Efficacy of risperidone in reducing positive and negative symptoms in medication-refractory schizophrenia: an open prospective study

Predictors of response to pharmacological treatments in treatment-resistant schizophrenia - A systematic review and meta-analysis

BACKGROUND

As the burden of treatment-resistant schizophrenia (TRS) on patients and society is high it is important to identify predictors of response to medications in TRS. The aim was to analyse whether baseline patient and study characteristics predict treatment response in TRS in drug trials.

METHODS

A comprehensive search strategy completed in PubMed, Cochrane and Web of Science helped identify relevant studies. The studies had to meet the following criteria: English language clinical trial of pharmacological treatment of TRS, clear definition of TRS and response, percentage of response reported, at least one baseline characteristic presented, and total sample size of at least 15. Meta-regression techniques served to explore whether baseline characteristics predict response to medication in TRS.

RESULTS

77 articles were included in the systematic review. The overall sample included 7546 patients, of which 41% achieved response. Higher positive symptom score at baseline predicted higher response percentage. None of the other baseline patient or study characteristics achieved statistical significance at predicting response. When analysed in groups divided by antipsychotic drugs, studies of clozapine and other atypical antipsychotics produced the highest response rate.

CONCLUSIONS

This meta-analytic review identified surprisingly few baseline characteristics that predicted treatment response. However, higher positive symptoms and the use of atypical antipsychotics - particularly clozapine -was associated with the greatest likelihood of response. The difficulty involved in the prediction of medication response in TRS necessitates careful monitoring and personalised medication management. There is a need for more investigations of the predictors of treatment response in TRS.

Rational pharmacotherapy in early psychosis

Background

An increased focus in research specific to first-episode schizophrenia has provided a rapidly growing body of evidence that can be directly translated to clinical practice.

Aims

To provide clinical recommendations specific to effective pharmacotherapy of first-episode schizophrenia.

Method

Evidence from clinical trials focused on the first-episode population is combined with data from other areas of investigation.

Results

In first-episode psychosis, when to initiate treatment is not always clear, being intimately linked to challenges regarding early detection and diagnosis. There may be differences in antipsychotic dosing, patterns of response and sensitivity to side-effects. Adherence appears to be even more problematic at this stage.

Conclusions

Clinicians currently treating early psychosis have considerably more information to guide their decision-making. However, the speed at which the field is growing is a reminder totreatthis knowledge as a work in progress.

Olanzapine: Psychopharmacology, Clinical Efficacy, and Adverse Effects

Olanzapine is an atypical antipsychotic that has a pharmacological profile similar that of clozapine. It is biotransformed by hepatic enzymes and can be dosed on a once-daily basis. In large, double-blind, placebo-controlled trials, olanzapine was shown to be efficacious in the treatment of schizophrenia relative to placebo. Many trials showed superior efficacy to haloperidol, especially against negative symptoms. Olanzapine is FDA-approved for the treatment of psychotic disorders, though data suggest possible use in depression, bipolar disorder, psychogenic polydipsia, and developmental disabilities. Olanzap-ine appears to be well-tolerated. Commonly reported adverse effects include orthostatic hypotension, sedation, hepatic transaminase elevations, weight gain, headache, agitation, dizziness, and constipation. The incidence of extrapyramidal symptoms and tardive dyskinesia is low. Few drug interactions have been reported. The recommended starting dose is 10 mg once daily. One trial indicated that the higher cost of this agent might be offset by a reduction in overall hospitalization costs.

Altered functional connectivity links in neuroleptic-naïve and neuroleptic-treated patients with schizophrenia, and their relation to symptoms including volition

In order to analyze functional connectivity in untreated and treated patients with schizophrenia, resting-state fMRI data were obtained for whole-brain functional connectivity analysis from 22 first-episode neuroleptic-naïve schizophrenia (NNS), 61 first-episode neuroleptic-treated schizophrenia (NTS) patients, and 60 healthy controls (HC). Reductions were found in untreated and treated patients in the functional connectivity between the posterior cingulate gyrus and precuneus, and this was correlated with the reduction in volition from the Positive and Negative Symptoms Scale (PANSS), that is in the willful initiation, sustenance, and control of thoughts, behavior, movements, and speech, and with the general and negative symptoms. In addition in both patient groups interhemispheric functional connectivity was weaker between the orbitofrontal cortex, amygdala and temporal pole. These functional connectivity changes and the related symptoms were not treated by the neuroleptics. Differences between the patient groups were that there were more strong functional connectivity links in the NNS patients (including in hippocampal, frontal, and striatal circuits) than in the NTS patients. These findings with a whole brain analysis in untreated and treated patients with schizophrenia provide evidence on some of the brain regions implicated in the volitional, other general, and negative symptoms, of schizophrenia that are not treated by neuroleptics so have implications for the development of other treatments; and provide evidence on some brain systems in which neuroleptics do alter the functional connectivity.

