Risperidone in the treatment of negative symptoms of schizophrenia: a meta-analysis

Atypical neuroleptics in child and adolescent psychiatry

Atypical neuroleptics have enriched our treatment programmes, especially in childhood and adolescent schizophrenia. This article reviews the use of atypical neuroleptics in children and adolescents with schizophrenic disorder. It considers the receptor binding profile and pharmacological properties, indications, side effects, clinical applications and trials of atypical neuroleptics in comparison to the classical neuroleptic haloperidol in adolescent schizophrenia. Special emphasis is placed on the most common atypical neuroleptics clozapine, olanzapine and risperidone since most studies are carried out with these compounds, especially with clozapine. More clinically controlled trials have to be conducted since only one was performed so far. The place of the atypical neuroleptics is discussed and further studies are necessary in order to differentiate the indications tested so far and to find out if the spectrum of indications can be broadened.

Antagonism at 5-HT(2A) receptors potentiates the effect of haloperidol in a conditioned avoidance response task in rats

High affinity for serotonin-2A (5-HT(2A)) over dopamine (DA) D(2) receptors is a leading hypothesis for clozapine's favorable therapeutic profile. Recent preclinical studies also indicate that a sufficient antipsychotic effect might be obtained by a combined high 5-HT(2A)/low D(2) receptor blockade. Thus, addition of a 5-HT(2A) receptor antagonist to an ineffective dose of a D(2) receptor antagonist produces a robust antipsychotic-like effect in the conditioned avoidance response (CAR) test. Electrophysiological and biochemical studies also show that 5-HT(2A) receptor antagonists can confer an atypical (clozapine-like) profile on a D(2) receptor antagonist. Improved therapeutic efficacy by adjunctive 5-HT(2A) receptor antagonist treatment to a traditional D(2) receptor blocking regimen has been suggested. However, the ability of 5-HT(2A) receptor blockade to protect against, or ameliorate, parkinsonian symptoms still remains unclear. Using the CAR and the catalepsy (CAT) tests as indices for antipsychotic activity and extrapyramidal side effect (EPS) liability, respectively, the effects of the selective 5-HT(2A) receptor antagonist MDL 100,907 in combination with the DA D(2) receptor antagonists haloperidol or raclopride were studied in rats. Haloperidol (0.025 or 0.1 mg/kg sc, -30 min) produced a dose-dependent suppression of CAR. Pretreatment with MDL 100,907 (0.5, 1.0, or 1.5 mg/kg sc; -60 min) enhanced and prolonged the haloperidol-induced suppression of CAR without escape failures. MDL 100,907 (1 mg/kg sc, -60 min) had no effect on CAT when coadministered with ineffective doses of raclopride. Raclopride (1 mg/kg sc, -30 min) alone produced a submaximal cataleptic response that was significantly enhanced by pretreatment with MDL 100,907. The present results confirm and extend previous results by showing that 5-HT(2A) receptor blockade can enhance the antipsychotic-like effects of a very low dose of a commonly used traditional antipsychotic. 5-HT(2A) receptor blockade does not, however, prevent EPS (CAT). The therapeutic advantage of this combination might, therefore, operate within a fairly narrow window.

Long-term treatment of chronic schizophrenia with risperidone: a study with plasma levels

Twenty-four chronic schizophrenic outpatients with a mean age of 37.21 years +/- 9.96 SD were treated with risperidone (RSP) at the dosage of 2-9 mg/die (mean 4.46 mg/die +/- 1.30 SD, mean 0.06 mg/kg +/- 0.01 SD) for a year. Clinical evaluation was assessed with the Brief Psychiatric Rating Scale (BPRS), Positive and Negative Symptoms Scale (PANSS), Extrapyramidal Side Effects Rating Scale (EPSE) and a checklist for Anticholinergic Side Effects (ACS) at T0, then after 1 (T1), 2 (T2), 3 (T3), 6 (T6), 9 (T9) and 12 (T12) months. RSP and 9-hydroxy-risperidone (9OH-RSP) plasma levels were determined at T12 by the HPLC method. BPRS and PANSS mean values showed a significant improvement during the study. No correlation between RSP dosage (mg/kg) and RSP, 9OH-RSP plasma levels or active moiety resulted. A positive correlation between age and active moiety was observed. A positive correlation between RSP and 9OH-RSP plasma levels was observed. A curvilinear relationship between active moiety and PANSS improvement (%) was observed. Patients with the higher PANSS amelioration showed RSP + 9OH-RSP plasma levels ranging from 15 to 30 ng/mL. RSP seems to be quite an effective drug. It seems, however, difficult to devise appropriate dose schedules and plasma level determination seems to be necessary in some cases.

