A preclinical and clinical rationale for quetiapine in mood syndromes

Effects of Chronic Combined Treatment with Ketanserin and Fluoxetine in B6.CBA-D13Mit76C Recombinant Mice with Abnormal 5-HT1A Receptor Functional Activity

The recombinant B6.CBA-D13Mit76C mouse strain is characterized by an altered sensitivity of 5-HT1A receptors and upregulated 5-HT1A gene transcription. Recently, we found that in B6.CBA-D13Mit76C mice, chronic fluoxetine treatment produced the pro-depressive effect in a forced swim test. Since 5-HT2A receptor blockade may be beneficial in treatment-resistant depression, we investigated the influence of chronic treatment (14 days, intraperitoneally) with selective 5-HT2A antagonist ketanserin (0.5 mg/kg), fluoxetine (20 mg/kg), or fluoxetine + ketanserin on the behavior, functional activity of 5-HT1A and 5-HT2A receptors, serotonin turnover, and transcription of principal genes of the serotonin system in the brain of B6.CBA-D13Mit76C mice. Ketanserin did not reverse the pro-depressive effect of fluoxetine, while fluoxetine, ketanserin, and fluoxetine + ketanserin decreased the functional activity of 5-HT1A receptors and Htr1a gene transcription in the midbrain and hippocampus. All tested drug regimens decreased the mRNA levels of Slc6a4 and Maoa in the midbrain. These changes were not accompanied by a significant shift in the levels of serotonin and its metabolite 5-HIAA. Notably, ketanserin upregulated enzymatic activity of tryptophan hydroxylase 2 (TPH2). Thus, despite some benefits (reduced Htr1a, Slc6a4, and Maoa transcription and increased TPH2 activity), prolonged blockade of 5-HT2A receptors failed to ameliorate the adverse effect of fluoxetine in the case of abnormal functioning of 5-HT1A receptors.

Serotonin Receptor 5-HT2A Regulates TrkB Receptor Function in Heteroreceptor Complexes

Serotonin receptor 5-HT_2A and tropomyosin receptor kinase B (TrkB) strongly contribute to neuroplasticity regulation and are implicated in numerous neuronal disorders. Here, we demonstrate a physical interaction between 5-HT_2A and TrkB in vitro and in vivo using co-immunoprecipitation and biophysical and biochemical approaches. Heterodimerization decreased TrkB autophosphorylation, preventing its activation with agonist 7,8-DHF, even with low 5-HT_2A receptor expression. A blockade of 5-HT_2A receptor with the preferential antagonist ketanserin prevented the receptor-mediated downregulation of TrkB phosphorylation without restoring the TrkB response to its agonist 7,8-DHF in vitro. In adult mice, intraperitoneal ketanserin injection increased basal TrkB phosphorylation in the frontal cortex and hippocampus, which is in accordance with our findings demonstrating the prevalence of 5-HT_2A–TrkB heteroreceptor complexes in these brain regions. An expression analysis revealed strong developmental regulation of 5-HT_2A and TrkB expressions in the cortex, hippocampus, and especially the striatum, demonstrating that the balance between TrkB and 5-HT_2A may shift in certain brain regions during postnatal development. Our data reveal the functional role of 5-HT_2A–TrkB receptor heterodimerization and suggest that the regulated expression of 5-HT_2A and TrkB is a molecular mechanism for the brain-region-specific modulation of TrkB functions during development and under pathophysiological conditions.

Quetiapine promotes oligodendroglial process outgrowth and membrane expansion by orchestrating the effects of Olig1

Oligodendroglial lineage cells go through a series of morphological changes before myelination. Prior to myelination, cell processes and membrane structures enlarge by approximately 7,000 times, which is required to support axonal wrapping and myelin segment formation. Failure of these processes leads to maldevelopment and impaired myelination. Quetiapine, an atypical antipsychotic drug, was proved to promote oligodendroglial differentiation and (re)myelination, pending detailed effects and regulatory mechanism. In this study, we showed that quetiapine promotes morphological maturation of oligodendroglial lineage cells and myelin segment formation, and a short-term quetiapine treatment is sufficient to induce these changes. To uncover the underlying mechanism, we examined the effect of quetiapine on the Oligodendrocyte transcription factor 1 (Olig1). We found that quetiapine upregulates Olig1 expression level and promotes nuclear Olig1 translocation to the cytosol, where it functions not as a transcription modulator, but in a way that highly correlates with oligodendrocyte morphological transformation. In addition, quetiapine treatment reverses the negative regulatory effect of the Olig1-regulated G protein-coupled receptor 17 (GPR17) on oligodendroglial morphological maturation. Our results demonstrate that quetiapine enhances oligodendroglial differentiation and myelination by promoting cell morphological transformation. This would shed light on the orchestration of oligodendroglia developmental mechanisms, and provides new targets for further therapeutic research.

Population Pharmacokinetics Analysis of Quetiapine Extended-release Formulation in Japanese Patients with Bipolar Depression

PURPOSE

The objectives of this study were to explore covariates of plasma quetiapine concentrations after oral administration of quetiapine extended-release formulation (XR), and to examine the exposure-response relationship in Japanese patients with bipolar depression, using population pharmacokinetics (PopPK) modeling.

METHODS

In a multicenter, randomized, double-blind, placebo-controlled study of quetiapine XR in patients with bipolar depression, plasma for the measurement of quetiapine concentration was collected at weeks 2, 4, 8, 12, 20, 28, and 52 during oral administration of 150 or 300 mg once daily of quetiapine XR before bedtime. A PopPK model of quetiapine XR was developed using nonlinear mixed-effects modeling with first-order conditional estimation with interactions. The exposure-response relationship was examined using post-hoc exposures. The post-hoc AUC estimate was plotted against the change in the Montgomery-Åsberg Depression Rating Scale (ΔMADRS) total score from baseline to 8 weeks following once-daily doses at 300 mg.

FINDINGS

The final PopPK analysis dataset contained 322 patients and 1162 observations (cutoff data at week 28; cutoff date, February 2016). The plasma quetiapine concentration-time profile in patients with bipolar depression after oral administration of quetiapine XR was represented well using a 1-compartment with first-order absorption model. Covariate analysis led to the selection of γ-glutamyl transpeptidase on apparent oral clearance and body weight on apparent volume of distribution as covariates. The final population mean values of apparent oral clearance and apparent volume of distribution were 87.7 L/h and 277 L, respectively, and the interindividual %CVs were 32.6% and 75.0%, respectively.

IMPLICATIONS

The effects of covariates on PK parameters were not large compared with the interindividual variability. In addition, there was no clear relationship between the AUC and ΔMADRS. ClinicalTrials.gov identifier: NCT01725308.

Evidence-based guidelines for the pharmacological treatment of schizophrenia: Updated recommendations from the British Association for Psychopharmacology

These updated guidelines from the British Association for Psychopharmacology replace the original version published in 2011. They address the scope and targets of pharmacological treatment for schizophrenia. A consensus meeting was held in 2017, involving experts in schizophrenia and its treatment. They were asked to review key areas and consider the strength of the evidence on the risk-benefit balance of pharmacological interventions and the clinical implications, with an emphasis on meta-analyses, systematic reviews and randomised controlled trials where available, plus updates on current clinical practice. The guidelines cover the pharmacological management and treatment of schizophrenia across the various stages of the illness, including first-episode, relapse prevention, and illness that has proved refractory to standard treatment. It is hoped that the practice recommendations presented will support clinical decision making for practitioners, serve as a source of information for patients and carers, and inform quality improvement.

Assessment of psychiatric and behavioral adverse effects of antiepileptic drugs monotherapy: Could they have a neuroendocrine correlation in persons with epilepsy?

OBJECTIVE

The study investigated overall adverse event (AE) burden and specifically psychiatric and behavioral side effects (PBAEs) in persons with epilepsy (PWE) on antiepileptic drugs (AEDs) monotherapy. It also assessed their correlation with neuroendocrine and oxidative stress biomarkers.

