Quetiapine. A review of its use in the management of schizophrenia

Soluble interleukin-2 receptor levels correlated with positive symptoms during quetiapine treatment in schizophrenia-spectrum disorders

BACKGROUND

Some but not all antipsychotics have been shown to modulate plasma cytokine levels in schizophrenia patients. Thus far, the most consistent finding has been the increase in plasma levels of soluble interleukin (IL)-2 receptor (sIL-2R) associated with clozapine treatment. Quetiapine is a second-generation antipsychotic with a pharmacological profile similar to that of clozapine, but its immunomodulatory effects have not been investigated in schizophrenia yet. The purpose of this exploratory study was to examine the changes in plasma levels of sIL-2R in schizophrenia during quetiapine treatment and association with psychopathology.

METHODS

Participants were 29 schizophrenia-spectrum disorder patients (DSM-IV criteria), and 28 healthy controls. Patients had a comorbid substance use disorder (cannabis>alcohol>cocaine), since quetiapine is increasingly used in this population of dual diagnosis. No participant suffered from infection or overt inflammatory diseases. On baseline, patients taking mostly second-generation antipsychotics were switched to quetiapine for a 12-week open-label trial. Five patients were drop-outs. Mean dose of quetiapine for trial completers (n=24) was 466.6mg±227.3. Psychiatric variables were evaluated with the Positive and Negative Syndrome Scale and the Calgary Depression Scale for Schizophrenia. Plasma sIL-2R levels were assessed at baseline, weeks 6 and 12 in patients, and in healthy controls, using sandwich immunoassay. Plasma IL-6 and IL-1 receptor antagonist (IL-1RA) were measured for comparison purposes.

RESULTS

On baseline, plasma sIL-2R, IL-6 and IL-1RA levels were higher in dual-diagnosis patients, compared to controls. Plasma sIL-2R further increased after quetiapine treatment (p=0.037), while plasma IL-6 and IL-1RA did not change. Clinical improvements were observed in positive, negative and depressive symptoms, and substance abuse severity (all p<0.01). Interestingly, changes in sIL-2R levels during treatment were inversely correlated with changes in positive symptoms (r=-0.524; p=0.009). That is, increases in sIL-2R levels were associated with reductions in positive symptoms.

CONCLUSION

These data show that quetiapine elevates, like clozapine, sIL-2R levels in schizophrenia. Furthermore, the results suggest that sIL-2R alterations in schizophrenia rely on complex interplays between antipsychotics and the positive symptoms of the disorder. Future randomized controlled trials involving larger samples of schizophrenia patients are warranted to determine whether changes in plasma sIL-2R are quetiapine-related.

Clinical and demographic characteristics associated with postural instability in patients with schizophrenia

As people with schizophrenia grow older, prevention of falls in this older population has become a public health priority. It is therefore critically important to identify risk factors to effectively prevent falls. For this purpose, the degree of postural sway can serve as a convenient index of risk assessment. The objective of this study was to find clinical and demographic characteristics associated with postural instability. Inpatients and outpatients with schizophrenia or related psychosis were recruited at 2 hospitals in Japan. The clinical stabilometric platform, which measured a range of the trunk motion, and extrapyramidal side effects were evaluated between 9 and 11 A.M. Four hundred two subjects were enrolled (age: mean, 55.5 [SD, 14.4] years). A univariate general linear model showed that the use of antipsychotic drugs with a chlorpromazine equivalent of 10 or greater, being overweight, and inpatient treatment setting were associated with a greater degree of the range of postural sway. Another general linear model, including a subgroup of 300 subjects who did not present any extrapyramidal side effects, not only consolidated these findings, but also revealed a great degree of postural sway in older subjects. In addition, quetiapine was found to be associated with a greater range of postural sway among atypical antipsychotics. Schizophrenia patients generally showed a greater degree of postural instability, compared with the reference data of healthy people. These findings highlight truncal instability as a risk factor of falls in patients with schizophrenia, especially when they are overweight, old, and/or receiving antipsychotics with a chlorpromazine equivalent of 10 or greater, including quetiapine.

Patient adherence and efficacy of quetiapine treatment in schizophrenia: results of a multicentre, naturalistic 6-month follow-up study

The aim of the study was to evaluate the adherence and efficacy of quetiapine treatment in a 6-month, multicentre, noninterventional naturalistic design. Overall, 710 schizophrenia patients using quetiapine or who had switched to quetiapine were included. The continuation rate for quetiapine treatment during 6-month follow-up period was 69%. Adherence improved with each subsequent visit for continued patients, 92.9% at the second visit to 96.1% at the last. Treatment adherence was correlated to improvement of symptoms, though not significantly. Patients having lower clinical global impression severity scores at the beginning were twice as likely to improve compared with patients with higher clinical global impression scores. Schizophrenia patients with antisocial behaviour problems had two and a half times higher drop-out rates. In conclusion, this naturalistic study showed that adherence to quetiapine treatment was high, and treatment was effective in schizophrenia patients during long-term treatment. Remission of symptoms in schizophrenia is much related to severity of symptoms at baseline, treatment adherence and characteristics of patients such as antisocial behavioural patterns.

Safety and tolerability of once-daily extended release quetiapine fumarate in acute schizophrenia: pooled data from randomised, double-blind, placebo-controlled studies

INTRODUCTION

Extended release quetiapine fumarate (quetiapine XR) is a new formulation that allows once-daily dosing and a titration regimen that is simpler than that of immediate release quetiapine (quetiapine IR) and may potentially increase patients' adherence to their prescribed medication.

METHODS

The tolerability of quetiapine XR was examined in an analysis of pooled data from three Phase III, double-blind, placebo-controlled, randomised studies with quetiapine IR as a reference treatment.

RESULTS

The overall incidence of adverse events (AEs) was similar for quetiapine XR (69.5%) and quetiapine IR (72.5%). Most AEs were mild to moderate in severity and in line with those observed with quetiapine IR. The more rapid dose titration of quetiapine XR did not produce any new safety concerns and was as well tolerated as the regimen for quetiapine IR.