Animal models for the negative symptoms of schizophrenia

Negative or defect symptoms refer to a reduction in normal functioning. In schizophrenia, negative symptoms encompass, among others, anhedonia, flat affect, avolition and social withdrawal. These symptoms have been found to be particularly prominent in the more chronic phase of the illness and seem to be virtually insensitive to current antipsychotic treatment. This review focuses on the possibilities and limitations of animal models for the negative symptoms of schizophrenia. Following a review of the negative symptoms in schizophrenia, attention is focused on the two symptoms most often modelled in animals - anhedonia and social withdrawal. We then look at the important question of how to model schizophrenic pathology in animals. Since the exact pathology is still far from clear, most efforts have in the past concentrated on using psychotomimetic drugs such as amphetamine or phencyclidine. The recently accumulated knowledge that schizophrenia probably results from disturbances in the normal development of the brain has led to a surge of new animal models in which the long-term consequences of early manipulations are investigated. However, so far these models have predominantly concentrated on the positive rather than the negative symptoms of schizophrenia. The last part of this review is dedicated to the question of validation of animal models for anhedonia and social withdrawal. The general conclusion is that very few models have so far been adequately tested. The lack of currently effective treatment further hampers the study of such validation.

Atypische Neuroleptika in der Kinder- und Jugendpsychiatrie

Zusammenfassung: Atypische Neuroleptika haben unsere Therapiemöglichkeiten in der Kinder- und Jugendpsychiatrie verbessert. Dieser Artikel faßt die Anwendung der atypischen Neuroleptika bei Kindern und Jugendlichen mit schizophrenen Psychosen zusammen. Es werden das Rezeptor-Bindungsprofil, pharmakologische Eigenschaften, Indikationen, Nebenwirkungen, klinische Anwendungen und Studien der atypischen Neuroleptika, im Vergleich zu dem klassischen Neuroleptikum Haloperidol, berücksichtigt. Besondere Betonung wurde auf die am häufigsten verwendeten atypischen Neuroleptika Clozapin, Olanzapin und Risperidon gelegt, da weltweit die meisten Studien mit diesen Medikamenten durchgeführt worden sind. Der Stellenwert der atypischen Neuroleptika wird diskutiert und es werden weitere Studien gefordert, um die Indikationen zu differenzieren, und um zu sehen, ob das Indikationsspektrum erweitert werden kann.

Risperidone versus typical antipsychotic medication for schizophrenia

BACKGROUND

The 'conventional' neuroleptic drugs, such as haloperidol and chlorpromazine, are frequently used as the first line treatment for people with schizophrenia. However, about 5-25% of these people show poor response to these treatments and side effects often makes compliance with the 'older generation' of drug treatment problematic. Although the efficacy of these medications with respect to 'positive' symptoms is well described, little evidence exists that 'conventional' antipsychotic treatment has any effect on the 'negative' symptoms of schizophrenia. Risperidone is one of the 'new generation' neuroleptic compounds. As well as its reputed tendency to cause fewer movement disorders it is claimed that risperidone may improve negative symptoms.

OBJECTIVES

To evaluate the effectiveness of risperidone for schizophrenia in comparison to 'conventional' neuroleptic drugs.