Chronic nicotine attenuates phencyclidine-induced impulsivity in a mouse serial reaction time task

Schizophrenia is a disorder characterized by positive, negative, and cognitive symptoms. While positive symptoms can be effectively treated with typical antipsychotic medication, which generally affects the dopaminergic system, negative and cognitive symptoms, including attentional deficits and impulsive behavior, are less sensitive to standard treatments. It has further been well documented that schizophrenic patients use tobacco products at a rate much higher than the general population, and this persists despite treatment. It has been argued this behavior may be a form of self-medication, to alleviate some symptoms of schizophrenia. It has further been posited that prefrontal glutamatergic hypofunction may underlie some aspects of schizophrenia, and in accordance with this model, systemic phencyclidine has been used to model the disease. We employed a modified 5-choice serial reaction time test, a paradigm that is often used to investigate many of the treatment-resistant symptoms of schizophrenia including impulsivity, selective attention, and sustained attention/cognitive vigilance, to determine the medicinal effects of nicotine. We demonstrate that chronic oral, but not acute injections of nicotine can selectively attenuate phencyclidine-induced increases in impulsivity without affecting other measures of attention. This suggests that nicotine use by schizophrenics may provide some relief of distinct symptoms that involve impulsive behaviors.

A case of resistant schizophrenia responding at a higher than recommended dose of risperidone without significant side effects

A patient, diagnosed with schizophrenia, non-responsive to two atypical antipsychotics and partially responsive to the third (risperidone) in therapeutic dose, ultimately showed complete response without any unacceptable side-effect in a dose (20mg) that was untried previously. This case makes an important observation that high dose of risperidone can be tried in a patient with good results if his clinical condition permits.

High-frequency prefrontal repetitive transcranial magnetic stimulation for the negative symptoms of schizophrenia: a case series

OBJECTIVES

The negative symptoms of schizophrenia are difficult to treat and are predictors of poor outcome. New somatic treatments are needed to reverse these symptoms and improve function. One promising approach is repetitive transcranial magnetic stimulation (rTMS), although results to date have been mixed. This pilot study assessed higher doses of rTMS and assessed particular demographic factors that may influence treatment response.

METHODS

Five patients with schizophrenia or schizoaffective disorder enrolled to receive 20 sessions of rTMS administered with a Magstim Super Rapid device (The Magstim Company Ltd, Wales, UK). Treatment was administered at 20 Hz for 2 seconds, intertrain interval of 28 seconds, and at 100% motor threshold to the left dorsolateral prefrontal cortex in an open-label pilot study. Positive and Negative Syndrome Scale symptom assessments occurred at 2-week intervals during treatment and twice at 4-week intervals after termination.

RESULTS

Treatments were well tolerated with no adverse events. One patient withdrew from the study in the setting of medication noncompliance. Of the patients who completed treatment, 2 had reductions in positive symptoms by 9% and 26%, maintained at 1 month. A third patient had a 14% reduction in negative symptoms at week 4, and a fourth patient had a 55% reduction at week 4. Negative symptom improvement was not related to depressive or extrapyramidal symptoms, which were unchanged with treatment.

CONCLUSIONS

This pilot study of rTMS treatment for the negative symptoms of schizophrenia is promising with respect to safety and feasibility. The promising preliminary evidence for improvements in this open-label setting should be followed up with a randomized clinical trial to establish efficacy. Further work may explore the potential utility of rTMS for the otherwise largely untreatable negative symptoms, which account for so much of the morbidity of schizophrenia.

Current perspectives in the treatment of resistant schizophrenia

This article summarizes the current knowledge base on the diagnosis and management of treatment resistant schizophrenia. While the prevalence of treatment resistant schizophrenia is definition dependent, estimates have ranged from 30% to up to 60%. This article first looks into the various diagnostic criteria of treatment resistant schizophrenia. Then the literature is reviewed about the pharmacotherapeutics of its management. Clozapine emerges to be the gold standard. In addition risperidone and high dose olanzapine also emerge as clinically useful options. Other emerging adjunctive treatment options are equally addressed.

Pharmacological treatment of primary negative symptoms in schizophrenia: a systematic review

BACKGROUND

Optimal treatment of primary negative symptoms is important because their presence is associated with poor outcome.

AIMS

To systematically review all studies dealing with the efficacy of pharmacological agents on primary negative symptoms.

METHOD

A comprehensive search of the relevant literature was undertaken using electronic database, reference lists and personal contact.

