A comparison of the relative safety, efficacy, and tolerability of quetiapine and risperidone in outpatients with schizophrenia and other psychotic disorders: the quetiapine experience with safety and tolerability (QUEST) study. Quetiapine has equivalent efficacy and superior tolerability to risperidone in the treatment of schizophrenia with predominantly negative symptoms. Risperidone, quetiapine, and fluphenazine in the treatment of patients with therapy-refractory schizophrenia. Comparison of quetiapine and risperidone in the treatment of schizophrenia: A randomized, double-blind, flexible-dose, 8-week study. Cognition, functioning and quality of life in schizophrenia treatment: results of a one-year randomized controlled trial of olanzapine and quetiapine. Effectiveness of olanzapine, quetiapine, risperidone, and ziprasidone in patients with chronic schizophrenia following discontinuation of a previous atypical antipsychotic. Effectiveness of clozapine versus olanzapine, quetiapine, and risperidone in patients with chronic schizophrenia who did not respond to prior atypical antipsychotic treatment. A double-blind comparison of risperidone, quetiapine and placebo in patients with schizophrenia experiencing an acute exacerbation requiring hospitalization. The impact upon extra-pyramidal side effects, clinical symptoms and quality of life of a switch from conventional to atypical antipsychotics (risperidone or olanzapine) in elderly patients with schizophrenia.
The few published direct comparative studies of the tolerability and efficacy of atypical antipsychotic agents were performed in relatively homogeneous populations that may not be typical of patients seen in clinical practice.
                The Quetiapine Experience with Safety and Tolerability (QUEST) study compared the relative safety, tolerability, and efficacy of quetiapine and risperidone in outpatients with a broad range of psychotic symptoms.
                This was a multicenter, 4-month, open-label, randomized clinical trial. Patients were randomized in a 3:1 ratio to receive quetiapine or risperidone. Doses were adjusted to maximize efficacy and to minimize adverse events. Extrapyramidal symptoms (EPS) were assessed with an EPS checklist; adverse events were recorded. Efficacy was assessed using the Clinical Global Impression (CGI) scale, Positive and Negative Symptom Scale (PANSS), and Hamilton Rating Scale for Depression (HAM-D).
                A total of 728 patients were randomized, 553 to quetiapine and 175 to risperidone. Mean prescribed doses over the study period were 253.9 mg/d quetiapine and 4.4 mg/d risperidone. At the end of 4 months, EPS declined in both treatment groups, but quetiapine-treated patients were significantly less likely to require dose adjustment or concurrent anti-EPS medication (P < 0.001). The most common adverse events in the quetiapine and risperidone groups were somnolence (31.3% and 15.4%, respectively), dry mouth (14.5% and 6.9%), and dizziness (12.7% and 6.9%). Overall, tolerance to side effects with the 2 drugs, measured by dropout rates, was comparable. At each visit, a higher percentage of quetiapine-treated patients showed improvement on the CGI scale, but there were no significant between-group differences on the PANSS. At end point, quetiapine-treated patients had significantly lower HAM-D scores (P = 0.028).
