Blonanserin: a review of its use in the management of schizophrenia

Characterization of stress degradation products of blonanserin by UPLC-QTOF-tandem mass spectrometry

Forced degradation study of blonanserin and structural elucidation of its degradation products was performed using high resolution tandem mass spectrometry.

Long-term efficacy and safety of blonanserin in patients with first-episode schizophrenia: a 1-year open-label trial

AIMS

The purpose of this study was to evaluate the long-term effectiveness and safety of blonanserin, a second-generation antipsychotic drug developed in Japan, in patients with first-episode schizophrenia.

METHODS

Twenty-three antipsychotic-naïve patients with first-episode schizophrenia were treated within an open-label, 1-year, prospective trial of blonanserin (2-24 mg/day). Clinical evaluations were conducted at baseline and 2, 6, and 12 months after the start of treatment. The main outcome measures were changes in subjective well-being and subjective quality of life, as assessed by the Subjective Well-being under Neuroleptic treatment scale Short form-Japanese version and the Schizophrenia Quality of Life Scale-Japanese version, respectively. Secondary outcome measures included the Positive and Negative Syndrome Scale, the Brief Assessment of Cognition in Schizophrenia-Japanese version, laboratory tests, bodyweight, and extrapyramidal symptoms.

RESULTS

Fourteen patients (60.9%) remained on the study at 1 year. In the intention-to-treat analysis, significant improvements were observed in several subscales on the Subjective Well-being under Neuroleptic treatment scale Short form-Japanese version, the Schizophrenia Quality of Life Scale-Japanese version, and the Brief Assessment of Cognition in Schizophrenia-Japanese version, and in all factor scores on the Positive and Negative Syndrome Scale. Improvement in depressive symptoms with blonanserin treatment was positively correlated with improvements in subjective well-being and subjective quality of life, as well as verbal memory. No significant changes were noted for any safety measure during the 1-year study period.

CONCLUSIONS

Blonanserin was well tolerated and effective for the treatment of first-episode schizophrenia in terms of subjective wellness, cognition, and a wide range of pathological symptoms. Further large-scale studies are warranted to confirm our findings.

Simple and sensitive analysis of blonanserin and blonanserin C in human plasma by liquid chromatography tandem mass spectrometry and its application

A highly sensitive, simple, and rapid liquid chromatography tandem mass spectrometry method to simultaneously determine blonanserin and blonanserin C in human plasma with AD-5332 as internal standard (IS) was established. A simple direct protein precipitation method was used for the sample pretreatment, and chromatographic separation was performed on a Waters XBridge C8 (4.6 × 150 mm, 3.5  μ m) column. The mobile phase consists of a mixture of 10 mM ammonium formate and 0.1% formic acid in water (A) and 0.1% formic acid in methanol (B). To quantify blonanserin, blonanserin C, and IS, multiple reaction monitoring (MRM) was performed in positive ESI mode. The calibration curve was linear in the concentration range of 0.012-5.78 ng·mL(-1) for blonanserin and 0.023-11.57 ng·mL(-1) for blonanserin C (r (2) > 0.9990). The intra- and interday precision of three quality control (QC) levels in plasma were less than 7.5%. Finally, the current simple, sensitive, and accurate LC-MS/MS method was successfully applied to investigate the pharmacokinetics of blonanserin and blonanserin C in healthy Chinese volunteers.

Cardiometabolic risks of blonanserin and perospirone in the management of schizophrenia: a systematic review and meta-analysis of randomized controlled trials

Background

The present study aimed to evaluate cardiometabolic risks [weight gain, blood lipid levels (total cholesterol and triglycerides), blood glucose levels, hemoglobin A_1c (HbA_1c) levels, and corrected QT interval (QTc) prolongation] associated with the use of blonanserin and perospirone versus other antipsychotics in the management of patients with schizophrenia.

Method

We conducted a systematic review and meta-analysis of patient data from randomized controlled trials comparing blonanserin or perospirone with other antipsychotics.

Results

In total, 4 blonanserin studies (n  = 1080) were identified [vs. risperidone (2 studies, n = 508); vs. haloperidol (2 studies, n = 572)]. Blonanserin produced less weight gain compared with risperidone (weighted mean difference = −0.86, 95% confidence intervals = −1.36 to −0.36, p = 0.0008; 2 studies, 480 patients). However, no significant differences were observed in blood lipid, glucose, and HbA_1c levels or QTc prolongation between blonanserin and risperidone or haloperidol. For perospirone studies, 5 studies [562 adult patients with schizophrenia randomized to perospirone (n = 256), olanzapine (n = 20), quetiapine (n = 28), risperidone (n = 53), aripiprazole (n = 49), haloperidol (n = 75), or mosapramine (n = 81)] were identified. Perospirone did not differ from other antipsychotics with regard to weight gain and total cholesterol levels.