CONCLUSIONS

The results of this pooled analysis show that quetiapine XR administered once daily is generally as well tolerated as quetiapine IR given twice daily. These data, together with the simpler dose-titration of quetiapine XR that allowed therapeutically effective doses to be reached by Day 2, suggest that this formulation potentially may improve adherence in patients with schizophrenia.

Functional SNPs in Genes Encoding the 5-HT2A Receptor Modify the Affinity and Potency of Several Atypical Antipsychotic Drugs

Atypical antipsychotic drugs (AADs) are the standard treatment for both the acute and long-term management of schizophrenia and an augmentation to mood stabilizers for bipolar disorder (BD). Yet many individuals who take AADs do not fully respond to them, while others experience side effects that include weight gain and metabolic disorder. This in vitro pharmacogenetic study examined whether allelic variants in the 5-hydroxytryptamine (HT)2A receptor alter the in vitro pharmacology of six AADs (clozapine, olanzapine, risperidone, quetiapine, ziprasidone, and aripiprazole). We selected 4 functional single-nucleotide polymorphisms (SNPs) for investigation (Thr25Asn, Ile197Val, Ala447Val, and His452Tyr), conducted site-directed mutagenesis studies to induce variants into human HEK-293 cell lines, and screened allelic variants for their effects on 5-HT 2A receptors in the cell lines. We conducted numerous binding assays and fluorescence-based assay system (FLEX station) experiments using the six AADs. Our results indicated that three polymorphic 5-HT2A receptors (Ile197Val, Ala447Val, and His452Tyr) exhibited statistically significant, though modest, changes in atypical antipsychotic affinity. In addition, three polymorphic receptors (Thr25Asn, Ile197Val, and His452Try) altered AAD potency. Our findings support in vivo evidence that functional SNPs in genes encoding neuroreceptor drug targets could explain interindividual differences in AAD drug response and tolerability. We suggest that more in vivo pharmacogenetic studies of well-characterized patients who are prescribed AADs be indicated. Future pharmacogenetic studies of well-characterized patients will likely involve tagging SNPs and the use of haplotypes related to other genes encoding neuroreceptor drug targets.

Antipsychotic dosing and drug delivery

This chapter addresses the current state of affairs regarding proposed mechanism of action for antipsychotic medications and how this mechanism relates to dosing and delivery strategies. The initial portion describes the history of antipsychotic medication, including key discoveries that contribute to the dopamine hypothesis of schizophrenia and provide evidence that dopamine D2 receptor antagonism remains the most copasetic explanation for both determination of dose and degree of efficacy for current antipsychotic medications. Early observations regarding the unique properties of clozapine and how those observations led to the misconception and misnomer of atypicality are also discussed. Subsequent sections relate the dosing of available medications using chlorpromazine equivalents, with a discussion of non-D2-related mechanisms to antipsychotic effects. The balance of the chapter explores the temporal pattern of receptor occupancy as a key determinant of antipsychotic effectiveness, noting that continuous infusion would present the optimal method of treatment. In addition to the pharmacodynamic benefits of continuous long-term delivery systems, the incidence, causes, and clinical consequences of poor adherence are addressed. These observations are then discussed in the context of clinical studies and meta-analyses, demonstrating superiority of long-term depot preparations over oral administration. However, despite overwhelming evidence in favor of long-term delivery systems, few options are available to provide such ideal medication delivery profiles. Barriers to creating traditional depot preparations for a large number of antipsychotic agents, as well as efforts to address these limitations with polymer-based microspheres are described. The potential extension of current formulations to very long-term delivery implants using biodegradable and nonbiodegradable platforms is then described. Benefits as well as limitations of such systems are discussed with respect to clinical and ethical issues as well as a brief description of potential regulatory and logistic barriers to developing better delivery options. In summary, this chapter describes the basis for relating the dose of all existing antipsychotic medications to dopamine D2 receptor affinity and the potential contribution of continuous occupancy to enhanced efficacy through superior biological effects and improved adherence.

Quetiapine treatment and improved cognitive functioning in borderline personality disorder

OBJECTIVE

We aimed to assess whether executive functioning improved over time in a sample of borderline personality disorder (BPD) subjects that took part in a quetiapine treatment trial.

METHODS

Performance on the following neurocognitive tasks was assessed at enrolment and at the end of the 12 weeks quetiapine treatment: Trail Making Task, Word Fluency Task and Tower of London Task. Forty-one BPD patients were recruited, of whom 32 completed the trial. An intention-to-treat analysis with a mixed linear model was applied.

RESULTS

The data show that participants significantly improved on most executive functioning measures. Patients' scores decreased significantly (mean [SD] difference; p-value) on the Trail Making Task Part A (11.7 [2.3]; p < 0.0001), Part B (51.8 [9.2]; p < 0.0001) and 'B minus A' (40.1 [8.2]; p < 0.0001), on a Phonological (15.9 [1.6]; p < 0.0001) and Semantic (9.8 [1.1]; p < 0.0001) Verbal Fluency tasks, and on the Tower of London total correct score (2.5 [0.4]; p < 0.0001), total move score (29.5 [4.5]; p < 0.0001) and total time (172.9 [35.8]; p < 0.0001).

CONCLUSIONS

In this study we have demonstrated that executive functioning in BPD is improved after treatment with quetiapine. Neurocognitive measures of executive functioning should be considered as valuable outcomes in the study of treatment efficacy in BPD.

