Randomized, controlled, double-blind multicenter comparison of the efficacy and tolerability of ziprasidone and olanzapine in acutely ill inpatients with schizophrenia or schizoaffective disorder. Effectiveness of olanzapine, quetiapine, risperidone, and ziprasidone in patients with chronic schizophrenia following discontinuation of a previous atypical antipsychotic. Efficacy of risperidone versus olanzapine in patients with schizophrenia previously on chronic conventional antipsychotic therapy: a switch study. International multisite double-blind trial of the atypical antipsychotics risperidone and olanzapine in 175 elderly patients with chronic schizophrenia. A comparison of weight change during treatment with olanzapine or aripiprazole: results from a randomized, double-blind study. Neuropsychological change in early phase schizophrenia during 12 months of treatment with olanzapine, risperidone, or haloperidol. The Canadian Collaborative Group for research in schizophrenia. Cognition, functioning and quality of life in schizophrenia treatment: results of a one-year randomized controlled trial of olanzapine and quetiapine. Childhood-onset schizophrenia: A double-blind, randomized clozapine-olanzapine comparison. Olanzapine versus risperidone in the treatment of post-psychotic depression in schizophrenic patients. Randomized double blind comparison of olanzapine vs. clozapine on subjective well-being and clinical outcome in patients with schizophrenia. The treatment of negative symptoms and deficit states of chronic schizophrenia: olanzapine compared to amisulpride and placebo in a 6-month double-blind controlled clinical trial. Cognitive improvement in schizophrenic patients does not require a serotonergic mechanism: randomized controlled trial of olanzapine vs amisulpride. Olanzapine vs risperidone in the management of schizophrenia: a randomized double-blind trial in Australia and New Zealand. A double-blind, randomized comparative trial of amisulpride versus olanzapine for 6 months in the treatment of schizophrenia. Atypical antipsychotic agents in the treatment of violent patients with schizophrenia and schizoaffective disorder. A double-blind randomised comparative trial of amisulpride versus olanzapine for 2 months in the treatment of subjects with schizophrenia and comorbid depression. Cerebral D2 and 5-HT2 receptor occupancy in Schizophrenic patients treated with olanzapine or clozapine. Effects of olanzapine, risperidone and haloperidol on prepulse inhibition in schizophrenia patients: a double-blind, randomized controlled trial. Adverse effects and laboratory parameters of high-dose olanzapine vs. clozapine in treatment-resistant schizophrenia. A randomized double-blind study of risperidone and olanzapine in the treatment of schizophrenia or schizoaffective disorder. Double-blind comparison of olanzapine versus risperidone in the treatment of schizophrenia and other psychotic disorders. A 24-week randomized study of olanzapine versus ziprasidone in the treatment of schizophrenia or schizoaffective disorder in patients with prominent depressive symptoms. Randomized, double-blind 6-month comparison of olanzapine and quetiapine in patients with schizophrenia or schizoaffective disorder with prominent negative symptoms and poor functioning. Efficacy of olanzapine and risperidone in schizophrenia: a randomized double-blind crossover design. Clozapine, olanzapine, risperidone, and haloperidol in the treatment of patients with chronic schizophrenia and schizoaffective disorder. Serum leptin and triglyceride levels in patients on treatment with atypical antipsychotics. Effect of switching to atypical antipsychotics on memory in patients with chronic schizophrenia. Olanzapine versus ziprasidone: results of a 28-week double-blind study in patients with schizophrenia. A pilot study of risperidone, olanzapine, and haloperidol in psychotic youth: a double-blind, randomized, 8-week trial. Quetiapine versus olanzapine for the treatment of negative symptoms in patients with schizophrenia. Randomized comparison of olanzapine versus risperidone for the treatment of first-episode schizophrenia: 4-month outcomes. Efficacy and tolerability of olanzapine, quetiapine, and risperidone in the treatment of early psychosis: a randomized, double-blind 52-week comparison. Double-blind comparison of olanzapine versus clozapine in schizophrenic patients clinically eligible for treatment with clozapine. Olanzapine versus clozapine in treatment-resistant or treatment-intolerant schizophrenia. Effectiveness of clozapine versus olanzapine, quetiapine, and risperidone in patients with chronic schizophrenia who did not respond to prior atypical antipsychotic treatment.
Limited randomized, controlled trial data exist on possible differences between atypical antipsychotics in efficacy, overall tolerability, and important indices of health status. The authors compared the efficacy and tolerability of ziprasidone and olanzapine in the treatment of acutely ill inpatients with schizophrenia or schizoaffective disorder.
                In this 6-week, multicenter, double-blind, parallel-design, flexible-dose trial, patients were randomly assigned to receive ziprasidone (N=136) or olanzapine (N=133). Primary efficacy measures were improvement in Brief Psychiatric Rating Scale and Clinical Global Impression (CGI) severity scale scores; secondary measures were scores on the CGI improvement scale, Positive and Negative Syndrome Scale, and Calgary Depression Scale for Schizophrenia. Tolerability assessments included fasting lipid profiles, fasting glucose and insulin measurements, electrocardiography, and monitoring of vital signs and body weight.
                The overall mean daily doses were 129.9 mg (SD=27.3) for ziprasidone and 11.3 mg (SD=2.8) for olanzapine. Both antipsychotics were efficacious in improving symptoms and global illness severity. The two treatment groups did not differ significantly in primary or secondary efficacy measures at endpoint or in by-visit analysis. Both agents were well tolerated. Body weight, total cholesterol, triglycerides, and low-density lipoprotein cholesterol significantly increased with olanzapine but not with ziprasidone; all between-group comparisons of these variables were significant and favored ziprasidone. Olanzapine, but not ziprasidone, was associated with significant increases in fasting insulin level. No patient in either group exhibited a corrected QT interval >/=500 msec.
                During 6 weeks' treatment, ziprasidone and olanzapine demonstrated comparable antipsychotic efficacy. Differences favoring ziprasidone were observed in metabolic parameters. In the treatment of schizophrenia, changing antipsychotics is common when one treatment is suboptimally effective, but the relative effectiveness of drugs used in this strategy is unknown. This randomized, double-blind study compared olanzapine, quetiapine, risperidone, and ziprasidone in patients who had just discontinued a different atypical antipsychotic.
