Monitoramento do horizonte tecnológico: Medicamentos para o tratamento do transtorno depressivo maior / Monitoring the technological horizon: Drugs for the treatment of major depressive disorder

A DOENÇA: O transtorno depressivo maior (TDM) é considerado um grave problema de saúde pública que afeta mais de 264 milhões de pessoas em todo o mundo (1). No Brasil, a prevalência nacional da depressão estimada pelo Global Burden of Disease 2017 foi de 3,3% e esta condição está entre as quatro principais causas de invalidez, afetando a produtividade e qualidade de vida dos pacientes. Nas populações vulneráveis como os idosos, esse número é significativamente maior, uma revisão sistemática publicada em 2019 estimou uma prevalência de 21,9% em idosos brasileiros residentes na comunidade. Segundo projeções da Organização Mundial da Saúde (OMS) para 2030, a depressão ocuparia o primeiro lugar entre as principais doenças incapacitantes. TRATAMENTO RECOMENDADO: Atualmente não existem Protocolos Clínicos e Diretrizes Terapêuticas (PCDT) do Ministério da Saúde, bem como avaliações da Conitec sobre esse tema. O tratamento da TDM depende da gravidade da doença, nos indivíduos com depressão grave, em que há risco de suicídio, o encaminhamento para o especialista deve ser imediato e a hospitalização pode ser um recurso necessário. Nos casos moderados, em geral, se sugere a combinação de psicoterapia e medicamentos antidepressivos, sendo que diversas classes são consideradas opções terapêuticas, como Inibidores seletivos da recaptação da serotonina; Inibidores seletivos da recaptação da noradrenalina; Antidepressivos atípicos; Moduladores da serotonina; Antidepressivos tricíclicos; Inibidores da monoaminoxidase. ESTRATÉGIA DE BUSCA: Uma busca no repositório de protocolos de estudos clínicos ClinicalTrials.gov foi realizada com o objetivo de localizar os medicamentos em fase de pesquisa clínica e/ou recentemente aprovados para TDM. Foram excluídos medicamentos com registro na Anvisa superior a dois anos para a indicação de depressão maior, assim como procedimentos, produtos da medicina tradicional chinesa, vitaminas e testes diagnósticos. MEDICAMENTOS APROVADOS RECENTEMENTE: ESCETAMINA SPRAY NASAL: A escetamina, o enantiômero "S" da cetamina racêmica, é um antagonista não seletivo, não competitivo do receptor N-metil-D-aspartato (NMDA), que atua como um modulador do receptor de glutamato, o que parece aumentar a sinalização entre as células, restaurando a função normal nas regiões cerebrais. Embora a ligação da escetamina ao receptor NMDA aumente o glutamato do sistema nervoso central (SNC), o mecanismo de ação exato como antidepressivo permanece incerto. Esse medicamento possui registro nas agências norte-americana e europeia (FDA e EMA) e, em dezembro de 2020, foi aprovado pela Anvisa para tratamento do TDM em pacientes com ideação suicida e de depressão resistente ao tratamento. Depressão resistente ao tratamento: MEDICAMENTOS EM FASE DE PESQUISA CLÍNICA: RAPASTINEL: O rapastinel (GLYX-13) é um anticorpo monoclonal com apresentação para administração endovenosa, que atua como agonista parcial funcional do receptor de N-metil-D-aspartato (NMDA) com ação no sistema glutamatérgico. INFORMAÇÕES ADICIONAIS: Atualmente existem diferentes tecnologias sendo estudadas para o tratamento de TDM, sendo que neste informe, foram descritas as tecnologias que estão em um horizonte mais próximo para aprovação por agências regulatórias ou foram aprovadas pela Anvisa recentemente. A escetamina spray nasal e brexpiprazol foram aprovados pela Anvisa em 2020, com o objetivo de avaliar a incorporação dessas tecnologias no mundo, uma busca foi realizada em novembro de 2021 nos websites das agências de ATS do Reino Unido, Canadá e Austrália. CONSIDERAÇÕES FINAIS O TDM: é um grave problema de saúde pública por afetar milhões de pessoas em todo o mundo. Apesar de haver muitos estudos em andamento para o tratamento dessa condição clínica, em geral os resultados dos estudos demonstraram que não há diferença significativa na eficácia dos medicamentos quando comparados ao placebo. O rapastinel, que recebeu designação Breakthough Therapy pela FDA em 2016, caracterizando-o como medicamento inovador para uma necessidade médica não atendida e que teria prioridade para avaliação na FDA, apresentou resultados promissores para estudo de fase 2, entretanto eles não foram confirmados nos ECR fase 3, duplo-cego, controlados por placebo, tanto em monoterapia como tratamento adjuvante para TDM. O medicamento REL-1017 (ou d-metadona), também é um inibidor do receptor NMDA e recebeu designação FastTrack pela FDA em 2017 para o tratamento adjuvante de TDM. Apesar dos dados do estudo de fase 2 mostrarem resultados promissores, o estudo de fase 3 ainda está em andamento. Também, esperam-se os dados das diversas pesquisas fase 3, realizadas em diferentes cenários (adjuvante ou monoterapia, por exemplo), e que avaliaram o medicamento SAGE-217, um modulador do receptor GABA que mostrou resultados positivos no estudo fase 2. O brexpiprazol foi aprovado pela Anvisa em 2020, indicado para o tratamento de depressão maior em adultos em associação a um antidepressivo, em caso de inefetividade da monoterapia com antidepressivo anterior. Os ensaios clínicos randomizados fase 3 avaliaram que o uso do medicamento reduziu o escore basal de MADRS na semana 6. O brexipiprazol para tratamento de depressão não foi avaliado por nenhuma agência de ATS até o momento. A escetamina spray nasal teve registro sanitário aprovado pela Anvisa em novembro de 2020 para pacientes com ideação suicida e de depressão resistente ao tratamento - a partir da avaliação da redução do escore basal de MADRS em 24h e após 28 dias. Mas esse medicamento não foi recomendado para incorporação pelas agências de ATS do Reino Unido e Canadá. Os medicamentos em desenvolvimento para depressão incluem populações específicas e frequentemente são usados em associação a outros antidepressivos. O tratamento da depressão grave e não responsiva a tratamentos prévios ainda é uma necessidade médica não atendida, assim como tratamentos específicos para populações vulneráveis como idosos. Também é importante destacar que todos os resultados descritos neste documento são dados precoces e devem ser avaliados com cautela. Dessa maneira, considerando os estudos de fase 3 citados neste documento, conclui-se que ainda são poucas as opções promissoras em estudo para um horizonte de curto a médio prazo.