Quetiapine extended release: in schizophrenia

Quetiapine is an atypical antipsychotic agent with well established efficacy and tolerability in the acute and maintenance treatment of adults with schizophrenia. The extended-release formulation of quetiapine (quetiapine XR) was developed to provide more convenient once-daily administration, as well as allowing simple and rapid dose escalation, with the aim of improving compliance (known to be a substantial issue in patients with schizophrenia). In several short-term clinical trials, oral quetiapine XR 400-800 mg once daily was generally effective across a range of symptoms in the acute treatment of schizophrenia. As a long-term maintenance treatment, quetiapine XR prevented relapse in patients with stable disease, with significantly longer times to relapse in patients treated with quetiapine XR compared with placebo. Quetiapine XR was generally well tolerated in clinical trials. According to pooled results from three 6-week trials, events occurring in >or=5% of quetiapine XR recipients with an incidence>or=2-fold that seen in placebo recipients were dry mouth, somnolence and dizziness. A generally low incidence of extrapyramidal symptoms (EPS) is seen in quetiapine XR recipients. The most common potentially EPS-associated adverse events seen with quetiapine treatment were akathisia, restlessness and tremor. Rates of worsening of Simpson-Angus Scale and Barnes Akathisia Rating Scale scores were not dissimilar among quetiapine XR, quetiapine immediate release and placebo.

Pharmacokinetics and time-course of D(2) receptor occupancy induced by atypical antipsychotics in stabilized schizophrenic patients

The (123)I-IBZM SPECT measured D(2) receptor occupancy (D(2)RO) in chronically dosed, stabilized schizophrenic patients and its relationship with antipsychotic (AP) pharmacokinetics (PK) over time is still unclear. The aims of this study were: 1) To define the relationship between striatal D(2) receptor occupancy (D( 2)RO) and plasma concentration (C(P)) in stabilized schizophrenic patients on clinically relevant doses using (123)I-IBZM SPECT; 2) To investigate the time course of AP-induced D(2)RO and corresponding C(P). Forty-six schizophrenic patients on their clinically required doses of risperidone, olanzapine, clozapine or quetiapine were included. D( 2)RO and C(P) were measured over time following a sparse-sampling experimental design, and individual PK and D(2)RO-time profiles were estimated using a population approach. Observed striatal D(2)RO and C(P) ranges were 28-75% and 9.4-60.5 ng/mL for risperidone, 22-84% and 8.6-89.5 ng/mL for olanzapine, 5-53% and 41.6-818.2 ng/mL for clozapine and 0-64% and 37.9-719.6 ng/mL for quetiapine. A PK-D(2)RO relationship was found for the four APs. D(2)RO pattern over time was stable for risperidone, olanzapine and clozapine but fluctuating for quetiapine. Stabilized schizophrenic patients show a wide range of both D(2)RO and C(P) at clinically effective doses of the four AP, suggesting that clinical response to these AP may be maintained with D(2)RO below 65%. D(2)RO patterns over time differ between AP. These results should be considered for accurate interpretation of D(2)RO measurements, proper design of studies and optimization of drug regimens for patients on AP treatment.

Quetiapine treatment for behavioural and psychological symptoms of dementia in Alzheimer's disease patients: a 6-week, double-blind, placebo-controlled study

SETTING

Treating elderly patients with Alzheimer's disease (AD) and behavioral and psychological symptoms of dementia (BPSD) is challenging due to the increased risk of iatrogenic movement disorders with old neuroleptics and the seemingly increasing risk of cardiovascular events with newer atypical agents. Quetiapine is an atypical antipsychotic agent that warrants further investigation.

OBJECTIVES

To assess tolerability, safety, and clinical benefit of quetiapine in AD patients with BPSD.

PARTICIPANTS AND DESIGN

AD patients with BPSD participated in a 6-week randomized, double-blind, placebo-controlled trial. Quetiapine was increased on the basis of clinical response and tolerability. Primary efficacy assessments included the Neuropsychiatric Inventory (NPI) and Clinical Global Impression of Change (CGI-C). Secondary efficacy measures included the Mini-Mental State Examination (MMSE), the Simpson-Angus Scale (SAS) and the Abnormal Involuntary Movement Scale (AIMS).

RESULTS

Forty patients (26 women), mean age 82.2 (SD 6.4) years were enrolled, 27 completed treatment. Median dose of quetiapine was 200 mg/day. Significant NPI total scores reductions (79% for placebo and 68.5% for quetiapine) were observed. The CGI-C score decreased significantly in the quetiapine group (p = 0.009 at 6 weeks) and did not change significantly in the placebo group (p = 0.48). The MMSE, AIMS, SAS scores and adverse events did not differ significantly between the two arms.

CONCLUSIONS

Quetiapine did not significantly improve psychosis scores. It did not cause cognitive and motor deterioration. These results might possibly be due to small sample size.

Promotion of choice in the care of people with bipolar disorder: a mental health nursing perspective

Inpatient nurse prescribing is proving to be a useful mechanism by which patients can have their medicines prescribed. A case study is described that outlines how a nurse prescriber worked with a patient who had been diagnosed with bipolar disorder. Key issues that have arisen from this case study include the importance of multidisciplinary team working, informed medicines management interventions and the ability to work with patients to promote patient choice. The case study will draw out the difficulties in managing bipolar conditions but enable other nurse prescribers to adopt similar values in their prescribing practice.

Quetiapine for elderly non-responsive schizophrenia patients

Ten elderly chronic schizophrenia patients who were not responding to an atypical antipsychotic were switched to quetiapine. The Brief Psychiatric Rating Scale (BPRS) demonstrated statistically significant improvement after 6 months of quetiapine treatment. Four patients discontinued treatment due to clinical exacerbation or sedation. There was no increase in abnormal movements or body weight.

A prospective 12-week study of quetiapine in adolescents with schizophrenia spectrum disorders

OBJECTIVE

The aim of this study was to investigate the effectiveness, tolerability, and safety of quetiapine in adolescents with schizophrenia, schizophreniform, and schizoaffective disorders in a prospective open-label study.