                The results of this study suggest that quetiapine is as effective as risperidone for the treatment of psychotic symptoms, is more effective for depressive symptoms, may have a more favorable EPS profile, and has comparable overall tolerability. Atypical antipsychotics are generally thought to be more effective than conventional agents in treating the negative symptoms of schizophrenia; however, there have been few direct comparisons among atypicals. We therefore investigated risperidone and quetiapine with respect to their efficacy against negative symptoms in a 12-week,double-blind, comparative pilot study involving 44 patients with schizophrenia with predominantly negative symptoms, as defined by Positive and Negative Syndrome Scale (PANSS) scores. Other efficacy measures included the Scale for the Assessment of Negative Symptoms (SANS) and the Clinical Global Impression (CGI) rating scale. Antipsychotic tolerability was assessed using the Simpson-Angus Scale (SAS) and various laboratory measures. Mean doses were 589.7 mg/ day quetiapine and 4.9 mg/day risperidone (observed cases). Both antipsychotics produced significant decreases in PANSS total, positive and negative scores, and SANS scores. Patients receiving risperidone were significantly more likely to experience extrapyramidal symptoms (EPS) [p <0.05], or to require anticholinergic medication (p <0.05), and had significantly higher prolactin levels (p <0.001) than quetiapine-treated patients. In conclusion, there is no significant difference in efficacy between quetiapine and risperidone in alleviating the negative symptoms of schizophrenia. Quetiapine is also well tolerated, with a lower incidence of EPS and prolactin increase than risperidone. This 12-week, double-blind study evaluated the effectiveness of risperidone (4 mg/day), quetiapine (400 mg/day), or fluphenazine (12.5 mg/day) in a stringently defined treatment-resistant population of people with schizophrenia. No differences were noted in total Brief Psychiatric Rating Scale (BPRS) or Clinical Global Impression scores among the drug groups (n = 38). More subjects tended to complete the study on risperidone (69%) or quetiapine (58%) than those treated with fluphenazine (31%; P value not significant). Eighty-nine percent of those who discontinued on fluphenazine (8 of 9) were due to lack of efficacy. Discontinuation due to adverse effects was low, with only 2 subjects (both on quetiapine) stopping due to side effects. Three of 13 risperidone-treated subjects (23%) and 3 of 12 quetiapine-treated subjects (25%) met response criteria (decrease of 20% of total BPRS score), whereas 2 of 13 subjects (15%) responded to fluphenazine. Side effect occurrence was similar among drug groups and EPS ratings on the Simpson Angus Scale improved in all drug groups (quetiapine, 1.64; risperidone, 1.30; fluphenazine, 0.69; P value not significant). Despite the newer class of second-generation antipsychotic medications, this treatment-resistant population remains difficult to treat. Many people have only minimal to modest improvements with antipsychotic treatment and most continue to have residual psychotic symptoms. Treatment with first- and second-generation antipsychotics may demonstrate similar efficacy; however, patients treated with second-generation antipsychotics may be more likely to adhere to treatment. To compare the efficacy and tolerability of quetiapine and risperidone in the treatment of schizophrenia.
                In this 8-week, double-blind, multicenter, flexible-dose study, patients with schizophrenia (DSM-IV diagnosis) were randomly assigned to quetiapine (200-800 mg/day) or risperidone (2-8 mg/day). The primary hypothesis was that quetiapine was not inferior to risperidone. The primary efficacy measure was change from baseline in Positive and Negative Syndrome Scale (PANSS) total scores; secondary outcomes included response rate (> or = 40% reduction in PANSS scores), Clinical Global Impression-Change (CGI-C), and cognitive and social functioning. Tolerability assessments included treatment-emergent adverse events and changes in weight, glucose, and prolactin. Patients were recruited from June 2001 to September 2002.
                Patients (N = 673) were randomly assigned to quetiapine (N = 338, mean dose = 525 mg/day) or risperidone (N = 335, mean dose = 5.2 mg/day). The primary analysis demonstrated noninferiority between treatments (p < .05). Improvements with both treatments were comparable on PANSS total, negative, and general psychopathology subscales. Risperidone-treated patients had a significantly (p = .03) greater improvement in PANSS positive subscale score among all patients, but not among completers. Improvements in PANSS response rates, CGI-C, and cognitive function were similar between treatment groups. Changes in serum glucose and weight were minimal and comparable. The rate of extrapyramidal symptom (EPS)-related adverse events was significantly higher with risperidone (22%) than quetiapine (13%; p < .01). Somnolence was more common with quetiapine (26%) than risperidone (20%; p = .04). Prolactin levels increased with risperidone (+35.5 ng/mL), but decreased with quetiapine (-11.5 ng/mL; p < .001).
                Quetiapine and risperidone had broadly comparable clinical efficacy. Both agents improved cognitive and social functioning, and neither had a clinically significant effect on weight or glucose. Somnolence was more common with quetiapine; EPS and elevated prolactin rates were significantly higher with risperidone. 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. 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. 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. This study compared the effects of atypical antipsychotics (risperidone or quetiapine) with placebo and with each other in recently exacerbated patients with schizophrenia requiring hospitalization.
                This international, randomized, double-blind study included a 2-week monotherapy phase followed by a 4-week additive therapy phase. Recently exacerbated patients with schizophrenia or schizoaffective disorder (DSM-IV) were randomized (2:2:1) to risperidone (n = 153), quetiapine (n = 156), or placebo (n = 73). Target doses were 4 or 6 mg/day of risperidone and 400 or 600 mg/day of quetiapine by day 5, with the ability to increase to 600 or 800 mg/day of quetiapine on day 8. The main outcome measures were the total Positive and Negative Syndrome Scale (PANSS) and need for additional psychotropic medications.
