Drug treatments for schizophrenia: pragmatism in trial design shows lack of progress in drug design

Aims.The introduction of second generation antipsychotic (SGA) medication over a decade ago led to changes in prescribing practices; these drugs have eclipsed their predecessors as treatments for schizophrenia. However, the metabolic side effects of these newer antipsychotics have been marked and there are increasing concerns as to whether these novel drugs really are superior to their predecessors in terms of the balance between risks and benefits. In this article, we review the literature regarding comparisons between first generation antipsychotic (FGA) and SGA in terms of clinical effectiveness.Methods.Large (n > 150) randomized-controlled trials (RCTs) comparing the effectiveness (efficacy and side effects) of FGA and SGA medications other than clozapine were reviewed, as were meta-analyses that included smaller studies.Results.The superiority in efficacy and reduced extrapyramidal side effects (EPSE) of SGAs is modest, especially when compared with low-dose FGAs. However, the high risk of weight gain and other metabolic disturbances associated with certain SGAs such as olanzapine is markedly higher than the risk with FGAs at the doses used in the trials.Conclusions.The efficacy profiles of various FGAs and SGAs are relatively similar, but their side effects vary between and within classes. Overall, large pragmatic trials of clinical effectiveness indicate that the care used in prescribing and managing drug treatments to ensure tolerability may be more important than the class of drug used.Key words: antipsychotic drugs, clinical effectiveness, schizophrenia, randomized controlled trials     

Side effects of atypical antipsychotics: extrapyramidal symptoms and the metabolic syndrome

In this article we examine the two major classes of side effects with atypical antipsychotics: extrapyramidal symptoms (EPS) and the metabolic syndrome (the triad of diabetes, dyslipidemia, and hypertension, with associated obesity). We conclude that atypical antipsychotics continue to have notable risks of EPS, particularly akathisia, and that these agents also appear to increase the risk of the metabolic syndrome, though this effect seems most marked with clozapine and olanzapine. Novel conclusions based on this review are as follows: we provide a classification scheme based on low versus high D2 binding affinity (which is, to our knowledge, a new means of classifying atypical antipsychotics); we emphasize that the akathisia risk is likely equal among agents and that tardive dyskinesia is an early, and not late, risk in treatment (a common misconception); we make the methodological point that in randomized clinical trials, there is a high risk of false-negatives regarding side effects; we raise the issue of confounding bias in epidemiological studies of metabolic syndrome; and we stress the need to compare side effects in the same studies and not different studies. Future prospective observational cohort studies must target side effects and be designed to collect and analyze data on confounding factors.     

Gamma Vinyl GABA: Current Role in the Management of Drug-Resistant Epilepsy

Summary: The goal of management in epilepsy is to make patients completely seizure-free without side effects. Currently, this goal can be achieved fully in only about one-half of the 50,000,000 people in the world with epilepsy. Epilepsy is not a benign condition. Uncontrolled epilepsy produces significant morbidity and mortality. Even infrequent seizures put a patient at risk of sudden death and compromise employability and other social functions. The potential risk of a new antiepileptic drug has to be weighed against the potential risk of continuing seizures and the potential for the new drug to control those seizures. Vigabatrin (gamma vinyl GABA, GVG) is one of the promising new antiepileptic drugs now under development. In four large clinical trials half of the patients in each trial had a ≥ 50% reduction in seizure frequency when GVG was added to existing antiepileptic drug. This represents a significant response rate in add-on trials, which are a severe test of a new antiepileptic drug. Although microvacuoles have been seen in the white matter of the brains of rats and dogs treated with GVG, such pathological changes have not yet been observed in humans. Evoked potential studies have failed to reveal any evidence of microvacuolization in humans. Because of the potential efficacy of GVG in controlling previously therapeutic-resistant seizures and of the absence of evidence of significant toxicity in humans, carefully monitored clinical trials of GVG in therapy-resistant patients with epilepsy should continue.     