SEARCH STRATEGY

Electronic searches of Biological Abstracts (1980-1997), Cochrane Schizophrenia Group's Register (1997), The Cochrane Library (1997, Issue1), EMBASE (1980-1997), MEDLINE (1966-1997), PsycLIT (1974-1997), and SCISEARCH (1997) were undertaken. References of all identified studies were searched for further trial citations. Pharmaceutical companies and authors of trials were contacted.

SELECTION CRITERIA

All randomised trials comparing risperidone to any 'conventional' neuroleptic treatment for those with schizophrenia or other serious mental illnesses.

DATA COLLECTION AND ANALYSIS

Citations and, where possible, abstracts were independently inspected by reviewers, papers ordered, re-inspected and quality assessed. Data were also independently extracted. Sensitivity analyses on dose of risperidone, haloperidol and duration of illness were undertaken for the primary outcomes of clinical improvement, side effects (movement disorders) and acceptability of treatment. For homogeneous dichotomous data the odds ratio (OR), 95% confidence interval (CI) and, where appropriate, the number needed to treat (NNT) were calculated on an intention-to-treat basis.

MAIN RESULTS

Twelve short-term studies and two long term studies provided data on 3401 people. This review provides no evidence relating to the effect of risperidone on cognitive or social functioning, quality of life, employment status, discharge from hospital and relapse rates. Risperidone increases the odds of moderate clinical improvement (OR 0.65, CI 0.55-0.77, NNT 10, CI 7-16). It appears to have little or no additional effect on the positive and negative symptoms of schizophrenia but did have less tendency to cause movement disorders, largely in comparison with haloperidol (OR 0.43, CI 0.34-0.55, NNT 7, CI 5-10) for use of antiparkinsonian medication. Risperidone seems to be more acceptable to those with schizophrenia (OR 0.69 CI 0.57-0.83, NNT 15, CI 10-30, 30% baseline risk of dropping out). Those taking risperidone are also marginally less likely to experience somnolence (OR 0.78, CI 0. 61-0.99, NNT 22). Weight gain, however, is more likely with risperidone (OR 1.51 CI 1.14-2.00, NNT 13). Funnel plots show that smaller studies generally show greater benefit for risperidone than larger studies. A publication bias in favour of risperidone amongst the included studies may explain this effect. Sensitivity analyses on dose of risperidone (excluding those receiving 1 or 2 mg) did not materially change the results for the principal outcomes. Excluding data from those on higher doses of haloperidol (>10mg/day) does marginally change the results. Risperidone is less effective in achieving clinical improvement and preventing dropout but outcomes relating to movement disorders change little.

REVIEWER'S CONCLUSIONS

Little can be concluded about the long term effects of risperidone and generalising results beyond a comparison with haloperidol would be imprudent. Risperidone may be more acceptable to those with schizophrenia and have marginal benefits in terms of limited clinical improvement and side

Amisulpride vs. risperidone in the treatment of acute exacerbations of schizophrenia. Amisulpride study group

Amisulpride, a substituted benzamide with high selectivity for dopamine D3 and D2 receptors, was compared with the antipsychotic risperidone in patients with acute exacerbations of schizophrenia. The study was double-blind and involved 228 patients allocated, after a 3-6-day wash-out period, to amisulpride 800 mg (n = 115) or risperidone 8 mg (n = 113) for 8 weeks. Both treatments produced a marked improvement in schizophrenic symptomatology. Decreases in mean BPRS total score were 17.7 +/- 14.9 for amisulpride and 15.2 +/- 13.9 for risperidone, and all of the individual factors on the BPRS showed a numerically greater improvement in the amisulpride than in the risperidone patients. Both treatments were equally effective against positive symptoms on the PANSS positive syndrome subscale; however, there was a trend in favor of greater improvement in negative symptoms assessed on the PANSS negative subscale in patients receiving amisulpride with a decrease of 6.9 +/- 7.5 vs. 5.3 +/- 6.6 for risperidone (P = 0.09). Both drugs demonstrated good safety profiles, and scores on neurological scales (SAS, AIMS, and BAS) did not increase during treatment. A comparable proportion of patients received antiparkinsonian medication, 30 and 23% in the amisulpride and risperidone groups, respectively (P = 0.21). Patients receiving risperidone experienced an increase in body weight, which was significantly greater than for amisulpride (P = 0.026).

