The use of atypical antipsychotics in the management of schizophrenia

Long-term drug treatment of schizophrenia with conventional antipsychotics has limitations: an estimated quarter to one third of patients are treatment-resistant; conventional antipsychotics have only a modest impact upon negative symptoms (poverty of thought, social withdrawal and loss of affect); and adverse effects, particularly extrapyramidal symptoms (EPS). Newer, so-called atypical, antipsychotics such as olanzapine, risperidone, sertindole and clozapine (an old drug which was re-introduced in 1990) are claimed to address these limitations. Atypical agents are, at a minimum, at least as effective as conventional drugs such as haloperidol. They also cause substantially fewer extrapyramidal symptoms. However, some other adverse effects are more common than with conventional drugs. For example, clozapine carries a significant risk of serious blood disorders, for which special monitoring is mandatory; it also causes troublesome drowsiness and increased salivation more often than conventional agents. Some atypical agents cause more weight gain or QT prolongation than older agents. The choice of therapy is, therefore, not straightforward. At present, atypical agents represent an advance for patients with severe or intolerable EPS. Most published evidence exists to support the use of clozapine, which has also been shown to be effective in schizophrenia refractory to conventional agents. However, the need for compliance with blood count monitoring and its sedative properties make careful patient selection important. The extent of any additional direct benefit offered by atypical agents on negative symptoms is not yet clear. The lack of a depot formulation for atypical drugs may pose a significant practical problem. To date, only two double-blind studies in which atypical agents were compared directly have been published. Neither provides compelling evidence for the choice of one agent over another. Atypical agents are many times more expensive than conventional drugs. Although drug treatment constitutes only a small proportion of the costs of managing schizophrenia, the additional annual cost of the use of atypical agents in, say, a quarter of the likely U.K. schizophrenic population would be about 56 M pound sterling. There is only limited evidence of cost-effectiveness. Atypical antipsychotics are not currently licensed for other conditions where conventional antipsychotics are commonly used, such as behaviour disturbance or dementia in the elderly. Their dose, and place in treatment in such cases have yet to be determined.     

Atypical antipsychotic agents: a critical review.

The pharmacology, efficacy, and adverse effects of atypical antipsychotic agents when used to treat schizophrenia and other disorders are reviewed. Atypical antipsychotic agents were developed in response to problems with typical agents, including lack of efficacy in some patients, lack of improvement in negative symptoms, and troublesome adverse effects, especially extrapyramidal symptoms (EPSs) and tardive dyskinesia CTD). Atypical antipsychotics differ from typical psychotics in their "limbic-specific" dopamine type 2 (D2)-receptor binding and high ratio of serotonin type 2 (5-HT2)-receptor binding to D2 binding. In clinical trials in patients with non-treatment-resistant schizophrenia, risperidone and olanzapine were superior to placebo for positive and negative symptoms. Risperidone and olanzapine were superior to haloperidol on some measures. Quetiapine was better than placebo but was not better than typical antipsychotics. Head-to-head comparisons of atypical antipsychotics in non-treatment-resistant schizophrenia have been inconclusive. Clozapine remains the standard agent for treatment-resistant schizophrenia. Atypical agents are substantially more expensive than their typical antipsychotic counterparts. To fully determine the overall efficiency of these drugs, other potential benefits, such as improved quality of life, need to be factored in. Atypical antipsychotics are associated with a decreased capacity to cause EPSs, TD, neuroleptic malignant syndrome, and hyperprolactinemia. Clozapine carries a risk of agranulocytosis; the white blood cell count must be monitored. Atypical antipsychotics are increasingly being used for indications other than schizophrenia, such as the management of aggression, mania, and depression. Atypical antipsychotics are often considered first-line agents for treating schizophrenia and are promising treatment alternatives for other psychiatric and neurologic conditions.     