Efficacy and tolerability of second-generation antipsychotics in children and adolescents with schizophrenia

Early-onset schizophrenia-spectrum (EOSS) disorders (onset of psychotic symptoms before 18 years of age) represent a severe variant associated with significant chronic functional impairment and poor response to antipsychotic treatment. All drugs with proven antipsychotic effects block dopamine D(2) receptors to some degree. The ongoing development of the dopamine and other neurotransmitter receptor systems during childhood and adolescence may affect clinical response and susceptibility to side effects in youth. A literature search was conducted of clinical trials of antipsychotics in children and adolescents with EOSS disorders between 1980 and 2007 from the Medline database, reference lists, and conference proceedings. Trials were limited to double-blind studies of duration of 4 or more weeks that included 15 or more patients. Ten clinical trials were identified. Antipsychotic medications were consistently found to reduce the severity of psychotic symptoms in children and adolescents when compared with placebo. The superiority of clozapine has been now demonstrated relative to haloperidol, standard-dose olanzapine, and "high-dose" olanzapine for EOSS disorders. However, limited comparative data are available regarding whether there are differences among the remaining second-generation antipsychotics (SGAs) in clinical effectiveness. The available data from short-term studies suggest that youth might be more sensitive than adults to developing antipsychotic-related adverse side effects (eg, extrapyramidal side effects, sedation, prolactin elevation, weight gain). In addition, preliminary data suggest that SGA use can lead to the development of diabetes in some youth, a disease which itself carries with it significant morbidity and mortality. Such a substantial risk points to the urgent need to develop therapeutic strategies to prevent and/or mitigate weight gain and diabetes early in the course of treatment in this population.     

Monitoring for Adverse Effects of Antiepileptic Drugs

Summary:  Best practices for monitoring the adverse effects of antiepileptic drugs (AEDs) have not been carefully studied. Routine blood and urine studies do not appear to be of value in asymptomatic patients to avoid severe acute reactions. Subtle chronic AED side effects exist but algorithms for their detection and treatment are not well developed. Randomized clinical trials do not support the value of routine AED serum levels to improve compliance, seizure control, or avoid side effects. Simple screening procedures for neurotoxicity have not been developed. Some personal suggestions are offered.     

Efficacy of second-generation antipsychotics in the treatment of schizophrenia

Because of their broader spectrum of efficacy and lower risk of motor side effects, second-generation antipsychotics (SGAs) have largely supplanted first-generation neuroleptics in the treatment of psychotic disorders. There are few data, however, comparing the overall efficacy of the firstline SGAs (aripiprazole, olanzapine, quetiapine, risperidone, and ziprasidone) in the treatment of schizophrenia and schizoaffective disorder. To address this issue, two separate analyses were undertaken. First, all published short-term, randomized controlled clinical trials of these agents were reviewed, and efficacy data for total clinical improvement, positive symptom resolution, and negative symptom reduction compiled. Although the degree of improvement reported in these studies varied widely, there were no differences in efficacy of the drugs when averaged across all studies. Second, all randomized controlled clinical trials directly comparing two of these agents were reviewed. In direct comparison studies, there were no differences between the drugs on most parameters, and only minor and conflicting differences on remaining measures. Data thus far suggest that the first-line SGAs are of comparable efficacy in the treatment of schizophrenia and schizoaffective disorder.     

Risperidone in acute and long-term therapy of schizophrenia--a clinical profile

Data from a range of well-controlled clinical trials, observational studies, and clinical use support the efficacy of risperidone for both acute and long-term therapy of schizophrenic psychoses. With regard to positive symptoms, the efficacy of risperidone was shown to be at least comparable with that of haloperidol. However, risperidone differs from conventional antipsychotics because it is more effective against the negative symptoms, has beneficial effects on affective and cognitive symptoms, and carries less risk of extrapyramidal side effects (EPS). To date, risperidone is the only atypical antipsychotic to have shown a significantly lower relapse rate compared with haloperidol in a long-term double-blind trial. This review describes comprehensive trial data and therapeutic observations gained with risperidone in the treatment of schizophrenia since its approval.     

The treatment of Parkinson’s disease with deep brain stimulation：current issues

Deep brain stimulation has become a well-established symptomatic treatment for Parkinson’s disease during the last 25 years. Besides improving motor symptoms and long-term motor com-plications, positiv...     

Search and appraisal of literatures and methods to use Internets in evidence based neurology]

A national guideline for stroke management is currently being made on the basis of evidence collected from randomized controlled trials (RCTs) and other types of clinical studies, which have been searched using computer system, as well as systematic reviews by the Cochrane Collaboration. In this guideline, grades of recommendation will be determined according to the levels of evidence. In critical appraisal for clinical trials, evaluation of validity in the methodology of trials and in the analysis of treatment effects are crucial. In estimating the quality of metaanalysis, a pivotal issue is to check the possibility of selection bias in RCTs. Indices for the assessment of treatment effects include relative risk reduction (RRR), absolute risk reduction (ARR), and number needed to treat (NNT). Besides, cost-effectiveness, cost-benefit, and cost-utility are used in medical economics. Quality-adjusted life years (QALY) and disability-adjusted years (DALY) have recently been proposed by the World Health Organization as the indices for the effect on quality of life as well.     