RESULTS

There is a lack of standardized research designs. Amisulpride is the most extensively studied drug with respect to efficacy against primary negative symptoms. At low doses it demonstrates a consistent, modest effect compared to placebo, though not to conventional antipsychotics and has yet to be tested against other atypicals. Evidence from multiple studies that used simple statistical analyses and inclusion criteria for patients with primary negative symptoms does not support a direct effect for clozapine. Path-analysis studies support the direct effects of risperidone, olanzapine, sertindole and aripiprazole, however, different statistical analyses of the same risperidone study produced conflicting results and the direct effects of olanzapine were not confirmed in selected patients with primary negative symptoms. There are no studies supporting the use of ziprasidone or quetiapine. The effects of typical antipsychotics on primary negative symptoms are inconclusive and likely to depend on drug dosages. Selective serotonin reuptake inhibitors (SSRIs), mirtazepine and NMDA agonists show early promise but require further study. Novel agents such as selegiline, naltrexone, dehydroepiandrosterone, galantamine, Ginkgo, nitric oxide, L-deprenyl and pergolide show positive effects on general negative symptoms but remain untested against primary negative symptoms.

CONCLUSIONS

Further studies using standardized selective inclusion criteria and controlling for chronicity are needed. Research guidelines are discussed.

[Atypical antipsychotics in therapy refractory schizophrenia]

Many studies have shown that treatment resistance is a substantial problem in schizophrenic patients, with 20-30% of patients responding only partially and about 7% showing no response to antipsychotic treatment. Clozapine has been consistently shown to be effective in this subgroup of schizophrenic patients. It is still the drug of choice, despite the restricted indication and the need for a careful evaluation of side effects. Recently, several double-blind studies of newer atypical antipsychotics have been conducted in therapy-resistant patients. Three studies compared risperidone with clozapine, one study zotepine with clozapine and two others olanzapine with dozapine. One study compared the efficacy of clozapine, olanzapine, risperidone with one another and with haloperidol. In these studies, dozapine showed increasing superiority the more restrictive the criteria for therapy-resistance chosen. Olanzapine was found to be as effective as clozapine and was better tolerated. However, the results of studies comparing different atypical anti-psychotics have to be interpreted carefully because of their limited number as well as methodological problems. Case studies also indicate the efficacy of combining different atypical antipsychotics, but no systematic research on this issue has been done so far.

Costs and outcomes of risperidone treatment in schizophrenia in the Czech Republic

The increasing cost of pharmaceuticals in the Czech Republic has led to restrictions on the prescription of more expensive atypical antipsychotics. The aim of the study was to compare the costs and outcomes of using risperidone versus classical neuroleptics in treatment of schizophrenia in order to see if there was any cost advantage in restricting use of more recent antipsychotics. Sixty-seven patients (39 women) with a mean age of 34.6 years (S.D. = 9.74) suffering from schizophrenia or schizoaffective disorder were treated with risperidone while 67 patients (39 women) with the same diagnoses with a mean age of 35.7 years (S.D. = 9.91) received standard neuroleptics. Yearly direct medical costs and outcomes (indicated by the average Global Assessment of Functioning score) were assessed retrospectively in an open, intent-to-treat study by abstracting psychiatric outpatient charts. The outcomes were not significantly different between the treatment groups while the risperidone treatment was significantly more expensive than the therapy with standard neuroleptics. This result which appears to be inconsistent with the literature was caused by the cheap labor force in the Czech Republic. The difference between the followed treatments in the direct costs will probably become insignificant in the future when the country's economy will be more developed.

Refractory schizophrenia and atypical antipsychotics

Treatment resistant or refractory schizophrenia is a difficult to define condition of largely unknown prevalence. For 10 years, clozapine has been the standard treatment in this condition and is recognized unequivocally as being effective. However, clozapine is sometimes poorly tolerated and has the potential for severe toxicity. Partly as a result of this, other atypicals have recently been evaluated as treatments for refractory schizophrenia. In order to evaluate the evidence base relating to the drug treatment of refractory schizophrenia, we developed a refractoriness rating based on previous work. Using this rating, we assessed all trials of atypicals in schizophrenia unresponsive to at least one drug. Overall, clozapine was consistently shown to be effective in refractory schizophrenia, even when stringently defined. Data relating to olanzapine and risperidone are equivocal at best, and there is some evidence to suggest that they are less effective than clozapine. There is essentially no cogent evidence to support the use of any other atypical in refractory schizophrenia. Clozapine remains the drug of choice in this condition.