儿童精神分裂症住院患者不同年代用药比较

目的探讨儿童精神分裂症住院患儿不同年代使用精神药物的变化趋势.方法回顾性分析相隔15年,1年内住院的儿童精神分裂症患儿病例资料共306例,比较两组使用精神药物情况、疗效和不良反应.结果15年前组用药前三位为氯丙嗪、奋乃静、舒必利,以典型抗精神病药为主;15年后组用药前三位为利培酮、氯氮平、奎硫平,以非典型抗精神病药为主.结论儿童精神分裂症住院患儿临床用药由典型抗精神病药转向非典型抗精神病药,利培酮、氯氮平等非典型抗精神病药可作为儿童精神分裂症的首选药物.     

Benefit-risk assessment of atypical antipsychotics in the treatment of schizophrenia and comorbid disorders in children and adolescents.

Evidence on the efficacy and safety of atypical antipsychotics in children and adolescents with schizophrenia is limited. The purpose of this review is to assess the published data on the use of atypical antipsychotics in children and adolescents with schizophrenia alone and with comorbid disorders, and to establish benefit-risk guidelines for clinicians.Risperidone, olanzapine and clozapine were found to be effective in the treatment of aggression and mania. Risperidone, and possibly also olanzapine, may be the drugs of choice in children with comorbid tic disorders. Ziprasidone has some monoamine reuptake inhibition properties and may be administered as an augmenting agent in children and adolescents with schizophrenia and comorbid anxiety and mood disorders.Compared with the typical antipsychotics, the atypical drugs seem to be more effective, better tolerated and lead to better patient adherence. Importantly, the atypical antipsychotics have a lower propensity to induce extrapyramidal symptoms and a potential (shown so far only in adults) to improve cognitive function and inhibit suicidal behaviour (especially clozapine). Yet, the adverse effects associated with these agents, especially weight gain, which may also have long-term effects, can lead to non-compliance in the young population. In children and adolescents receiving clozapine, olanzapine and quetiapine (but not ziprasidone, which does not have a pro-appetite effect), particularly those with obesity or a family history of diabetes mellitus, fasting blood glucose and lipid levels must be monitored frequently. Weight gain might be better controlled when the children and their parents are properly informed about this adverse effect and diet is regulated. Another major disadvantage of the atypical antipsychotics, especially risperidone, is their association with hyperprolactinaemia, which can lead to hypogonadism-induced osteoporosis, galactorrhoea, gynaecomastia, irregular menstruation and sexual dysfunction, all seen also with typical antipsychotics. Other atypical antipsychotics, namely olanzapine and ziprasidone, have been reported to be prolactin sparing in adults, but may not be completely devoid of hyperprolactinaemic effects in children and adolescents. Thus, prolactin levels should be assessed routinely in young patients treated with atypical antipsychotics. Further, children and adolescents with hyperprolactinaemia-related effects should be switched to a prolactin-sparing agent, such as quetiapine. All atypical antipsychotics may induce sedation and they are not devoid of extrapyramidal symptoms (especially risperidone). The use of typical antipsychotics has been limited to patients who are resistant to atypical antipsychotics, intolerant to their adverse effects, or require injections or depot preparations.Further double-blind, placebo-controlled trials and long-term safety assessments are needed before definitive conclusions can be reached about the place of atypical antipsychotics in the therapeutic armamentarium of childhood-onset schizophrenia.     

Overdose of atypical antipsychotics: clinical presentation, mechanisms of toxicity and management

Historically, treatment for schizophrenia focused on sedation. The advent of the typical antipsychotics resulted in treatment aimed specifically at the underlying disease, but these agents were associated with numerous adverse effects, and were not particularly effective at treatment of the negative symptoms of schizophrenia. As a result, numerous atypical agents have been developed over the past 2 decades, including several agents within the past 5 years. Overdose of antipsychotics remains quite common in Western society. In 2010, poison control centres in the US received nearly 43,000 calls related to atypical antipsychotics alone. Due to underreporting, the true incidence of overdose with atypical antipsychotics is likely much greater. Following overdose of an atypical antipsychotic, the clinical effects observed, such as CNS depression, tachycardia and orthostasis are largely predictable based on the unique receptor binding profile of the agent. This article, which focuses on the atypical antipsychotics commonly used in the treatment of schizophrenia, discusses the features commonly encountered in overdose. Specifically, agents that result in QT prolongation and the corresponding potential for torsades de pointes, as well as unique features encountered with the various medications are discussed. The diagnosis of this overdose is largely based on history. Routine use of drug screens is unlikely to be beneficial. The primary goal of management is aggressive supportive care. Patients with significant CNS depression with associated loss of airway reflexes and respiratory failure need advanced airway management. Hypotension should be treated first with intravenous fluids, with the use of direct acting vasopressors reserved for persistent hypotension. Benzodiazepines should be used for seizures, with barbiturates used for refractory seizures. Intravenous magnesium can be administered for patients with a corrected QT interval exceeding 500 milliseconds.     