METHODS

This cross-sectional observational study was conducted at a tertiary care hospital between 2016 and 2018. Persons with epilepsy above 18 years on monotherapy of levetiracetam (LEV) and conventional AEDs {carbamazepine (CBZ), phenytoin (PHT), or valproate (VPA)} for at least 6 months were enrolled. Validated questionnaires, 'Mini-International Neuropsychiatric Interview (MINI 7.02)', 'Depression, Anxiety, and Stress Scale 21 (DASS-21)', 'Buss-Perry Aggression Questionnaire (BPAQ)', 'patient-weighted Quality of life Index in Epilepsy (QOLIE-10)', 'Pittsburgh Sleep Quality Index (PSQI)', and 'Liverpool Adverse Events Profile (LAEP)' were used to assess the PBAEs, quality of life, sleep quality, and AE profile. A subgroup of PWE recruited consecutively were considered for estimation of the following neuroendocrine biomarker levels: brain-derived neurotrophic factor (BDNF), homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5-HIAA), and total antioxidant capacity (TAC) which were then correlated with scores of above questionnaires.

RESULTS

After screening 220 PWE, 163 PWE (58 on LEV and 105 on conventional AEDs) with a mean age of 29 ± 10 years were enrolled. Mini-International Neuropsychiatric Interview revealed that LEV group had higher association with PBAEs and lower quality of sleep compared to conventional AEDs (p = 0.032 and 0.046, respectively). Other scales did not show significant difference between LEV and conventional AEDs. In the subset of PWE (n = 74, 36 on LEV and 38 on conventional AEDs), LEV group had more association with the PBAEs (p = 0.010), higher physical aggression and anger components of BPAQ (p = 0.03 and 0.02, respectively), and more AE (p = 0.049) than conventional AED group. However, there was no significant difference in neuroendocrine biomarker levels.

CONCLUSION

Levetiracetam had a higher association with PBAEs and more AE when compared to conventional AEDs. There was no differential correlation of AEDs with the following neuroendocrine markers: BDNF, HVA, 5-HIAA, and TAC. These facts necessitate exploration of other mechanisms for LEV-induced PBAEs.

Risperidone versus other antipsychotics for people with severe mental illness and co-occurring substance misuse

BACKGROUND

Up to 75% of people with serious mental illness (SMI) such as schizophrenia and bipolar disorder have co-occurring substance use disorders (dual diagnosis). Dual diagnosis can have an adverse effect on treatment and prognosis of SMI.

OBJECTIVES

To evaluate the effects of risperidone compared to treatment with other antipsychotics (first-generation and other second-generation antipsychotics) used in people with serious mental illness and co-occurring substance misuse.

SEARCH METHODS

On 6 January 2016 and 9 October 2017, we searched the Cochrane Schizophrenia Group's Study-Based Register of Trials (including trial registers).

SELECTION CRITERIA

We selected randomised trials of risperidone versus any other antipsychotic in people with SMI and substance abuse (dual diagnosis). We included trials meeting our inclusion criteria and reporting useable data. We excluded trials that either did not meet our inclusion criteria or met our inclusion criteria but did not report any useable data.

DATA COLLECTION AND ANALYSIS

We independently inspected citations and selected studies. For included studies, we independently extracted data and appraised study quality. For binary outcomes we calculated the risk ratios (RRs) and their 95% confidence intervals. For continuous outcomes we calculated the mean differences (MDs) and their 95% confidence intervals. We pooled data using random-effects meta-analyses and assessed the quality of evidence, creating a 'Summary of findings' table using the GRADE approach.

MAIN RESULTS

We identified eight randomised trials containing a total of 1073 participants with SMI and co-occurring substance misuse. Seven of these contributed useable data to the review. There was heterogeneity in trial design and measurement. Risperidone was compared to clozapine, olanzapine, perphenazine, quetiapine and ziprasidone. Few trials compared risperidone with first-generation agents. Few trials examined participants with a dual diagnosis from the outset and most trials only contained separate analyses of subgroups with a dual diagnosis or were secondary data analyses of subgroups of people with a dual diagnosis from existing larger trials.For risperidone versus clozapine we found no clear differences between these two antipsychotics in the reduction of positive psychotic symptoms (1 randomised controlled trial (RCT), n = 36, mean difference (MD) 0.90, 95% CI -2.21 to 4.01, very low quality evidence), or reduction in cannabis use (1 RCT, n = 14, risk ratio (RR) 1.00, 95% CI 0.30 to 3.35, very low quality evidence), improvement in subjective well-being (1 RCT, n = 36, MD -6.00, 95% CI -14.82 to 2.82, very low quality evidence), numbers discontinuing medication (1 RCT, n = 36, RR 4.05, 95% CI 0.21 to 78.76, very low quality evidence), extrapyramidal side-effects (2 RCTs, n = 50, RR 2.71, 95% CI 0.30 to 24.08; I² = 0%, very low quality evidence), or leaving the study early (2 RCTs, n = 45, RR 0.49, 95% CI 0.10 to 2.51; I² = 34%, very low quality evidence). Clozapine was associated with lower levels of craving for cannabis (1 RCT, n = 28, MD 7.00, 95% CI 2.37 to 11.63, very low quality evidence).For risperidone versus olanzapine we found no clear differences in the reduction of positive psychotic symptoms (1 RCT, n = 37, MD -1.50, 95% CI -3.82 to 0.82, very low quality evidence), reduction in cannabis use (1 RCT, n = 41, MD 0.40, 95% CI -4.72 to 5.52, very low quality evidence), craving for cannabis (1 RCT, n = 41, MD 5.00, 95% CI -4.86 to 14.86, very low quality evidence), parkinsonism (1 RCT, n = 16, MD -0.08, 95% CI -1.21 to 1.05, very low quality evidence), or leaving the study early (2 RCT, n = 77, RR 0.68, 95% CI 0.34 to 1.35; I² = 0%, very low quality evidence).For risperidone versus perphenazine, we found no clear differences in the number of participants leaving the study early (1 RCT, n = 281, RR 1.05, 95% CI 0.92 to 1.20, low-quality evidence).For risperidone versus quetiapine, we found no clear differences in the number of participants leaving the study early (1 RCT, n = 294, RR 0.96, 95% CI 0.86 to 1.07, low-quality evidence).For risperidone versus ziprasidone, we found no clear differences in the number of participants leaving the study early (1 RCT, n = 240, RR 0.96, 95% CI 0.85 to 1.10, low-quality evidence).For many comparisons, important outcomes were missing; and no data were reported in any study for metabolic disturbances, global impression of illness severity, quality of life or mortality.

AUTHORS' CONCLUSIONS

There is not sufficient good-quality evidence available to determine the effects of risperidone compared with other antipsychotics in people with a dual diagnosis. Few trials compared risperidone with first-generation agents, leading to limited applicability to settings where access to second-generation agents is limited, such as in low- and middle-income countries. Moreover, heterogeneity in trial design and measurement of outcomes precluded the use of many trials in our analyses. Future trials in this area need to be sufficiently powered but also need to conform to consistent methods in study population selection, use of measurement scales, definition of outcomes, and measures to counter risk of bias. Investigators should adhere to CONSORT guidelines in the reporting of results.