Efficacy of risperidone, olanzapine and clozapine in the treatment of therapy resistant schizophrenia

Therapy-resistance for positive symptoms is one of the most important problems that occurs with the medical treatment of schizophrenia. In the past years, clozapine has proven its effectiveness in this area and has been included in the treatment protocols and guidelines. Because of the risk of agranulocytosis with this compound and the intensive laboratory controls to be done, several studies have been performed with the new antipsychotics risperidone and olanzapine as alternative treatments. A review of the literature suggests that both drugs are as effective as the classic antipsychotics for therapy-resistant patients. A switch to risperidone or olanzapine possibly would be a alternative for those patients who have favourable effects on a low dose of clozapine. Furthermore the new antipsychotics have less side effects and ameliorating effects on negative and cognitive symptoms, so contributing to overall improvement in chronic schizophrenic disorders. However, in case of persistent positive symptopathology, clozapine remains the golden standard. The new antipsychotics should be included in treatment protocols before clozapine.

Atypical antipsychotics in ordinary clinical practice: a pharmaco-epidemiologic survey in a south London service

The introduction of atypical antipsychotics has triggered a reevaluation of treatment strategies in schizophrenia. Although research findings inform about the efficacy and safety of drugs, it is the decisions made daily in ordinary practice that affect the vast majority of patients. The aim of this paper was to examine the use of atypical antipsychotics in clinical care, by means of a survey of prescribing practices for clozapine, risperidone, olanzapine, sertindole and quetiapine for all patients treated for DSM-IV schizophrenia within a psychiatric service. Seventy-five (26%) of the 286 patients identified were on atypical antipsychotics. Patients on clozapine were mostly male, had more than 15 years of contact with psychiatric services and were poor responders. Patients prescribed other atypicals had responded to prior treatment with typical neuroleptics and had less than five years of contact with psychiatric services. Gender distribution was equal in this group. The use of research criteria for treatment resistance identified only one patient, as prolonged use of high-dose neuroleptics was uncommon. The new atypical antipsychotics appear to be replacing older neuroleptics as the first-line treatment of schizophrenia while clozapine is mostly reserved for poor responders. Clinicians' definition of treatment resistance was variable and below the threshold used in research.

Use of BPRS-A percent change scores to identify significant clinical improvement: accuracy of treatment response classification in acute psychiatric inpatients

Use of Brief Psychiatric Rating Scale [Overall J.E., Gorham D.R., 1988. The Brief Psychiatric Rating Scale (BPRS): recent developments in ascertainment and scaling. Psychopharmacology Bulletin 24, 97-99] percent change scores (PCSs) to measure treatment effects may be problematic because two different item-weighting systems (0-6 and 1-7) have been employed to represent the seven rating options and PCSs have demonstrated sensitivity to the item-weighting system used. This study compared the ability of a range of BPRS total scale PCS categories generated by both item-weighting procedures to predict estimates of clinical improvement in a large (N = 1415) heterogeneous acute sample of adult psychiatric inpatients. Results revealed significant differences between the two scaling systems in the proportion of patients classified into categories of PCS symptom improvement. Additional analysis suggested different optimal predictive PCS classifications for each item-weighting system: > 19% for 1-7 and > 39% for 0-6. Guidelines for BPRS publications are presented to facilitate study interpretation and replication. In light of their demonstrated limitations, it is suggested that the use of BPRS PCSs to measure treatment effects be reconsidered.

Issues of choice in second-generation antipsychotic agents

OBJECTIVE

To identify and describe the most significant issues in optimal clinical use of the second-generation antipsychotics.

METHODS

A case report of an elderly female with treatment-refractory psychosis, negative symptoms, and tardive dyskinesia is used to focus the discussion of the clinical decisions. The rationale for switching, the choice of an appropriate compound, and the practical issues of transition from her present treatment are addressed.

CONCLUSIONS

The case illustrates a common clinical scenario, focusing on the practical clinical issues in changing treatments. It draws attention to the need to carefully monitor the switch from traditional to second-generation antipsychotics. This is particularly important in patients with severe symptoms, so as not to confuse withdrawal effects from present medications with apparent failure of the new treatments.

New antipsychotic medications: strategies for evaluation and selected findings

The unprecedented level of activity in the development of new antipsychotic medications can be traced to the 1989 approval of clozapine by the US Food and Drug Administration for treatment of refractory schizophrenia. This has encouraged the development of other new agents that share some of clozapine's receptor binding characteristics. A wide range of clinical trial designs are being used during the development of new antipsychotic medications. This article describes both basic designs and more innovative ones: flexible-dose designs that include placebo and conventional neuroleptic agents as controls; fixed-dose designs with multiple doses of experimental medication; and fixed-dose designs with multiple doses of the experimental and comparator medication. The strengths and weaknesses of each are identified. The need for long-term maintenance studies of newer agents is emphasized because psychotic disorders in general, and schizophrenia in particular, are chronic relapsing illnesses. The current status of four newer antipsychotic medications is considered: clozapine, risperidone, olanzapine, and sertindole. The importance of direct comparison among the newer antipsychotic medications in both short- and long-term trials is highlighted.