Aripiprazole in the treatment of schizophrenia: a consensus report produced by schizophrenia experts in Italy

Schizophrenia is generally a chronic and disabling mental illness. Pharmacological therapy, which is used for relief of acute psychotic episodes and prevention of subsequent relapse, is essential for the effective management of schizophrenia. In order to alleviate the positive symptoms of schizophrenia, all antipsychotic agents act on the dopaminergic system. However, strong, high-affinity dopamine D(2)-receptor blockade may also be responsible for debilitating extrapyramidal symptoms (EPS) and hyperprolactinaemia. Unlike conventional antipsychotic agents, atypical antipsychotics also exert activity at other receptors, and it is generally acknowledged that, compared with conventional antipsychotics, atypical agents are associated with a broader spectrum of clinical efficacy and are better tolerated. However, other adverse effects such as weight gain and metabolic changes are cause for concern with some atypical antipsychotics. The novel atypical antipsychotic agent aripiprazole is a partial agonist at D(2) receptors that has been shown in clinical trials to be effective in treating both the positive and the negative symptoms of schizophrenia, and to be well tolerated, with a low propensity for EPS and no clinically significant weight gain, hyperprolactinaemia or corrected QT-interval prolongation. Aripiprazole thus provides clinicians with another treatment option, and in October 2005, schizophrenia experts participated in an expert consensus meeting that aimed to agree on a set of guidelines for best-practice use of aripiprazole in the acute and long-term management of schizophrenia in Italy. This report describes the outcome of the meeting. Our recommendations for dosage and administration of aripiprazole are in agreement with the manufacturer's prescribing information. Ideally, optimal dosing should be evaluated on an individual basis, taking into account patients' characteristics such as the presence or absence of agitation. Overall, in our experience, aripiprazole is generally a well accepted, well tolerated, safe and broadly effective first-line antipsychotic agent. Switching to aripiprazole from maintenance therapy with another antipsychotic also works well, provided the change is made gradually, involving tapering of the original medication.     

The role of atypical antipsychotic agents in the treatment of schizophrenia and schizoaffective disorders in the elderly

Schizophrenia and schizoaffective disorder are prevalent in 1% of the adult population. The condition was thought to predominantly affect the young however recent studies have shown that the condition occurs in individuals throughout the life-span. The aim of this review is to discuss the role of atypical antipsychotics in treating schizoaffective disorder and schizophrenia in the elderly. The advent of atypical antipsychotics has made significant strides in the pharmacotherapy of schizophrenia in the elderly. They are as efficacious as conventional agents in reducing the positive symptoms, possibly some what more efficacious in reducing negative symptoms and appear to have a relatively safer adverse effect profile. However metabolic side affects particularly glucose abnormalities and weight gain, cerebrovascular effects, and mortality risk noted in dementia patients are gaining increasing attention. Appropriate monitoring for the metabolic side effects has been recommended by agencies such as the FDA (United States Food and Drug Administration), ADA (American Diabetic Association) and APA (American Psychiatric Association). Treatment of elderly patients is complicated by age related biological factors affecting drug response and presence of comorbid medical conditions and concomitant medication. Current research supports the role of atypical antipsychotics in the treatment of schizophrenia and schizoaffective disorder in the elderly. Despite advantages compared with conventional agents, challenges to successful therapy remain, even with these better tolerated agents.     

