Risperidone and clozapine combination for the treatment of refractory schizophrenia

Outdoor cycling improves clinical symptoms, cognition and objectively measured physical activity in patients with schizophrenia: A randomized controlled trial

PURPOSE

The therapeutic effects of outdoor cycling (OC) and its benefits on physical activity (PA) were investigated in people with schizophrenia.

METHODS

Sixty patients with schizophrenia were randomly assigned to 16-weeks of Outdoor Cycling (OC) (n = 30, 50% male; mean age, 38.7 ± 10.1) or Occupational Therapy (OT) (n = 30, 50% male; mean age, 39.0 ± 8.6). OC and OT involved one 90-min group session per week. OC consisted of structured exercise programs and OT addressed daily living skills. Primary outcome measurements were mental health variables, such as Brief Psychiatric Rating Scale, Beck's Depression Inventory, State and Trait Anxiety Inventory, Rosenberg Self-Esteem Scale, Global Assessment of Functioning and executive function (Wisconsin Card Sorting Test, WCST). Secondary measures were the adherence and PA. PA was measured by responding to the Physical Activity Scale (K-PASE) and wearing a pedometer for 2 days.

RESULTS

Repeated measures ANOVA revealed improved psychotic symptoms (p = .014), depression (p = .007), state (p = .031) and trait anxiety (p = .002) and global functions (p = .024) in the OC group compared with OT group. The OC group showed increased correct rates (p = .022) and categories completed (p = .033) in the WCST. There was no difference in total K-PASE score between groups; however, there was a significant improvement in the number of daily steps in the OC group compared with the OT group (p = .030).

CONCLUSION

OC significantly improved mental health and executive function in individuals with schizophrenia. Further, OC significantly increased PA measured by the pedometers. These findings suggest that OC offers a safe and attrition-lowering intervention promoting mental health and PA.

TRIAL REGISTRATION

cris.nih.go.kr identifier: KCT-0000873.

Formulation and characterization of clozapine and risperidone co-entrapped spray-dried PLGA nanoparticles

In the current study, polylactide-co-glycolide (PLGA) nanoparticles entrapping both clozapine (CLZ) and risperidone (RIS) were formulated by spray-drying using Buchi Nano Spray Dryer B-90 (Flawil, Switzerland). Parameters such as inlet temperature, spray mesh diameter, sample flow rate, spray rate and applied pressure were optimized to produce nanoparticles having desired release profile using both low- and high-molecular weight PLGA polymer. Smallest size nanoparticle of size around 248 nm could be prepared using a 4.0 μm mesh diameter with low-molecular weight polymer. The load of CLZ and RIS was 126.3 and 58.2 μg/mg of polymer particles, respectively. Entrapment efficiency of drugs in PLGA nanoparticles was 94.74% for CLZ and 93.12% for RIS. Both the drugs released continuously from the nanoparticle formulations. PLGA nanoparticles formulated using low-molecular weight polymer released around 80% of the entrapped drug over 10 days of time. Nature of drug inside polymer particles was amorphous, and there was no chemical interaction of CLZ and RIS with polymer. Polymeric nanoparticles were found to be non-toxic in nature using PC12 cell line. This nanospray drying process proved to be suitable for developing polymeric nanoformulation delivering dual drugs for the treatment of Schizophrenia.

In vitro and in vivo evaluation of the inhibition potential of risperidone toward clozapine biotransformation

AIMS

To study the impact of risperidone (RISP) on clozapine (CLZ) biotransformation in vitro in microsomal fractions containing varying expression of CYP oxidases and in vivo in patients.

METHODS

Human liver microsomes (n= 11) were assessed for expression of CYPs 1A2, 2D6 and 3A4, because these enzymes mediate RISP and CLZ oxidation. Inhibition of CLZ oxidation by RISP was assessed. Plasma CLZ elimination was estimated in patients with schizophrenia who received either CLZ alone or the CLZ-RISP combination (n= 10 per group).