                Monotherapy Phase: The combined atypical antipsychotic group (n = 308) reached borderline superiority to placebo (n = 71) at the 2-week endpoint on mean change in total PANSS score (-24.1 +/- 1.2 and -20.2 +/- 2.0, respectively; p = 0.067). The change in the atypical group was driven by the improvement with risperidone (-27.7 +/- 1.5 vs. -20.2 +/- 2.0 with placebo, p < 0.01; and vs. -20.5 +/- 1.5 with quetiapine, p < 0.01); the improvement with quetiapine was similar to placebo, p = 0.879. Results were similar on other efficacy endpoints. Additive Therapy Phase: Additional psychotropics were prescribed to fewer (p < 0.01) risperidone (36%) than quetiapine (53%) or placebo patients (59%). The overall discontinuation rate was 18%, 26%, and 38%, respectively. Risperidone, compared with placebo, was associated with more parkinsonism, akathisia, plasma prolactin changes, and weight gain; while quetiapine was associated with more somnolence, sedation, dizziness, constipation, tachycardia, thyroid dysregulation, and weight gain.
                While the combined atypical antipsychotic group did not experience greater improvements than the placebo group, risperidone, but not quetiapine, was significantly superior in all measured domains to placebo in the management of recently exacerbated hospitalized patients with schizophrenia or schizoaffective disorder, with no unexpected tolerability findings. Atypical antipsychotics are commonly used in the management of schizophrenia in late life with evidence suggesting they induce lower rates of motor disturbance, but have similar efficacy to conventional antipsychotics. Trials in the elderly have been either retrospective, small, of short duration or of a single-arm design.
                To demonstrate the effects upon motor side-effects, efficacy, safety and quality of life (QOL) of switching elderly patients with schizophrenia from conventional antipsychotics to olanzapine or risperidone.
                Elderly patients with schizophrenia were randomly allocated to olanzapine or risperidone and followed through an open-label crossover period. Between and within group intention to treat analyses were conducted.
                66 patients were randomised (mean age 69.6 [SD +/- 6.2]). Four (11.8%) patients on olanzapine and 8 (26.7%) patients on risperidone failed to complete the crossover because of treatment failure [Odds Ratio (OR) = 2.73[0.73-10.2] p = 0.14]. The mean doses upon completion of switching in each arm were 9.9 mg (SD = 4.2) and 1.7 mg (SD = 1.2) for olanzapine and risperidone respectively. In both arms there was improvement in Parkinsonism, though only olanzapine was associated with a reduction in dyskinetic symptoms. The Brief Psychiatric Rating Scale, Scale for the assessment of Negative Symptoms and Montgomery and Asberg Depression Rating Scale scores all improved through the crossover period in both arms with no between group differences. Treatment with olanzapine was associated with a better response over risperidone on the psychological domain of the World Health Organisation-Quality Of Life [Brief] (WHO-QOL-BREF) scale ( p = 0.02). Patients in the olanzapine arm also demonstrated improvement from baseline in the WHO-QOL-BREF physical, psychological and health satisfaction domains, but risperidone had no effect on any Quality of Life (QOL) measure.
                After switching from a conventional antipsychotic, olanzapine and risperidone were associated with improvement in core symptoms of schizophrenia and motor side effects. Subjects switched to olanzapine were more likely to complete the switching process and show an improvement in psychological QOL.
                Copyright 2003 John Wiley & Sons, Ltd.
Quetiapine is effective for the treatment of schizophrenia, but it is not much different from first-generation antipsychotics and risperidone with respect to treatment withdrawal and efficacy. In comparison to first-generation antipsychotics and risperidone, quetiapine has a lower risk of movement disorders but higher risks of dizziness, dry mouth and sleepiness. More clearly reported pragmatic randomised controlled trials should be carried out to determine its position in everyday clinical practice. Studies of medium and long-term effects, including cost-effectiveness, quality of life, social functioning and service utilisation, in comparison with the effects of typical and atypical antipsychotics should be priority areas.