Paediatric uses of atypical antipsychotics

Antipsychotics are commonly prescribed to children and adolescents. With the relatively recent availability of the atypical antipsychotics, physicians have begun prescribing these agents to young people in the hope of finding safe, effective alternatives to the typical antipsychotics. This report reviews what is currently known about the use of the atypical antipsychotics in young people. Most of the currently available data are based on case reports and case series. The results of only a handful of prospective trials pertaining to the use of the atypical antipsychotics in youths have been reported. Based on the available information, it appears that clozapine has a role in juvenile treatment resistant schizophrenia. When considered as a group, the 'first-line' atypical antipsychotics risperidone, olanzapine and quetiapine appear to have promise as treatments for several neuropsychiatric disorders in young people. These conditions include psychotic, mood, disruptive, movement and pervasive developmental disorders. Unfortunately, as has historically been the case, the demand to address the clinical needs of young patients with neuropsychiatric disorders has outpaced empirically based information. This is particularly important because significant side effects can occur when children or adolescents are treated with atypical antipsychotics. Since there is a paucity of short-term and almost no long-term safety data pertaining to these agents in young people, careful consideration must be made prior to initiating atypical antipsychotic treatment for a child or teenager. Based upon what is known about these agents, a rational approach to the use of these drugs in juveniles is offered.     

A review of atypical antipsychotic drugs versus conventional medication in schizophrenia

Atypical antipsychotics are replacing conventional antipsychotics for the treatment of schizophrenia. They are considered to be at least as effective as conventional agents, with most producing fewer extrapyramidal symptoms. This review presents the evidence from published meta-analyses and describes differences in clinical effectiveness and tolerability between conventional and atypical antipsychotic agents. In addition, it discusses some of the more significant adverse effects including tardive dyskinesia, weight gain, diabetes and sudden death. Results from meta-analyses are conflicting, with some finding no significant advantages on measures of efficacy or tolerability for atypical antipsychotics over moderate daily doses of conventional drugs. Other results have shown that some atypical drugs have at least minor efficacy advantages over conventional comparators. Atypical antipsychotics exhibit a much reduced risk for tardive dyskinesia compared with conventional drugs. However, weight gain is more common with some atypical drugs (especially clozapine and olanzapine). Both conventional and atypical antipsychotics have been associated with diabetes, with most reports implicating both clozapine and olanzapine. Finally, atypical antipsychotics (unlike conventional drugs) have little or no effect on QT and are not associated with sudden death.     

A review of atypical antipsychotic drugs versus conventional medication in schizophrenia

Atypical antipsychotics are replacing conventional antipsychotics for the treatment of schizophrenia. They are considered to be at least as effective as conventional agents, with most producing fewer extrapyramidal symptoms. This review presents the evidence from published meta-analyses and describes differences in clinical effectiveness and tolerability between conventional and atypical antipsychotic agents. In addition, it discusses some of the more significant adverse effects including tardive dyskinesia, weight gain, diabetes and sudden death. Results from meta-analyses are conflicting, with some finding no significant advantages on measures of efficacy or tolerability for atypical antipsychotics over moderate daily doses of conventional drugs. Other results have shown that some atypical drugs have at least minor efficacy advantages over conventional comparators. Atypical antipsychotics exhibit a much reduced risk for tardive dyskinesia compared with conventional drugs. However, weight gain is more common with some atypical drugs (especially clozapine and olanzapine). Both conventional and atypical antipsychotics have been associated with diabetes, with most reports implicating both clozapine and olanzapine. Finally, atypical antipsychotics (unlike conventional drugs) have little or no effect on QT and are not associated with sudden death.     