RESULTS

(i) The CYP3A4 and CYP1A2 inhibitors ketoconazole and fluvoxamine inhibited CLZ oxidation to varying extents in individual microsomal fractions. (ii) RISP did not inhibit CLZ oxidation, regardless of variations in CYP expression. (iii) RISP co-administration did not impair CLZ clearance.

CONCLUSIONS

No evidence was found for CYP-mediated inhibitory or pharmacokinetic interactions between RISP and CLZ. Occasional literature reports of such interactions may involve other pathways that participate in CLZ disposition.

Antipsychotic polypharmacy in patients with schizophrenia in a brief hospitalization unit

INTRODUCTION

Antipsychotic monotherapy is considered the gold standard in pharmacological treatment of schizophrenia and other psychotic disorders. Only 2 of the main clinical guides recommend the use of antipsychotic polypharmacy (AP) for those patients refractory to monotherapy. Nonetheless, there is a large rate of studies, conducted in many different settings, showing that AP is more frequent as would be expected attending experts' recommendations.

METHODS

In this retrospective study, we review all the psychotropic drugs dispensed to inpatients of a brief hospitalization psychiatric unit diagnosed as having schizophrenia or schizoaffective disorder (International Statistical Classification of Diseases, 10th Revision) at time of discharge in the year 2005. These included a total of 209 patients older than 18 years.

RESULTS

Of the 209 studied patients, 55.5% were discharged under AP treatment. Inpatients were given a mean of 3.06 psychotropic drugs and a mean of 1.61 antipsychotics at the time of hospital discharge. A total of 33.2% of the studied patients got anticholinergic drugs, and 66.2% were given benzodiazepines. The most prevalent combination of drugs was intramuscular long-acting risperidone plus an atypical antipsychotic. Amisulpride was the most used antipsychotic as adjuvant treatment.

CONCLUSIONS

Despite different clinical guidelines, AP is a common pharmacological strategy as it is shown in our study and in the reviewed literature. Data in our study indicate that the observed rates of AP cannot exclusively be attributed to the treatment of patients with clozapine-resistant schizophrenia.

Benefits and risks of antipsychotic polypharmacy: an evidence-based review of the literature

Combination antipsychotic prescription is an increasingly common practice in clinical psychiatry. This clinical practice is at odds with clinical guidelines promoting antipsychotic monotherapy. Moreover, there has been increased concern over the safety profile of atypical antipsychotics in the last 10-15 years. We reviewed the literature on antipsychotic combinations with a focus on safety and efficacy. Multiple electronic database searches were complemented by relevant bibliography cross-checking and expert discussions. The review showed a literature that is dominated by case reports and uncontrolled studies. Polypharmacy was unequally studied, with some recent combinations (i.e. clozapine and risperidone) being extensively, albeit inconclusively, studied and other more commonly used combinations (first- with second-generation agents) receiving little attention. From an evidence-based perspective, further trials of antipsychotic association of sufficient power to address safety issues are needed before recommending any antipsychotic combination. Particular weaknesses of the present literature are low number of participants, lack of adequate control of confounding variables, short duration of experimental follow-up and inadequate monitoring of potential adverse effects.

Real-world antipsychotic treatment practices

This article examines real-world antipsychotic use in the treatment of schizophrenia by comparing real-world prescribing with medication algorithms and guidelines, by evaluating the evidence underlying recommendations and guidelines, and by examining the roles of side effects and medication adherence in real-world prescribing decisions.

Adjunctive Treatment With Risperidone in Clozapine-Resistant Schizophrenia

OBJECTIVES

Long-term studies show that 47% to 63% of schizophrenic patients treated with clozapine fail to respond after 12 years of treatment. Such high rates of resistance justify the growing interest in therapeutic strategies based on enhancing the effect of clozapine with other antipsychotics. The combination of clozapine and risperidone in the treatment of partial responders to clozapine has been one of those receiving most interest from research.

METHODS AND RESULTS

The present work reports the case of a 26-year-old man, diagnosed with schizophrenia who, after treatment with clozapine at appropriate doses over 12 weeks without observable response, showed a marked and sustained improvement after the addition of risperidone to the clozapine treatment. We also present a detailed review of publications related to the therapeutic combination of clozapine and risperidone in clozapine-resistant schizophrenia.