METHOD

A total of 56 subjects (all-subjects-treated, AST), ages 12-17, received 200-800 mg of quetiapine per day (forced titration to 400 mg within week 1; median study dose 600 mg/day at week 6) in Germany, 2002 through 2004. Primary outcome measure was the change of Positive and Negative Syndrome Scale (PANSS) total score (based on the intent-to-treat (ITT) population, n = 52), secondary outcome measures were changes of PANSS subscales, severity of illness, subjective wellbeing, and safety/tolerability (the latter based on the AST population). Correlates of PANSS response (=50% reduction in PANSS total score) and discontinuation due to lack of effectiveness were analyzed by Cox regression analyses.

RESULTS

Twenty-seven subjects (48%) completed the study; 17 subjects (30%) were discontinued due to lack of effectiveness. A significant reduction of PANSS total score (last observation carried forward, LOCF; p < 0.0001; effect size = 0.92) and of secondary effectiveness outcomes were detected. In all, 34.6% fulfilled the PANSS response criterion, correlated with the degree of PANSS total change within week 1. Somnolence (21.4%) and fatigue (17.9%) were the most frequent adverse events. A significant mean weight gain (6.2 kg) and mean decrease in total serum thyroxine (2.5 ng/dl) were detected.

CONCLUSIONS

In this sample of mostly drug-naïve patients with early-onset schizophrenia spectrum disorders, significant reductions in PANSS total and positive scores were detected. Controlled studies are needed to confirm these findings. The significant weight gain with its potentially severe medical consequences must be weighed against quetiapine's effectiveness.

A review of quetiapine in combination with antidepressant therapy in patients with depression

BACKGROUND

Atypical antipsychotics are increasingly used in the treatment of a broad spectrum of psychiatric disorders. There is evidence that in addition to treating the positive and negative symptoms of schizophrenia, as well as mania in bipolar disorder, these agents may have a potential role to play in the treatment of depressive disorders. In the following article we review the literature regarding the role of atypical antipsychotics, and specifically, quetiapine, in the treatment of major depressive disorder.

MATERIALS AND METHODS

In March 2007 the authors performed a Medline search (English-language) using the keywords quetiapine and depression, revealing a total of 47 articles published. We also looked for cross-references in the published articles, obtained data-on-file from AstraZeneca Pharmaceutical L.P., and included abstracts presented at conferences and recent meetings.

RESULTS

From our review we found that there is increasing literature supporting the efficacy of add-on quetiapine in the treatment of major depressive disorder.

CONCLUSION

There is a need, however, for further well-designed, adequately powered, randomized, controlled trials to confirm this finding, specifically in unipolar depression.

Safety and tolerability of quetiapine in the treatment of acute mania in bipolar disorder

OBJECTIVE

To review the safety/tolerability of quetiapine in four placebo-controlled studies in patients with bipolar I disorder experiencing acute mania.

METHODS

Four double-blind, placebo-controlled studies evaluated quetiapine monotherapy (12 weeks) or quetiapine in combination with lithium (mean serum concentration 0.76 mEq/L) or divalproex (mean serum concentration 68.6 microg/mL) (Li/DVP) (3 and 6 weeks) in patients with acute mania. Pooled data from the two monotherapy studies and the two combination therapy studies have been evaluated in the analysis presented here. Adverse event reporting, Simpson Angus Scale (SAS), and Barnes Akathisia Rating Scale (BARS) scores were recorded.

RESULTS

Most adverse events were mild to moderate. Common adverse events (> or = 5% and at least twice the placebo rate) with quetiapine monotherapy and combination therapy were somnolence, dry mouth, weight gain, dizziness, asthenia, pharyngitis, and postural hypotension. Treatment-related discontinuations due to adverse events were not significantly different between quetiapine and placebo, nor was the incidence of extrapyramidal symptoms (including akathisia) (quetiapine monotherapy 12.9% vs placebo 13.1%; combination therapy 21.4% vs placebo 19.2%). Mean change from baseline to endpoint in SAS and BARS scores was not significantly different between groups. Mean weight change at treatment end with quetiapine compared with placebo was +1.8 vs -0.15 kg in monotherapy; and +1.97 vs +0.27 kg with combination therapy. No patients discontinued due to weight gain. The effect of quetiapine monotherapy on serum prolactin levels was no different from placebo.

CONCLUSIONS

Quetiapine monotherapy and combination therapy were well tolerated in the treatment of acute mania.

Dose-dependent constipation with higher doses of quetiapine: a case series

Quetiapine is a dopamine D2 and serotonin 5-HT2 antagonist with antipsychotic and mood-stabilizing properties. Recent studies suggest that higher doses of quetiapine combine superior therapeutic efficacy with good tolerability. We present five patients, in whom treatment with higher doses of quetiapine was associated with constipation. Our observations raise the question of dose-dependent constipation under treatment with quetiapine.

Quetiapine in the treatment of psychotic adolescents: a case series of 23 patients with severe early onset psychosis

Clinical efficacy, safety and tolerability of quetiapine in the treatment of 23 hospitalized psychotic adolescents were evaluated retrospectively. Twelve patients were changed to quetiapine from another antipsychotic medication during their hospital stay. In these patients, CGI-S improved from 4.75+/-0.87 to 2.92+/-0.67 (observation period 3.7+/-1.6 months). The most common adverse events were transient tachycardia and sedation. Mild EPS occurred only in one patient under quetiapine monotherapy. Transaminase increases more than threefold above norm were observed in two patients. fT4 values were slightly below the norm in 67% of the cases. In 11 patients, quetiapine was initiated using a rapid titration schedule with high dosages in the acute phase. Receiving a mean maximum daily dose of 927+/-300 mg, CGI-S improved from 6.00+/-0.63 to 3.18+/-1.25 (observation period 2.9+/-1.8 months). Severe adverse events did not occur. Besides applying lorazepam temporarily in nine of the 11 patients, antipsychotic co-medication was not necessary in this group. In line with other studies, quetiapine may be considered as an effective treatment for adolescents with a severe psychotic disorder showing a favourable side-effect profile. Our preliminary data suggest that a rapid initiation with high doses could be a promising approach in acute psychotic adolescents.