Cost-Effectiveness of Dopamine Agonists and Monoamine Oxidase B Inhibitors in Early Parkinson's Disease.

BACKGROUND: The PD MED study reported small but persistent benefits in patient-rated mobility scores and quality of life from initiating therapy with levodopa compared with levodopa-sparing therapies in early Parkinson's disease (PD). OBJECTIVES: The objective was to estimate the cost-effectiveness of levodopa-sparing therapy (dopamine agonists or monoamine oxidase type B inhibitors compared with levodopa alone. METHODS: PD MED is a pragmatic, open-label randomized, controlled trial in which patients newly diagnosed with PD were randomly assigned between levodopa-sparing therapy (dopamine agonists or monoamine oxidase type B inhibitors ) and levodopa alone. Mean quality-adjusted life-years and costs were calculated for each participant. Differences in mean quality-adjusted life-years and costs between levodopa and levodopa-sparing therapies and between dopamine agonists and monoamine oxidase type B inhibitors were estimated using linear regression. RESULTS: Over a mean observation period of 4 years, levodopa was associated with significantly higher quality-adjusted life-years (difference, 0.18; 95% CI, 0.05-0.30; P < 0.01) and lower mean costs (£3390; £2671-£4109; P < 0.01) than levodopa-sparing therapies, the difference in costs driven by the higher costs of levodopa-sparing therapies. There were no significant differences in the costs of inpatient, social care, and institutional care between arms. There was no significant difference in quality-adjusted life-years between those allocated dopamine agonists and monoamine oxidase type B inhibitors (0.02; -0.17 to 0.13 in favor of dopamine agonists; P = 0.81); however costs were significantly lower for those allocated monoamine oxidase type B inhibitors (£2321; £1628-£3015; P < 0.01) because of the higher costs of dopamine agonists. There were no significant differences between arms for other costs. CONCLUSIONS: Initial treatment with levodopa is highly cost-effective compared with levodopa-sparing therapies. Monoamine oxidase type B inhibitors, as initial levodopa-sparing therapy was more cost-effective, with similar quality-adjusted life-years but lower costs than dopamine agonists. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

The Medicinal Chemistry of Natural and Semisynthetic Compounds against Parkinson's and Huntington's Diseases.