Acute and chronic treatment with quetiapine induces antidepressant-like behavior and exerts antioxidant effects in the rat brain

Many studies note that changes in oxidative balance are involved in the pathogenesis of major depressive disorder (MDD) and in the success of some antidepressants. Quetiapine exerts a therapeutic response and induces changes in physiological mechanisms that appear to underlie MDD. The objective of this study was to evaluate the antidepressant and antioxidant effects of quetiapine (20 mg /kg) in adult animals. Sixty minutes after an acute treatment or the last administration of chronic treatment (14 days) with quetiapine, animals were subjected to the forced swimming test (FST) to evaluate mobility parameters. Then, the hippocampus, prefrontal cortex (CPF), amygdala and nucleus accumbens (NAc) were removed for the assessment of oxidative stress parameters. Both acute and chronic treatments exerted antidepressant-like effects. Myeloperoxidase (MPO) activity was reduced in the amygdala after acute treatment and in the hippocampus, PFC and amygdala after chronic treatment. In addition, after chronic treatment, the levels of thiobarbituric reactive species (TBARS) were reduced in the amygdala and NAc, and the protein carbonyl content was reduced in the CPF. Superoxide dismutase (SOD) activity increased in the NAc after acute and chronic treatments. Catalase (CAT) activity increased in the PFC after acute treatment and in the NAc after acute and chronic treatments. The concentration of nitrite/nitrate was lower in the CPF after chronic treatment. These results corroborate the antidepressant effect of quetiapine and indicate that quetiapine exhibits an antioxidant profile, a physiological mechanism that appears be involved in the therapeutic function of quetiapine in individuals resistant to classical antidepressant treatments.

Identification of 5-hydroxytryptamine receptor gene polymorphisms modulating hyperprolactinaemia in antipsychotic drug-treated patients with schizophrenia

OBJECTIVES

Hyperprolactinaemia (HPRL) is a classical side effect of antipsychotic drugs primarily attributed to blockade of dopamine D2 subtype receptors in the pituitary gland. Although dopamine is considered the primary factor inhibiting prolactin release, the activity of prolactin-producing lactotrophs is also regulated by the secretagogues thyrotrophin releasing hormone, vasoactive intestinal polypeptide and serotonin (5-hydroxytryptamine; 5-HT).

METHODS

We describe the association between HPRL and a set of 29 SNPs from 5-HT receptor genes HTR1A, HTR1B, HTR2A, HTR2C, HTR3A, HTR3B and HTR6 in a population of 446 Caucasians (221 males/225 females) with a clinical diagnosis of schizophrenia (according to ICD-10: F20) who were treated with classical and/or atypical antipsychotic drugs.

RESULTS

None of the studied autosomal markers were found to be associated with HPRL. However, a significant association was established between various HTR2C polymorphisms and HPRL.

CONCLUSIONS

This study revealed an association between HPRL and X-chromosome haplotypes comprised of the rs569959 and rs17326429 polymorphisms.

The preclinical discovery and development of quetiapine for the treatment of mania and depression

INTRODUCTION

Bipolar disorder is a chronic disabling condition characterized by alternating manic and depressive episodes. Bipolar disorder has been associated with functional impairment, poor quality of life, morbidity and mortality. Despite its significant clinical, social and economic burden, treatment options for bipolar disorder are still limited. Several clinical trials have shown efficacy of the atypical antipsychotic quetiapine (QTP) in the treatment of this condition. However, the mechanisms underlying the antidepressant and anti-manic effects of QTP remain poorly understood. Areas covered: The article provides the emerging evidence from pre-clinical studies regarding the antidepressant and anti-manic mechanisms of action of QTP. In combination with its primary active metabolite norquetiapine, QTP modulates several neurotransmitter systems, including serotonin, dopamine, noradrenaline and histamine. QTP also seems to influence mediators of the immune system. Expert opinion: Pre-clinical studies have provided valuable information on the potential antidepressant mechanisms of action of QTP, but pre-clinical studies on QTP's anti-manic effects are still scarce. A major problem refers to the lack of valid experimental models for bipolar disorder. Additionally, immune and genetic based studies are largely descriptive. The role of the QTP metabolite norquetiapine in modulating non-neurotransmitter systems also needs to be further addressed.

Comparative Physicochemical and Pharmacokinetic Properties of Quetiapine and Its Active Metabolite Norquetiapine

Quetiapine (QTP) is an atypical antipsychotic drug commonly used to treat several psychiatric disorders and is metabolized into the active metabolite norquetiapine (NQTP). This study was designed to evaluate and compare the physicochemical properties, metabolic stability, brain distribution, and pharmacokinetics of QTP and NQTP. Compared to QTP, NQTP had a higher pK_a, solubility, and rat liver microsomal stability, optimal log D and similar log P values. For pharmacokinetic evaluation, QTP and NQTP were administered orally and intravenously to rats at various doses. The plasma QTP and NQTP concentrations in rats were determined by a fully-validated liquid-chromatography tandem mass spectrometry (LC-MS/MS). Over the investigated dosing range, both QTP and NQTP showed linear pharmacokinetics. Following oral administration of the same dose, the area under the concentration-time curve (AUC_0-∞) and maximum serum concentration (C_max) were larger after NQTP administration compared to QTP administration. In addition, NQTP had a greater absolute oral bioavailability compared to QTP (15.6% vs. 0.63%, respectively). The brain-to-plasma concentration ratio was greater after NQTP administration compared to the QTP and NQTP ratios after QTP administration. NQTP administration results in increased systemic exposure and brain distribution compared to QTP administration. Future studies are needed to evaluate the pharmacologic and toxicologic effects of increased NQTP exposures.

Cardiac effects of sertindole and quetiapine: analysis of ECGs from a randomized double-blind study in patients with schizophrenia

The QT interval is the most widely used surrogate marker for predicting TdP; however, several alternative surrogate markers, such as Tpeak-Tend (TpTe) and a quantitative T-wave morphology combination score (MCS) have emerged. This study investigated the cardiac effects of sertindole and quetiapine using the QTc interval and newer surrogate markers. Data were derived from a 12 week randomized double-blind study comparing flexible dosage of sertindole 12-20mg and quetiapine 400-600mg in patients with schizophrenia. ECGs were recorded digitally at baseline and after 3, 6 and 12 weeks. Between group effects were compared by using a mixed effect model, whereas assessment within group was compared by using a paired t-test. Treatment with sertindole was associated with QTcF and QTcB interval prolongation and an increase in MCS, T-wave asymmetry, T-wave flatness and TpTe. The mean increase in QTcF from baseline to last observation was 12.1ms for sertindole (p<0.001) and -0.5ms for quetiapine (p=0.8). Quetiapine caused no increase in MCS, T-wave asymmetry, T-wave flatness or TpTe compared to baseline. In the categorical analysis, there were 11 patients (9.6%) receiving quetiapine who experienced more than 20ms QTcF prolongation compared with 36 patients (33.3%) in the sertindole group. Sertindole (12-20mg) was associated with moderate QTc prolongation and worsening of T-wave morphology in a study population of patients with schizophrenia. Although, quetiapine (400-600mg) did not show worsening of repolarization measures some individual patients did experience significant worsening of repolarization. Clinical Trials NCT00654706.

Comparative analysis of the treatment of chronic antipsychotic drugs on epileptic susceptibility in genetically epilepsy-prone rats

Antipsychotic drugs (APs) are of great benefit in several psychiatric disorders, but they can be associated with various adverse effects, including seizures. To investigate the effects of chronic antipsychotic treatment on seizure susceptibility in genetically epilepsy-prone rats, some APs were administered for 7 weeks, and seizure susceptibility (audiogenic seizures) was evaluated once a week during treatment and for 5 weeks after drug withdrawal. Furthermore, acute and subchronic (5-day treatment) effects were also measured. Rats received haloperidol (0.2-1.0 mg/kg), clozapine (1-5 mg/kg), risperidone (0.03-0.50 mg/kg), quetiapine (2-10 mg/kg), aripriprazole (0.2-1.0 mg/kg), and olanzapine (0.13-0.66 mg/kg), and tested according to treatment duration. Acute administration of APs had no effect on seizures, whereas, after regular treatment, aripiprazole reduced seizure severity; haloperidol had no effects and all other APs increased seizure severity. In chronically treated rats, clozapine showed the most marked proconvulsant effects, followed by risperidone and olanzapine. Quetiapine and haloperidol had only modest effects, and aripiprazole was anticonvulsant. Finally, the proconvulsant effects lasted at least 2-3 weeks after treatment suspension; for aripiprazole, a proconvulsant rebound effect was observed. Taken together, these results indicate and confirm that APs might have the potential to increase the severity of audiogenic seizures but that aripiprazole may exert anticonvulsant effects. The use of APs in patients, particularly in patients with epilepsy, should be monitored for seizure occurrence, including during the time after cessation of therapy. Further studies will determine whether aripiprazole really has a potential as an anticonvulsant drug and might also be clinically relevant for epileptic patients with psychiatric comorbidities.