                Subjects with schizophrenia (N=444) who had discontinued the atypical antipsychotic randomly assigned during phase 1 of the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) investigation were randomly reassigned to double-blind treatment with a different antipsychotic (olanzapine, 7.5-30 mg/day [N=66]; quetiapine, 200-800 mg/day [N=63]; risperidone, 1.5-6.0 mg/day [N=69]; or ziprasidone, 40-160 mg/day [N=135]). The primary aim was to determine if there were differences between these four treatments in effectiveness measured by time until discontinuation for any reason.
                The time to treatment discontinuation was longer for patients treated with risperidone (median: 7.0 months) and olanzapine (6.3 months) than with quetiapine (4.0 months) and ziprasidone (2.8 months). Among patients who discontinued their previous antipsychotic because of inefficacy (N=184), olanzapine was more effective than quetiapine and ziprasidone, and risperidone was more effective than quetiapine. There were no significant differences between antipsychotics among those who discontinued their previous treatment because of intolerability (N=168).
                Among this group of patients with chronic schizophrenia who had just discontinued treatment with an atypical antipsychotic, risperidone and olanzapine were more effective than quetiapine and ziprasidone as reflected by longer time until discontinuation for any reason. 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 authors compared the effects of the two most commonly used atypical antipsychotics, risperidone and olanzapine, in elderly patients with schizophrenia.
                In an 8-week, international, double-blind study, patients (outpatients, hospital inpatients, and residents of nursing or boarding homes) were randomly assigned to receive risperidone (1 mg to 3 mg/day) or olanzapine (5 mg to 20 mg/day). The main outcome measures were changes in Positive and Negative Syndrome Scale (PANSS) total scores and rates of extrapyramidal symptoms (EPS).
                Subjects were 175 patients age 60 years or over with schizophrenia or schizoaffective disorder. The mean duration of illness was 36.5 years. Median doses were 2 mg/day of risperidone and 10 mg/day of olanzapine. PANSS total scores and four of the five PANSS factor scores (positive symptoms, negative symptoms, disorganized thoughts, and anxiety/depression) improved significantly at all time-points and at endpoint in both groups; between-treatment differences were not significant. EPS-related adverse events were reported by 9.2% of patients in the risperidone group and 15.9% in the olanzapine group; the between-treatment difference was not significant. Total scores on the Extrapyramidal Symptom Rating Scale were reduced in both groups at endpoint; between-treatment differences were not significant. Clinically relevant weight gain was seen in both groups, but was significantly less frequent in risperidone patients than in olanzapine patients.
                Stable elderly patients with chronic schizophrenia receiving appropriate doses of risperidone or olanzapine over an 8-week period experienced significant reductions in the severity of psychotic and extrapyramidal symptoms, with a relatively low risk of side effects. Weight gain is a side effect of therapy with many atypical antipsychotics and may have important clinical repercussions with respect to long-term health and treatment compliance. The primary objective of this double-blind study was to compare the safety and tolerability of aripiprazole and olanzapine in patients with schizophrenia as evidenced by the percentage of patients exhibiting significant weight gain.
                This was a 26-week, multicenter, randomized, double-blind, active-controlled trial in patients with DSM-IV schizophrenia who were in acute relapse and required hospitalization. Significant weight gain was defined as a > or = 7% increase in body weight from baseline. Body weight, Positive and Negative Syndrome Scale, and Clinical Global Impressions-Improvement scale (CGI-I) assessments were performed at baseline and at regular intervals during the study. The study period was from April 2000 through June 2001.
                317 patients were randomly assigned to aripiprazole (N = 156) or olanzapine (N = 161). Compared with those treated with aripiprazole, a greater proportion of patients treated with olanzapine exhibited clinically significant weight gain during the trial. By week 26, 37% of olanzapine-treated patients had experienced significant weight gain compared with 14% of aripiprazole-treated patients (p < .001). Statistically significant differences in mean weight change were observed between treatments beginning at week 1 and sustained throughout the study. At week 26, there was a mean weight loss of 1.37 kg (3.04 lb) with aripiprazole compared with a mean increase of 4.23 kg (9.40 lb) with olanzapine among patients who remained on therapy (p < .001). Changes in fasting plasma levels of total cholesterol, high-density lipoprotein cholesterol, and triglycerides were significantly different in the 2 treatment groups, with worsening of the lipid profile among patients treated with olanzapine. There was a consistent and sustained improvement in symptoms in patients who remained on therapy with either olanzapine or aripiprazole as assessed by CGI-I scores and responder rates throughout the study.
                Olanzapine had a greater impact on patients' weight than aripiprazole. Significant differences in favor of aripiprazole were also observed in the effects of therapy on plasma lipid profile. Both treatment groups achieved comparable clinically meaningful improvements on efficacy measures. The observed effects on weight and lipids indicate a potentially lower metabolic and cardiovascular risk in patients treated with aripiprazole compared with those treated with olanzapine. The purpose of this investigation was to test the efficacy of novel antipsychotic medications in the treatment of cognitive impairment in early phase schizophrenia.
                Sixty-five patients in this multicenter double-blind study were randomly assigned to olanzapine (5-20 mg), risperidone (4-10 mg), or haloperidol (5-20 mg). Standard measures of clinical and motor syndromes were administered, as well as a comprehensive battery of tests to assess (1) motor skills, (2) attention span, (3) verbal fluency and reasoning, (4) nonverbal fluency and construction, (5) executive skills, and (6) immediate recall at baseline and after 6, 30, and 54 weeks of treatment.
                The general cognitive index derived from the 6 domain scores revealed a significantly greater benefit from treatment with olanzapine relative to haloperidol and olanzapine relative to risperidone, but no significant difference was shown between risperidone and haloperidol. The improvement related to olanzapine was apparent after 6 weeks and enhanced after 30 and 54 weeks of treatment. Exploratory within-group analyses of the 6 cognitive domains after a conservative Bonferroni adjustment revealed a significant improvement with olanzapine only on the immediate recall domain, and similar analyses of the 17 individual tests revealed a significant improvement with olanzapine only on the Hooper Visual Organization Test.
