Quetiapine versus olanzapine for the treatment of negative symptoms in patients with schizophrenia. Quetiapine has equivalent efficacy and superior tolerability to risperidone in the treatment of schizophrenia with predominantly negative symptoms. Quetiapine is not associated with increase in prolactin secretion in contrast to haloperidol. Nizatidine for the treatment of patients with quetiapine-induced weight gain. A multicentre, double-blind, randomized comparison of quetiapine (ICI 204,636, 'Seroquel') and haloperidol in schizophrenia. A comparison of quetiapine and chlorpromazine in the treatment of schizophrenia. Quetiapine in patients with schizophrenia. A high- and low-dose double-blind comparison with placebo. Seroquel Study Group. A comparison of the effects of quetiapine ('seroquel') and haloperidol in schizophrenic patients with a history of and a demonstrated, partial response to conventional antipsychotic treatment. PRIZE Study Group. Differential effect of quetiapine on depressive symptoms in patients with partially responsive schizophrenia.
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. 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. Typical antipsychotic drugs frequently cause hyperprolactinemia and even galactorrhea. In addition, these side effects may result in noncompliance with antipsychotic treatment. Capacity to avoid hyperprolactinemia has been accepted as one atypical criterion. The aim of the present study was to compare effects of haloperidol, the most commonly used antipsychotic, and quetiapine, a novel antipsychotic agent used in Turkey, on serum prolactin (PRL) levels.
                The study consisted of 35 females diagnosed with schizophrenia according to the Diagnostic and Statistical Manual of Mental Disorders, 4(th) ed. (DSM-IV). Thirty-five patients in a drug-free period for at least 2 weeks were included to randomized quetiapine (n = 18) and haloperidol (n = 17) treatment group. All patients were assessed by Brief psychiatric rating scale (BPRS), Positive and negative syndrome scale (PANSS), and Extrapyramidal symptoms rating scale (ESRS). PRL levels were measured both at the beginning and at the sixth week of the study.
                Both treatment groups exhibited significant improvements in clinical signs as evaluated by BPRS and PANSS. While there was no significant difference in PRL level between groups at the beginning of the study, control prolactin (PRL) levels were significantly lower in quetiapine compared to haloperidol group. While no quetiapine group patients exhibited galactorrhea, we observed that two patients from the haloperidol group had galactorrhea related to hyperprolactinemia.
                The present study revealed that quetiapine is not associated with increase in PRL secretion in contrast to the conventional antipsychotic haloperidol. It has been reported that nizatidine may reduce weight gain in schizophrenic patients on olanzapine treatment. Leptin has been reported to be associated with antipsychotic-induced weight gain. Thus, the purpose of the study was to evaluate whether nizatidine might be useful for the treatment of quetiapine-induced weight gain. Among the patients on the quetiapine monotherapy, 47 participated in the study for the two and half months of the open-label screening period. However, 28 patients who gained considerable weight in this period entered the 8-week, double-blind and placebo-controlled phase. These patients were randomly divided into two groups; quetiapine plus nizatidine (group I) and quetiapine plus placebo (group II) for the 8-week double-blind phase. The patients were evaluated at the baseline and at week 8 with respect to the positive and negative syndrome scale, body mass index, weight and serum leptin levels. The mean weight and leptin levels exhibited modest increases in both groups for the open-label screening period. In the double-blind period, in group I, a minimal, but not statistically significant, decrease in weight was observed, with a mean of 1.0 +/- 0.6 kg. The weight increased in group II. The leptin levels decreased by a mean of 0.6 +/- 0.6 ng/ml in group I, and increased by 1.0 +/- 0.9 ng/ml in group II. At evaluation at week 8, a trend toward statistical significance in the mean serum leptin levels between groups was detected. The results suggest that nizatidine treatment may stop but not reduce the weight gain and is correlated with leptin levels in patients with schizophrenia on quetiapine treatment.
                Copyright 2003 John Wiley & Sons, Ltd. Quetiapine (ICI 204,636, 'Seroquel') is a new atypical antipsychotic agent with a similar binding profile to the original atypical antipsychotic, clozapine. Its clinical efficacy has already been demonstrated at multiple fixed doses (150-750 mg/day) and has been suggested to be comparable with haloperidol (12 mg/day).