Some behavioural effects of risperidone in rats: comparison with haloperidol

Risperidone is a dopaminergic as well as a 5-HT2 antagonist. The drug was found to exert beneficial effects on both positive and negative symptoms of schizophrenia. Since recently, schizophrenia is regarded as a composite of not only positive and negative but also affective and cognitive symptoms, in this study the effects of risperidone compared with typical neuroleptic haloperidol, on affective and cognitive functions were investigated in rats (anxiolytic, antidepressive and memory tests). We found, that in contrast to haloperidol, risperidone had antidepressive, anxiolytic and memory enhancing effects. The results obtained correspond with favourable effects of risperidone on mood disturbances and cognitive functions of schizophrenic patients observed under clinical conditions.

Recent antipsychotics in the treatment of psychoses

Antipsychotic drugs are effective in psychoses, whatever the etiology of the disorder. The positive symptoms tend to respond more readily. The need for developing new drugs arises from the refractoriness of the negative symptoms, the 10-25% of the patients that are treatment-resistant and the problems of short-, and long-term extrapyramidal side-effects. Thus far, six drugs, differing from the classical antipsychotics, have been licensedfor use: olanzepine, risperidone and quetiapine; the longest registration exists for sulpiride and clozapine while the most recent one is for amisulpride. This review starts with a brief introduction to symptomatology, and takes differences with the classical drugs in pharmacology, pharmacokinetics, clinical aspects and side-effects into consideration. Clozapine, risperidone and sulpiride may be considered for clinical use in refractory patients; these three, olanzapine and amisulpride when extrapyramidal side-effects cause a clinical problem. Amisulpride and sulpiride have a dual therapeutic acion: On negative symptoms at low dose, on positive symptomen at high doses.

Switching from therapy with typical antipsychotic agents to risperidone: long-term impact on patient outcome

This paper reports the results of a retrospective, open-label study in 31 schizophrenic patients who had been switched from therapy with a typical antipsychotic agent to risperidone, a novel antipsychotic agent, in the course of their treatment in an outpatient/community program. The study was based on both a review of all 31 patients' charts and a structured interview of 26 of the patients. The change to risperidone had been made because of lack of efficacy or intolerance to typical antipsychotic agents after a mean of 3.5 years of therapy. Patients had been maintained on risperidone for a mean of 1.7 years at the time of the review. The impact of switching to risperidone was assessed by comparing clinical variables for the patients with their own historic control data. The current levels of symptoms, side effects, and social functioning were also assessed by means of the Interview for Retrospective Assessment of Onset of Schizophrenia and rating scales. Seventy-one percent and 81% of the patients exhibited a positive response, as measured by a 30% reduction in psychotic and disorganization syndromes, respectively. After the switch, significant declines were noted in service utilization; the level of psychotic, disorganization, and negative symptom dimensions; and the use of anticholinergic drugs (P < 0.01 for all). Assessments conducted at the time of the review revealed a low level of psychotic (mean, 3.5) and disorganization (mean, 3.0) symptoms, a moderate level of negative symptoms (mean, 19.5), and a low level of extrapyramidal symptoms (total mean parkinsonism score, 6.0). No significant changes were seen in the level of employment or in living conditions. Results of this study suggest that a switch to risperidone therapy because of the inefficacy of typical antipsychotic agents or patients' inability to tolerate them may lead to sustained and significant improvement in a substantial proportion of patients with schizophrenia.

