Risperidone versus clozapine in treatment-resistant schizophrenia: a randomized pilot study. Risperidone versus clozapine in treatment-resistant chronic schizophrenia: a randomized double-blind study. The Risperidone Study Group. A double-blind comparative study of clozapine and risperidone in the management of severe chronic schizophrenia. Clozapine, olanzapine, risperidone, and haloperidol in the treatment of patients with chronic schizophrenia and schizoaffective disorder. Effectiveness of clozapine versus olanzapine, quetiapine, and risperidone in patients with chronic schizophrenia who did not respond to prior atypical antipsychotic treatment. Comparison of clozapine-amisulpride and clozapine-quetiapine combinations for patients with schizophrenia who are partially responsive to clozapine: a single-blind randomized study. A double-blind study of combination of clozapine with risperidone in patients with schizophrenia: effects on cognition. Olanzapine vs risperidone in the management of schizophrenia: a randomized double-blind trial in Australia and New Zealand. Efficacy of risperidone versus olanzapine in patients with schizophrenia previously on chronic conventional antipsychotic therapy: a switch study.
1. The atypical antipsychotic risperidone may constitute an alternative to clozapine, the current treatment of choice for refractory schizophrenia. The objectives of this study were to evaluate the effectiveness of risperidone in comparison to clozapine in everyday practice and to assess the feasibility of a pragmatic trial procedure. 2. Patients were randomly assigned to open-label clozapine or risperidone treatment for 10 weeks and treatment outcomes were assessed blindly. Twenty-one patients were recruited and nineteen entered the randomized phase. 3. Five of 10 participants allocated to clozapine and one of nine risperidone participants dropped out before study completion. Five clozapine patients and six risperidone patients achieved clinical improvement, defined as a 20% decrease in the Positive and Negative Symptom Scale (PANSS) total score. No significant differences between the groups were detected in baseline or endpoint positive or negative symptoms, disease severity, or global or social functioning scores. Patients' opinion on the drugs did not differ between groups. 4. The findings of the intention-to-treat analysis of this study corroborates previous findings that risperidone may be equally effective as clozapine, and supports the feasibility and need of a multicenter randomized pragmatic trial with sufficient power to detect differences between treatments. The purpose of this study was to compare the short-term efficacy and safety of risperidone and clozapine in treatment-resistant chronic schizophrenic patients.
                In a controlled double-blind, multicenter study, 86 inpatients with chronic schizophrenia (DSM-III-R), who were resistant to or intolerant of conventional neuroleptics, were randomly assigned to receive risperidone or clozapine for 8 weeks after a 7-day washout period. After a 1-week dose-titration phase, doses were fixed at 6 mg/day of risperidone and 300 mg/day of clozapine for 1 week and then adjusted according to each patient's response. The final mean doses were 6.4 mg/day of risperidone and 291.2 mg/day of clozapine. Treatment efficacy and safety were evaluated with several well-known rating scales.
                Both risperidone and clozapine significantly reduced the severity of psychotic symptoms (scores on the Positive and Negative Syndrome Scale and the Clinical Global Impression scale) from baseline, with no significant between-group differences. At endpoint, 67% of the risperidone group and 65% of the clozapine group were clinically improved (reduction of 20% or more in total Positive and Negative Syndrome Scale score). Risperidone appeared to have a faster onset of action. In both groups extrapyramidal symptoms and other adverse events were few, and their severity was generally mild. Neither group showed evidence of a relation between drug plasma concentrations and clinical effectiveness.
                Risperidone was well tolerated and as effective as medium doses of clozapine in patients with chronic schizophrenia who had been resistant to or intolerant of conventional neuroleptics. This prospective, double-blind, multicenter, parallel-group study compared the efficacy and safety of therapeutic doses of clozapine and risperidone in patients with severe chronic schizophrenia and poor previous treatment response.
                Male or female patients aged 18-65 years who met DSM-IV criteria for schizophrenia and study requirements for poor previous treatment response (N=273) were randomly assigned to double-blind treatment with either clozapine or risperidone administered over 12 weeks in increasing increments. The primary efficacy measures were the magnitude of improvement in Brief Psychiatric Rating Scale (BPRS) and Clinical Global Impression (CGI) scores. Adverse events were recorded throughout the study.
                The magnitude of improvement in mean BPRS and CGI scores from baseline to end of the study was significantly greater in the clozapine group than in the risperidone group. Statistically significant differences in favor of clozapine were also seen for most of the secondary efficacy measures (Positive and Negative Syndrome Scale, Calgary Depression Scale, Psychotic Depression Scale, and Psychotic Anxiety Scale). The adverse event profile was similar for both treatment groups, with a lower risk of extrapyramidal symptoms in the clozapine group.