Among the diseases affecting the central nervous system (CNS), neurodegenerations attract the interest of both the clinician and the medicinal chemist. The increasing average age of population, the growing number of patients, and the lack of long-term effective remedies push ahead the quest for novel tools against this class of pathologies. We present a review on the state of the art of the molecules (or combination of molecules) of natural origin that are currently under study against two well-defined pathologies: Parkinson's disease (PD) and Huntington's disease (HD). Nowadays, very few tools are available for preventing or counteracting the progression of such diseases. Two major parameters were considered for the preparation of this review: particular attention was reserved to these research works presenting well-defined molecular mechanisms for the studied compounds, and where available, papers reporting in vivo data were preferred. A literature search for peer-reviewed articles using PubMed, Scopus, and Reaxys databases was performed, exploiting different keywords and logical operators: 91 papers were considered (preferentially published after 2015). The review presents a brief overview on the etiology of the studied neurodegenerations and the current treatments, followed by a detailed discussion of the natural and semisynthetic compounds dividing them in different paragraphs considering their several mechanisms of action.

Assessment of Enzyme Inhibition: A Review with Examples from the Development of Monoamine Oxidase and Cholinesterase Inhibitory Drugs.

The actions of many drugs involve enzyme inhibition. This is exemplified by the inhibitors of monoamine oxidases (MAO) and the cholinsterases (ChE) that have been used for several pharmacological purposes. This review describes key principles and approaches for the reliable determination of enzyme activities and inhibition as well as some of the methods that are in current use for such studies with these two enzymes. Their applicability and potential pitfalls arising from their inappropriate use are discussed. Since inhibitor potency is frequently assessed in terms of the quantity necessary to give 50% inhibition (the IC50 value), the relationships between this and the mode of inhibition is also considered, in terms of the misleading information that it may provide. Incorporation of more than one functionality into the same molecule to give a multi-target-directed ligands (MTDLs) requires careful assessment to ensure that the specific target effects are not significantly altered and that the kinetic behavior remains as favourable with the MTDL as it does with the individual components. Such factors will be considered in terms of recently developed MTDLs that combine MAO and ChE inhibitory functions.

Prescribing pattern and resource utilization of monoamine oxidase-B inhibitors in Parkinson treatment: comparison between rasagiline and selegiline.

Difference between selegiline and rasagiline for effectiveness in Parkinson's disease (PD) is uncertain, nevertheless their costs highly differ: rasagiline is more expensive than selegiline. This study was aimed to compare prescribing pattern and resource utilization in PD patients treated with rasagiline or selegiline. Historic cohort study, based on databases of three Italian Local Health Authorities was performed. Patients with PD and receiving rasagiline or selegiline between 01-07-2009 and 31-12-2011 were selected and followed-up for 12 months. As outcomes, and relevant costs, were evaluated: (a) anti-parkinson prescriptions; (b) hospitalization for PD and for fracture; (c) antiinflammatory and antirheumatic prescriptions; (d) antipsychotic prescriptions; (e) hospitalization for cardiovascular diseases; (f) cardiovascular prescriptions; (g) ambulatory visits or diagnostic tests. Average annual cost per patient was considered for both PD-related expenditure (a + b + c) and overall cost (a + b + c + d + e + f + g). Differences between rasagiline and selegiline were analysed by generalized linear model. Overall 1607 patients were selected: 63.7 % under selegiline and 36.2 % under rasagiline. Hospitalizations for PD occurred more in rasagiline group than in selegiline one (13.6 vs. 8.0 %, p < 0.001), whereas hospitalizations for fractures less in rasagiline group than in selegiline one (1.4 vs. 3.8 %, p = 0.005). Dopamine agonists (66.0 vs. 31.0 %, p < 0.001) and levodopa (73.9 vs. 49.0 %, p < 0.001) were prescribed more frequently in rasagiline group than in selegiline one. The choice to prescribe rasagiline produced a statistically significant increase in both overall cost (+2404 €, p < 0.001) and PD-related cost (+2363 €, p < 0.001). In conclusion, prescribing patterns and health resource utilization highly differ between rasagiline and selegiline. There is no homogeneous prescription behaviour among clinicians in preferring one or the other MOAB-I, on the basis of demographic, clinical and therapeutic characteristics of patients with PD.