Differential effects of acute and chronic treatment with typical and atypical neuroleptics on c-fos mRNA expression in rat forebrain regions using non-radioactive in situ hybridization

The regional difference in the expression of c-fos mRNA in rat forebrain after either acute or chronic administration of typical (haloperidol and fluphenazine) and atypical neuroleptics (clozapine and (+/-)-sulpiride) was investigated. Rats were injected intraperitoneally with vehicle or neuroleptics daily for 14 days. Twenty-four hours after the last injection, the rats were challenged with vehicle or neuroleptics. C-fos mRNA expression was determined by non-radioactive in situ hybridization. Acute treatment with typical neuroleptics induced a remarkable induction of c-fos mRNA in the dorsolateral striatum, whereas this induction was greatly attenuated by chronic administration. All neuroleptics examined induced c-fos mRNA in the shell region of N. accumbens by acute administration and this expression was still elevated after chronic treatment. Since chronic neuroleptics do not induce tolerance to their antipsychotic activities, our study suggests that the shell region of N. accumbens is an important target site for antipsychotic effects of neuroleptics.

Therapeutic drug monitoring of risperidone using a new, rapid HPLC method: reappraisal of interindividual variability factors

Because of the enormous gap between premarketing studies in physically healthy subjects and clinical practice in patients, the present study reconsidered interindividual variability factors affecting risperidone concentrations under routine therapeutic drug monitoring conditions. The study included 92 patients, 27% of whom were 70 years or older. The patients received risperidone orally (dose range, 0.5-11 mg per day) and had concentrations of risperidone and the active metabolite 9-hydroxyrisperidone measured at steady state by a new, rapid, and sensitive method of high-performance liquid chromatography (HPLC). After normalization to a dose of 4 mg/day, median concentrations were 2.9 ng/ml (80% range, 0.9-27.9 ng/ml) for the parent compound and 24.1 ng/ml (80% range, 12.0-57.6 ng/ml) for the metabolite. When considering linear regression models, age was identified as a major source of interindividual variability, with expected increases of 340% and 220% for concentrations of parent compound and metabolite, with age increasing from 20 to 80 years. Body weight provided an additional significant contribution to the variability of 9-hydroxyrisperidone concentration, a 20-kg higher body weight associated with a concentration decrease of 23%. Serotonin-specific reuptake inhibitor (SSRI) comedication (fluoxetine, two patients; citalopram, two patients; paroxetine, one patient; fluvoxamine, one patient) was significantly associated with 4.6-fold higher concentrations of parent compound, in keeping with an inhibitory action on CYP2D6 enzyme. Significantly higher concentrations of 9-hydroxy-risperidone (+ 29%) were also observed in the 17 patients with biperiden comedication. Therapeutic drug monitoring data, collected in patients representative of the population for which the drug was intended, allowed us to quantify the dose reduction needed in elderly patients and thus provided valuable information in addition to the one collected during premarketing studies performed with strict inclusion and exclusion criteria.

Efficacy and extrapyramidal side-effects of the new antipsychotics olanzapine, quetiapine, risperidone, and sertindole compared to conventional antipsychotics and placebo. A meta-analysis of randomized controlled trials

The objective of this meta-analysis is to summarize the efficacy and tolerability of the new antipsychotics risperidone, olanzapine, sertindole and quetiapine in schizophrenia compared to placebo and conventional antipsychotics. The main results are: (1) All of the 4 new drugs are more effective than placebo, but the magnitude of the effect is only moderate [mean effect size, r, of all antipsychotics vs. placebo = 0.25, with a 95% confidence interval (CI) = 0.22-0.28, n = 2477]. (2) According to the studies published to date, sertindole and quetiapine are as effective as haloperidol, and risperidone and olanzapine are slightly more effective than haloperidol in the treatment of global schizophrenic symptomatology. (3) With respect to negative symptoms, all new antipsychotics are more effective than placebo. However, contrary to widespread opinion, so is the 'conventional' antipsychotic haloperidol. Risperidone and olanzapine are slightly superior, sertindole is as effective and--according to the only study fully published to date--quetiapine is even slightly less effective than haloperidol in this regard. (4) All new antipsychotics are associated with less frequent use of antiparkinson medication than haloperidol, with risperidone appearing to have a slightly less favourable EPS-profile than the other new antipsychotics. The methodological limitations of this review, the generalizability of the results and expectations from future research are discussed.