                This international, 6-week, multicentre, double-blind, randomized, parallel-group trial compared quetiapine with haloperidol (455 mg and 8 mg mean total daily doses, respectively) in 448 hospitalized patients with acute exacerbation of chronic or subchronic schizophrenia (DSM-III-R), in order to establish their equivalence in terms of efficacy, and the nature of their tolerability profiles, especially in terms of extrapyramidal symptoms (EPS) and serum prolactin levels.
                Both quetiapine and haloperidol produced a clear reduction in the Positive and Negative Syndrome Scale (PANSS) scores and Clinical Global Impression (CGI) Severity of Illness and Global Improvement scores. At day 42, the PANSS total score was reduced by -18.7+/-1.63 in the quetiapine group, and -22.1+/-1.63 in the haloperidol group (P = 0.13, between-treatment). Quetiapine was better tolerated than haloperidol in terms of EPS as demonstrated by the significant differences in the Simpson Scale and Abnormal Involuntary Movement Scale scores (P < 0.05). Although patients in both groups had elevated serum prolactin concentrations at baseline, mean serum prolactin concentration decreased (by 16.5 microg/l) in quetiapine-treated patients, yet increased (by 5.9 microg/l) in patients treated with haloperidol.
                Quetiapine is an effective and well tolerated antipsychotic of comparable efficacy to haloperidol and lacks the latter compound's effect on prolactin and EPS. A 6-week, double-blind, randomized, multicentre, parallel-group study was conducted to compare the efficacy of quetiapine ('Seroquel') (n=101) with that of chlorpromazine (n=100) in hospitalized patients with acute exacerbation of subchronic or chronic schizophrenia, or schizophreniform disorder. The tolerabilities of the two treatments were also compared. The mean daily doses of quetiapine and chlorpromazine at the end of the study were 407 mg and 384 mg, respectively. Both treatments were effective in the treatment of positive and negative symptoms, with a trend towards superior efficacy for quetiapine. The quetiapine group had a lower incidence of adverse events than the chlorpromazine group, and a low incidence of treatment-emergent extrapyramidal symptoms. Quetiapine was not associated with a sustained increase in serum prolactin. These clinical data support the preclinical profile of quetiapine as an atypical antipsychotic agent. Quetiapine fumarate (Seroquel [ICI 204,636]) is an atypical dibenzothiazepine antipsychotic with a greater affinity for 5-hydroxytryptamine2 (5-HT2) receptors than for D2 dopamine receptors; its efficacy in patients with schizophrenia was shown in early phase 2 trials (maximum dose, 750 mg/d).
                In this multicenter, double-blind, placebo-controlled trial, 286 patients hospitalized with chronic or subchronic schizophrenia (DSM-III-R) were randomized to 6 weeks of treatment with high-dose quetiapine fumarate (< or = 750 mg/d), n = 96; low-dose quetiapine fumarate (< or = 250 mg/d), n = 94; or placebo, n = 96. The Brief Psychiatric Rating Scale (BPRS) and Clinical Global Impression Severity of Illness item scores were the primary efficacy variables. Secondary efficacy variables included the BPRS positive-symptom cluster score, the Modified Scale for the Assessment of Negative Symptoms summary score (United States only), and the total score from the negative scale of the Positive and Negative Syndrome Scale (Europe only). Scores were analyzed using an analysis of covariance for change from baseline at end point with last observations carried forward. The model included baseline score (covariate), center, and treatment. Extrapyramidal symptoms were assessed using the Simpson-Angus Scale and the Barnes Akathisia Scale; abnormal involuntary movements were assessed using the Abnormal Involuntary Movement Scale. Frequency distributions of grouped change-from-baseline scores were analyzed using chi 2 tests.