Novel monoamine oxidase inhibitors: a patent review (2012 - 2014).

INTRODUCTION: Monoamine oxidase (MAO) inhibitors, despite the initial pharmacological interest, are used in clinic for their antidepressant effect and in the management of Parkinson symptoms, due to the established neuroprotective action. Efficacy and tolerability emerged from large-scale and randomized clinical trials. AREAS COVERED: Thirty-six patents range from April 2012 to September 2014. The number of chemotypes with inhibitory effects on MAO is truly high (40 synthetic compounds, 22 natural products and 6 plant extracts reported and licensed), and the present review is comprehensive of all compounds, which have been patented for their relevance to clinical medicine in this period range (27 patents). Moreover, some of the collected patents deal with new formulations of compounds endowed with MAO inhibitory properties (two patents) and new therapeutic options/drug associations for already known MAO inhibitors (seven patents). EXPERT OPINION: The patents reported in this review showed that the interest in this field is constant and mainly devoted to the study of selective MAO-B inhibitors, used as drugs for the treatment of neurological disorders. The development of novel human MAO inhibitors took advantage of the discovery of new therapeutic targets (cancer, hair loss, muscle dystrophies, cocaine addiction and inflammation), the recognized role of MAOs as molecular biomarkers and their activity in other tissues.

Rasagiline: a review of its use in the treatment of idiopathic Parkinson's disease.

Rasagiline (Azilect(®)) is an oral, second-generation, selective, irreversible monoamine oxidase-B (MAO-B) inhibitor approved in the US for the treatment of Parkinson's disease. In randomized, controlled trials, oral rasagiline 1 mg once daily was superior to placebo in the symptomatic treatment of early Parkinson's disease, both as monotherapy or as an adjunct to dopamine agonists. Comparisons of early-start and delayed-start treatment suggested a disease-modifying effect for rasagiline, but the results were equivocal. Rasagiline 0.5 or 1 mg/day was also superior to placebo as adjunctive therapy to levodopa in Parkinson's disease patients with motor fluctuations. Rasagiline was generally well tolerated in clinical trials, displaying a placebo-like tolerability profile in several studies. Cost-utility studies predicted that rasagiline, either as monotherapy or adjunctive therapy, would be a cost-effective treatment option. Therefore, oral rasagiline is a valuable therapeutic option for use in all stages of Parkinson's disease.

Long-term effectiveness of dopamine agonists and monoamine oxidase B inhibitors compared with levodopa as initial treatment for Parkinson's disease (PD MED): a large, open-label, pragmatic randomised trial.

BACKGROUND: Whether initial treatment for Parkinson's disease should consist of levodopa, dopamine agonists, or monoamine oxidase type B inhibitors (MAOBI) is uncertain. We aimed to establish which of these three classes of drug, as initial treatment, provides the most effective long-term control of symptoms and best quality of life for people with early Parkinson's disease. METHODS: In this pragmatic, open-label randomised trial, patients newly diagnosed with Parkinson's disease were randomly assigned (by telephone call to a central office; 1:1:1) between levodopa-sparing therapy (dopamine agonists or MAOBI) and levodopa alone. Patients and investigators were not masked to group assignment. Primary outcomes were the mobility dimension on the 39-item patient-rated Parkinson's disease questionnaire (PDQ-39) quality-of-life scale (range 0-100 with six points defined as the minimally important difference) and cost-effectiveness. Analysis was intention to treat. This trial is registered, number ISRCTN69812316. FINDINGS: Between Nov 9, 2000, and Dec 22, 2009, 1620 patients were assigned to study groups (528 to levodopa, 632 to dopamine agonist, 460 to MAOBI). With 3-year median follow-up, PDQ-39 mobility scores averaged 1·8 points (95% CI 0·5-3·0, p=0·005) better in patients randomly assigned to levodopa than those assigned to levodopa-sparing therapy, with no increase or attrition of benefit during 7 years' observation. PDQ-39 mobility scores were 1·4 points (95% CI 0·0-2·9, p=0·05) better in patients allocated MAOBI than in those allocated dopamine agonists. EQ-5D utility scores averaged 0·03 (95% CI 0·01-0·05; p=0·0002) better with levodopa than with levodopa-sparing therapy; rates of dementia (hazard ratio [HR] 0·81, 95% CI 0·61-1·08, p=0·14), admissions to institutions (0·86, 0·63-1·18; p=0·4), and death (0·85, 0·69-1·06, p=0·17) were not significantly different, but the upper CIs precluded any substantial increase with levodopa compared with levodopa-sparing therapy. 179 (28%) of 632 patients allocated dopamine agonists and 104 (23%) of 460 patients allocated MAOBI discontinued allocated treatment because of side-effects compared with 11 (2%) of 528 patients allocated levodopa (p<0·0001). INTERPRETATION: Very small but persistent benefits are shown for patient-rated mobility scores when treatment is initiated with levodopa compared with levodopa-sparing therapy. MAOBI as initial levodopa-sparing therapy was at least as effective as dopamine agonists. FUNDING: UK National Institute for Health Research Health Technology Assessment Programme and UK Department of Health.