Clinical effectiveness of quetiapine in children and adolescents with Tourette's syndrome : a retrospective case-note survey

BACKGROUND AND OBJECTIVE

Tourette's syndrome is a relatively common biological genetic disorder with a broad spectrum of neurobehavioural manifestations. Unfortunately, treatment of the condition is often unsatisfactory and all available drugs are associated with potential adverse effects. We therefore aimed to investigate the efficacy of quetiapine, a newer atypical antipsychotic, in the treatment of children and adolescents with Tourette's syndrome.

METHODS

This was a retrospective study carried out in outpatient clinics. Twelve patients aged 8-18 years with Tourette's syndrome (diagnosed according to Diagnostic and Statistical Manual IV criteria) who were receiving quetiapine therapy and had no diagnosis of epilepsy, major depression or psychotic disorder, were included in the study. The main outcome measure was the Yale Global Tic Severity Scale (YGTSS) score.

RESULTS

The initial dose of quetiapine was 25 mg/day, but the mean dose was increased to 114.6 +/- 51.6 mg/day and 175.0 +/- 116.8 mg/day at the fourth and eighth weeks of treatment, respectively. The YGTSS score, which was 21.6 +/- 4.0 at baseline, showed significant decreases at 4 and 8 weeks (reducing to 7.5 +/- 7.4 and 5.6 +/- 8.1, respectively; p < 0.003). Routine laboratory parameters and serum prolactin level were all normal and did not change throughout treatment. Mild but significant increases in both bodyweight and body mass index at 4 and 8 weeks compared with baseline were observed.

CONCLUSION

Other than causing mild weight gain, quetiapine appears to be an effective, safe and well tolerated drug in children and adolescents with Tourette's syndrome.

Quetiapine and breast feeding

OBJECTIVE

To quantify the relative infant dose of quetiapine during breast feeding, describe the milk:plasma (M:P) ratio, and determine the well-being of the exposed infant.

CASE SUMMARY

A 26-year-old mother and her 3-month-old son were studied over a 24 hour quetiapine dose interval at steady-state. Quetiapine concentrations were quantified by high-performance liquid chromatography. Infant exposure was calculated as the concentration in milk multiplied by an estimated milk production of 0.15 L/kg/day and normalized to the weight-adjusted maternal dose. The average concentration in milk was 41 microg/L, the M:P ratio (measured using average concentrations in the elimination phase) was 0.29, and the relative infant dose was 0.09% of the maternal weight-adjusted dose (7273 microg/kg/day). The infant plasma concentration of 1.4 microg/L was some 6% of the corresponding maternal plasma concentration. No adverse effects were noted in the infant.

DISCUSSION

Our findings of an infant exposure to quetiapine of less than 0.1% of the maternal dose and a lack of adverse effects confirm and extend the findings of 2 previous studies.

CONCLUSIONS

Although limited, the data shown here support the prescription of quetiapine to a breast-feeding mother following a careful individual risk/benefit analysis. We suggest regular monitoring of infant progress and occasional measurement of quetiapine in the infant's plasma.

Atypical antipsychotics and polydipsia: a cause or a treatment?

Primary polydipsia (PP) is a frequent complication that affects many chronic schizophrenic inpatients. Due to possible lethal consequences, for example, hyponatremia, coma and death, it's fundamental for the physician achieving early diagnosis and treating this condition. The first step is identifying polydipsia by clinical, biochemical and pharmacological means. Nowadays, the pathophysiology of PP remains unclear, and this limits the possibility of detecting an appropriate drug treatment. Typical antipsychotics have been associated to a worsening of polydipsic behavior, while more recently atypical antipsychotics have been reported as being useful. However results are still mixed and controversial. It appears that risperidone and olanzapine are not clearly effective; clozapine may improve symptoms, although it is difficult to manage from a therapeutic point of view; quetiapine has been poorly studied so far, nonetheless it has given interesting results. Through a case study analysis, this report presents a brief, yet selective, overview of the current state of psychopharmacology in the treatment of PP with atypical antipsychotics in schizophrenia.

An open-label study of quetiapine in the treatment of fibromyalgia

The aim of this exploratory study was to systematically assess the potential effectiveness and tolerability of quetiapine, an atypical antipsychotic, for the treatment of patients with fibromyalgia. This was a unicentre, open-label study conducted in thirty-five outpatients, 18 years or older, who met the ACR criteria for fibromyalgia and who had not satisfactorily responded to their previous fibromyalgia treatment. Quetiapine, flexibly dosed (25-100 mg/day), was added to their original treatment regimen for 12 weeks. The primary outcome measure was the mean change from baseline to endpoint in the Fibromyalgia Impact Questionnaire (FIQ) total score. Secondary efficacy measures included mean changes from baseline to endpoint in the scores of the Clinical Global Impression (CGI) of Severity scale, Pittsburgh Sleep Quality Index (PSQI), Beck Depression Inventory (BDI), State-Trait Anxiety Inventory (STAI), 12-Item Short Form Health Survey (SF-12), and individual items of the FIQ. Thirty (85.7%) patients (mean age 47+/-7.9, 93.3% females) had a postbaseline evaluation and constituted the intent-to-treat efficacy sample. Mean FIQ total score decreased significantly by 10.2 points from a baseline of 63.2 to 53.0 at study endpoint (p<0.001). A statistically significant reduction was observed in FIQ stiffness and FIQ fatigue subscores but not in FIQ pain subscore. Large effect sizes were observed for the FIQ total (1.04), CGI-severity (1.00) and PSQI (1.07), while moderate effect sizes (i.e.> or =0.50) were encountered in the FIQ fatigue, FIQ stiffness and SF-12 mental component summary. Quetiapine was safely administered and well tolerated. Despite the lack of effect on pain, the significant and relevant improvement in overall efficacy measures and quality of life suggests that quetiapine may be a valuable drug for treatment of patients with fibromyalgia that should be further tested in double-blind, placebo-controlled trials.