                Of 280 patients in whom the efficacy of quetiapine was evaluated, 159 (42% of those receiving high-dose treatment; 57%, low-dose treatment; and 59%, placebo) withdrew before trial completion, primarily because of treatment failure. Significant (P < .001, BPRS; P = .003, Clinical Global Impression Severity of Illness item; and P = .003, BPRS positive-symptom cluster) differences were identified between patients receiving high-dose quetiapine and placebo for both primary efficacy variables, with end point differences in the BPRS positive-symptom cluster score showing quetiapine's consistency in reducing positive symptoms. The reduction of negative symptoms was less consistent; high-dose quetiapine was superior on the Modified Scale for the Assessment of Negative Symptoms but not on the negative scale of the Positive and Negative Syndrome Scale. Quetiapine was well tolerated and did not induce extrapyramidal symptoms, sustained elevations of prolactin, or clinically significant changes in hematologic parameters.
                Quetiapine is an effective antipsychotic with a favorable safety profile. The optimum dose is probably greater than 250 mg/d. Quetiapine ('Seroquel') is a well-tolerated, novel, atypical antipsychotic with consistent efficacy in the treatment of schizophrenia. To date, no clinical studies have evaluated the effect of quetiapine in patients who only partially respond to conventional antipsychotics, yet this type of patient is most frequently seen by psychiatrists. Therefore, this international, multicentre, double-blind study was conducted to compare the efficacy and tolerability of 8 weeks' treatment of quetiapine 600 mg/day with haloperidol 20 mg/day in 288 patients who had a history of partial response to conventional antipsychotics and displayed a partial or no response to 1 month of fluphenazine (20 mg/day) treatment. Patients on quetiapine tended to have greater improvement than those on haloperidol in the primary efficacy measure, mean Positive and Negative Symptom Scale (PANSS) score, after 4 weeks' treatment (-9.05, -5.82, respectively, P = 0.061) and at study end (-11.50, -8.87, respectively, P = 0.234). Similarly, there was a trend towards patients on quetiapine demonstrating greater improvements in the secondary efficacy measures (Clinical Global Impression, PANSS subscale and Brief Psychiatric Rating Scale scores) [week 4 (baseline) to week 12 (end)], but the difference between treatments did not reach significance. Significantly more patients on quetiapine than on haloperidol showed a clinical response-patient response rates, defined as > 20% reduction in PANSS total score between weeks 4 and 12, were 52.2% for quetiapine and 38.0% for haloperidol (P = 0.043). Patients receiving quetiapine required less anticholinergic medication (P < 0.011), had greater reduction in extrapyramidal symptoms (EPS) (P = 0.005) and fewer treatment-emergent EPS-related adverse events compared to those on haloperidol (P < 0.001). Serum prolactin concentrations were elevated at the end of fluphenazine treatment in 73% of patients. Between weeks 4 and 12, elevated serum prolactin concentrations significantly decreased in quetiapine-treated patients compared to those receiving haloperidol (P < 0.001). At the end of quetiapine treatment, 83% of patients had normal prolactin levels while only 21% of patients receiving haloperidol were within the normal range. These results suggest that quetiapine may make a valuable contribution to the management of patients with a history of partial response to conventional antipsychotics. While atypical antipsychotics appear to be effective in reducing depressive symptoms in the acute phase of schizophrenia, little is known about their efficacy in patients with ongoing symptoms. The present study assessed whether quetiapine (Seroquel) is more effective than haloperidol in treating depressive symptoms in patients with persistent positive symptoms, and investigated whether this effect is independent, or secondary to, reductions in other symptoms such as positive, negative or extrapyramidal symptoms. Patients with schizophrenia and a history of partial refractoriness to conventional antipsychotics who had not responded to 4 weeks of fluphenazine treatment (20 mg/day) were randomized to receive either quetiapine (600 mg/day) or haloperidol (20 mg/day) for a further 8 weeks. Change in the Positive and Negative Syndrome Scale depression factor score from baseline to endpoint was calculated and path analyses were performed on data from 269 patients. Quetiapine produced a greater reduction in depressive scores than haloperidol (-1.60 versus -0.54; p = 0.006). The path analyses indicated that this was a direct effect on depressive symptoms. These findings extend the evidence for an antidepressant effect for the novel antipsychotics in schizophrenia, and suggest that this is not limited to acutely psychotic patients.
Quetiapine may not differ from typical antipsychotics in the treatment of positive symptoms and general psychopathology. There are no clear differences in terms of the treatment of negative symptoms. However, it causes fewer adverse effects in terms of abnormal ECG, extrapyramidal effects, abnormal prolactin levels and weight gain.