                These data suggest that olanzapine has some superior cognitive benefits relative to haloperidol and risperidone. A larger sample replication study is necessary to confirm and generalize the observations of this study and begin evaluation of the implications of this change to cerebral function and quality of life for people with schizophrenia. Cognitive deficits are recognized as a critical determinant of functional outcomes in schizophrenia; and second generation antipsychotic drugs have been touted for their potential to enhance cognitive functioning and community tenure.
                The study examined the relative merits of olanzapine and quetiapine in improving cognitive deficits and enhancing psychosocial functioning in a sample of community dwelling adults previously treated with first generation antipsychotic drugs for schizophrenia.
                In a prospective, rater-blinded study, 86 participants were randomized to receive either olanzapine or quetiapine, and assessed at baseline and after 3, 6, 9 and 12 months. Outcome measures included, besides symptoms and side effects rating scales, the subjective scale to investigate cognition in schizophrenia (SSTICS), a computer-assisted cognitive test battery (COGLAB), the sickness impact profile (SIP), the global assessment of functioning (GAF) scale, and the drug attitude inventory (DAI).
                Both olanzapine and quetiapine were equally effective in improving symptom severity and decreasing the neurological side effects. Quetiapine was significantly better tolerated (p=0.002), improved self-rated cognitive dysfunction (p=0.002) and subjects' performance on selected neurocognitive tasks (p=0.01). Olanzapine use was associated with greater symptom stability, fewer drop outs (p=0.01) and frequent metabolic aberrations (p=0.001). The accrued benefits of drug therapy, however, were not reflected as significant gains in daily functioning and quality of life.
                Quetiapine is noted to have specific cognition enhancing properties in schizophrenia that warrants further exploration. The observed clinical and cognitive benefits associated with quetiapine may likely be attributable to its loose binding to, and fast dissociation from the dopamine receptors. Olanzapine has proved to be a reliable antipsychotic drug with a greater liability to cause metabolic abnormalities. Childhood-onset schizophrenia is a rare but severe form of the disorder that is frequently treatment resistant. The psychiatrist has a limited evidence base to guide treatment, particularly as there are no trials in children comparing atypical antipsychotics, the mainstay of current treatment.
                To compare the efficacy and safety of olanzapine and clozapine, hypothesizing that clozapine would be more efficacious.
                Double-blind randomized 8-week controlled trial, with a 2-year open-label follow-up.
                National Institute of Mental Health study, January 1998 to June 2005. Patients underwent reassessment 2 years after discharge.
                Children and adolescents recruited nationally, aged 7 to 16 years, meeting unmodified DSM-IV criteria for schizophrenia, and resistant to treatment with at least 2 antipsychotics.
                After drug washout and a 1- to 3-week antipsychotic-free period, patients were randomized to treatment with clozapine (n = 12) or olanzapine (n = 13).
                The Clinical Global Impression Severity of Symptoms Scale and Schedule for the Assessment of Negative/Positive Symptoms.
                Clozapine was associated with a significant reduction in all outcome measures, whereas olanzapine showed a less consistent profile of clinical improvement. While there were moderate to large differential treatment effects in favor of clozapine, these reached significance only in the alleviation of negative symptoms from an antipsychotic-free baseline (P = .04; effect size, 0.89). Clozapine was associated with more overall adverse events. At 2-year follow-up, 15 patients were receiving clozapine with evidence of sustained clinical improvement, but additional adverse events emerged, including lipid anomalies (n = 6) and seizures (n = 1).
                While not demonstrating definitively the superiority of clozapine compared with olanzapine in treatment-refractory childhood-onset schizophrenia, the study suggests that clozapine has a more favorable profile of clinical response, which is balanced against more associated adverse events. To compare the efficacy of two atypical antipsychotic drugs, olanzapine and risperidone, in schizophrenic patients with post-psychotic depression.
                A clinically significant decrease of MADRS scores occurred in patients treated with both drugs for 8 weeks.
                Atypical antipsychotic drugs may be particularly appropriate when treating schizophrenic patients with depression. This randomized double-blind multicenter trial evaluated the effects of olanzapine vs. clozapine on subjective well-being, quality of life (QOL) and clinical outcome.
                The primary objective was to demonstrate non-inferiority of olanzapine, mean dosage 16.2 +/- 4.8 (5-25 mg/day) vs. clozapine, mean dosage 209 +/- 91 (100-400 mg/day) regarding improvement on the 'Subjective Well-Being under Neuroleptic Treatment' (SWN) Scale after 26 treatment weeks in 114 patients with schizophrenia. Secondary outcome parameters included: Munich QOL Dimension List (MLDL), Positive and Negative Symptom Scale (PANSS), Clinical Global Impression (CGI).
                SWN scores improved significantly in both groups, olanzapine was non-inferior to clozapine (group difference 3.2 points in favor of olanzapine; 95% CI: 4.2;10.5). MLDL-satisfaction, PANSS and CGI-S improved similarly, olanzapine yielded a higher CGI Therapeutic Index. Individual SWN and PANSS changes correlated only moderately (r = -0.45).
                Olanzapine was non-inferior to clozapine. The lack of a marked correlation between PANSS and SWN improvements indicates that patients and psychiatrists perceive treatment differently. The aim of the study was to evaluate the efficacy of olanzapine (5 and 20 mg/day) over a 6-month period in chronic schizophrenic patients experiencing predominantly negative symptoms.
                Two hundred and forty-four patients participated in a 6-month multicenter double-blind trial of placebo (n = 34), olanzapine 5 mg/day (n = 70), olanzapine 20 mg/day (n = 70), or amisulpride 150 mg/day (n = 70). Primary measure was the scale for the assessment of negative symptoms.
                Olanzapine 5 mg/day showed significantly greater improvement than placebo in negative symptoms and in the Positive and Negative Syndrome Scale total score. Baseline positive symptoms were low at baseline and changed minimally. The neurological tolerance of olanzapine, amisulpride and placebo were comparable.