The effect of quetiapine (Seroquel™) on conditioned place preference and elevated plus maze tests in rats when administered alone and in combination with (+)-amphetamine

RATIONALE

Recent case reports describe recreational use of quetiapine and drug-seeking behaviour to obtain quetiapine, an atypical antipsychotic.

OBJECTIVE

We examined the hypothesis that quetiapine (10, 20 or 40 mg/kg) alone or co-administered with (+)-amphetamine (0.25, 0.5, 0.75 or 2.0 mg/kg) will affect reward and/or decrease anxiety in rats, as measured by conditioned place preference (CPP) and elevated plus maze (EPM) test, respectively.

RESULTS

Quetiapine (20 mg/kg) produced greater open arm time and entries in the EPM test compared to 10 and 40 mg/kg, and quetiapine (10 mg/kg) significantly increased open arm entries and time when co-administered with (+)-amphetamine (0.5 mg/kg) compared to (+)-amphetamine (0.5 mg/kg) alone, suggesting decreased anxiety. Quetiapine (10, 20 or 40 mg/kg) produced no CPP when administered alone; the lowest dose of quetiapine (10 mg/kg) reduced CPP produced by a low dose of (+)-amphetamine (0.25 mg/kg), but had no significant effect on CPP produced by a higher dose (0.5 mg/kg).

DISCUSSION

The quetiapine-induced anxiolytic effect in the EPM might explain why humans are misusing quetiapine and combining it with (+)-amphetamine. It is possible that humans experience an anxiolytic effect of the combined drugs and relatively unaltered rewarding effects of (+)-amphetamine. The results shed some light on the question of why humans are abusing and misusing quetiapine, despite its dopamine (DA) D2 receptor antagonism; it will be the task of future studies to identify the pharmacological mechanism mediating this behaviour.

Use of second generation antipsychotics for treatment-resistant major depressive disorder

Many of the second generation antipsychotics (SGAs) have been studied as adjunctive agents in the management of treatment-resistant major depressive disorder. Two have also been examined for use as monotherapy for depression. Currently, aripiprazole, olanzapine (in combination with fluoxetine), and quetiapine XR are approved by the FDA for use as adjunctive agents in the treatment of major depressive disorder, and no SGAs are FDA-approved as monotherapy for the disorder. This article reviews the available evidence regarding the use of SGAs in patients with treatment-resistant major depressive disorder and the subsequent role for these agents based on this evidence. There is evidence that aripiprazole, quetiapine, olanzapine, and risperidone can be effective in improving depressive symptoms when added to antidepressant therapy, but the benefits have to be weighed against their risk of producing serious adverse effects.

On 'polypharmacy' and multi-target agents, complementary strategies for improving the treatment of depression: a comparative appraisal

Major depression is a heterogeneous disorder, both in terms of symptoms, ranging from anhedonia to cognitive impairment, and in terms of pathogenesis, with many interacting genetic, epigenetic, developmental and environmental causes. Accordingly, it seems unlikely that depressive states could be fully controlled by a drug possessing one discrete mechanism of action and, in the wake of disappointing results with several classes of highly selective agent, multi-modal treatment concepts are attracting attention. As concerns pharmacotherapy, there are essentially two core strategies. First, multi-target antidepressants that act via two or more complementary mechanisms and, second, polypharmacy, which refers to co-administration of two distinct drugs, usually in separate pills. Both multi-target agents and polypharmacy ideally couple a therapeutically unexploited action to a clinically established mechanism in order to enhance efficacy, moderate side-effects, accelerate onset of action and treat a broader range of symptoms. The melatonin MT1/MT2 agonist and 5-HT(2C) antagonist, agomelatine, which is effective in the short- and long-term treatment of depression, exemplifies the former approach, while evidence-based polypharmacy is illustrated by the adjunctive use of second-generation antipsychotics with serotonin reuptake inhibitors for treatment of resistant depression. Histone acetylation and methylation, ghrelin signalling, inflammatory modulators, metabotropic glutamate-7 receptors and trace amine-associated-1 receptors comprise attractive substrates for new multi-target and polypharmaceutical strategies. The present article outlines the rationale underpinning multi-modal approaches for treating depression, and critically compares and contrasts the pros and cons of established and potentially novel multi-target vs. polypharmaceutical treatments. On balance, the former appear the most promising for the elaboration, development and clinical implementation of innovative concepts for the more effective management of depression.

Quetiapine extended release: preliminary evidence of a rapid onset of the antidepressant effect in bipolar depression

BACKGROUND AND AIMS

Quetiapine (QTP) has been shown to be effective as an acute treatment in patients with bipolar depression. Nonetheless, the time at onset of QTP antidepressant action has not been clarified. We aimed to evaluate the onset of the antidepressant effect of QTP extended release (XR) in bipolar depression. We also compared the different efficacy and adverse effect profile of 300- and 600-mg/d dosages.

METHODS

Twenty-one acutely bipolar depressed patients were recruited; 13 were treated with QTP XR 300 and 8 with 600 mg/d. Assessment was performed with Hamilton Depression Rating Scale (also considering clusters "core," "somatic anxiety," "psychic anxiety," "activity," and "delusion"), Hamilton Anxiety Rating Scale, Dosage Record and Treatment Emergent Symptom Scale.

RESULTS

Quetiapine XR was effective since the first 3 days of treatment in reducing all the efficacy measures except for somatic anxiety. The comparison of 300- and 600-mg dosages was limited by the small sample size. However, the analysis did not show any significant difference in terms of efficacy, although with a trend in favor of 600 mg. The incidence of hypotension was significantly higher in patients taking QTP 600 mg (P = 0.004).

DISCUSSION AND CONCLUSION

Quetiapine seems to be effective in bipolar depression within the first days of treatment. There may be not a significant advantage for the 600-mg dose in comparison with the 300-mg one. The clinical effect seems to be not associated with sedation, suggesting that it may be due to the molecular drug effect. Further studies focusing on the first days of treatment are needed to confirm our findings.

Quetiapine extended-release (Seroquel-XR) versus amitriptyline monotherapy for treating patients with fibromyalgia: a 16-week, randomized, flexible-dose, open-label trial

RATIONALE

Previous open-label studies have suggested that quetiapine could be a valuable alternative for treating fibromyalgia.

OBJECTIVE

This study aims to compare the efficacy and tolerability of extended-release quetiapine with amitriptyline for treating fibromyalgia.

METHODS

This study was a randomized, open-label, flexible-dose, non-inferiority trial. Patients with fibromyalgia were randomized to receive quetiapine extended-release (XR) (N = 45) (50 to 300 mg daily) or amitriptyline (N = 45) (10 to 75 mg daily) for 16 weeks. The primary endpoint was the change from baseline to endpoint in the Fibromyalgia Impact Questionnaire (FIQ) total score; the non-inferiority threshold was established at 8 points. The secondary outcomes included sleep quality, anxiety, depression, and quality of life.

RESULTS

Twenty-two (49%) patients in the quetiapine group and 34 (76%) patients in the amitriptyline group completed the study. We found a reduction of 9.8 points in the total FIQ score at the endpoint for the quetiapine-treated patients compared to 13.9 points for the amitriptyline-treated patients, for a difference of 4.14 points (80% confidence interval (CI) -0.70 to 8.98). No significant differences were found between the quetiapine XR and amitriptyline groups for any of the secondary outcomes. The proportion of patients discontinuing treatment due to adverse events was higher in the quetiapine group (n = 14, 31.1%) than the amitriptyline group (n = 3, 6.6%).