Conclusions

Our results suggest that blonanserin is associated with a lower of weight gain compared with other antipsychotics. Because the number of studies was small, additional controlled clinical trials with larger number of patients are indicated.

Blonanserin-induced Mood Alteration in Schizophrenia and Schizoaffective Disorder: Two Cases

We report two outpatients, one with schizophrenia and one with schizoaffective disorder, who developed manic or hypomanic episodes following the initiation of blonanserin during the course of treatment. Blonanserin is a novel antipsychotic that acts as a 5-HT and D2 receptor antagonist. Both patients developed hypomanic episodes within 2 weeks of receiving a small dose (6-8 mg) of blonanserin, and one patient later developed full-blown mania; both episodes ended within 1 month of discontinuing blonanserin. The mood alteration observed in these cases suggests a possible antidepressant effect of blonanserin; thus, clinicians should monitor mood changes when administering this antipsychotic.

Blonanserin, an antipsychotic and dopamine D₂/D₃receptor antagonist, and ameliorated alcohol dependence

Blonanserin (BNS) is used for treatment of both positive and negative symptoms of schizophrenia in Japan and Korea. Because BNS has weak α1 receptor blocking activities and is almost devoid of histamine H1 and muscarinic M1 antagonist activity, BNS is better tolerated than other atypical antipsychotics. A high degree of D₃ receptor blockage is reported to be predictive of drug abuse and alcoholism, and BNS has strong D₃ receptor antagonism. Thus, BNS may be useful in the treatment of alcoholism. We present a case in which BNS ameliorated alcohol dependence.

Japan useful medication program for schizophrenia (JUMPs)-long-term study on discontinuation rate, resolution and remission, and improvement in social functioning rate associated with atypical antipsychotic medications in patients with schizophrenia

BACKGROUND

It is desirable to establish evidence for the selection of antipsychotics from the viewpoint of recovery of social activity in individual patient with schizophrenia receiving medication. From this perspective, awareness of the importance of studies about drug effectiveness on treatment discontinuation rate, remission rate, and improvement in QOL has grown recently. In Western countries, numerous reports are available in effectiveness studies, which are related to olanzapine and risperidone primarily, whereas evidence for other second-generation antipsychotics (SGAs) is poor. In Japan, no effectiveness study has been reported: thus, it is desirable to collect data that will serve as evidence for selection of the 3 SGAs approved after olanzapine.

METHODS

The present study was a long-term effectiveness study under healthcare setting in Japan. It was designed as an open-label, multicenter, randomized, comparative study involving 104-week oral treatment with 1 of the 3 drugs (aripiprazole, blonanserin, and paliperidone) in patients with schizophrenia aged 20 years or over who required antipsychotic medication or switching of the current medication to others for reasons such as lack of efficacy and intolerability. The primary endpoint is treatment discontinuation rate for any causes. The secondary endpoints include remission rate, improvement of social activity, alleviation, aggravation or recurrence of psychiatric symptoms, and safety. The target number of subjects was set at 300.

DISCUSSION

Because this study is expected to yield evidence regarding the selection of antipsychotics for facilitating the recovery of social activity in patients with schizophrenia, it is considered highly valuable to perform this effectiveness study under ordinary healthcare setting in Japan.

TRIAL REGISTRATION

UMIN Clinical Trials Registry 000007942.

One-year follow-up study of psychotic patients treated with blonanserin: a case series

INTRODUCTION

Blonanserin is a relatively new atypical antipsychotic drug, and has been used in Korea and Japan for 1 and 3 years, respectively. Therefore, the clinical characteristics of blonanserin remain unclear. In this study, to clarify the features of blonanserin, we performed prospective and long-term comparative investigations of patients treated with blonanserin.

METHODS

We followed 10 psychiatric patients who were switched to blonanserin from other antipsychotics for 1 year (schizophrenia: 8; mental retardation: 2). In the light of quality of life, we focused on adverse effects of patients during the follow-up.

RESULTS

In the long-term follow-up, (i) hyperprolactinemia is more frequently in risperidone than in blonanserin; however, it is more often in blonanserin than in olanzapine; and (ii) weight gain is more common in olanzapine than in blonanserin.

DISCUSSION

We switched to blonanserin from other antipsychotic drugs within the same case, and then followed the case for 1 year. We consider that long-term observations within the same case lead to obvious comparisons among drugs. On the basis of our findings, we conclude that blonanserin may be useful for the maintenance treatment of schizophrenia without inducing hyperprolactinemia and weight gain.