CONCLUSIONS

Despite the contradictory nature of the published data, our results are in support of other work reporting that treatment with a combination of clozapine and risperidone, apart from being well tolerated, may constitute an effective alternative in this type of patient. Nevertheless, there is a need for further, controlled studies, with larger samples, with a view to drawing definitive conclusions and making specific recommendations.

Pharmakotherapie der Schizophrenie

The management of schizophrenia patients remains one of the great challenges in psychiatry. Despite the undisputed effectiveness of antipsychotic drugs, patients and their physicians still face considerable difficulties mainly related to incomplete or lacking treatment response and the inability to predict the individual efficacy and tolerability. In this manuscript we review the key elements of pharmacological treatment of this disorder, encompassing acute and long-term management as well as specific management problems ranging from acutely violent patients to treatment-resistant subjects. Along with general treatment principles, the document provides specific information regarding efficacy and safety features of antipsychotics. Many of the currently available treatment recommendations/guidelines are based on the evidence reviewed here. This review is meant to serve as a guide for clinicians involved in managing schizophrenia, whether in a psychiatric hospital setting or as family physicians in private practice.

Risperidone augmentation of clozapine: a critical review

OBJECTIVE

Atypical antipsychotics are frequently used as augmentation agents in clozapine-resistant schizophrenic patients. Risperidone (RIS) is the one most studied as a clozapine (CLZ) adjunct. The aim of this study is to critically review all published studies regarding the efficacy and safety of RIS as an adjunctive agent in CLZ-resistant schizophrenic or schizoaffective patients.

METHODS

A MEDLINE search from January 1988 to June 2005 was conducted. Identified papers were examined against several clinical, pharmacological and methodological parameters.

RESULTS

A total of 15 studies were found (2 randomized controlled trials, 3 open-label trials (OTs) and 8 case-studies (CSs)) comprising 86 schizophrenic or schizoaffective patients (mean age 38.4 years). Mean CLZ dosage during the combined treatment was 474.2 mg/day. Plasma CLZ levels were assessed in 62 patients (72.1%). RIS was added at a mean dosage of 4.6 mg/day for a mean of 7.9 weeks. Significant improvement in psychopathology was reported for 37 patients (43%). A lower RIS dosage and a longer duration of the trial seemed to be associated with a better outcome. Main side effects reported were: extrapyramidal symptoms or akathisia (9.3%), sedation (7%) and hypersalivation (5.8%).

CONCLUSIONS

Existing evidence encourages the use of RIS as an adjunctive agent in CLZ-resistant schizophrenic or schizoaffective patients.

Augmentation strategies of clozapine with antipsychotics in the treatment of ultraresistant schizophrenia

BACKGROUND

Approximately 40% to 70% of neuroleptic-resistant schizophrenic patients are nonresponders to clozapine. Several clozapine augmentation strategies have come into clinical practice although often without evidence-based support. Among these strategies, the combined use of clozapine with another antipsychotic has been reported for up to 35% of patients receiving clozapine.

OBJECTIVE

The purposes of the present work were to (1) review the available literature on the efficacy and safety of the clozapine augmentation with another antipsychotic using a MEDLINE search of the literature from 1978 to December 2005 and (2) to propose an operational definition of schizophrenia refractory to clozapine ("ultraresistant schizophrenia") for the implementation and homogenization of future therapeutic trials.

CONCLUSION

Case controls and open clinical trials largely dominate the literature, and there are only 4 double-blind studies of clozapine augmentation with antipsychotics. The results of these studies are somewhat discrepant. Moreover, the heterogeneity of definitions of resistance to clozapine, of outcome measures and of dose and duration of pharmacological trials is a major limitation for drawing conclusions.