Paediatric uses of atypical antipsychotics

Antipsychotics are commonly prescribed to children and adolescents. With the relatively recent availability of the atypical antipsychotics, physicians have begun prescribing these agents to young people in the hope of finding safe, effective alternatives to the typical antipsychotics. This report reviews what is currently known about the use of the atypical antipsychotics in young people. Most of the currently available data are based on case reports and case series. The results of only a handful of prospective trials pertaining to the use of the atypical antipsychotics in youths have been reported. Based on the available information, it appears that clozapine has a role in juvenile treatment resistant schizophrenia. When considered as a group, the ‘first-line’ atypical antipsychotics risperidone, olanzapine and quetiapine appear to have promise as treatments for several neuropsychiatric disorders in young people. These conditions include psychotic, mood, disruptive, movement and pervasive developmental disorders. Unfortunately, as has historically been the case, the demand to address the clinical needs of young patients with neuropsychiatric disorders has outpaced empirically based information. This is particularly important because significant side effects can occur when children or adolescents are treated with atypical antipsychotics. Since there is a paucity of short-term and almost no long-term safety data pertaining to these agents in young people, careful consideration must be made prior to initiating atypical antipsychotic treatment for a child or teenager. Based upon what is known about these agents, a rational approach to the use of these drugs in juveniles is offered.     

Quetiapine fumarate (Seroquel): a new atypical antipsychotic

The goal of antipsychotic drug development efforts over the past 10 years has been to develop agents with increased efficacy and safety and fewer of the side effects commonly associated with the older antipsychotic medications. The newer agents, often called atypical antipsychotics, are effective in treating both the positive and negative symptoms of schizophrenia and are associated with fewer neurological- and endocrine-related side effects compared to the older agents. As a result, patients are likely to remain on therapy longer, preventing relapses and costly hospitalizations. Quetiapine fumarate (Seroquel) is the most recently introduced atypical antipsychotic and is indicated for the management of the manifestations of psychotic disorders and schizophrenia. Quetiapine, like clozapine (the archetypal atypical antipsychotic), interacts with a broad range of neurotransmitter receptors and has a higher affinity for serotonin (5-HT(2A)) receptors relative to dopamine (D(2)) receptors in the brain. Further, quetiapine's pharmacological effects appear selective for the mesolimbic and mesocortical dopamine systems, which are believed to be the areas of the brain responsible for the therapeutic effects of antipsychotics. In contrast to most standard antipsychotics and some atypical antipsychotics, quetiapine's effects on the nigrostriatal dopamine system, which is responsible for the extrapyramidal (or motor) side effects, are minimal. Quetiapine also has minimal activity on dopamine receptors in the tuberoinfundibular dopamine system, thereby avoiding the problem of hyperprolactinemia, common with the standard antipsychotics and some atypical antipsychotics. Because of these properties, quetiapine is an effective antipsychotic agent with a relatively benign side effect profile. Several large, placebo- and active-controlled, multicenter trials have shown quetiapine to be effective against both positive (e.g., hallucinations, delusions) and negative symptoms (e.g., emotional withdrawal, apathy) and to have benefits in reducing hostility, aggression and affective symptoms. Patients on long-term treatment report high compliance, good satisfaction, increased ability to function and improvements consistent with a better quality of life. Because of quetiapine's excellent tolerability profile, its use is particularly appropriate in patients especially sensitive to adverse effects, e.g., elderly patients with psychotic symptoms and other neurological disorders such as Parkinson's and Alzheimer's disease.     

The revised dopamine hypothesis of schizophrenia: evidence from pharmacological MRI studies with atypical antipsychotic medication

The revised dopamine (DA) hypothesis states that clinical symptoms of schizophrenia are caused by an imbalance of the DA system. In this article, we aim to review evidence for this hypothesis by evaluating functional magnetic resonance imaging studies in schizophrenia. Because atypical drugs are thought to have a normalizing effect on DA neurotransmission, we have focused on pharmacological MRI (PhMRI) studies that explore the effect of these drugs on prefrontal and striatal brain activity in schizophrenia patients. We encountered a total of 13 studies, most of which reported enhanced prefrontal activity associated with alleviation of negative symptoms and improvement of cognitive functions, following treatment with atypical antipsychotics. Besides increasing prefrontal cortex activity, atypical antipsychotics have also shown to be effective in the regulation of striatal functioning. The current PhMRI findings support the revised DA hypothesis of schizophrenia by confirming hypoactivity of the prefrontal cortex in schizophrenia and, following atypical antipsychotics, improvement of prefrontal and subcortical functions reflecting enhanced DA activity.     