                Clozapine showed superior efficacy over risperidone in this patient population. Both treatments were equally well tolerated as demonstrated through their adverse event profiles, although as expected clozapine was associated with a lower risk of extrapyramidal symptoms than risperidone. The authors compared the efficacy and safety of three atypical antipsychotics (clozapine, olanzapine, and risperidone) with one another and with haloperidol in the treatment of patients with chronic schizophrenia or schizoaffective disorder.
                In a double-blind trial, 157 inpatients with a history of suboptimal treatment response were randomly assigned to treatment with clozapine, olanzapine, risperidone, or haloperidol for 14 weeks (an 8-week escalation and fixed-dose period followed by a 6-week variable-dose period).
                Clozapine, risperidone, and olanzapine (but not haloperidol) resulted in statistically significant improvements in total score on the Positive and Negative Syndrome Scale. Improvements seen in total and negative symptom scores with clozapine and olanzapine were superior to haloperidol. The atypical drugs, particularly olanzapine and clozapine, were associated with weight gain.
                The effects of atypical antipsychotics in this population were statistically significant but clinically modest. The overall pattern of results suggests that clozapine and olanzapine have similar general antipsychotic efficacy and that risperidone may be somewhat less effective. Clozapine was the most effective treatment for negative symptoms. However, the differences among treatments were small. When a schizophrenia patient has an inadequate response to treatment with an antipsychotic drug, it is unclear what other antipsychotic to switch to and when to use clozapine. In this study, the authors compared switching to clozapine with switching to another atypical antipsychotic in patients who had discontinued treatment with a newer atypical antipsychotic in the context of the Clinical Antipsychotic Trials for Interventions Effectiveness (CATIE) investigation.
                Ninety-nine patients who discontinued treatment with olanzapine, quetiapine, risperidone, or ziprasidone in phase 1 or 1B of the trials, primarily because of inadequate efficacy, were randomly assigned to open-label treatment with clozapine (N=49) or blinded treatment with another newer atypical antipsychotic not previously received in the trial (olanzapine [N=19], quetiapine [N=15], or risperidone [N=16]).
                Time until treatment discontinuation for any reason was significantly longer for clozapine (median=10.5 months) than for quetiapine (median=3.3), or risperidone (median=2.8), but not for olanzapine (median=2.7). Time to discontinuation because of inadequate therapeutic effect was significantly longer for clozapine than for olanzapine, quetiapine, or risperidone. At 3-month assessments, Positive and Negative Syndrome Scale total scores had decreased more in patients treated with clozapine than in patients treated with quetiapine or risperidone but not olanzapine. One patient treated with clozapine developed agranulocytosis, and another developed eosinophilia; both required treatment discontinuation.
                For these patients with schizophrenia who prospectively failed to improve with an atypical antipsychotic, clozapine was more effective than switching to another newer atypical antipsychotic. Safety monitoring is necessary to detect and manage clozapine's serious side effects. Schizophrenia is a devastating psychiatric disorder. Clozapine has long been the gold standard for treatment of patients with treatment-resistant schizophrenia; however, some patients are only partially responsive to clozapine treatment. Augmentation of clozapine treatment might enhance its effectiveness in partial responders, but only a few studies have investigated possible augmentation strategies. This study compared the effectiveness and tolerability of the combination of amisulpride and clozapine with the combination of quetiapine and clozapine in patients who were only partially responsive to clozapine monotherapy. Fifty-six treatment-resistant patients who were partially responsive to clozapine were randomly assigned to receive amisulpride or quetiapine along with an ongoing stable dose of clozapine. Fifty patients completed the study. Patients were evaluated at baseline and at the first, third, sixth, and eighth weeks. Efficacy measures consisted of the Brief Psychiatric Rating Scale (BPRS), the Scale for the Assessment of Negative Symptoms (SANS), the Scale for the Assessment of Positive Symptoms (SAPS), and the Clinical Global Impression (CGI) scale. Tolerability and adverse effects were assessed with the Udvalg for Kliniske Undersogelser (UKU) Side Effect Rating Scale and the Simpson Angus Scale (SAS). A substantial improvement occurred in both groups by the end of the eighth week; however, the improvement associated with amisulpride was significantly greater than that seen with quetiapine. This difference was noted as early as the third week of follow-up in terms of CGI scores, and by the sixth week with regard to BPRS, SANS, and SAPS scores. Both drugs were well tolerated, as measured by UKU and SAS. Improvement favoring clozapine+amisulpride could be attributed to the selective D2/D3 binding property of amisulpride, which had an additional effect in improving symptoms of schizophrenia. The authors concluded that amisulpride seems to be effective and well tolerated for augmentation purposes in clozapine-resistant patients. Atypical antipsychotic drugs produce improvement in some domains of cognition as well as psychopathology in patients with schizophrenia. However, the effect of combinations of atypical antipsychotic drugs on cognitive function is unknown. The aim of this study was to compare the effect of risperidone or placebo on cognitive function in patients with schizophrenia who were previously treated with clozapine monotherapy.