Advanced strategies for treatment of Parkinson's disease: the role of early treatment.

Parkinson's disease (PD) is associated with significant patient disability and costs to the healthcare system. It is questioned whether early treatment may improve outcomes and delay disability. Early treatment relies on early diagnosis, which can be difficult to achieve because the diagnosis of PD is based on motor symptoms, is clinical in nature, and is complicated by potential presentation of nonmotor symptoms prior to motor symptoms. Economic analyses demonstrate that treatments other than levodopa may be cost-effective. The lack of correlation between Unified PD Rating Scale (UPDRS) outcomes and imaging studies of dopamine uptake may reflect the inappropriate selection of study end points, since activities of daily living scores may be more applicable than motor function scores. Levodopa, the standard therapy for motor control of PD and one of the most effective options, is associated with complications (a wearing-off effect) when used long term. Other therapies, including dopamine agonists and monoamine oxidase type-B (MAO-B) inhibitors, may limit the rate of dyskinesia relative to levodopa-based regimens. It appears that early treatment with the MAO-B inhibitor rasagiline (1 mg), as compared with late treatment, delays the onset of worsened UPDRS score, especially the nonmotor activities of daily living subscore.

Pirlindole in the treatment of depression and fibromyalgia syndrome.

Depression and fibromyalgia syndrome are debilitating chronic conditions that impose a significant burden on individuals, families and society. Both depression and fibromyalgia have many overlapping symptoms, and antidepressants of several classes are among recommended treatment options for patients with fibromyalgia syndrome. Pirlindole is a selective and reversible inhibitor of monoamine oxidase (MAO) subtype A (MAO-A) that is approved in some European and non-European countries for the treatment of depression. The antidepressant efficacy and safety of pirlindole have been demonstrated in a number of placebo- and active comparator-controlled studies and are supported by many years of clinical experience in the treatment of depression. The drug's efficacy and safety have also been demonstrated, more recently, in the treatment of fibromyalgia syndrome. Pirlindole has a favourable tolerability profile, with no deleterious effect on cardiovascular dynamics. The effect of pirlindole on sensorimotor performance relevant to driving a motor vehicle is similar to that of placebo, as pirlindole appears to have an activating rather than a sedating antidepressant profile. Because of its specific and reversible inhibition of MAO-A and relatively short elimination half-life, no tyramine or 'cheese' effect is likely after short- or long-term administration. The available evidence supports pirlindole as a safe and effective treatment option for the management of depression and fibromyalgia syndrome.

Synthesis, biological assessment and molecular modeling of new multipotent MAO and cholinesterase inhibitors as potential drugs for the treatment of Alzheimer's disease.

The synthesis, biological evaluation and molecular modeling of new multipotent inhibitors of type I and type II, able to simultaneously inhibit monoamine oxidases (MAO) as well as acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), is described. Compounds of type I were prepared by sequential reaction of 2,6-dichloro-4-phenylpyridine-3,5-dicarbonitrile (14) [or 2,6-dichloropyridine-3,5-dicarbonitrile (15)] with prop-2-yn-1-amine (or N-methylprop-2-yn-1-amine) and 2-(1-benzyl-piperidin-4-yl)alkylamines 22-25. Compounds of type II were prepared by Friedländer type reaction of 6-amino-5-formyl-2-(methyl(prop-2-yn-1-yl)amino)nicotinonitriles 32 and 33 with 4-(1-benzylpiperidin-4-yl)butan-2-one (31). The biological evaluation of molecules 1-11 showed that most of these compounds are potent, in the nanomolar range, and selective AChEI, with moderate and equipotent selectivity for MAO-A and MAO-B inhibition. Kinetic studies of compound 8 proved that this is a EeAChE mixed type inhibitor (IC(50) = 16 ± 2; Ki = 12 ± 3 nM). Molecular modeling investigation on compound 8 confirmed its dual AChE inhibitory profile, binding simultaneously at the catalytic active site (CAS) and at the peripheric anionic site (PAS). In overall, compound 11, as a potent and selective dual AChEI, showing a moderate and selective MAO-A inhibitory profile, can be considered as an attractive multipotent drug for further development on two key pharmacological targets playing key roles in the therapy of Alzheimer's disease.