CONCLUSIONS

Our results appear to indicate that quetiapine XR does not provide similar efficacy to amitriptyline for treating patients with fibromyalgia. Quetiapine XR had a worse tolerability than amitriptyline in this population, possibly due to a relatively high starting dose.

A neurobiological hypothesis of treatment-resistant depression - mechanisms for selective serotonin reuptake inhibitor non-efficacy

First-line treatment of major depression includes administration of a selective serotonin reuptake inhibitor (SSRI), yet studies suggest that remission rates following two trials of an SSRI are <50%. The authors examine the putative biological substrates underlying "treatment resistant depression (TRD)" with the goal of elucidating novel rationales to treat TRD. We look at relevant articles from the preclinical and clinical literature combined with clinical exposure to TRD patients. A major focus was to outline pathophysiological mechanisms whereby the serotonin system becomes impervious to the desired enhancement of serotonin neurotransmission by SSRIs. A complementary focus was to dissect neurotransmitter systems, which serve to inhibit the dorsal raphe. We propose, based on a body of translational studies, TRD may not represent a simple serotonin deficit state but rather an excess of midbrain peri-raphe serotonin and subsequent deficit at key fronto-limbic projection sites, with ultimate compromise in serotonin-mediated neuroplasticity. Glutamate, serotonin, noradrenaline, and histamine are activated by stress and exert an inhibitory effect on serotonin outflow, in part by "flooding" 5-HT1A autoreceptors by serotonin itself. Certain factors putatively exacerbate this scenario - presence of the short arm of the serotonin transporter gene, early-life adversity and comorbid bipolar disorder - each of which has been associated with SSRI-treatment resistance. By utilizing an incremental approach, we provide a system for treating the TRD patient based on a strategy of rescuing serotonin neurotransmission from a state of SSRI-induced dorsal raphe stasis. This calls for "stacked" interventions, with an SSRI base, targeting, if necessary, the glutamatergic, serotonergic, noradrenergic, and histaminergic systems, thereby successively eliminating the inhibitory effects each are capable of exerting on serotonin neurons. Future studies are recommended to test this biologically based approach for treatment of TRD.

Acute anxiolytic effects of quetiapine during virtual reality exposure--a double-blind placebo-controlled trial in patients with specific phobia

Anxiety disorders are among the most frequent psychiatric disorders. With regard to pharmacological treatment, antidepressants, the calcium modulator pregabalin and benzodiazepines are recommended according to current treatment guidelines. With regard to acute states of anxiety, so far practically only benzodiazepines provide an immediate anxiolytic effect. However, the risk of tolerance and dependency limits the use of this class of medication. Therefore, there is still a need for alternative pharmacologic strategies. Increasing evidence points towards anxiety-reducing properties of atypical antipsychotics, particularly quetiapine. Therefore, we aimed to evaluate the putative acute anxiolytic effects of this compound, choosing the induction of acute anxiety in patients with specific phobia as a model for the evaluation of ad-hoc anxiolytic properties in a proof-of-concept approach. In a randomized, double-blind, placebo-controlled study, 58 patients with arachnophobia were treated with a single dose of quetiapine XR or placebo prior to a virtual reality spider challenge procedure. Treatment effects were monitored using rating scales for acute anxiety as well as measurements of heart rate and skin conductance. Overall, quetiapine showed significant anxiolytic effects compared to placebo. However, effects were not seen on the primary outcome measure (VAS Anxiety), but were limited to somatic anxiety symptoms. Additionally, a significant reduction of skin conductance was observed. Further exploratory analyses hint towards a mediating role of the (COMT) val158met genotype on treatment response. The present results thus suggest a possible suitability of quetiapine in the acute treatment of anxiety, particularly with regard to somatic symptoms.

Unique pharmacological actions of atypical neuroleptic quetiapine: possible role in cell cycle/fate control

Quetiapine is an atypical neuroleptic with a pharmacological profile distinct from classic neuroleptics that function primarily via blockade of dopamine D2 receptors. In the United States, quetiapine is currently approved for treating patients with schizophrenia, major depression and bipolar I disorder. Despite its widespread use, its cellular effects remain elusive. To address possible mechanisms, we chronically treated mice with quetiapine, haloperidol or vehicle and examined quetiapine-specific gene expression change in the frontal cortex. Through microarray analysis, we observed that several groups of genes were differentially expressed upon exposure to quetiapine compared with haloperidol or vehicle; among them, Cdkn1a, the gene encoding p21, exhibited the greatest fold change relative to haloperidol. The quetiapine-induced downregulation of p21/Cdkn1a was confirmed by real-time polymerase chain reaction and in situ hybridization. Consistent with single gene-level analyses, functional group analyses also indicated that gene sets associated with cell cycle/fate were differentially regulated in the quetiapine-treated group. In cortical cell cultures treated with quetiapine, p21/Cdkn1a was significantly downregulated in oligodendrocyte precursor cells and neurons, but not in astrocytes. We propose that cell cycle-associated intervention by quetiapine in the frontal cortex may underlie a unique efficacy of quetiapine compared with typical neuroleptics.

Atypical antipsychotics as a possible treatment option for irritable bowel syndrome

INTRODUCTION

Irritable bowel syndrome (IBS) is a prevalent functional gastrointestinal disorder (FGID) that is characterised by chronic abdominal pain, discomfort, bloating, and alteration of bowel habits. Although the pathophysiology of IBS is not fully understood, it is believed that psychiatric comorbidities are highly common in such patients. A variety of psychotropic medications are widely used in the treatment of IBS, particularly older antidepressants such as tricyclic antidepressants (TCAs).

AREAS COVERED

With the advent of newer antidepressant classes with better safety and tolerability compared with TCAs, such as serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs), clinicians now have more advanced treatment options for treating IBS. Additionally, some atypical antipsychotics (AAs) have recently received approval for treatment of major depressive disorder (MDD). Some AAs may have potentials based on their pharmacodynamic profile and proven benefit for mood symptoms, pain, anxiety and sleep disturbances. This article describes the potential rationale, clinical data and practical aspects involved in the use of AAs for patients with IBS.

EXPERT OPINION

Atypical antipsychotics (AAs) may have a role in the treatment of irritable bowel syndrome (IBS) based on the currently available findings, although there is no clear evidence, and a number of clinical issues to be addressed in the use of AAs for the treatment of IBS.

Evidences for the involvement of sigma receptors in antidepressant like effect of quetiapine in mice

Although quetiapine is routinely used in the treatment of schizophrenia and bipolar disorders, the precise mechanism of its antidepressant activity is poorly understood. Since quetiapine binds with sigma receptor, the possibility exists that antidepressant action of quetiapine may be mediated through interaction with sigma receptors. In the present study, quetiapine [40-80 μg/mouse, intracerebroventricular (i.c.v.) and 40 mg/kg, intraperitoneal (i.p.)], sigma1 receptor agonist, (+)-pentazocine (120 μg/mouse, i.c.v.) and sigma2 receptor agonist, PB-28 [1-Cyclohexyl-4-[3-(1,2,3,4-tetrahydro-5-methoxy-1-naphthalenyl)propyl]piperazine] (20 μg/mouse, i.c.v.) significantly decreased immobility time in forced swim test. In combination studies, the antiimmobility effect of quetiapine (20 μg/mouse, i.c.v.) was significantly potentiated by pretreatment with (+)-pentazocine (30 and 60 μg/mouse, i.c.v.) or PB-28 (5 and 10 μg/mouse, i.c.v.). Conversely, prior administration of sigma1 receptor antagonist, BD-1063 [1-[2-(3,4-Dichlorophenyl)ethyl]-4-methylpiperazine] and sigma2 receptor antagonists, SM-21 [(±)-Tropanyl 2-(4-chlorophenoxy)butanoate] antagonized the antiimmobility effect induced by quetiapine and its synergistic combination with sigma receptor agonists. These results demonstrated the involvement of sigma receptors in the antidepressant like effect of quetiapine and suggest that sigma receptors can be explored as a potential therapeutic target for the treatment of depressive disorders.