Pharmakotherapie der Schizophrenie

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

Quetiapine-induced neuroleptic malignant syndrome in dementia with Lewy bodies: a case report

Patients with dementia with Lewy bodies (DLB) are particularly vulnerable to adverse effects of neuroleptics; this sensitivity is included among the clinical diagnostic criteria for DLB. Recently atypical neuroleptics, which carry less risk of extrapyramidal side effects than typical agents, have come into increasing use in treating psychotic symptoms and behavioral disturbances related to DLB. The present report is the first to describe a DLB patient who developed neuroleptic malignant syndrome (NMS) induced by quetiapine, an atypical neuroleptic known to have relatively infrequent extrapyramidal side effects in DLB patients. Physicians should be aware of the possibility of the occurrence of NMS in DLB even when atypical neuroleptics are administered.

Quetiapine: efficacy, tolerability and safety in schizophrenia

Quetiapine, a dibenzothiazepine derivative, is an atypical antipsychotic, multireceptor antagonist that has a preclinical profile similar to clozapine. Randomized studies have demonstrated the efficacy of quetiapine relative to placebo in the treatment of acute relapse and the long-term management of schizophrenia. Quetiapine is generally well tolerated relative to other antipsychotic medications, although side effects include sedation, orthostatic hypotension, anticholinergic and metabolic side effects. The purpose of this article is to critically review the current literature on quetiapine with an emphasis on emergent themes and key findings in the use of this agent for the treatment of schizophrenia. There are also continued efforts to understand, predict and manage the side-effect risk with quetiapine.

Quetiapine in patients with comorbid schizophrenia-spectrum and substance use disorders: an open-label trial

BACKGROUND

Preliminary evidence suggests that clozapine relieves the craving for psychoactive substances in schizophrenia patients. Quetiapine shares crucial pharmacological properties with clozapine. Promising results have been described with quetiapine therapy in patients with psychosis and substance use disorder.

METHODS

Based on Diagnostic and Statistical Manual of Mental Disorders - fourth edition (DSM-IV) criteria, patients were diagnosed with comorbid schizophrenia-spectrum and substance use disorders. Patients were switched to quetiapine for a 12-week open-label trial. Craving, quantities used, days of consumption, and severity of substance abuse were assessed every 3 weeks. Alcohol and Drug Use Scales were administered on baseline and end-point. Psychiatric symptoms, depressive symptoms, extrapyramidal symptoms, and cognition were also assessed at baseline, week 6 and week 12.

RESULTS

Twenty-four schizophrenia-spectrum patients were included in the last observation carried forward (LOCF) analyses, responding to one or more of the following substance use disorders: cannabis (15 patients), alcohol (10 patients), and other psychoactive substances (nine patients). Overall, severity of substance abuse improved during the study. Less weekly days were spent on drugs of abuse. A decrease in the weekly Canadian dollars spent on psychoactive substances was also observed. Cognition, psychiatric, depressive, and extrapyramidal symptoms also significantly improved (p < 0.05).

CONCLUSIONS

In this open-label, uncontrolled trial, significant improvements were noted in substance abuse, psychiatric symptoms, extrapyramidal symptoms, and cognition during quetiapine therapy. The study suffered from three main limitations: (1) the open-label design of the study; (2) the patients' poor compliance; and (3) the small sample size involved. Controlled studies on the use of quetiapine in dual diagnosis schizophrenia are warranted to confirm that the effects are drug-related.

World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for biological treatment of schizophrenia, part 2: long-term treatment of schizophrenia

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

Increased extrapyramidal symptoms in patients with schizophrenia and a comorbid substance use disorder

Few data have been gathered about the impact of psychoactive substances on extrapyramidal symptoms (EPS) in schizophrenia, and so far, inconsistent results have been reported. We studied 41 outpatients with schizophrenia (based on DSM-IV criteria), who were divided into two groups: with (n = 17) and without (n = 24) a substance use disorder (alcohol, cannabis, and/or cocaine). Both groups were matched for sociodemographic data and psychiatric symptoms (Positive and Negative Syndrome Scale). EPS were evaluated with the Extrapyramidal Symptoms Rating Scale and the Barnes Akathisia Scale, and all patients were stable on either quetiapine or clozapine. Patients receiving anticholinergic drugs were excluded. Analyses of variance were conducted on both groups and showed that schizophrenia patients with a comorbid substance use disorder (especially cocaine) displayed more EPS compared with non-abusing patients.

Review of evidence that posttransplantation psychiatric treatment commonly affects prolactin levels and thereby influences graft fate

Delirium, depression and other psychiatric difficulties are commonly encountered by posttransplantation patients, and antipsychotic medicines are frequently used to treat these difficulties. This article reviews previous research data concerning the immunological effects of these medicines, with particular focus on the consequences of prolactin elevation. Unproven but of concern is that these effects may influence graft fate. Older antipsychotic medicines such as haloperidol and chlorpromazine have a high likelihood of elevating prolactin. Prolactin is an immunologically active molecule generally promoting bone marrow function. This may be of benefit post-stem-cell transplant, helping engraftment, but could further rejection of solid-organ transplants. Elevated prolactin is implicated in the facilitation of graft-versus-host disease. Aripiprazole is the antipsychotic medicine least likely to increase prolactin (and may actually decrease prolactin); risperidone, the most likely to increase prolactin. Olanzapine, quetiapine and ziprazadone are antipsychotic medicines with a lower likelihood of elevating prolactin. Older ("neuroleptic") antipsychotics, such as chlorpromazine, droperidol and haloperidol, perphenazine and many others, are likely to elevate serum prolactin. Among antidepressants, most serotonin reuptake inhibitors, with the exception of sertraline, can slightly elevate prolactin. The atypical (i.e., alone in their class) antidepressants bupropion and mirtazapine are prolactin neutral. The immunological consequences of psychiatric medicines should be considered when treating transplant patients for delirium, depression and thought disorders; in addition, if elevation of prolactin is thought to be of immunological importance during psychiatric treatment, then it should be monitored and treated. The dopamine agonists used to treat Parkinson's disease--bromocriptine, pergolide, pramipexole, ropinerole--usually reverse antipsychotic-induced prolactin increases without compromising psychiatric effectiveness.