Use of antiparkinson medications among elderly Medicare beneficiaries with Parkinson's disease.

BACKGROUND: Antiparkinson drugs (APDs) are the mainstay in the management of Parkinson's disease (PD). However, the use of APDs has not been investigated in a nationally representative sample. OBJECTIVES: This study aimed to describe the prevalence and patterns of APD use and to identify determinants of APD use among elderly Medicare beneficiaries with PD. METHODS: Data from the Medicare Current Beneficiary Survey and Medicare claims from 2000 to 2003 were used to identify beneficiaries ≥65 years of age with PD. The APDs included in the study were levodopa, dopamine agonists, monoamine oxidase-B inhibitors, amantadine, anticholinergic agents, and catechol-O-methyltransferase inhibitors. The annual prevalence of APD use was calculated; patterns of APD use were measured by drug class and type of drug regimens (monotherapy or combination therapy). Potential determinants of APD use included sociodemographic characteristics (age, sex, race, education, marital status, and annual income), self-reported health status, residential status (institution or community), prescription drug coverage, disability (functional, physical, and mental), and disease-specific factors (dementia, depression, and other comorbidities). Multivariate logistic regression analyses with generalized estimating equations were used to estimate odds ratios (ORs) of any APD use associated with the determinants. RESULTS: The data revealed 571 beneficiaries with PD (30.1% aged ≥85 years, 55.0% female, 88.3% white), who were observed for a total of 924 person-years. The annual prevalence of APD use was 58.2% (538/924). Levodopa was the most frequently used agent, either as monotherapy or in combination with other APDs (85.5%; 460/538). Multivariate analyses found that patients 65 to 74 years of age (OR = 0.70; 95% CI, 0.49-0.99; P < 0.05) and those ≥85 years of age (OR = 0.57; 95% CI, 0.40-0.81; P < 0.01) were less likely to use APDs than were patients aged 75 to 84 years of age. Patients who had attained a high level of education (more than a high school diploma) were more likely to use APDs than were patients with a low level of education (a high school diploma or less) (OR = 1.51; 95% CI, 1.04-2.19; P < 0.05). In addition, institutionalization (OR = 1.78; 95% CI, 1.17-2.71; P < 0.01), prescription drug coverage (OR = 1.50; 95% CI, 1.15-1.94; P < 0.01), activities of daily living (ADLs) (OR = 1.47; 95% CI, 1.16-1.87; P < 0.01), and depression (OR = 1.25; 95% CI, 1.02-1.53; P < 0.05) were significantly associated with use of APDs. The probability of APD use was lower among those with dementia than among those without dementia (OR = 0.62; 95% CI, 0.48-0.80; P < 0.001). CONCLUSIONS: Almost half of the elderly Medicare beneficiaries with PD in this study did not use any APD between 2000 and 2003. Levodopa was the most frequently used APD, either as monotherapy or in combination with other APDs. The identified determinants of APD use (age, education, prescription drug coverage, ADLs, dementia, depression, and residing in an institution) may be helpful in developing interventions for this population.

Cost effectiveness of rasagiline and pramipexole as treatment strategies in early Parkinson's disease in the UK setting: an economic Markov model evaluation.