Polypharmacy in schizophrenia

In contrast to research studies that limit the use of concomitant psychotropic medications in the treatment of schizophrenia, polypharmacy is common in real-world, clinical practice. The use of psychotropic medications as an adjunct to antipsychotic agents is often necessitated by the poor response to monotherapy with one antipsychotic agent. This paper discusses the prevalence of polypharmacy in clinical settings, reviews the evidence for the adjunctive use of antipsychotics, anticonvulsants, lithium, antidepressants, benzodiazepines and other psychotropics in the treatment of schizophrenia, and offers suggestions toward use of polypharmacy in difficult and practical clinical settings.

World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for biological treatment of schizophrenia, Part 1: acute treatment of schizophrenia

These guide lines for the biological treatment of schizophrenia were developed by an international Task Force of the World Federation of Societies of Biological Psychiatry (WFSBO). The goal during the development of these guidelines was to review systematically all available evidence pertaining to the treatment of schizophrenia, and to reach a consensus on a series of practice recommendations that are clinically and scientifically meaningful based on the available evidence. These guidelines are intended for use by all physicians seeing and treating people with schizophrenia. The data used for developing these guidelines have been extracted primarily from various national treatment guidelines and panels for schizophrenia, as well as from meta-analyses, reviews and randomised clinical trials on the efficacy of pharmacological and other biological treatment interventions identified by a search of the MEDLINE database and Cochrane Library. The identified literature was evaluated with respect to the strength of evidence for its efficacy and then categorised into four levels of evidence (A-D). This first part of the guidelines covers disease definition, classification, epidemiology and course of schizophrenia, as well as the management of the acute phase treatment. These guidelines are primarily concerned with the biological treatment (including antipsychotic medication, other pharmacological treatment options, electroconvulsive therapy, adjunctive and novel therapeutic strategies) of adults suffering from schizophrenia.

Augmentation strategies in clozapine-resistant schizophrenia

The introduction of antipsychotics in the 1950s revolutionised the treatment of schizophrenia, but it soon became apparent that a substantial number of patients demonstrated a suboptimal response to these antipsychotics. Clozapine proved to be beneficial in patients whose symptoms were treatment resistant, but it too had limitations, with as many as 40-70% of those treated with clozapine demonstrating inadequate response to this drug as well. The availability of other 'atypical' antipsychotics offers options, but clozapine appears to remain the most effective option in treatment-resistant schizophrenia. This, of course, raises the question of what to do when clozapine is only partially effective. To address the issue of treatment in patients who have demonstrated a suboptimal response to clozapine, efforts have focused on a variety of augmentation strategies, including numerous medications and electroconvulsive therapy. The current body of evidence consists largely of data from smaller open trials and case series/reports, although data from a limited number of controlled studies are now available. Not surprisingly, the evidence drawn from the former is more supportive of augmentation strategies, although the controlled trials are not without positive findings. The available information is certainly not so overwhelming as to endorse any single augmentation approach. Indeed, it argues for more controlled data and cautions us regarding the cost-benefit ratio in adopting this strategy. Over and above the added adverse effects of another treatment, there is evidence to indicate that actual clinical worsening can occur. Without compelling evidence, clinicians must resort to guiding principles. The potential benefits of augmentation cannot be ruled out, but it should be approached with caution and in a systematic fashion. Factors compromising clozapine response should first be ruled out, and any augmentation trials should be guided by existing evidence and a treatment plan that incorporates a clear understanding of target symptoms. A means of evaluating outcome effectively needs to be in place, and the trial should be circumscribed to prevent needless polypharmacy. A priori, an endpoint needs to be established and the trial discontinued unless results firmly support added benefits.