Dose response and atypical antipsychotics in schizophrenia

Based on information from clinical trials, both the efficacy and adverse effects of conventional antipsychotics in the treatment of schizophrenia are dose related. The overlapping nature of these dose-response profiles limits the use of these agents. Atypical antipsychotics provide greater relief across the comorbid symptom domains of schizophrenia, but dose-response studies and clinical experience have revealed that some of these drugs also have dose limitations. This article reviews the dose-response relationships of the atypical antipsychotics as presented predominantly in pivotal, randomised studies (double-blind and otherwise).Limited data indicate that clozapine shows dose-related efficacy up to 600 mg/day in patients with treatment-resistant schizophrenia. However, higher dosages of clozapine may be associated with the risk of seizures. Risperidone demonstrates dose-related adverse events that compromise efficacy. The dose-response relationships for ziprasidone, quetiapine and aripiprazole are less well established. The efficacy of olanzapine appears to be dose related within the recommended dosage range of 10-20 mg/day, but clinical trials that have explored higher dosages suggest improved efficacy. Furthermore, the higher doses are not associated with a significantly increased incidence of adverse events.Further studies are clearly needed to fully characterise the dose-response relationships of atypical antipsychotics.     

A systematic review of meta-analyses of the efficacy of oral atypical antipsychotics for the treatment of adult patients with schizophrenia

INTRODUCTION: Meta-analyses are a convenient way for clinicians and researchers to review data regarding different interventions. Meta-analyses can overcome many of the limitations of individual studies, namely the power to detect differences, and help resolve the results of inconsistent studies. AREAS COVERED: This paper is a review of meta-analyses of oral atypical antipsychotics for the treatment of schizophrenia, located through PubMed and the Cochrane Database of Systematic Reviews. A total of 91 meta-analyses were identified that included efficacy outcome data for the 10 atypical antipsychotics available in the USA (11 focused on clozapine, 17 for risperidone, 8 for olanzapine, 5 for quetiapine, 3 for ziprasidone, 10 for aripiprazole, 5 for paliperidone, 1 for iloperidone, 0 for asenapine or lurasidone, and 31 others that were classified more broadly). These include Cochrane Reviews and other similarly executed reports, as well as pooled analyses meta-tagged in PubMed as a meta-analysis. EXPERT OPINION: In general, there is heterogeneity among the atypical antipsychotics in terms of efficacy, with clozapine evidencing consistent superiority over typical antipsychotics, trailed behind by olanzapine and risperidone. Meta-analyses generally do not support efficacy differences between the other atypical antipsychotics compared with the older typical agents. Although this review is focused on efficacy, other considerations are also important, including the large tolerability differences among all the agents and the need to individualize medication choice based on past history of therapeutic response, past history of tolerability issues and the individual's personal values and preferences.     

Selective serotonin reuptake inhibitor augmentation in the treatment of negative symptoms of schizophrenia

The treatment of negative symptoms of schizophrenia presents a major clinical challenge. This review examines the evidence pertaining to the efficacy, tolerability and safety of adding selective serotonin reuptake inhibitors (SSRIs) to antipsychotic agents in the treatment of negative symptoms in schizophrenia. Important methodological issues such as differentiating primary and secondary negative symptoms are discussed. The balance of available evidence indicates that at least some SSRIs, fluvoxamine and fluoxetine, can ameliorate primary negative symptoms in chronic schizophrenia patients who are treated with typical antipsychotics. The combination is safe and well tolerated although, as antipsychotic drug concentrations may be elevated, attention to dose and drug monitoring should be considered as appropriate. The effect of SSRI augmentation of atypical antipsychotics requires further study. Combination with clozapine may require particular caution because of potential toxicity if serum clozapine levels rise steeply. SSRI augmentation may be a useful addition to the treatment of schizophrenia.     