The economic value of atypical antipsychotics: A comparison of risperidone and olanzapine revisited

Careful analysis of clinical experience to date throws fresh light on the optimal and actual doses used in clinical practice of risperidone and olanzapine. Since launch, the optimal dose for treatment of schizophrenia of risperidone has been established at 4-6 mg/day and that of olanzapine at around 15 mg/day. We have applied these more realistic dosing assumptions to the published economic comparisons between the various atypical agents and conclude that there are economic and efficacy arguments for risperidone to be considered as the first choice for treatment of patients with schizophrenia. The other atypicals, such as olanzapine and clozapine, should be used as second-line therapy in preference to conventional agents such as haloperidol. Funding arguments support this approach and reinforce the need to reconsider therapy for patients whose current treatment may not be optimal.

The pharmaco-economics of atypical antipsychotics

Atypical antipsychotics are claimed to show advantages in efficacy and tolerability when compared with older, typical drugs. However, the purchase cost of atypicals far exceeds that of typical drugs. Pharmaco-economic evaluations of the use of atypical agents are used, in essence, to determine whether or not the benefit gained by using atypicals is greater than the extra cost of their acquisition. Several forms of pharmaco-economic evaluation have been developed, but none provides definitive, unarguable findings. In psychiatry, the most commonly used method is the mirror-image technique, which retrospectively compares costs and outcomes before and after the use of a particular drug. Despite the large number of phamacoeconomic evaluations undertaken and published, the cost-effectiveness of atypical drugs remains unproven. Data relating to clozapine are the most compelling, but they remain ultimately equivocal. However, ethical considerations may prevent conclusive research being conducted. Some data support the cost-effectiveness of olanzapine and risperidone, but, again, the overall picture is far from clear. Little or nothing is known of the pharmaco-economics of other atypicals. Further research is needed before any atypical can be said to be cost-effective.

Schizophrenia: do we really need placebo-controlled studies?

OBJECTIVE

To investigate whether placebo control is necessary to prove efficacy in short-term studies in schizophrenia.

DESIGN

This study compares the efficacy results of placebo-controlled studies versus positive controlled studies, that is controlled studies without a placebo control, in the short-term treatment of chronic schizophrenia.

RESULTS

Concerning mean improvement on the BPRS, the placebo arms showed in two cases a worsening, in one case almost no change, and in the remaining studies (6) the improvement was between 1 and 5%. The percentage mean improvement in the haloperidol arms of the placebo-controlled studies was comparable to the percentage mean improvement in the corresponding arms of the non-placebo-controlled studies. The highest percentage responders in the placebo-groups was 43% and the lowest was 6%. Moreover the responder rates in the atypical antipsychotic and haloperidol arms of the non-placebo-controlled studies were, in two of the three studies, in the same order of magnitude as the responder rates of the placebo arms in the placebo-controlled studies. The overall dropout rates in the placebo arms was between 48% and 80% and were higher than the drop out rates in the atypical neuroleptic arms and haloperidol arms of the placebo-controlled studies. The dropout rates due to an insufficient response in the atypical neuroleptic arms and haloperidol arms of the non-placebo-controlled studies were lower when compared to corresponding treatment arms of the placebo-controlled studies.

CONCLUSION

In contrast to the mean improvement on the BPRS, responder rates in the placebo arms varied considerably from study to study. Responder rates in the atypical antipsychotic and haloperidol arms of the non-placebo-controlled studies were, in two of the three studies, of the same order of magnitude as the responder rates of the placebo arms in the placebo-controlled studies. These results indicate that placebo control is necessary. Moreover as responders are a more clinically relevant outcome measure when compared to mean improvement on a rating scale, placebo-controlled studies are still needed. However, consensus on responder definition should be agreed upon. For the moment, alternatives to placebo-controlled studies are inadequate in demonstrating efficacy in studies with schizophrenic patients.

Enhancement of antipsychoticlike properties of raclopride in rats using the selective serotonin2A receptor antagonist MDL 100,907

BACKGROUND

Selective suppression of conditioned avoidance response (CAR) is a standard animal screening test for predicting antipsychotic effect. Ability to suppress CAR is presumed to be due to antagonism at dopamine receptors, a property shared by all known antipsychotics.