Peripheral brain-derived neurotrophic factor changes along treatment with extended release quetiapine during acute mood episodes: an open-label trial in drug-free patients with bipolar disorder

Molecules that are involved in neuronal intercommunication and adaptability of neural networks, such as brain-derived neurotrophic factor (BDNF), are targets of pathophysiological investigation in bipolar disorder (BD). Quetiapine is an attested treatment in this disorder, used in acute mood episodes. The aim of this study was to report prospective changes in serum BDNF levels in drug-free patients in acute mood episodes of BD who received treatment with extended-release quetiapine along a 16 week follow-up. Assessments were performed at baseline and weeks 2, 4, 8 and 16 with the Young Mania Rating Scale, the Hamilton Depression Rating Scale and the Clinical Global Impression severity scale. In these visits, serum BDNF levels were measured. Mixed effect models were used to investigate longitudinal changes. Twenty-five patients were included for this analysis, seventeen in a current depressive episode and eight in a manic/mixed episode. A significant improvement from baseline to endpoint was displayed. In the mixed model, significant main effects for episode and time appeared, and a time versus episode interaction showing increasing BDNF levels with time in those with a depressive episode, but a decrease in BDNF levels with time in those with a manic/mixed episode. BDNF may be a biomarker with differential response according to the polarity of mood episodes.

Comparison of quetiapine and risperidone in Chinese Han patients with schizophrenia: results of a single-blind, randomized study

OBJECTIVE

To evaluate the efficacy and safety of 750 mg/day quetiapine fumarate (Seroquel) in the treatment of Chinese Han patients with schizophrenia.

METHODS

In this 6-week, multicenter, randomized, rater single-blind study, a total of 119 patients with schizophrenia were randomly assigned to quetiapine (n = 60, 750 mg/day) or risperidone (n = 59, 4 mg/day). The efficacy was assessed by the Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression-Change (CGI-C) and the Calgary Depression Scale for Schizophrenia (CDSS). Safety and tolerability assessments included treatment-emergent adverse events, laboratory tests and electrocardiograms.

RESULTS

The primary analysis demonstrated no significant difference between treatment in the two groups (quetiapine vs. risperidone: 31.9 ± 17.5 vs. 33.3 ± 17.3; P = 0.668). Improvements with both treatments were comparable for total PANSS, positive and negative subscores, general psychopathology subscales, and excitement and attack symptoms. Improvements in CGI-S were similar between treatment groups (P = 0.046). A more favorable trend was detected for quetiapine than risperidone in the reduction of CDSS scores from baseline, especially at week 1 (1.1 ± 2.2 vs. 0.3 ± 2.1, P < 0.050). The rate of extrapyramidal symptom (EPS) and hyperprolactinemia-related adverse events was significantly lower in the quetiapine group than the risperidone group (13.3% vs. 43.3%, P < 0.001). Dizziness and somnolence were more common in the quetiapine group than the risperidone group.

CONCLUSION

Quetiapine fumarate (750 mg/day) has broad clinical efficacy comparable to 4 mg/day risperidone. Dizziness was common in the quetiapine group (P = 0.029), but the rate of somnolence was similar between the two groups (P = 0.114). EPS and hyperprolactinemia rates were significantly higher with risperidone (P < 0.001). Key limitations of this study include small sample size, short treatment periods, and no increase to 6 mg/day for risperidone because of its safety profile.

The Affective and Emotional Composite Temperament (AFECT) model and scale: a system-based integrative approach

Based on many temperament frameworks, here we propose an integration of emotional and affective temperaments (the AFECT model), forming a common substrate for mood, behavior, personality and part of cognition. Temperament is conceived as a self-regulated system with six emotional dimensions: volition, anger, inhibition, sensitivity, coping and control. The different combinations of these emotional dimensions result in 12 affective temperament types, namely depressive, anxious, apathetic, obsessive, cyclothymic, dysphoric, irritable, volatile, disinhibited, hyperthymic and euphoric. We also developed and validated a self-report scale to evaluate this construct, the Affective and Emotional Composite Temperament Scale (AFECTS).

METHODS

Exploratory and confirmatory psychometric analyses were performed with the internet version of the AFECTS in 2947 subjects (72% females, 35±11years old).

RESULTS

The factors interpreted as volition, anger, inhibition, sensitivity, coping and control showed very good Cronbach's alphas for 5 dimensions (0.87-0.90) and acceptable alpha for inhibition (0.75). Confirmatory factor analysis corroborated this 6-factor structure when considering inhibition as a second-order factor with fear and caution as first-order factors (SRMR=0.061; RMSEA=0.053). In the Affective section, all 12 categorical affective temperaments were selected in the categorical choice, with 99% of volunteers identifying at least one adequate description of their affective temperament.

LIMITATIONS

Only the internet version was used in a general population sample.

CONCLUSION

The AFECT model provides an integrated framework of temperament as a self-regulated system, with implications for mental health, psychiatric disorders and their treatment. The AFECTS showed good psychometric properties to further study this model.

Quetiapine: a review of its use in the management of bipolar depression

Quetiapine (Seroquel®) is an orally administered atypical antipsychotic that is indicated for the treatment of schizophrenia and bipolar disorder, including bipolar depression. An extended-release (XR) formulation of quetiapine is also available. This review summarizes the pharmacological properties, efficacy and tolerability of quetiapine and quetiapine XR in patients with bipolar depression. Quetiapine is an antagonist at both serotonin 5-HT2 and dopamine D2 receptors, and its antipsychotic effects are thought to stem from interactions at these receptors. The antidepressant effects of quetiapine are poorly understood, but may be related to antagonism of 5-HT2A receptors in cortical regions, partial agonism of 5-HT1A in the prefrontal cortex in association with increased extracellular dopamine release in the region, or to reduced synaptic reuptake of noradrenaline resulting from inhibition of the noradrenaline reuptake transporter by the quetiapine metabolite norquetiapine. The efficacy and tolerability of quetiapine was evaluated in five 8-week, randomized, double-blind, placebo-controlled, multicentre or multinational trials in patients with a major depressive episode (MDE) associated with bipolar disorder. Across trials, monotherapy with oral quetiapine 300 or 600 mg/day (or quetiapine XR 300 mg/day) produced significantly greater improvements than placebo in depressive symptoms (primary endpoint), according to the change in the Montgomery-Asberg Depression Rating Scale total score. In general, quetiapine and quetiapine XR were also associated with significantly higher MDE response and remission rates than placebo. Across trials, quetiapine and quetiapine XR produced significantly greater improvements in global severity of illness scores than placebo, according to changes in the Clinical Global Impressions scale score. There were no differences in treatment outcomes between quetiapine 300 mg/day and 600 mg/day dosage groups. Patients with bipolar depression who responded to quetiapine during two 8-week acute treatment trials also benefited from continuing quetiapine therapy for up to 52 weeks. Compared with quetiapine responders randomized to placebo, quetiapine responders who continued quetiapine 300 or 600 mg/day had a significantly reduced risk of recurrence of any mood events and of depression mood events, but not of hypomanic/manic events. In a randomized, double-blind, placebo-controlled trial, quetiapine maintenance therapy for up to 104 weeks was more efficacious than placebo or lithium in prolonging the time to recurrence of any mood event (primary endpoint). Patients in this trial had bipolar I disorder with mania, depression or a mixed episode as the index episode, and the trial included only patients who were responsive to acute phase quetiapine, which may have introduced a positive bias in favour of quetiapine over lithium during maintenance therapy. Quetiapine 300 or 600 mg/day and quetiapine XR 300 mg/day was generally well tolerated in patients with bipolar depression, with most treatment-emergent adverse events being of mild to moderate severity. The most frequent adverse events occurring during the acute treatment phase were dry mouth, sedation, somnolence, dizziness (quetiapine and quetiapine XR), constipation (quetiapine) and increased appetite (quetiapine XR). Extrapyramidal symptoms (EPS) occurred across quetiapine and placebo groups, but there were no significant differences between quetiapine and placebo recipients on objective measures of EPS and akathisia. In some trials, quetiapine recipients experienced significantly greater weight gain than placebo recipients. Across trials, some quetiapine recipients had clinically relevant increases in blood glucose or lipid parameters, although these also occurred in patients from other treatment groups. The clinical significance of these changes is uncertain. In conclusion, quetiapine and quetiapine XR are valuable additions to the first-line treatments for bipolar depression. Further head-to-head trials of quetiapine versus other drug regimens that are effective in bipolar depression would be of considerable interest.