Aripiprazole: the evidence of its therapeutic impact in schizophrenia

INTRODUCTION: An ideal antipsychotic would rapidly stabilize acute psychotic symptoms and maintain the patient, without relapse, for prolonged periods in the absence of extrapyramidal, endocrine, diabetic, or cardiovascular side effects, and without weight gain. The dopamine partial agonist aripiprazole is compared with this ideal and with conventional antipsychotics, such as haloperidol, and with atypical antipsychotics. AIMS: To review the evidence for the clinical impact of aripiprazole in the treatment of patients with schizophrenia. EVIDENCE REVIEW: There is clear evidence that aripiprazole is as effective as haloperidol in reducing the positive and negative symptoms of schizophrenia and schizoaffective disorder. In patients with schizophrenia, aripiprazole has been shown to stabilize acute psychotic symptoms, prevent relapse in stabilized patients, and maintain patients with schizophrenia following acute relapse. Furthermore, in common with other atypical antipsychotics, aripiprazole appears to be associated with a lower incidence of side effects than typical antipsychotics and may reduce discontinuation of drug therapy. Evidence also suggests that aripiprazole may be associated with a lower incidence of extrapyramidal symptoms than conventional antipsychotics, but further long-term studies concerning tardive dyskinesia are required. Studies on the cost effectiveness of aripiprazole, as well as the quality of life and general functioning of patients taking the drug are still required, although there is some evidence of improved quality of life. Further evidence comparing aripiprazole with other atypical antipsychotics would be welcome. CLINICAL VALUE: In conclusion, aripiprazole is an atypical antipsychotic suitable for first-line use in patients with schizophrenia. Its clinical value in relation to other atypical antipsychotics remains to be elucidated.     

Epidemiology, etiology, diagnosis, and treatment of schizophrenia.

The epidemiology, etiology, diagnosis, and treatment of schizophrenia are reviewed. In the United States, at least 1 in every 100 persons is afflicted with schizophrenia. The theory that schizophrenia is a biochemical disorder has gained wide acceptance, although none of the etiological theories are conclusive. Criteria contained in the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised, are most commonly used to diagnose schizophrenia. Accuracy in diagnosing schizophrenia is critical because the treatments and prognoses for different types of psychoses can vary considerably. Treatment primarily involves the use of antipsychotic drugs, which are thought to act by blocking central dopamine receptors. The classical antipsychotics are the phenothiazines; of these, the prototype is chlorpromazine. Other classes of antipsychotics are the thioxanthenes, butyrophenones, dihydroindolones, dibenzoxazepines, diphenylbutylpiperidines, and dibenzodiazepines. Selecting an appropriate agent involves consideration of adverse effects, dosage forms, and the agent's ability to relieve target symptoms. Adverse effects of these agents include sedation, extrapyramidal effects, and anticholinergic effects. Tardive dyskinesia is a serious, irreversible condition associated with long-term antipsychotic therapy. Clozapine, a newer atypical antipsychotic, has been shown to be more effective than chlorpromazine and haloperidol and seems to cause few neurological adverse effects. Treatment of schizophrenia has not changed much since the advent of antipsychotic drug use nearly 30 years ago. Newer atypical antipsychotics show promise in improving target symptoms while causing fewer adverse effects.     

Long-acting formulations of atypical antipsychotics: time to reconsider when to introduce depot antipsychotics

The current availability of a long-acting injectable formulation of risperidone and the potential future availability of long-acting formulations of other atypical antipsychotics (such as paliperidone) should prompt a reconsideration of at what stage in the treatment of schizophrenia such long-acting agents should be introduced. At present, long-acting formulations, particularly of conventional antipsychotics (depots), are usually reserved for patients with chronic schizophrenia who are at high-risk of noncompliance. Recent and increasing data from other patient groups, such as those with first-episode psychosis, suggest that long-acting risperidone is associated with good efficacy and tolerability leading to high patient acceptance, and treatment continuation rates that are greater than with oral antipsychotics. The benefits of an atypical antipsychotic coupled with the assurance of medication delivery in the form of a long-acting injection imply that these novel formulations should be considered in first-episode patients, for whom optimal outcome is frequently compromised by early treatment discontinuation and poor adherence.