                Olanzapine 5 mg/day was effective in treating negative symptoms in a group of schizophrenic with predominantly negative symptoms during the stabilization phase. Improvement in positive symptoms or extrapyramidal symptoms (EPS) was unlikely to explain this result while improvement in depression may have partially contributed. Combined serotonin-2A (5-HT(2A)) and dopamine-2 (D2) receptor blockade has been proposed as a candidate mechanism by which second-generation antipsychotics (SGAs) improve both cognition and negative symptoms in schizophrenic patients, in contrast to antipsychotics of the first generation. The SGA amisulpride, however, only binds to D2/D3 receptors, which makes it an interesting tool to test this assumption. In a randomized controlled trial, 52 schizophrenic patients were allocated to treatment with either olanzapine (10-20 mg/day) or amisulpride (400-800 mg/day). A comprehensive neuropsychological test battery and clinical ratings were used to assess participants at inclusion and after 4 and 8 weeks. Cognitive improvements of moderate size were observed, with effect sizes similar to those obtained in previous studies on the cognitive effects of SGAs. Importantly, amisulpride was not inferior to olanzapine for any cognitive domain. Combined 5-HT(2A)/D2 receptor blockade is probably not necessary for cognitive improvement by SGAs. 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. Atypical antipsychotics offer advantages over earlier drugs for the treatment of schizophrenia, although few data exist on the relative merits of different atypical antipsychotics. A multicentre, double-blind, randomized trial was performed to compare amisulpride and olanzapine in the treatment of acute schizophrenia. Adult schizophrenic patients with dominant positive symptomatology received amisulpride (200-800 mg/day) or olanzapine (5-20 mg/day) for 6 months. The primary efficacy variable was change from baseline of the Brief Psychiatric Rating Scale (BPRS) score, assessed with a non-inferiority analysis. The evolution of positive and negative symptomatology, depression, social functioning and quality of life were assessed. Safety evaluation included adverse event reporting, neurological status and body weight. The improvement of BPRS score was 32.7% in the amisulpride group and 33.0% in the olanzapine group; thus, the efficacy of amisulpride was not inferior to that of olanzapine. All other secondary efficacy outcome variables evolved to a similar extent in both groups. Adverse event frequency was similar in both groups. Amenorrhoea was encountered only in the amisulpride group (6.2% of patients), whereas elevations of liver transaminases were more frequent in the olanzapine group (17% versus 3.7% of patients). The incidence and mean extent of clinically relevant weight gain were higher in the olanzapine group (35.1% and 3.9 kg) than in the amisulpride group (20.6% and 1.6 kg). The efficacy of amisulpride is not inferior to that of olanzapine in the treatment of acute schizophrenia. The side-effect profile of the two drugs differed. Violent behavior of patients with schizophrenia prolongs hospital stay and interferes with their integration into the community. Finding appropriate treatment of violent behaviors is of primary importance.
                To compare the efficacy of 2 atypical antipsychotic agents, clozapine and olanzapine, with one another and with haloperidol in the treatment of physical assaults and other aggressive behaviors in physically assaultive patients with schizophrenia and schizoaffective disorder.
                Randomized, double-blind, parallel-group, 12-week trial. Physically assaultive subjects with schizophrenia or schizoaffective disorder who were inpatients in state psychiatric facilities were randomly assigned to treatment with clozapine (n = 37), olanzapine (n = 37), or haloperidol (n = 36).
                Number and severity of physical assaults as measured by the Modified Overt Aggression Scale (MOAS) physical aggression score and the number and severity of all aggressive events as measured by the MOAS overall score. Psychiatric symptoms were assessed through the Positive and Negative Syndrome Scale (PANSS).
                Clozapine was superior to both olanzapine and haloperidol in reducing the number and severity of physical assaults as assessed by the MOAS physical aggression score and in reducing overall aggression as measured by the MOAS total score. Olanzapine was superior to haloperidol in reducing the number and severity of aggressive incidents on these 2 MOAS measures. There were no significant differences among the 3 medication groups in improvement of psychiatric symptoms as measured by the PANSS total score and the 3 PANSS subscales.
                Clozapine shows greater efficacy than olanzapine and olanzapine greater efficacy than haloperidol in reducing aggressive behavior. This antiaggressive effect appears to be separate from the antipsychotic and sedative action of these medications. To compare the efficacy and safety of amisulpride and olanzapine in subjects with schizophrenia and comorbid depression in a randomised double-blind trial.
                Eighty-five adult patients fulfilling DSM-IV criteria for schizophrenia and presenting a depressive episode were randomised to amisulpride (200-600 mg/day) or olanzapine (5-15 mg/day) for 8 weeks. Primary efficacy variables were change in Calgary Depression Scale (CDS) score and Clinical Global Impression (CGI) of Change. Safety was monitored by adverse event reporting and determination of extrapyramidal function and metabolic variables.
                The mean change from baseline of CDS score was -6.84 in the amisulpride group and -7.36 in the olanzapine group. 65.9% and 61.5% of subjects, respectively, were considered "much" or "very much" improved. No significant inter-group difference in effect size was observed. The frequency of adverse events was low and emergence of extrapyramidal symptoms was not seen. Four patients in the olanzapine group developed abnormal triglyceride levels. Mean weight gain was 1.45 and 0.5 kg, respectively, in the olanzapine and amisulpride groups.