BACKGROUND: Levodopa is the most effective treatment for the symptoms of Parkinson's disease (PD). However, after an initial period of benefit, several limitations become apparent, including motor complications such as dyskinesia. Dyskinesia can severely affect patients' quality of life and increases healthcare resource use. Thus, delaying the need for levodopa, and therefore the onset of levodopa-induced dyskinesia, is important. OBJECTIVE: The aim of this study was to compare the cost effectiveness, from a UK healthcare payer perspective, of two antiparkinsonian treatment strategies in early PD: first-line monotherapy with rasagiline, a novel monoamine oxidase B inhibitor; and the non-ergoline dopamine receptor agonist pramipexole. METHODS: An economic Markov model was developed as a pragmatic tool to derive comparative information on the effectiveness, utility and costs of these two strategies over a 5-year period. Model input data were obtained from the TEMPO study for rasagiline and from a study by the Parkinson Study Group for pramipexole. Effectiveness outcomes were time to levodopa and time to levodopa-induced dyskinesia. Cost and quality-adjusted life-year (QALY) data were derived from published sources. RESULTS: Rasagiline was the dominant strategy. Compared with pramipexole, use of the rasagiline strategy was estimated to reduce costs by 18% per patient over 5 years and was associated with an additional 10% delay in dyskinesia onset (0.41 years; 95% CI 0.27, 0.55). This strategy was also found to prolong the time to levodopa initiation by 25% through a gain of 0.83 levodopa-free years (95% CI 0.56, 1.1). In addition, use of the rasagiline strategy was found to generate a 5% gain in QALYs over 5 years compared with the pramipexole strategy (3.7 +/- 0.02 vs 3.51 +/- 0.03). Sensitivity analyses confirmed that the model was robust. CONCLUSIONS: Rasagiline represents a cost-effective alternative to pramipexole in the treatment of early PD in the UK.

Levodopa-related wearing-off in Parkinson's disease: identification and management.

BACKGROUND: Levodopa is currently the most effective treatment for Parkinson's disease (PD); however, long-term levodopa therapy often results in motor complications, such as motor fluctuations and dyskinesia. The initial complication is commonly wearing-off, which is the re-emergence of motor and non-motor symptoms before the next scheduled levodopa dose. OBJECTIVE: The purpose of this article was to review published literature that discusses wearing-off, focusing on the role of the healthcare professional, including the primary care physician, in the effective management of wearing-off. METHODS: An electronic literature search was conducted using MEDLINE and EMBASE to find articles discussing wearing-off and its management using the following keywords: 'Parkinson's disease'; 'wearing-off'; 'levodopa'; 'primary care'. FINDINGS AND CONCLUSIONS: Current evidence indicates that a consistent delivery of levodopa should improve long-term symptomatic efficacy and may prevent or delay motor complications. A number of therapeutic options are available to optimize therapeutic outcome, including modification of the levodopa dose or dosing schedule,switching to another levodopa formulation and the use of adjunct therapies, such as catechol-O-methyl transferase inhibitors, dopamine agonists and monoamine oxidase-B inhibitors. The management of wearing-off is dependent upon the early identification of symptoms and the initiation of effective treatment. Key issues are the need to educate patients and to facilitate good communication with both primary and secondary healthcare professionals. In most cases, patients with PD initially present to primary healthcare professionals who may refer the patient to a neurologist once disease management becomes more complex. However, in many cases, especially in rural areas where neurologists may not be widely available, the primary healthcare professionals may manage the patient throughout the disease course. Limitations of this review include the restricted search criteria and selected search period.

Uncovering the potential risk of serotonin toxicity in Australian veterans using pharmaceutical claims data.

AIMS: We examined potential risk of serotonin toxicity in Australian veterans by quantifying the concomitant use of serotonergic medicine combinations from claims data collected by the Department of Veterans' Affairs (DVA). METHODS: This was a retrospective cohort study of 273 228 Australian veterans, war widows, widowers and dependents aged >or=55 years and holding full treatment entitlement for the period July 2000 to June 2004 or until death. The main outcome measure was potential concomitant use, estimated as the number of cohort members with an overlap in days of supply for serotonergic medicine combinations over the 4 year period for all medicine combinations and potentially life threatening combinations. RESULTS: From July 2000 to June 2004, 115 969 (42%) cohort members were dispensed at least one serotonergic medicine. 20 658 (8%) had at least one episode of potential concomitant use. We identified 1811 (0.7%) cohort members with at least one overlapping period of potentially life-threatening serotonergic medicine combinations, 937 of whom had the combinations dispensed within the recommended washout period. Three hundred and seventeen of these individuals were dispensed potentially life-threatening medicine combinations on the same day. The most common combinations were moclobemide with a selective serotonin reuptake inhibitor or tramadol. CONCLUSIONS: The individuals potentially at risk of mild to moderate serotonin toxicity were considerable and potentially life threatening combinations were not infrequent. While we were unable to determine how many individuals experienced serotonin toxicity this study indicates, for the first time, the potential size of the problem in a subgroup of elderly Australians. Clinicians and patients need to be vigilant regarding inadvertent concomitant use, especially that of moclobemide with a selective serotonin reuptake inhibitor or tramadol.