Clozapin-Augmentation mit atypischen Antipsychotika

Typical antipsychotic medications have considerably improved clinical outcome of patients suffering from schizophrenic psychoses, but up to 40% of the cases show treatment resistant symptoms. Even therapy with atypical antipsychotic drugs such as risperidone, quetiapine, olanzapine, sulpiride, amisulpride, and ziprasidone often fails to reach complete remission due to resistant, positive or negative symptoms or dose-limiting side effects. As this also holds true in the case of monotherapy with clozapine, a substance known to be effective against treatment-resistant schizophrenia, increasing numbers of patients receive atypical antipsychotic drugs in addition to clozapine. This review systematically evaluates case reports and clinical investigations on the use of clozapine combined with risperidone, olanzapine, quetiapine, sulpiride, amisulpride, or ziprasidone. Details on indication, methodology, and effects of the investigations are summarized. Only one double blind, placebo-controlled trial on the combination with sulpiride exists within a number of altogether 31 publications about 1182 treatments. Favorable effects on positive and/or negative symptoms or improvements of clozapine-induced side effects were described for every combination approach. In some cases pharmacokinetic interactions or serious unfavorable effects occurred. In conclusion it might be accepted that most of the combination therapies follow a neurobiological rational. There a major differences in the level of evidence that they are safe, tolerable and effective. We discuss criteria for the indication for augmenting clozapine therapy and the differential indication for existing alternatives. Additional randomized prospective trials are needed in order to evaluate these strategies systematically.

Antipsychotic polypharmacy: is there evidence for its use?

Antipsychotic polypharmacy occurs frequently in clinical practice; however, there is a lack of controlled clinical studies testing the efficacy of the combinations used. The purpose of this literature review was to examine studies and other reports that have assessed the incremental benefits and deficits of combination antipsychotic therapy versus monotherapy. A PUBMED search covering a 26-year period from 1976 to 2002 was conducted. The search was limited to clinical trials, case series, and reports. Fifty-two reports were identified that systematically assessed the efficacy of combination therapy as opposed to monotherapy: 4 double-blind studies, 13 open-label clinical trials, and 35 case reports. Only one open-label trial and 2 case reports met the design criteria of having trials of each medication and the combination in the same patients and using some type of standardized assessment to evaluate outcome. The most frequent combination was clozapine-risperidone. Of the clinical trials, 75% (3/4) of the double-blind studies and 69% (9/13) of the open-label trials found that combination therapy was effective in reducing symptoms, while 37% (13/35) of case reports documented an overall positive outcome. Currently, the clinical practice of antipsychotic polypharmacy is not evidence-based; however, there is also no evidence against its use. Expanded systematic research to assess this clinical practice is needed.

Case Studies of Adjunctive Agents in Clozapine-Resistant Schizophrenic Patients

Approximately 40%-70% of neuroleptic-resistant schizophrenic patients are nonresponders even to clozapine. Several clozapine augmentation strategies have come into clinical practice, although often without evidence-based support. This study aims to critically review all the reported case studies regarding the efficacy and safety of adjunctive agents in clozapine-resistant schizophrenic or schizoaffective patients. All published case studies examining the efficacy and safety of adjunctive agents in clozapine-resistant schizophrenic patients were searched for in the MEDLINE database from January 1980 to February 2004. Case studies regarding ECT as a clozapine augmentation strategy were not included in our study. All the included papers were critically reviewed and examined against a set of clinical and pharmacological parameters, outcome measures, and reported side effects. Fifteen case studies regarding the efficacy and safety of sulpiride, risperidone, olanzapine, lithium, lamotrigine, fluvoxamine, and bromocriptine as clozapine adjuncts were found. A total of 33 schizophrenic or schizoaffective patients were included. Of the 15 studies, 8 were associated with risperidone. The duration and dosage of previous clozapine monotherapy was adequate for 16 patients. Plasma clozapine level was assessed for only 7 patients. Outcome measures were used for only 11 patients. The outcome was positive in 13 studies. Combined treatments were generally well tolerated, and side effects never resulted in discontinuation of treatment. Most case studies favor the use of risperidone as an adjunctive agent in clozapine-resistant schizophrenic or schizoaffective patients. However, small numbers of patients and other methodological shortcomings limit the impact of evidence provided.

[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.

Combination of "atypical" antipsychotic medication in the management of treatment-resistant schizophrenia and schizoaffective disorder

BACKGROUND

This article reviews the published clinical data on treatment-resistant schizophrenic and schizoaffective patients managed with combinations of "atypical" antipsychotic medication.