METHODS

Using CAR behavior, in a conventional shuttle-box paradigm, as an index for antipsychotic efficacy, the effects of the selective serotonin2A receptor antagonist MDL 100,907 alone, and in combination with the dopamine D2 receptor antagonist raclopride, were studied in adult male Sprague-Dawley rats. Nonparametric procedures were employed for statistical evaluation.

RESULTS

MDL 100,907 (0.1-1.5 mg/kg, SC) alone did not suppress CAR in a manner predictive of antipsychotic activity; however, in the presence of an ED50 (0.14 mg/kg, SC) dose of raclopride, MDL 100,907 enhanced and prolonged the suppression of CAR. In the presence of a subthreshold (0.05 mg/kg, SC) dose of raclopride, MDL 100,907 induced a suppression of CAR.

CONCLUSIONS

The results suggest that treatment with a selective serotonin2A receptor antagonist alone may not produce a robust antipsychotic effect; however, a selective serotonin2A receptor antagonist in the presence of a minimal dopamine D2 receptor blocking action could potentially be an adjunctive therapy resulting in improved antipsychotic efficacy and fewer extrapyramidal symptoms.

Drug treatment of the negative symptoms of schizophrenia

The traditional antipsychotics are generally poorly effective or ineffective against the negative symptoms of schizophrenia and are also associated with extensive side effects which can themselves cause or exacerbate secondary negative symptomatology. As well as having a low propensity to cause extrapyramidal side effects (EPS), the currently available, putative, atypical antipsychotics (clozapine, risperidone, sertindole, and olanzapine), developmental antipsychotics (zotepine, quetiapine and ziprasidone) and low doses of certain traditional antipsychotics, such as amisulpride and fluphenazine, have been reported to ameliorate negative symptoms in comparison with placebo or standard antipsychotics such as fluphenazine, haloperidol or perphenazine. To date, few trials have specifically examined primary negative symptomatology and it has been suggested that the improvements observed with these drugs may be related to decreases in positive symptoms and/or reduced sedation or extrapyramidal side effects. Although atypicality has been ascribed to 5-HT2/D2 antagonism, the exact pharmacological mechanism(s) underlying the efficacy of the atypical antipsychotics have not been elucidated. Many of these drugs bind to multiple other receptors and/or inhibit neurotransmitter uptake and it seems probable that some of these other pharmacological properties may also contribute to their clinical features.

Risperidone versus haloperidol: I. Meta-analysis of efficacy and safety

Haloperidol is widely considered a reference standard in antipsychotic therapy and is commonly used in comparative studies of the efficacy and safety of antipsychotic medication. Comparative clinical trials have shown that the novel antipsychotic agent risperidone tends to have greater efficacy (i.e., clinical response defined as a > or = 20% reduction in total scores on the Positive and Negative Syndrome Scale) than haloperidol in patients with chronic schizophrenia and poses less risk of extrapyramidal symptoms (EPS). We used DerSimonian and Laird's random-effects model to analyze pooled patient data from available randomized, double-masked, comparative trials of risperidone and haloperidol in patients with schizophrenia treated for at least 4 weeks at recommended doses. The purpose of the analysis was to determine whether there are significant overall differences in the rates of patient clinical response, prescription of anticholinergic agents, and treatment dropout. Six of the nine trials revealed in a literature search met all criteria for inclusion in the meta-analysis. The meta-analysis showed that in patients with chronic schizophrenia, risperidone therapy is associated with significantly higher response rates, significantly less prescribing of anticholinergic medication, and significantly lower treatment dropout rates than haloperidol. These results demonstrate the greater treatment efficacy associated with risperidone compared with haloperidol and suggest both a lower incidence of EPS and improved treatment compliance.