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

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

A 6-month prospective observational study on the effects of quetiapine on sexual functioning

OBJECTIVE

The aim of this study was to assess the long-term impact of quetiapine on sexual functioning of patients with schizophrenia treated in a real practice setting.

METHODS

This was a multicenter, noncomparative, open-label, and naturalistic study conducted in outpatients with a diagnosis of schizophrenia or schizophreniform disorder as defined by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. Patients were evaluated at baseline, day 15, and at the end of months 1, 3, and 6 using the Brief Psychiatry Rating Scale, the Clinical Global Impression Severity and Improvement Scales, and the Psychotropic-Related Sexual Dysfunction Questionnaire. All primary effectiveness analyses were based on the intent-to-treat sample and consisted primarily of last-observation-carried-forward analysis of Psychotropic-Related Sexual Dysfunction Questionnaire, Brief Psychiatry Rating Scale, and Clinical Global Impression Improvement of Illness Scale.

RESULTS

Eighty-six patients were recruited by 19 investigators, and 82 patients were included in the intent-to-treat sample. Psychotropic-Related Sexual Dysfunction Questionnaire total scores for the patients decreased progressively and significantly from baseline to the study end point. When only patients who initiated quetiapine treatment without being switched from another antipsychotic (n = 28) were included in the intent-to-treat analysis, Psychotropic-Related Sexual Dysfunction Questionnaire scores remained almost unchanged throughout the study. Sexual dysfunction rates, defined as a change in the score of any item greater than 0, were 3.7%, 2.4%, 2.4%, and 4.9% for decreased libido, delayed ejaculation/orgasm, lack of ejaculation/orgasm, and difficulties with erection/lubrication, respectively. Overall, quetiapine was efficacious and well tolerated.

CONCLUSION

Despite the limitations of the design, our results suggest that quetiapine shows a low frequency of sexual dysfunction during long-term treatment of patients with schizophrenia or schizophreniform disorder in the clinical practice setting.

Quetiapine has equivalent efficacy and superior tolerability to risperidone in the treatment of schizophrenia with predominantly negative symptoms

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.

Clinical trial design in schizophrenia: implications for clinical decisions

PURPOSE OF REVIEW

Results from clinical trials do not necessarily provide information for decisions in clinical practice. This review aims to present strengths and limitations of different methodological types of clinical trials and to offer an overview of how knowledge from clinical trails can be distilled for clinical practice. Selected key questions in the treatment of schizophrenia are presented, with a focus on the possibilities and restrictions of translating trial results into real-world practice.

RECENT FINDINGS

Randomized controlled trials are the gold standard for proving efficacy of a diagnostic or therapeutic procedure. They have a high degree of internal validity and a clear-cut message when conducted to good-quality standards but suffer from a lack of generalizability (external validity). Effectiveness studies evaluate effects of treatments under conditions approximating usual care. They may include patient-centred outcomes or health economic evaluations. According to the type of trial, specific problems arise in the interpretation of results. Typical examples are given for the treatment of acute exacerbations of schizophrenia, for relapse prevention and for the treatment of cognitive impairment.

SUMMARY

Clinical decisions have to be made upon the best knowledge. Therefore, well conducted studies addressing all major issues from all relevant perspectives are needed. The assessment of a treatment regimen for clinical utility requires both efficacy and effectiveness studies. An understanding of the design, analysis and conventions of both study types is essential for the interpretation of results and their translation to the clinical decision-making process.

Aripiprazole: a review of its use in schizophrenia and schizoaffective disorder

Aripiprazole, a quinolinone derivative, is an atypical antipsychotic drug indicated for the treatment of adult patients with schizophrenia. Aripiprazole 10 or 15 mg once daily is effective and well tolerated in patients with schizophrenia or schizoaffective disorder. Although aripiprazole has only been directly compared with haloperidol and olanzapine in treatment-responsive patients to date, current data generally indicate that aripiprazole has a beneficial profile in terms of a low potential for bodyweight gain. Dosage titration is not necessary and the drug is effective in the first few weeks of treatment. Head-to-head comparative trials with atypical antipsychotic agents are required, as are long-term (> or =1 year) studies, to fully define the position of aripiprazole in relation to other antipsychotic drugs. Aripiprazole is a valuable new therapeutic option in the management of patients with schizophrenia. PHARMACOLOGICAL PROPERTIES: Aripiprazole is a quinolinone derivative with a high affinity for dopamine D2 and D3 receptors, and serotonin 5-HT1A, 5-HT2A and 5-HT2B receptors. The mechanism of action of aripiprazole is not yet known, but evidence suggests that its efficacy in the treatment of the positive and negative symptoms of schizophrenia and its lower propensity for extrapyramidal symptoms (EPS) may be attributable to aripiprazole's partial agonist activity at dopamine D2 receptors. At serotonin 5-HT1A receptors, in vitro studies have shown that aripiprazole acts as a partial agonist whereas at serotonin 5-HT2A receptors aripiprazole is an antagonist. The main active metabolite, dehydro-aripiprazole, has affinity for dopamine D2 receptors and thus has some pharmacological activity similar to that of the parent compound. Aripiprazole is rapidly absorbed after oral administration. The mean time to peak plasma concentration is 3 hours following multiple-dose administration of aripiprazole 10 or 15 mg and the absolute oral bioavailability of the drug is 87%. Steady-state plasma drug concentrations are achieved by 14 days; however, the drug appears to accumulate over this period, since mean peak plasma concentration and mean area under the plasma concentration-time curve values of aripiprazole 10 or 15 mg/day are 4-fold greater on day 14 than on day 1. This accumulation may be expected, since the mean elimination half-life of a single dose of aripiprazole is about 75 hours. Aripiprazole has extensive extravascular distribution and more than 99% of aripiprazole and dehydro-aripiprazole (the main active metabolite of aripiprazole) is bound to plasma protein. Elimination of the drug is primarily hepatic; the cytochrome P450 (CYP) 3A4 and CYP2D6 enzyme systems transform aripiprazole to dehydro-aripiprazole, with the latter enzyme system subject to genetic polymorphism. Thus, dosage adjustment of aripiprazole is necessary when it is coadministered with CYP3A4 and CYP2D6 inhibitors (since aripiprazole concentration is increased) and with inducers of CYP3A4 (since aripiprazole concentration is decreased). THERAPEUTIC EFFICACY: The efficacy of aripiprazole has been demonstrated in patients with schizophrenia or schizoaffective disorder. In general, significant reductions from baseline in mean Positive and Negative Syndrome Scale total, positive and negative symptom scores, and Clinical Global Impression Severity of Illness scores were observed in patients with acute relapse of chronic schizophrenia or schizoaffective disorder receiving recommended (10 or 15 mg/day) or higher-than-recommended (20 or 30 mg/day) dosages of aripiprazole versus those receiving placebo in three well controlled, short-term trials. No additional therapeutic benefit was observed at the higher-than-recommended dosages. The drug is effective as early as the first or second week of treatment. The efficacy of aripiprazole was maintained for up to 52 weeks. The drug was significantly more effective than placebo in preventing relapse in patients with stable chronic schizophrenia in a 26-week, randomised trial. In a 52-week trial in patients with acute relapse of schizophrenia, the percentage of responders maintaining a response at study end was 77% of aripiprazole versus 73% of haloperidol recipients. Aripiprazole may improve cognitive function. In a nonblind, 26-week trial, patients with chronic schizophrenia receiving aripiprazole 30 mg/day experienced similar (general cognitive function) or better (verbal learning) changes from baseline in the neurocognitive parameters evaluated compared with recipients of olanzapine 10-15 mg/day.