                This prospective, randomized, double-blind, placebo-controlled, 6-week study included 30 patients with DSM-IV schizophrenia. Patients whose psychopathology was no more than partially responsive to clozapine treatment were randomly assigned to receive adjunctive treatment with risperidone (N = 16) up to 6 mg/day or placebo (N = 14). Cognitive test scores for verbal learning and memory, verbal fluency, attention, executive function, verbal working memory, and motor function were the primary outcome measures. Secondary outcome measures included assessment of psychopathology, extrapyramidal side effects, and global functioning. Data were collected between November 2001 and July 2003.
                Significant improvement was found in both treatment groups in a variety of cognitive measures, but there was significantly greater improvement in the placebo-augmented group on measures of initial learning acquisition and attention. The improvement in cognition was not correlated with improvement in psychopathology. There were significant correlations between improvement in verbal working memory, verbal learning and memory, and attention and quality of life and global functioning in the placebo-augmented but not the risperidone-augmented group.
                Adjunctive treatment with risperidone for 6 weeks in patients with schizophrenia who had received chronic treatment with clozapine does not significantly improve cognitive function. Improved drug therapy for schizophrenia may represent the best strategy for reducing the costs of schizophrenia and the recurrent chronic course of the disease. Olanzapine and risperidone are atypical antipsychotic agents developed to meet this need. We report a multicenter, double-blind, parallel, 30-week study designed to compare the efficacy, safety, and associated resource use for olanzapine and risperidone in Australia and New Zealand. The study sample consisted of 65 patients who met DSM-IV criteria for schizophrenia, schizoaffective disorder, or schizophreniform disorder. Olanzapine-treated patients showed a significantly greater reduction in Positive and Negative Syndrome Scale (PANSS) total, Brief Psychiatric Rating Scale (BPRS) total, and PANSS General Psychopathology scores at endpoint compared to the risperidone-treated patients. Response rates through 30 weeks showed a significantly greater proportion of olanzapine-treated patients had achieved a 20% or greater improvement in their PANSS total score compared to risperidone-treated patients. Olanzapine and risperidone were equivalent in their improvement of PANSS positive and negative scores and Clinical Global Impression-Severity of Illness scale (CGI-S) at endpoint. Using generic and disease-specific measures of quality of life, olanzapine-treated patients showed significant within-group improvement in most measures, and significant differences were observed in favor of olanzapine over risperidone in Quality of Life Scale (QLS) Intrapsychic Foundation and Medical Outcomes Study Short Form 36-item instrument (SF-36) Role Functioning Limitations-Emotional subscale scores. Despite the relatively small sample size, our study suggests that olanzapine has a superior risk:benefit profile compared to risperidone. The objective of the study was to examine whether patients with schizophrenia who were judged to be stable on long-term treatment with conventional antipsychotic medications would further benefit from a switch to an atypical antipsychotic drug. Thirty-six subjects with schizophrenia spectrum disorder, on conventional antipsychotic medication therapy for at least 2 years, were randomized in double-blind fashion to risperidone versus olanzapine. Patients were titrated up to 6 mg risperidone or 15 mg olanzapine as tolerated, followed by tapering and discontinuation of conventional antipsychotic medication. Atypical antipsychotic agents were then administered alone (monotherapy) for 12 weeks. Efficacy and tolerability were assessed using the Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression Scale, and Simpson Angus Scale. Body weight was measured at each visit. Both treatment groups exhibited marked and similar improvement in the total PANSS score from baseline to study endpoint (22 weeks) [risperidone: baseline=59.3 (SE 3.1), 22 weeks=44.3 (SE 2.3) (p<0.001); olanzapine: baseline=55.9 (SE 3.3), 22 weeks=46.9 (SE 3.2) (p<0.001). Both groups also exhibited significant reductions in PANSS factor scores for positive and negative symptoms and disorganized thoughts. Only risperidone-treated patients exhibited significant decreases in uncontrolled hostility/excitement and anxiety and depression. Of note, while positive factor scores exhibited the majority of change within the first 10 weeks, negative factor scores continued to decline significantly in both treatment groups throughout the study. Tolerability assessments did not differ between groups. The results indicate that both atypical antipsychotic medications provided significant additional improvement in symptom severity in patients with schizophrenia previously on conventional antipsychotic agents.
The equivalence of clozapine and risperidone for treatment resistant schizophrenia cannot yet be assumed and there seems to be little to chose between risperidone and both olanzapine and amisulpiride. The research is limited in many respects, and longer term studies measuring clinically important outcomes, including service use and quality of life are needed to judge the comparative value of the various atypical drugs.