The QT interval and the atypical antipsychotic, sertindole

Sertindole is a limbic-selective antipsychotic agent with a strong affinity for D2, 5-HT2 and α1-adrenergic receptors. Prolongation of the QT interval and other adverse cardiac or cardiovascular reactions are known effects of most antipsychotic drugs. For this reason such effects have been extensively monitored during clinical trials of sertindole. A small proportion of sertindole-treated patients were found to exhibit an increase in QT interval. Detailed analysis revealed no increased risk with sertindole of lethal complications due to an increase in QT interval. Nevertheless, as with other antipsychotics, electrocardiogram (ECG) recordings should be made prior to starting and during treatment with sertindole.

The new antipsychotics, and their potential for early intervention in schizophrenia

Over almost four decades, few fundamentally different antipsychotic drugs evolved to challenge classical neuroleptics as the mainstay of the pharmacotherapy of schizophrenia. However, the recent re-emergence of clozapine, together with the emergence of risperidone, portends an increasing number of new antipsychotics which are now either traversing the stages of regulatory approval or else well-advanced in clinical development. This article first evaluates the significance of clozapine and risperidone; it then reviews some of the new antipsychotics and how they might be classified vis-a-vis potential advantages for patients, outlines putative mechanisms and new therapeutic targets, and considers whether such agents may act on any disease process inherent to schizophrenia. One fundamental issue is the extent to which the new antipsychotics might shift materially the risk benefit balance towards intervention, not just at the earliest possible stage following the onset of psychosis but at a yet earlier, 'prodromal' phase of the disorder where there is a considerably greater likelihood of 'treating' behavioural disturbances that prove not to be the harbingers of psychotic illness.

Risperidone versus haloperidol in the treatment of schizophrenia: a meta-analysis comparing their efficacy and safety

The aim of this study was to compare the short-term clinical efficacy and safety of risperidone with haloperidol and placebo. A meta-analysis of seven published randomized double-blind controlled trials was carried out. Study quality was assessed. The proportion of patients failing to reach at least 20% improvement on the positive and negative syndrome scale (PANSS) or brief psychiatric rating scale (BPRS), the proportion of patients discontinuing treatment because of adverse effects and the number of patients who needed antiparkinsonian medication were abstracted for use as outcome measures. Treatment failure was present in 50% of risperidone-treated patients compared to 66% in those treated with haloperidol and 83% in those treated with placebo. It would be necessary to treat 11 patients with risperidone to prevent one treatment failure in those patients treated with haloperidol (Odds ratio (OR) = 0.74, 95% CI of 0.58-0.94, P = 0.02). Pooling of the three multicentre trials which included placebo as a treatment arm, showed that one in three patients treated with risperidone 4-16 mg/day (OR = 0.22, 95% CI of 0.13-0.39, P < 0.00001) and one in six treated with haloperidol 10-20 mg/day. (OR = 0.44, 95% CI of 0.22-0.84, P = 0.02) would derive significant benefit. Moreover, there was a highly significant greater need for anticholinergic medication due to extrapyramidal symptoms (EPS) in the haloperidol-treated patients compared to risperidone (OR = 0.54, 95% CI of 0.42-0.70, P < 0.00001). In conclusion, risperidone seems to be more effective and causes less EPS than haloperidol, as suggested by the significantly lower requirement for antiparkinsonian medication.

Proper psychosocial rehabilitation for stabilised patients with schizophrenia: the role of new therapies

Schizophrenia impairs the development of social skills needed for useful, independent living. Psychotherapeutic approaches increase the value of antipsychotic drugs by helping patients cope with the social pressures to which they are particularly vulnerable. Antipsychotic drugs reduce psychosis, protect against stressors and, taken lifelong, provide considerable relapse protection. Low-dose or intermittent medication regimens reduce the incidence of side effects but give less protection against relapse than continuous full-dose therapy. For the move towards community- rather than hospital-based care to succeed, comprehensive, multidisciplinary, integrated services are essential. Individually tailored psychosocial rehabilitation enables patients to make the best use of their capabilities. In addition, family therapy increases the effectiveness of drugs and reduces relapse rates. New antipsychotic drugs are likely to be more effective than conventional neuroleptics because they offer broader spectra of activity, induce fewer side effects and are more likely to be taken as directed.