                Amisulpride and olanzapine are effective in patients with schizophrenia and comorbid depression. Tolerance of both drugs was acceptable, although use of olanzapine was associated with a trend toward greater metabolic side-effects . We report the results of a double-blind, randomized prospective trial on D2 and 5-HT2 receptor occupancy and the clinical effects of olanzapine versus clozapine in a sample of neuroleptic-refractory schizophrenic patients. Receptor occupancy was evaluated in different cortical areas and in basal ganglia using [18F] fluoro-ethyl-spiperone ([18F] FESP) and positron emission tomography (PET). A total of 15 neuroleptic-free patients completed the study undergoing a baseline and a post-treatment PET scan (olanzapine, nine patients, one female; clozapine, six patients, three female) 8 weeks after starting treatment. PET data were analysed both by regions of interest and on a voxel-by-voxel basis using Statistical Parametric Mapping (SPM96). Olanzapine and clozapine induced a similar and significant inhibition of [18F] FESP binding index in the cortex. In the basal ganglia, receptor occupancy was significantly higher with olanzapine than with clozapine (p=0.0018). By contrast, no differences in receptor occupancy were detected at the level of the pituitary gland. Clinical outcomes, in particular a full extra pyramidal tolerability, were similar. In this sample of neuroleptic-refractory schizophrenic patients, olanzapine and clozapine showed a different pattern of occupancy of D2-like receptor despite a common lack of extrapyramidal side-effects. Prepulse inhibition (PPI), whereby the startle eyeblink response is inhibited by a relatively weak non-startling stimulus preceding the powerful startle eliciting stimulus, is a measure of sensorimotor gating and has been shown to be deficient in schizophrenia patients. There is considerable interest in whether conventional and/or atypical antipsychotic medications can "normalize" PPI deficits in schizophrenia patients. 51 schizophrenia patients participated in a randomized, double-blind controlled trial on the effects of three commonly-prescribed antipsychotic medications (risperidone, olanzapine, or haloperidol) on PPI, startle habituation, and startle reactivity. Patients were tested at baseline, Week 4 and Week 8. Mixed model regression analyses revealed that olanzapine significantly improved PPI from Week 4 to Week 8, and that at Week 8 patients receiving olanzapine produced significantly greater PPI than those receiving risperidone, but not haloperidol. There were no effects of medication on startle habituation or startle reactivity. These results support the conclusion that olanzapine effectively increased PPI in schizophrenia patients, but that risperidone and haloperidol had no such effects. The results are discussed in terms of animal models, neural substrates, and treatment implications. Patients with treatment-resistant schizophrenia pose a major challenge to caregivers since only clozapine is documented as having superior efficacy in this population. Although olanzapine is similar to clozapine in structure and receptor profile, it has not been proven to have superior efficacy for this patient group. Nonetheless, olanzapine is being increasingly used in higher doses as clinicians attempt to find a more effective and tolerable therapy for refractory patients. Furthermore, there are little data comparing olanzapine and clozapine in this population. Thirteen patients participated in a randomized double-blind 16-week crossover study of clozapine therapy (450 mg/day) compared to high doses of olanzapine (50 mg/day). No patients on olanzapine responded while 20% responded to clozapine treatment. Olanzapine patients tended to experience higher rates of anticholinergic effects such as dry mouth (80 vs. 20%) and blurry vision (40 vs. 0%). Clozapine-treated patients had higher rates of sialorrhea (80 vs. 10%), sweating (50 vs. 10%), dyspepsia (70 vs. 30%), and lethargy (90 vs. 60%). Neither treatment was associated with significant akathisia. Liver enzyme elevation and lipids were higher with clozapine treatment. Mean weight gain in the initial 8 weeks was 3.4 kg for olanzapine and 1.2 kg for clozapine. High doses of olanzapine during 8 weeks of treatment did not increase lipids and liver enzymes like clozapine did. Olanzapine at 50 mg/day may be associated with more anticholinergic effects and weight gain than clozapine. The safety and efficacy of risperidone and olanzapine were compared in a double-blind trial that used doses widely accepted in clinical practice.
                Subjects (N=377) who met DSM-IV criteria for schizophrenia or schizoaffective disorder were randomly assigned to receive 2-6 mg/day of risperidone (mean modal dose=4.8 mg/day) or 5-20 mg/day of olanzapine (mean modal dose=12.4 mg/day) for 8 weeks.
                The two study groups were similar at baseline except that the olanzapine group was slightly younger than the risperidone group. Seventy-five percent of the participants completed the trial, with no between-treatment differences in the proportion of dropouts. Similar proportions of the risperidone and olanzapine groups reported extrapyramidal symptoms (24% and 20%, respectively). Severity of extrapyramidal symptoms was low in both groups, with no between-group differences. Total Positive and Negative Syndrome Scale scores and scores on the five Positive and Negative Syndrome Scale factors were improved in both groups at week 8 (subjects who completed the study) and endpoint (all subjects, including dropouts). There were overall between-treatment differences in efficacy. Comparison of individual factors found no significant differences at endpoint; at week 8, however, improvements on Positive and Negative Syndrome Scale factors for positive symptoms and anxiety/depression were greater with risperidone than olanzapine. An increase in body weight of > or =7% was seen in 27% of olanzapine participants and 12% of risperidone participants.
                Both treatments were well tolerated and efficacious. The frequency and severity of extrapyramidal symptoms were similar in the two treatment groups. Greater reductions in severity of positive and affective symptoms were seen with risperidone than with olanzapine treatment among study completers. There was no measure on which olanzapine was superior. Greater weight gain was associated with olanzapine than with risperidone treatment. Olanzapine and risperidone, both second-generation antipsychotic agents, represent two different pharmacologic strategies. Although they share some in vitro properties, they differ by virtue of their chemical structure, spectrum of receptor binding affinities, animal neuropharmacology, pharmacokinetics, and in vivo neuroimaging profile. Based on such differences, it was hypothesized that the two compounds would show distinct safety and/or efficacy characteristics. To test this hypothesis, an international, multicenter, double-blind, parallel-group, 28-week prospective study was conducted with 339 patients who met DSM-IV criteria for schizophrenia, schizophreniform disorder, or schizoaffective disorder. Results of the study indicated that both olanzapine and risperidone were safe and effective in the management of psychotic symptoms. However, olanzapine demonstrated significantly greater efficacy in negative symptoms (Scale for Assessment of Negative Symptoms summary score), as well as overall response rate (> or = 40% decrease in the Positive and Negative Syndrome Scale total score). Furthermore, a statistically significantly greater proportion of the olanzapine-treated than risperidone-treated patients maintained their response at 28 weeks based on Kaplan-Meier survival curves. The incidence of extrapyramidal side effects, hyperprolactinemia, and sexual dysfunction was statistically significantly lower in olanzapine-treated than risperidone-treated patients. In addition, statistically significantly fewer adverse events were reported by olanzapine-treated patients than by their risperidone-treated counterparts. Thus, the differential preclinical profiles of these two drugs were also evident in a controlled, clinical investigation. Olanzapine seemed to have a risk-versus-benefit advantage. The objective of this study is to compare olanzapine with ziprasidone therapy in patients with schizophrenia or schizoaffective disorder and experiencing depressive symptoms.