Depression: the benefits of early and appropriate treatment.

Depression has a profound impact on patient health, individual and family quality of life, activities of daily living, and daily functioning, as well as on healthcare providers, payers, and employers. Persons with depression tend to have multiple comorbidities that compound the negative effects and increase costs. The economic burden of the disease is significant, with direct medical costs estimated at $3.5 million per 1000 plan members with depression. Depression is significantly underdiagnosed and undertreated, particularly in primary care where the majority of patients with depression seek care. Effective strategies to achieve remission have been identified and have proven effective in clinical trials. Early detection, intervention, and appropriate treatment can promote remission, prevent relapse, and reduce the emotional and financial burden of the disease.

Pharmacotherapy for Parkinson's disease.

The available pharmacotherapies for Parkinson's disease address symptomatology because no agent has been demonstrated to provide definite neuroprotection against the disease. Choice of pharmacotherapy must include consideration of short-term benefits as well as long-term consequences. Patients with mild Parkinson's disease often function adequately without symptomatic treatment. However, recent data suggest that initiation of treatment with a well-tolerated agent (e.g., the monoamine oxidase [MAO]-B inhibitor rasagiline) in the absence of functional impairment is associated with improved long-term outcomes. Consideration should also be given to many patient-specific factors, including patient expectations, level of disability, employment status, functional as well as chronologic age, expected efficacy and tolerability of drugs, and response to previous Parkinson's disease therapies. Increasingly, initial monotherapy begins with a nondopaminergic agent or, if the patient is considered functionally young, a dopamine agonist. Since Parkinson's disease is a progressive disorder, adjustments to pharmacotherapy must be expected over time. When greater symptomatic relief is desired, or in the more frail elderly patient, levodopa therapy should be considered. If motor fluctuations develop, addition of a catechol-O-methyltransferase inhibitor or MAO-B inhibitor should be considered. For management of levodopa-induced dyskinesias, addition of amantadine is an option. Surgery may be considered when patients need additional symptomatic control or are experiencing severe motor complications despite pharmacologically optimized therapy.

Metareview on short-term effectiveness and safety of antidepressants for depression: an evidence-based approach to inform clinical practice.

OBJECTIVES: To examine the available scientific literature for answers to clinically relevant questions regarding the effectiveness and tolerability of antidepressant drugs (ADs) for the acute phase treatment of depression and to assess the degree to which the literature supports the findings. METHODS: We used several sources to identify primary reviews: MEDLINE (1955 to April 2006), EMBASE (1980 to April 2006), PsycINFO (1980 to April 2006), and the Cochrane Library 2006 Issue 1. Additional searches were also carried out on the following databases of the National Health Service Centre for Reviews and Dissemination: Abstracts of Reviews of Effects, Health Technology Assessment, and Turning Research into Practice. We also searched the National Institute of Health and Clinical Excellence guidance website. We carried out a metareview of selected high-quality systematic reviews of short-term pharmacologic interventions with ADs for major depression. To assess efficacy, we followed the hierarchy of evidence proposed by the Centre for Evidence Based Medicine (Oxford), including only reviews of randomized controlled trials. To assess tolerability, we also considered observational data when randomized evidence was not available. RESULTS: There was randomized evidence that ADs are efficacious in primary care settings and that there may be small, but clinically important, differences in efficacy between ADs. There was no good evidence that an AD combined with an antipsychotic is superior to AD monotherapy in cases of psychotic depression or that intravenous administration leads to more rapid response. There was evidence that monoamine oxidase inhibitors are superior to tricyclic antidepressants, but not to selective serotonin reuptake inhibitors (SSRIs), in treating atypical depression. There is some evidence of harm related to the use of SSRIs in pregnancy but not to their use when breastfeeding. There is evidence that SSRIs may increase suicidal thoughts, but not actual suicide, in early-phase therapy. CONCLUSIONS: We found a substantial body of evidence regarding the benefits and harms of ADs in the treatment of depressive disorder. Nonetheless, there remains considerable residual uncertainty. The evidence is inadequate for generally applicable recommendations; in most cases, the balance between risks and benefits will need to be considered for individual patients. Clinicians should also be guided by the recommendations and warnings issued by drug regulatory authorities.