METHOD

A computerized MEDLINE literature search covering an 18-year period (1985-2003) was conducted. All pertinent papers on the subject of the use of combination "atypical" antipsychotic medication in the management of treatment-resistant schizophrenia and schizoaffective disorder were obtained with subsequent analysis and discussion of the retrieved data.

RESULTS

The search identified 29 case reports and case series reports (172 patients) and one double-blind placebo-controlled trial (28 patients) describing the use of combination "atypical" antipsychotic medication (clozapine-risperidone; clozapine-sulpiride; clozapine-olanzapine; clozapine-quetiapine; olanzapine-sulpiride; olanzapine-quetiapine; risperidone-olanzapine; risperidone-quetiapine) in the treatment of resistant schizophrenic and schizoaffective patients. An overview of results suggests that the combinations were beneficial in the described patients with reduction of positive symptoms and occasionally negative symptoms. Significant adverse effects, while rare, were reported in a few cases and did not appear to different in nature from those managed on monotherapeutic regimens.

CONCLUSION

Combinations of "atypical" antipsychotic medications are well tolerated and may be effective in the management of treatment refractory schizophrenia and schizoaffective disorder. However, further double-blind placebo-controlled trials are required in order to test and confirm these observations.

The use of atypical antipsychotics in traumatic brain injury

The use of antipsychotic medication in treating individuals with traumatic brain injury (TBI) has been controversial. Much of the caution derives from animal studies (and limited human data) with regard to typical antipsychotics. Of note, however, is that similar assumptions have been made about the newer generation of atypical antipsychotics as well. Because these agents have different mechanisms of action as well as different neurotransmitter targets, this may very well be unwarranted. In this article, mechanisms of action of typical and atypical antipsychotics are discussed, with particular attention paid to their use in TBI. Indications and contraindications are presented, and recommendations are made for the responsible prescribing of antipsychotic medications after TBI.

Antipsychotic combination therapy in schizophrenia. A review of efficacy and risks of current combinations

OBJECTIVE

To review the literature on efficacy and risks of combining antipsychotics (atypical with atypical or conventional) and suggest a rationale and strategies for future clinical trials.

METHOD

A computerized Medline search supplemented by an examination of cross-references and reviews was performed.

RESULTS

Empirical evidence for the efficacy of combining antipsychotics is too limited to draw firm conclusions. The practice of augmenting clozapine with more 'tightly bound' D2 receptor antagonists as exemplified by risperidone augmentation of clozapine has some empirical and theoretical support. The risks of augmentation strategies have not been studied systematically. No study has examined the economic impact of combination treatment.

CONCLUSION

Further trials of antipsychotic combination therapies are needed before this currently unsupported practice can be recommended. Rationales for combination treatment include a broadening of the range of receptor activity or an increase in D2 receptor occupancy with certain atypical agents. Trial methodology needs to take into account subject characteristics, duration of treatment, optimization of monotherapy comparators, and appropriate outcome measures.

Toxic interaction between risperidone and clozapine: a case report

Although atypical antipsychotics have generally a decreased risk of neurotoxicity, there are reports regarding various neurotoxic or idiosyncratic reactions including neuroleptic malignant syndrome (NMS). The authors present here the toxic interaction between risperidone (RIS) and clozapine (CLZ) in a first-episode schizophrenic patient. A 20-year-old man suffering from first-episode schizophrenia--catatonic subtype, developed a neurotoxic syndrome, which has been characterized as a mild form of NMS, after CLZ (100 mg/day) was added to a regimen of RIS (16 mg/day). The NMS symptomatology subsided only by drug discontinuation and supportive care. Later, CLZ monotherapy restarted without further complications. This case report shows that neurotoxic syndromes, even NMS, may occur during combination therapy with RIS and CLZ.

Treatment of the special patient with schizophrenia

Special patient populations with schizophrenia have received little attention. These populations include adolescents, the elderly, substance abusers, and patients who are considered treatment-resistant. Interest in these populations is rapidly growing, especially with regard to their treatment with second-generation antipsychotics. This article describes the treatment of special patient populations and summarizes the research that has been done in this field.

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.