                This randomized, double-blind, 24-week, fixed-dose study compared olanzapine (n = 202) and ziprasidone (n = 192) for patients with schizophrenia or schizoaffective disorder and experiencing prominent depressive symptoms. Outcome measures included change in Calgary Depression Scale for Schizophrenia (CDSS) score from baseline to 8 weeks (primary outcome) and changes in CDSS, Montgomery-Asberg Depression Rating Scales, Positive and Negative Syndrome Scale, and Global Assessment of Functioning (GAF) scores for 24 weeks. Statistical analyses included mixed-effects model repeated measures (primary analysis) and change from baseline to last observation carried forward (LOCF).
                At baseline, patients had moderate depressive symptoms (mean Montgomery-Asberg Depression Rating Scales total score, 27.3). For 8 weeks, patients treated with olanzapine or ziprasidone had significant improvements on CDSS. Treatment group differences were not statistically significant (P = 0.493, mixed-effects model repeated measures; P = 0.497, LOCF). For 24 weeks, olanzapine-treated patients showed significantly greater improvements in depressive symptoms (results varied by depression measure and statistical approach) and GAF (P < 0.017, LOCF). A significantly higher proportion of olanzapine-treated patients completed the study (44.6% vs 29.7%; P = 0.003) and remained longer on medication (median, 163 vs 73 days, P < 0.001), compared with ziprasidone-treated patients. Olanzapine-treated patients experienced significantly (P < 0.05) greater increases in triglycerides, HgbA1c, and weight.
                For 24 weeks, olanzapine-treated patients had greater and more sustained participation in treatment, during which time significantly greater improvements were observed in depressive symptoms and GAF scores, along with increases in weight and certain metabolic parameters as compared with ziprasidone-treated patients. This study compared the effects of olanzapine (OLZ) with those of quetiapine (QUE) for improving negative symptoms in patients diagnosed with schizophrenia or schizoaffective disorder who had prominent negative symptoms and marked deficits in social or occupational functioning. In this 6-month, multicenter, double-blind clinical trial, patients were randomized to treatment with OLZ (n = 171, 10-20 mg/d) or QUE (n = 175, 300-700 mg/d). Patients were treated at community mental health centers and assigned case managers who developed individualized psychosocial treatment plans. The primary efficacy measure was the reduction in negative symptoms using the Scale for the Assessment of Negative Symptoms. Secondary measures assessed changes in functioning, psychopathology, and treatment tolerability. Treatment with OLZ or QUE led to a significant reduction in negative symptoms, with no between-group difference (P = 0.09). Both treatment groups also showed significant improvement on most efficacy measures. Olanzapine-treated patients showed significantly greater improvement on positive symptoms and on several measures of functioning including Global Assessment of Functioning Scale, Quality of Life Instrumental Role domain, and level of effort in psychosocial or occupational rehabilitation programs. Significantly more OLZ-treated patients completed the study (52.6% OLZ, 37.7% QUE, P = 0.007). Treatment differences in safety were relatively small and not thought to be clinically relevant. Patients with schizophrenia who manifest prominent negative symptoms and marked functional deficits demonstrated significant improvement in negative symptoms after treatment with OLZ or QUE. Greater improvement in positive symptoms and a greater study completion rate may hold relevance to enhanced functional outcomes observed after OLZ therapy. This article compares the efficacy of olanzapine and risperidone for positive and negative symptoms using an 18-week, randomized, double-blind, crossover design. The hypotheses were that olanzapine would be more efficacious for treating negative symptoms, and that risperidone would be superior in treating positive symptoms. Positive and negative symptoms scores improved throughout treatment, regardless of medication type. Differences between the medications were found for negative and general psychopathology rating scales. Overall, olanzapine led to greater improvements in negative symptoms than did risperidone. When each scale was analyzed individually, greater improvements were found for olanzapine on Positive and Negative Symptoms Scale (PANSS) General,PANSS total, and Scale for the Assessment of Negative Symptoms (SANS)attention. A nearly significant trend favoring olanzapine was found for the Calgary Depression Scale. Several negative symptom subscales followed a nonsignificant trend toward olanzapine being more efficacious than risperidone.Thus, there was a very consistent pattern of greater efficacy for olanzapine, particularly for negative symptoms. Despite the small number of subjects, this study shows the potential of a within-subject design to elucidate differences in efficacy. 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. Weight gain is a common adverse effect associated with the use of most antipsychotic drugs. Leptin has been reported to be associated with antipsychotic-induced weight gain. Previous studies have demonstrated a relationship between the atypical antipsychotics clozapine and olanzapine and serum leptin levels. We planned to comparatively investigate the effects of the atypical antipsychotics quetiapine, olanzapine, risperidone, and clozapine on leptin and triglyceride levels and weight gain.
                The study population comprised 56 patients with DSM-IV schizophrenia, who were divided into 4 treatment groups: quetiapine (N = 14), olanzapine (N = 14), risperidone (N = 14), or clozapine (N = 14) monotherapy, and a control group of 11 patients receiving no psychopharmacologic treatment. The patients were evaluated at baseline and at the sixth week according to the Positive and Negative Syndrome Scale (PANSS), body mass index (BMI), weight, and fasting serum leptin and triglyceride levels. Data were gathered in 2001 and 2002.
                Olanzapine and clozapine caused a marked increase in weight and serum triglyceride and leptin levels, though increases in these variables were modest in the patients receiving quetiapine and minimal in those receiving risperidone. There were positive correlations between serum leptin levels and BMI and triglyceride levels. Clinical efficacy, as indicated by decrease in total PANSS scores, was associated with leptin levels in all atypical antipsychotic groups.