Receptor targets for antidepressant therapy in bipolar disorder: an overview

The treatment of bipolar depression is one of the most challenging issues in contemporary psychiatry. Currently only quetiapine and the olanzapine-fluoxetine combination are officially approved by the FDA against this condition. The neurobiology of bipolar depression and the possible targets of bipolar antidepressant therapy remain relatively elusive. We performed a complete and systematic review to identify agents with definite positive or negative results concerning efficacy followed by a second systematic review to identify the pharmacodynamic properties of these agents. The comparison of properties suggests that the stronger predictors for antidepressant efficacy in bipolar depression were norepinephrine alpha-1, dopamine D1 and histamine antagonism, followed by 5-HT2A, muscarinic and dopamine D2 and D3 antagonism and eventually by norepinephrine reuptake inhibition and 5HT-1A agonism. Serotonin reuptake which constitutes the cornerstone in unipolar depression treatment does not seem to play a significant role for bipolar depression. Our exhaustive review is compatible with a complex model with multiple levels of interaction between the major neurotransmitter systems without a single target being either necessary or sufficient to elicit the antidepressant effect in bipolar depression.

Clinical Need and Rationale for Multi-Target Drugs in Psychiatry

High attrition in attempts to discover new pharmacological agents for the treatment of psychiatric disorders has triggered a decline in R&D investment in important disease categories such as schizophrenia and mood disorders. Poor knowledge about disease molecular pathology and molecular target validation coupled with notable costly failures involving clinical trials with highly novel and selective single target agents (STAs) have contributed to the development of this trend. One positive development arising from the current situation is the renewed interest in investigating approaches involving multi-target agents (MTAs), which have historically shown a strong track record of success and utility in the treatment of psychiatric disorders. However, it is clear that the traditional serendipity-dependent drug discovery approach for multi-target agents is suboptimal and has to evolve towards a new model of rationally designed and tailored MTAs. It is of course highly challenging to optimise compounds across several therapeutic targets whilst minimising potential broad receptor promiscuity as well as other properties to generate high quality drug candidates. Nevertheless, recent developments in medicinal chemistry approaches and pharmacological evaluation suggest that feasibility for tailored MTAs is not unrealistic. Appropriately designed MTAs, such as hybrids of validated and unprecedented novel molecular targets, offer a multi-functional pharmacology with the potential for multi-symptomatic efficacy and multi-indicational use. If successful this will help to address the compelling unmet medical need and the treatment requirements of schizophrenia and mood disorder patients as well as easing the burden of carers and the societal costs arising from these devastating illnesses.

Quetiapine extended release: adjunctive treatment in major depressive disorder

Quetiapine extended release (XR) is a once-daily oral formulation of the atypical antipsychotic quetiapine that is available for use as adjunctive therapy in major depressive disorder (MDD). Systemic quetiapine exposure after orally administered quetiapine XR is similar to that of quetiapine immediate release at the same dosage, although quetiapine XR is absorbed more slowly and plasma concentrations are more stable over time. In two 6-week, randomized, double-blind, placebo-controlled, multinational trials in patients with MDD with an inadequate response to antidepressants, quetiapine XR 300 mg/day adjunctive to antidepressant reduced depressive symptoms significantly more than antidepressant plus placebo, according to changes in Montgomery-Åsberg Depression Rating Scale (MADRS) total scores. In one trial, adjunctive quetiapine XR 150 mg/day also led to significantly greater reductions in MADRS total scores than antidepressant plus placebo. MDD response rates were significantly higher with adjunctive quetiapine XR 300 mg/day (but not 150 mg/day) than with antidepressant plus placebo. The numbers needed to treat to achieve an additional response over antidepressant plus placebo were 11-18 and 8-9 in the quetiapine XR 150 and 300 mg/day dosage groups, respectively. Treatment-emergent adverse events were mostly of mild to moderate severity; 1% of adjunctive quetiapine XR and 1.3% of antidepressant plus placebo recipients reported serious adverse events.

Anti-depressive effectiveness of olanzapine, quetiapine, risperidone and ziprasidone: a pragmatic, randomized trial

BACKGROUND

Efficacy studies indicate anti-depressive effects of at least some second generation antipsychotics (SGAs). The Bergen Psychosis Project (BPP) is a 24-month, pragmatic, industry-independent, randomized, head-to-head comparison of olanzapine, quetiapine, risperidone and ziprasidone in patients acutely admitted with psychosis. The aim of the study is to investigate whether differential anti-depressive effectiveness exists among SGAs in a clinically relevant sample of patients acutely admitted with psychosis.

METHODS

Adult patients acutely admitted to an emergency ward for psychosis were randomized to olanzapine, quetiapine, risperidone or ziprasidone and followed for up to 2 years. Participants were assessed repeatedly using the Positive and Negative Syndrome Scale-Depression factor (PANSS-D) and the Calgary Depression Scale for Schizophrenia (CDSS).

RESULTS

A total of 226 patients were included. A significant time-effect showing a steady decline in depressive symptoms in all medication groups was demonstrated. There were no substantial differences among the SGAs in reducing the PANSS-D score or the CDSS sum score. Separate analyses of groups with CDSS sum scores > 6 or ≤6, respectively, reflecting degree of depressive morbidity, revealed essentially identical results to the primary analyses. There was a high correlation between the PANSS-D and the CDSS sum score (r = 0.77; p < 0.01).

CONCLUSIONS

There was no substantial difference in anti-depressive effectiveness among olanzapine, quetiapine, risperidone or ziprasidone in this clinically relevant sample of patients acutely admitted to hospital for symptoms of psychosis. Based on our findings we can make no recommendations concerning choice of any particular SGA for targeting symptoms of depression in a patient acutely admitted with psychosis.

TRIAL REGISTRATION

ClinicalTrials.gov ID; URL: http://www.clinicaltrials.gov/: NCT00932529.

Quetiapine anxiolytic-like effect in the Vogel conflict test is serotonin dependent

There is growing evidence to show that atypical antipsychotic quetiapine might exert an anxiolytic effect in patients. Nevertheless, the mechanism underlying this effect has not yet been fully explored. Like other anxiolytic drugs, quetiapine exhibits partial agonistic activity toward serotonergic 1A (5HT1A) receptors. The involvement of the serotonin system in anxiety, particularly of 5HT1A receptors, has been widely documented. In this study we have investigated whether different doses of quetiapine (5, 10, and 30 mg/kg, oral gavage) administered to C57BL6/N mice could produce an anxiolytic effect in the Vogel conflict test, a classical model of anxiety, and whether or not the selective 5HT1A antagonist WAY100635 (0.1 mg/kg, subcutaneously) might prevent such an effect. Our results show that 10 mg/kg quetiapine exhibits an anxiolytic effect, that is, at least in part, 5HT1A-mediated, because it is completely eliminated by WAY100635.