TOLERABILITY

Aripiprazole 10-30 mg/day was generally well tolerated. The tolerability profile of aripiprazole was broadly similar to that observed with placebo in a meta-analysis of short-term trials in patients with acute relapse of schizophrenia or schizoaffective disorder and in a 26-week trial in patients with chronic stable schizophrenia. The most frequent treatment-emergent adverse events included insomnia and anxiety, and additionally, headache and agitation (in short-term trials) or akathisia and psychosis (in a 52-week trial). In general, the drug was associated with a placebo-level incidence of EPS and EPS-related adverse events. Significantly fewer aripiprazole recipients experienced EPS-related adverse events than haloperidol recipients in a 52-week trial. Changes in severity of EPS were minimal and usually no different from those observed with placebo. Moreover, there was less severe EPS in the aripiprazole group than the haloperidol group in a long-term trial. Treatment-emergent tardive dyskinesia was reported in only 0.2% of patients receiving aripiprazole (short-term trials), an incidence similar to that seen in placebo recipients (0.2%). Aripiprazole has a low propensity to cause clinically significant bodyweight gain, hyperprolactinaemia or corrected QT interval prolongation in patients with schizophrenia or schizoaffective disorder. In addition, there were no clinically relevant differences in mean changes from baseline in measures of diabetes and dyslipidaemia between the aripiprazole or placebo groups in a 26-week, placebo-controlled trial.

Efficacy of quetiapine for the treatment of schizophrenia: a combined analysis of three placebo-controlled trials

OBJECTIVE

To determine the effectiveness of quetiapine (Seroquel) against specific aspects of schizophrenic symptomatology.

RESEARCH DESIGN AND METHODS

Combined data from three placebo-controlled, double-blind, randomised trials that had previously demonstrated quetiapine's overall clinical effectiveness and tolerability were analysed. Efficacy assessments evaluated were the Clinical Global Impression (CGI) Severity of Illness score, Brief Psychiatric Rating Scale (BPRS) factors I-V, BPRS positive symptom cluster score and 18 individual BPRS items. The Simpson-Angus Scale (SAS), the Abnormal Involuntary Movements Scale (AIMS), changes in weight and prolactin concentrations and the recording of adverse events comprised the main tolerability measures.

RESULTS

Efficacy assessments were available for a total of 426 quetiapine patients (mean age 36.9 years) with a DSM-IIIR diagnosis of schizophrenia; 502 patients were included in the tolerability analyses. The mean quetiapine dose was 300.5 mg/day with a mean maximum dose of 686.0 mg/day. Quetiapine was efficacious across a broad range of symptoms, including depression, anxiety and hostility. Significant improvements compared with placebo were noted for CGI Severity of Illness (p < 0.001) and in 14 of the 18 individual BPRS items (p < 0.001). Positive symptoms also improved (p < 0.01 at Week 2 and p < 0.001 from Week 3); greater improvements were observed in patients who received at least 400 mg/day quetiapine. Quetiapine was generally well tolerated: 4.0% of patients withdrew from treatment due to adverse events compared with 3.0% of placebo patients. Akathisia occurred in 2.0% and 2.5% of quetiapine and placebo patients, respectively. Similar decreases in prolactin levels for quetiapine (-10.0 microg/L) and placebo (-10.9 microg/L) were noted from baseline to end of treatment. Agitation and headache, the most common adverse events, were comparable in the quetiapine and placebo groups (agitation: 19.3% vs. 20.3%, respectively; headache: 19.1% vs. 17.3%, respectively).

CONCLUSIONS

The results of this combined analysis confirm the individual findings of the three pivotal studies to demonstrate that quetiapine is effective across several domains of schizophrenia, improving positive, negative and depressive symptoms and reducing agitation, aggression and hostility. Similarly, the analysis reiterated the good tolerability profile of quetiapine, particularly in terms of its placebo-like effects on prolactin levels and incidence of extrapyramidal symptoms (EPS).