Current status of neuroprotective agents in the treatment of acute ischemic stroke

To keep ischemic brain cells alive, neuroprotective agents target events in the ischemic cascade that might be injurious to the cells. They can be divided broadly into groups that restore ion balance, block receptors, prevent reperfusion injury, or promote neuronal healing. To date, neuroprotective agents have either shown a lack of efficacy in clinical stroke trials or been limited by side effects. Ongoing clinical trials with novel agents are trying to enroll a more homogeneous population of stroke patients in an effort to demonstrate treatment benefit.     

Demented patients' participation in a clinical trial: factors affecting the caregivers' decision

Clinical trials for Alzheimer's disease take place in medical centers all over the world. Patients and caregivers have to decide whether or not to agree to participate in clinical trials. This study aimed to investigate the motivation that determines the caregivers' choice. Nineteen caregivers of demented patients who consented to participate in a clinical trial in our Memory Clinic and 10 caregivers who refused to participate were interviewed. The data were gathered by a self-report questionnaire covering various aspects of the caregivers' decision-making process. Among the reasons for agreeing to participate in the clinical trial were the respondents' belief that it would improve or help to maintain the patients' condition. Most of the respondents of both groups indicated that information regarding side effects and success probability was adequately provided in advance. The primary reason for refusal was the potential side effects of the drug. The implications of the findings are discussed.     

The importance of assessing behaviour and cognition in antiepileptic drug trials in children and adolescents

It has long been recognised that uncontrolled childhood epilepsy is detrimental to cognition and behaviour, impacting on a patient’s ability to succeed academically. Patients who experience more frequent and serious seizures are at greater risk for cognitive decline, emphasising the need for more effective epilepsy treatments to bring seizures under control. That said, although more effective antiepileptic drugs (AEDs) have the potential to limit the impact of uncontrolled seizures on cognitive and behavioural function, recently it has been acknowledged that deficits in these functions may be caused by AEDs themselves. The cognitive and behavioural effects of older-generation AEDs have been determined largely from AE reporting rather than from specific assessment. Recently, clinical trials of newer-generation AEDs, such as topiramate, levetiracetam and perampanel, have included standardised neuropsychological tests as outcome measures to assess their impact on cognition and behaviour in children and adolescents. However, to understand how we may limit the cognitive and behavioural side effects of AEDs, it is necessary for us to gain a fuller, more accurate, characterisation of their true impact. Such insight will depend on sophisticated and standardised approaches to the design of AED clinical trials. This review provides a general overview of our current understanding of the impact of both epilepsy and AEDs on cognition and behaviour, before focusing on the AEDs for which more detailed assessment, using standardised cognitive and behavioural measures, has been undertaken. We will then go on to discuss the key elements in the design of future AED clinical trials to address current unmet needs.     

Efficacy and Safety of Antiepileptic Drugs: A Review of Controlled Trials

Summary: Twenty randomized, double-blind, controlled clinical trials of antiepileptic drugs (AEDs) in mostly adult patients with mostly partial onset and/or generalized tonic-clonic seizures have been reported, with a total of 1,336 patients. None of these studies has demonstrated significant differences in antiepileptic efficacy between available antiepileptic drugs, but the results show that there are considerable individual differences between patients' responses to the same drug. While side effects are common with all of the antiepileptic drugs currently available, these are usually mild and reversible. Although some toxic effects may occur more frequently with certain drugs, there is sufficient overlap between the effects of various antiepileptic drugs that most side effects cannot be attributed with certainty to any one drug. Since side effects are generally dose-related, they can frequently be avoided or minimized by careful dosage titration and individualization of therapy.     

Do SSRIs or antidepressants in general increase suicidality?