                Our results suggest that leptin may be associated with olanzapine- and clozapine-induced weight gain and that quetiapine appears to have modest influence and risperidone appears to have minimal influence on leptin and triglyceride levels and weight gain compared with olanzapine and clozapine. While the usefulness of atypical antipsychotics for improving cognitive function has been proven, the specific effects of these drugs are still unknown. The objective of this study was to investigate changes of the immediate memory and verbal working memory in patients with chronic schizophrenia after switching to one of four atypical antipsychotic agents and cessation of anticholinergic therapy. The subjects included 77 schizophrenic patients who were treated primarily with typical antipsychotics. Treatment was randomly switched to one of four atypical antipsychotics (olanzapine, perospirone, quetiapine, or risperidone) over a 4-week period, and then the drug was continued for another 4 weeks while the patient was taken off anticholinergics. The immediate memory, verbal working memory, and symptoms were evaluated. Significant improvement of immediate memory was only seen with olanzapine and risperidone. Improvement was also seen after switching to perospirone, but immediate memory worsened after treatment with this anticholinergic drug was discontinued. Deterioration was seen after switching to quetiapine, but immediate memory improved and reached the previous level after treatment with anticholinergic drugs was discontinued. Significant improvement of the verbal working memory was only seen during risperidone administration. The findings suggested that switching chronic schizophrenic patients to atypical antipsychotics can improve both the immediate memory and the verbal working memory when risperidone is used, while improvement of immediate memory can be expected with olanzapine. From the viewpoint of improving the memory, quetiapine should not be administered concomitantly with anticholinergic drugs, and caution should be exercised when discontinuing anticholinergic drugs during treatment with perospirone. The efficacy and safety of olanzapine were compared with those of ziprasidone.
                This was a multicenter randomized, double-blind, parallel-group, 28-week study of patients with schizophrenia. Patients were randomly assigned to treatment with 10-20 mg/day of olanzapine or 80-160 mg/day of ziprasidone. The primary efficacy measure was the Positive and Negative Syndrome Scale total score. Secondary efficacy and safety measures included Positive and Negative Syndrome Scale subscales as well as mood, quality of life, and extrapyramidal symptom scales. Safety was evaluated by recording treatment-emergent adverse events and measuring vital signs and weight.
                The study was completed by significantly more olanzapine-treated patients (165 of 277, 59.6%) than ziprasidone-treated patients (115 of 271, 42.4%). At 28 weeks, the olanzapine-treated patients showed significantly more improvement than the ziprasidone-treated patients on the Positive and Negative Syndrome Scale overall scale and all subscales and on the Clinical Global Impression ratings of severity of illness and improvement. The responder rate was higher for olanzapine than for ziprasidone. Extrapyramidal symptoms were not significantly different between groups in change-to-endpoint analyses, but results favored olanzapine on baseline-to-maximum changes. Weight change was significantly greater with olanzapine (mean=3.06 kg, SD=6.87) than with ziprasidone (mean=-1.12 kg, SD=4.70). Fasting lipid profiles were significantly superior in the ziprasidone group; there was no significant difference in fasting glucose level.
                Olanzapine treatment resulted in significantly greater psychopathology improvement and higher response and completion rates than ziprasidone treatment, while ziprasidone was superior for weight change and lipid profile. This pilot study was undertaken to estimate the acute antipsychotic effect size and side effect propensity of risperidone and olanzapine in the pediatric population, in comparison to haloperidol, a conventional antipsychotic with established efficacy. Risperidone and olanzapine are widely used as first-line treatments to ameliorate psychotic symptoms in youth, but their abilities to specifically treat children and adolescents presenting due to psychotic symptoms have not been rigorously studied. Subjects, selected because of prominent positive psychotic symptoms, were randomly assigned to double-blind, parallel treatment with risperidone, olanzapine, or haloperidol for 8 weeks. The primary outcome was reduction in the Brief Psychiatric Rating Scale for Children total score from baseline to termination. An exploratory, descriptive analysis was done to compare the three treatments. A total of 50 patients, 8-19 years, participated. All treatments reduced symptoms significantly with p-values (corrected for multiple comparisons) of 0.0018 for each of the atypical agents and 0.012 for haloperidol. In all, 88% of subjects treated with olanzapine, 74% treated with risperidone, and 53% treated with haloperidol met response criteria. The primary side effects observed in all patients were mild to moderate sedation, extrapyramidal symptoms, and weight gain. Risperidone and olanzapine acutely reduced psychotic symptoms in this pediatric sample. Exploratory comparisons indicate the magnitude of the antipsychotic response with these atypical agents is comparable to that observed with haloperidol. However, youth treated with risperidone and olanzapine experienced weight gain and extrapyramidal effects that appear more prevalent and severe than reported in adults. Negative symptoms are considered the most debilitating and refractory aspect of schizophrenia, being associated with poor social, occupational and global outcomes. Conventional antipsychotics have limited efficacy against these symptoms and poor tolerability profiles. Atypical antipsychotics are an alternative treatment, and this 12-week, randomised, flexibly dosed study compared the efficacy, safety and tolerability of quetiapine and olanzapine in this regard. Of the 40 patients who entered the study (32 male; 8 female), 19 were randomised to quetiapine (mean dose 637 mg/day, mean treatment duration 80 days) and 21 to olanzapine (mean dose 16 mg/day, mean treatment duration 78 days). Quetiapine and olanzapine were similarly effective: in each treatment group significant improvements at Week 12 were observed for negative symptom scores on the SANS and the PANSS, and for subscale scores of affective flattening and alogia on the SANS. Both treatments were well tolerated in this patient population, with no worsening of extrapyramidal symptoms in either case. Anxiety and insomnia were the most common adverse events (> or =7% of patients in each group), but were not drug-related. Although this is a small study with limited power, the results support the effectiveness of quetiapine and olanzapine in treating the negative symptoms of schizophrenia.
                Copyright 2006 John Wiley & Sons, Ltd. The authors compared 4-month treatment outcomes for olanzapine versus risperidone in patients with first-episode schizophrenia spectrum disorders.
                One hundred twelve subjects (70% male; mean age=23.3 years [SD = 5.1]) with first-episode schizophrenia (75%), schizophreniform disorder (17%), or schizoaffective disorder (8%) were randomly assigned to treatment with olanzapine (2.5-20 mg/day) or risperidone (1-6 mg/day).