Acute quetiapine dose-dependently exacerbates anhedonia induced by withdrawal from escalating doses of d-amphetamine

Recent clinical studies show that the atypical antipsychotic medication, quetiapine, may be beneficial in the treatment of substance abuse by alleviating the withdrawal-negative affect stage of addiction. Since the effect of quetiapine on central reward function is largely unknown we studied its effects on brain stimulation reward in animals under withdrawal from escalating doses of d-amphetamine. Male Sprague-Dawley rats were trained to produce an operant response to receive a short train of electrical stimulation to the lateral hypothalamus. Measures of reward threshold were determined with the curve-shift method in different groups of rats before, and during four days after treatment with escalating doses (1 to 10mg/kg, i.p.) of d-amphetamine or its vehicle. At 24h of withdrawal, the effects of two doses of quetiapine (2 and 10mg/kg i.p.) were tested. Animals treated with d-amphetamine showed a 25% reward deficit at 24h of withdrawal, an effect that decreased progressively over the next three days. Quetiapine attenuated reward in the vehicle-control animals, and amplified the anhedonia at the moderate, but not the low, dose in the animals under withdrawal. These results show that acute treatment with clinically relevant doses of quetiapine for the treatment of schizophrenia may exacerbate anhedonia induced by amphetamine withdrawal. Further research should investigate whether repeated treatment with quetiapine has the ability to reverse amphetamine withdrawal-induced anhedonia.

Low-dose quetiapine for patients with dysregulation of hyperthymic and cyclothymic temperaments

Patients with hyperthymic and cyclothymic temperaments often develop symptoms that fail to meet diagnostic criteria for bipolar disorders. These patients can be conceived as having bipolar disorder NOS (not otherwise specified), a bipolar spectrum disorder, cyclothymic disorder or cluster B personality traits. Here, we describe four of these patients with mild to moderate symptoms affecting mood, behaviour, emotional reactivity and sleep. Treatment with low-dose quetiapine (25-75 mg/day at night) lead to sustained symptom remission. Two of them were on quetiapine monotherapy. Such low doses occupy a minority of D2 and 5-HT2 receptors, which may nevertheless be of therapeutic value in mild cases. Alternatively, other mechanisms more likely to occur at low doses, such as antagonism of H1, alpha(1B)-adrenergic and other serotonin receptors, as well as reduction cortisol secretion, may be involved in the therapeutic efficacy of quetiapine.

Quetiapine XR efficacy and tolerability as monotherapy and as adjunctive treatment to conventional antidepressants in the acute and maintenance treatment of major depressive disorder: a review of registration trials

Results from pivotal registration trials in major depressive disorder cohere with outcomes from effectiveness studies indicating that the majority of individuals receiving single-agent pharmacotherapy fail to achieve and sustain symptomatic remission. Several factors provided the impetus for this review: suboptimal efficacy with existing pharmacotherapy for major depressive disorder, quetiapine XR efficacy in the acute and maintenance treatment of bipolar depression, emerging pharmacodynamic evidence that quetiapine XR (and/or its metabolites) uniquely engages monoaminergic systems salient to symptom relief in depressive syndromes, the increasing use of second-generation antipsychotics in the treatment of major depressive disorder and the recent FDA review of quetiapine XR in major depressive disorder. Studies reviewed herein are pivotal registration trials that evaluated the acute and maintenance efficacy and tolerability of quetiapine XR (as monotherapy and as adjunctive treatment) in major depressive disorder. In addition, we also review recent investigations characterizing the pharmacodynamic effect of quetiapine's principal active metabolite, norquetiapine. All studies were obtained from AstraZeneca (Wilmington, DE, USA) and have been presented at national/international scientific meetings. Taken together, extant studies demonstrated that quetiapine XR (50 - 300 mg) provides rapid and sustained symptomatic improvement in the acute and maintenance treatment of major depressive disorder. Quetiapine XR may also offer advantages relative to duloxetine in time to onset of antidepressant action. The major limitations of quetiapine XR use in major depressive disorder relate to weight gain and disrupted glucose/lipid homeostasis as well as sedation/somnolence. Quetiapine XR has tolerability advantages compared with duloxetine on measures of sexual dysfunction. The data from the studies reviewed herein also indicate that quetiapine XR poses a low risk for extrapyramidal side effects in middle-aged and elderly individuals with major depressive disorder.

Generalized anxiety disorder: between now and DSM-V

This article presents the current evidence base for pharmacotherapy of generalized anxiety disorder (GAD) and an update on the phenomenology of GAD and its association with other psychiatric and somatic conditions. It discusses nosological issues and suggests ways to improve recognition, treatment, and care for patients who have GAD.

Metabolism of quetiapine by CYP3A4 and CYP3A5 in presence or absence of cytochrome B5

The antipsychotic drug quetiapine is extensively metabolized by CYP3A4, but little is known about the possible influence of the polymorphic enzyme CYP3A5. This in vitro study investigated the relative importance of CYP3A4 and CYP3A5 in the metabolism of quetiapine and compared the metabolic pattern by the two enzymes, in the presence or absence of cytochrome b(5). Intrinsic clearance (CL(int)) of quetiapine was determined by the substrate depletion approach in CYP3A4 and CYP3A5 insect cell microsomes with or without coexpressed cytochrome b(5). Formation of the metabolites quetiapine sulfoxide, N-desalkylquetiapine, O-desalkylquetiapine, and 7-hydroxyquetiapine by CYP3A4 and CYP3A5 were compared in the different microsomal preparations. CL(int) of quetiapine by CYP3A5 was less than 35% relative to CYP3A4. CL(int) was higher (3-fold) in CYP3A4 microsomes without cytochrome b(5) compared with CYP3A4 microsomes with coexpressed cytochrome b(5), whereas in CYP3A5 microsomes CL(int) was similar for both microsomal preparations. Metabolism of quetiapine by CYP3A5 revealed a different metabolic pattern compared with CYP3A4. The results indicated that O-desalkylquetiapine constituted a higher proportion of the formed metabolites by CYP3A5 compared with CYP3A4. In conclusion, the present study indicates that CYP3A5 is of minor importance for the overall metabolism of quetiapine, regardless of the presence of cytochrome b(5). However, a different metabolic pattern by CYP3A5 compared with CYP3A4 could possibly result in different pharmacological and/or toxicological effects of quetiapine in patients expressing CYP3A5.

The co-administration of quetiapine or placebo to cognitive-behavior therapy in treatment refractory depression: a preliminary trial

BACKGROUND

Patients with major depression refractory to repeated pharmacological trials (TRD) may remain symptomatic for many years after their index episode. Augmentation strategies (with lithium or an atypical antipsychotic) or combining an antidepressant with short-term psychotherapy have been used with relative success in these patients. The aim of this study was to assess the effectiveness of the concomitant administration of quetiapine, an atypical antipsychotic, or placebo, to cognitive-behavior therapy (CBT) in TRD.

METHODS

Thirty-one patients who met entrance criteria for unipolar major depression (TRD stage II or greater) underwent 3 weeks of lithium augmentation after which non-responders (N = 22) were randomized to receive either quetiapine or placebo as an adjunct to their 12 weekly CBT sessions (quetiapine/CBT or placebo/CBT groups). Primary efficacy measures were the Hamilton and the Montgomery-Asberg rating scales for depression.

RESULTS

Overall, there was a significant reduction in both primary efficacy measure scores at LOCF for the 11 patients in the quetiapine/CBT group but not in the placebo/CBT treated patients. Patients in the quetiapine/CBT group, compared to those receiving placebo/CBT, showed a significantly greater degree of improvement on one primary and one secondary efficacy measure, were more likely to complete the trial and, completed a greater number of CBT sessions.

CONCLUSION

Although preliminary, our results suggest that the adjunctive administration of quetiapine to CBT may prove useful in the treatment of stage II TRD.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN12638696.