In the past few years several papers have reported critically on the risk of suicidal thoughts and behaviour associated with antidepressants, primarily SSRIs. The risk-benefit ratio of antidepressant (AD) treatment has been questioned especially in children and adolescents. The critical publications led to warnings being issued by regulatory authorities such as the FDA, MHRA and EMEA and stimulated new research activity in this field. However, potential harmful effects of antidepressants on suicidality are difficult to investigate in empirical studies because these have several methodological limitations. Randomised controlled trials (RCTs) are the most reliable way to test the hypothesis that AD have such side effects. In addition to meta-analyses of RCTs, complementary research methods should be applied to obtain the most comprehensive information. We undertook a comprehensive review of publications related to the topics ADs, suicide, suicidality, suicidal behaviour and aggression. Based on this comprehensive review we conclude that ADs, including SSRIs, carry a small risk of inducing suicidal thoughts and suicide attempts, in age groups below 25 years, the risk reducing further at the age of about 30–40 years. This risk has to be balanced against the well-known beneficial effects of ADs on depressive and other symptoms (anxiety, panic, obsessive-compulsive symptoms), including suicidality and suicidal behaviour. According to the principles of good clinical practice, decision making should consider carefully the beneficial effects of AD treatment as well as potentially harmful effects and attempt to keep the potential risks of AD treatment to a minimum. It is the major problem facing efforts to identify the possible ‘suicidal effects’ of antidepressants.

     

Quality of life of schizophrenic patients on medications and implications for new drug trials.

The quality of life of schizophrenic patients participating in clinical trials of new neuroleptics is rarely systematically assessed. Factors that may have contributed to the neglect of such assessments include the difficulty of measuring changes affecting quality of life during short-term trials and the continued belief that schizophrenic patients' self-reports about inner states are unreliable. A model of determinants specifically related to the quality of life of schizophrenic patients in such trials would include symptoms, side effects of neuroleptics, and psychosocial performance. In view of the importance of assessing the quality of life of patients on medications, the author recommends that regulatory agencies require such assessments in clinical trials of new neuroleptics.     

Pharmacological vigilance and pharmacological epidemiology: principles, definition, methods and current trends in neurology]

It is now well established that only clinical trials performed before drug approval are not sufficient for a full modern pharmacological evaluation of drugs and treatments. The need of both pharmacovigilance and pharmacoepidemiology is underlined in order to evaluate drugs under real conditions. After a summary of methods used in pharmacoepidemiological trials (spontaneous reports, imputability assessment, cohorts, case control studies etc.), recent pharmacoepidemiological data useful for the neurologist are summarized: side effects of tacrine and vaccines, serotoninergic syndrome and side effects of new antiepileptic drugs.     

Gene-based Therapies in Parkinson’s Disease

Parkinson’s disease (PD) is a progressive neurological disorder characterized primarily by the degeneration of nigrostriatal dopaminergic neurons and diminution of the neurotransmitter dopamine. Though dopamine replacement therapies such as levodopa can improve the symptoms of PD, the benefits may be overshadowed by side effects and the onset of symptoms not responsive to dopaminergic treatments (e.g., autonomic symptoms, gait and balance problems, and cognitive impairment). Furthermore, no therapies have proven to slow the neurodegenerative process. Novel approaches to address these difficult problems, and others, are being sought. Over the last decade, several innovative gene therapies for PD have entered human clinical trials in an effort to address both symptomatic and potential disease-modifying effects. Though the results of these trials have been mixed, the therapies have generally been safe and well-tolerated, suggesting gene therapy may be a viable treatment for PD in the future. This article will review past and current clinical trials of gene therapies for PD. In addition, novel preclinical approaches to gene therapy for PD will be described.     

Do SSRIs or antidepressants in general increase suicidality? WPA Section on Pharmacopsychiatry: consensus statement

In the past few years several papers have reported critically on the risk of suicidal thoughts and behaviour associated with antidepressants, primarily SSRIs. The risk-benefit ratio of antidepressant (AD) treatment has been questioned especially in children and adolescents. The critical publications led to warnings being issued by regulatory authorities such as the FDA, MHRA and EMEA and stimulated new research activity in this field. However, potential harmful effects of antidepressants on suicidality are difficult to investigate in empirical studies because these have several methodological limitations. Randomised controlled trials (RCTs) are the most reliable way to test the hypothesis that AD have such side effects. In addition to meta-analyses of RCTs, complementary research methods should be applied to obtain the most comprehensive information. We undertook a comprehensive review of publications related to the topics ADs, suicide, suicidality, suicidal behaviour and aggression. Based on this comprehensive review we conclude that ADs, including SSRIs, carry a small risk of inducing suicidal thoughts and suicide attempts, in age groups below 25 years, the risk reducing further at the age of about 30-40 years. This risk has to be balanced against the well-known beneficial effects of ADs on depressive and other symptoms (anxiety, panic, obsessive-compulsive symptoms), including suicidality and suicidal behaviour. According to the principles of good clinical practice, decision making should consider carefully the beneficial effects of AD treatment as well as potentially harmful effects and attempt to keep the potential risks of AD treatment to a minimum. It is the major problem facing efforts to identify the possible 'suicidal effects' of antidepressants.