                Response rates did not significantly differ between olanzapine (43.7%, 95% CI=28.8%-58.6%) and risperidone (54.3%, 95% CI=39.9%-68.7%). Among those responding to treatment, more subjects in the olanzapine group (40.9%, 95% CI=16.8%-65.0%) than in the risperidone group (18.9%, 95% CI=0%-39.2%) had subsequent ratings not meeting response criteria. Negative symptom outcomes and measures of parkinsonism and akathisia did not differ between medications. Extrapyramidal symptom severity scores were 1.4 (95% CI=1.2-1.6) with risperidone and 1.2 (95% CI=1.0-1.4) with olanzapine. Significantly more weight gain occurred with olanzapine than with risperidone: the increase in weight at 4 months relative to baseline weight was 17.3% (95% CI=14.2%-20.5%) with olanzapine and 11.3% (95% CI=8.4%-14.3%) with risperidone. Body mass index at baseline and at 4 months was 24.3 (95% CI=22.8-25.7) versus 28.2 (95% CI=26.7-29.7) with olanzapine and 23.9 (95% CI=22.5-25.3) versus 26.7 (95% CI=25.2-28.2) with risperidone.
                Clinical outcomes with risperidone were equal to those with olanzapine, and response may be more stable. Olanzapine may have an advantage for motor side effects. Both medications caused substantial rapid weight gain, but weight gain was greater with olanzapine. This 52-week randomized, double-blind, flexible-dose, multicenter study evaluated the overall effectiveness (as measured by treatment discontinuation rates) of olanzapine, quetiapine, and risperidone in patients early in the course of psychotic illness.
                Patients were randomly assigned to treatment with olanzapine (2.5-20 mg/day), quetiapine (100-800 mg/day), or risperidone (0.5-4 mg/day) administered in twice-daily doses. Statistical analyses tested for noninferiority in all-cause treatment discontinuation rates up to 52 weeks (primary outcome measure) based on a prespecified noninferiority margin of 20%.
                A total of 400 patients were randomly assigned to treatment with olanzapine (N=133), quetiapine (N=134), or risperidone (N=133). The mean modal prescribed daily doses were 11.7 mg for olanzapine, 506 mg for quetiapine, and 2.4 mg for risperidone. At week 52, all-cause treatment discontinuation rates were 68.4%, 70.9%, and 71.4% for olanzapine, quetiapine, and risperidone, respectively. Reductions in total score on the Positive and Negative Syndrome Scale (PANSS) were similar for the three treatment groups, but reductions in PANSS positive subscale scores were greater in the olanzapine group (at 12 weeks and at 52 weeks or withdrawal from study) and the risperidone group (at 12 weeks). The most common elicited adverse events for olanzapine were drowsiness (53%), weight gain (51%), and insomnia (38%); for quetiapine, drowsiness (58%), increased sleep hours (42%), and weight gain (40%); and for risperidone, drowsiness (50%), menstrual irregularities in women (47%), and weight gain (41%).
                Olanzapine, quetiapine, and risperidone demonstrated comparable effectiveness in early-psychosis patients, as indicated by similar rates of all-cause treatment discontinuation. The treatment of schizophrenic patients who fail to respond to adequate trials of neuroleptic drugs is a major challenge. Clozapine has been one treatment option; however, it is not universally effective and is limited in its use by safety concerns. With the introduction of newer agents, their performance relative to clozapine is of great clinical interest.
                The primary objective of this study was to evaluate the efficacy and safety of olanzapine versus clozapine among treatment resistant DSM-IV schizophrenic patients. The study was primarily designed to demonstrate the "noninferiority" of olanzapine compared to clozapine after 18 weeks of double-blind treatment. Conclusions were based on the one-sided lower 95% confidence limit about the treatment effect observed from the primary efficacy variable (Positive and Negative Syndrome Scale [PANSS] Total).
                Mean changes from baseline to end point in PANSS Total score, using a last observation carried forward technique, showed that both agents were comparably effective in neuroleptic resistant patients, i.e., demonstrated the "noninferiority" of olanzapine when compared to clozapine. Overall, significantly fewer olanzapine-treated patients (4%) discontinued for an adverse event than their clozapine-treated (14%) counterparts (p =.022). Among spontaneously reported adverse events, increased salivation, constipation, dizziness, and nausea were reported significantly more often among clozapine-treated patients, whereas only dry mouth was reported more often among olanzapine-treated patients.
                Olanzapine was demonstrated to be noninferior to clozapine and better tolerated among resistant schizophrenic patients clinically eligible for treatment with clozapine. Clozapine has been the gold standard for treatment of patients with refractory schizophrenia but is associated with serious safety liabilities. This has prompted the search for therapeutic alternatives for treatment-resistant schizophrenia. The objective of this study was to compare the efficacy and safety of olanzapine versus clozapine in schizophrenic patients who failed to respond adequately to antipsychotic medication or who experienced intolerable adverse effects associated with the medication. This 18-week, randomized, double-blind, parallel study compared treatment with either olanzapine (5-25 mg/day, n=75) or clozapine (100-500 mg/day, n=72) in patients with schizophrenia who were nonresponsive to, or intolerant of, standard acceptable antipsychotic therapy. At the 18-week endpoint, no statistically significant differences were found between olanzapine and clozapine in any efficacy measure used: Positive and Negative Syndrome Scale (PANSS) total, positive, negative, or general psychopathology or Clinical Global Impression severity (CGI-S). Response rates based on the criteria of Kane et al. [Arch. Gen. Psychiatry 45 (1988) 789] were also not significantly different between olanzapine-treated (57.9%) and clozapine-treated patients (60.8%). There were no significant differences in measurements of extrapyramidal symptoms or electrocardiography, and no clinically and statistically significant changes were seen in vital signs or laboratory measures in either group. Both treatments were well tolerated. Olanzapine demonstrated similar efficacy to clozapine in patients who had failed previous treatment because of lack of efficacy (treatment resistance) or intolerable side effects (treatment intolerance). Olanzapine therefore presents a safe alternative in the treatment of refractory schizophrenia. 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.
Olanzapine may be a somewhat more efficacious drug than some other second generation antipsychotic drugs. This small superiority in efficacy needs to be weighed against a larger weight gain and associated metabolic problems than most other second generation antipsychotic drugs, except clozapine. These conclusions are tentative due to the large number of people leaving the studies early which possibly limits the validity of the findings. Further large, well-designed trials are necessary to establish the relative effects of different second generation antipsychotic drugs.