de la Apolipoproteína E (ApoE) se han relacionado con deterioro cognitivo. Objetivos: (1) Encontrar una explicación para las variaciones en la respuesta a LD. (2) Confirmar la elevación de Hc en pacientes tratados con LD y su relación con la vitamina B12 (B12) y folato. (3) Influencia de Hc y genotipo de la ApoE en el deterioro cognitivo. Métodos: Se administraron distintas dosis y formulaciones de LD, con y sin entacapona, a 58 pacientes con EP. Se determinaron niveles plasmáticos de LD, catecolaminas, Hc, B12, y folato, y genotipo de la ApoE. Variables clínicas: estadio de la EP, UPDRS, evaluación neuropsicológica. Resultados: Existía una disociación entre la respuesta clínica y los niveles de LD, además de una marcada diferencia interindividual. Añadir entacapona a LD elevaba su nivel plasmático, pero no mejoraba la respuesta. El tratamiento con LD se acompañaba de una elevación significativa del nivel de Hc, dependiente de los niveles de B12 y folato, que no se modificaba con entacapona. Niveles elevados de Hc se asociaron con deterioro cognitivo, por lo que sería razonable añadir suplementos de folato y B12 a la LD. Los portadores de un alelo E4 tenían una evolución más benigna en la sintomatología motora. / Levodopa (LD) being still the best pharmacological treatment for Parkinson's disease (PD), has variable clinical response and may increase homocysteine (Hc) plasmatic levels. Apolipoprotein E4 (Apo E) allele and high levels of Hc were related to cognitive decline. Objectives: (1) To find an explanation for variation in LD response. (2) To confirm high Hc in patients treated with LD and its relation with vitamin B12 (B12) and folic acid (FA). (3) To determine Hc and genotype influence in cognitive decline. Methods: Different LD doses and formulations, with and without entacapone were given to 58 PD patients. LD, catecholamines, Hc, B12 and FA levels and ApoE genotype were determined. Clinical variables were: PD stage, UPDRS and neuropsychological examination. Results: We found dissociation between clinical response and LD levels, and also clear interindividual variations. Entacapone increased LD plasmatic levels, but did not improve its clinical response. LD treatment was associated with increased Hc levels, related to B12 and FA levels; none was modified by entacapone. High Hc levels were related to cognitive decline. Supplements of B12 and FA to LD seem to be reasonable. E4 allele patients had more benign motor evolution.

The aim of this work is to evaluate the fuzzy system for different types of patients for levodopa infusion in Parkinson Disease based on simulation experiments using the pharmacokinetic-pharmacodynamic model. Fuzzy system is to control patient’s condition by adjusting the value of flow rate, and it must be effective on three types of patients, there are three different types of patients, including sensitive, typical and tolerant patient; the sensitive patients are very sensitive to drug dosage, but the tolerant patients are resistant to drug dose, so it is important for controller to deal with dose increment and decrement to adapt different types of patients, such as sensitive and tolerant patients. Using the fuzzy system, three different types of patients can get useful control for simulating medication treatment, and controller will get good effect for patients, when the initial flow rate of infusion is in the small range of the approximate optimal value for the current patient’ type.

Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains xi, 101 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 95-99).

Pharmacotherapy for Parkinson’s disease (PD) is based on levodopa, the most effective dopaminergic drug. The development of motor complications constitutes the major challenge for new or refined therapies. To evaluate the impact of levodopa pharmacokinetics on motor function, an observational study in the patients’ home environment was carried out. A high variability in plasma levodopa levels was found in all patients, irrespective of treatment regimen. The impact of levodopa pharmacokinetics was further studied in a crossover trial comparing sustained-release tablets and continuous daytime intestinal infusion. Infusion produced significantly decreased variability in plasma levels of levodopa, resulting in significantly normalised motor function. A permanent system for long-term levodopa infusion has been developed and 28 patients have been followed for 87 patient-years. Motor response was generally preserved during the long-term observation period, implying that there is no development of tolerance to infusion therapy. Levodopa tablets are normally used in multiples of 50 or 100 mg, thus a rough estimate of individual dosage. A new concept for individualising levodopa/carbidopa doses with microtablets of 5/1.25 mg is under development. An electronic drug-dispensing device for administering the microtablets was tested on patients with PD. All were able to handle the dispenser and most were interested in future use of the concept. Self-assessment of symptoms is accurate in PD, but traditional paper diaries are associated with low compliance. A wireless electronic diary was compared with a corresponding paper diary. The time-stamped and thus completely reliable patient compliance was 88% with the electronic diary. To conclude, pharmacokinetics of levodopa is the major determinant for motor fluctuations in PD. Every effort to individualise dosage and to smooth out the fluctuations in levodopa concentrations should be made, e.g. by means of microtablets or enteral infusion. Electronic patient diaries for real-time data capture are suitable for PD studies.