The impact of prolactin-raising antipsychotics on bone mineral density in patients with schizophrenia: findings from a longitudinal observational cohort

To examine the effect of prolactin-raising antipsychotics on bone mineral density (BMD), data of 164 schizophrenia patients who received ≥2 dual-energy x-ray absorptiometry scans were analyzed (49.3% men; mean ± SD age: 58.5 ± 11.0 years; duration of treatment: 26.7 ± 13.8 years). Patients were divided into a prolactin-raising antipsychotic (n=141) or prolactin-sparing (n=23) group, and time x group interaction was examined using mixed effect model. Although the BMD difference did not reach significance over 3.4 ± 1.6 years, a significant antipsychotic-class vs. time interaction was found (p=0.011), indicating a negative impact of prolactin-raising antipsychotics on BMD. Large-scale, randomized-controlled data are required to replicate and extend these findings.

Newer antipsychotics and upcoming molecules for schizophrenia

BACKGROUND

The management of schizophrenia has seen significant strides over the last few decades, due to the increasing availability of a number of antipsychotics. Yet, the diminished efficacy in relation to the negative and cognitive symptoms of schizophrenia, and the disturbing adverse reactions associated with the current antipsychotics, reflect the need for better molecules targeting unexplored pathways.

PURPOSE

To review the salient features of the recently approved antipsychotics; namely, iloperidone, asenapine, lurasidone and blonanserin.

METHODS

We discuss the advantages, limitations and place in modern pharmacotherapy of each of these drugs. In addition, we briefly highlight the new targets that are being explored.

RESULTS

Promising strategies include modulation of the glutamatergic and GABAergic pathways, as well as cholinergic systems.

CONCLUSIONS

Although regulatory bodies have approved only a handful of antipsychotics in recent years, the wide spectrum of targets that are being explored could eventually bring out antipsychotics with improved efficacy and acceptability, as well as the potential to revolutionize psychiatric practice.

Striatal and extrastriatal dopamine D2 receptor occupancy by a novel antipsychotic, blonanserin: a PET study with [11C]raclopride and [11C]FLB 457 in schizophrenia

Blonanserin is a novel antipsychotic with high affinities for dopamine D(2) and 5-HT(2A) receptors, and it was recently approved for the treatment of schizophrenia in Japan and Korea. Although double-blind clinical trials have demonstrated that blonanserin has equal efficacy to risperidone, and with a better profile especially with respect to prolactin elevation, its profile of in vivo receptor binding has not been investigated in patients with schizophrenia. Using positron emission tomography (PET), we measured striatal and extrastriatal dopamine D(2) receptor occupancy by blonanserin in 15 patients with schizophrenia treated with fixed doses of blonanserin (ie, 8, 16, and 24 mg/d) for at least 4 weeks before PET scans, and in 15 healthy volunteers. Two PET scans, 1 with [(11)C]raclopride for the striatum and 1 with [(11)C]FLB 457 for the temporal cortex and pituitary, were performed on the same day. Striatal dopamine D(2) receptor occupancy by blonanserin was 60.8% (3.0%) [mean (SD)] at 8 mg, 73.4% (4.9%) at 16 mg, and 79.7% (2.3%) at 24 mg. The brain/plasma concentration ratio calculated from D(2) receptor occupancy in the temporal cortex and pituitary was 3.38, indicating good blood-brain barrier permeability. This was the first study to show clinical daily dose amounts of blonanserin occupying dopamine D(2) receptors in patients with schizophrenia. The clinical implications obtained in this study were the optimal therapeutic dose range of 12.9 to 22.1 mg/d of blonanserin required for 70% to 80% dopamine D(2) receptor occupancy in the striatum, and the good blood-brain barrier permeability that suggested a relatively lower risk of hyperprolactinemia.

Population pharmacokinetics of blonanserin in Chinese healthy volunteers and the effect of the food intake

OBJECTIVE

The aim of the study was to better understand blonanserin population pharmacokinetic (PK) characteristics in Chinese healthy subjects.

METHODS

Data from two studies with 50 subjects were analyzed to investigate the population PK characteristics of blonanserin at single dose (4, 8, and 12 mg) under fasting, multidose (4 mg bid or 8 mg qd for 7 days) and under food intake condition (single dose, 8 mg). Blonanserin plasma concentrations were detected using the high performance liquid chromatography tandem mass spectrometry (LC/MS/MS). A nonlinear mixed-effects model was developed to describe the blonanserin concentration-time profiles.

RESULTS

A two compartment model with first-order absorption was built to describe the time-course of blonanserin. The population-predicted system apparent clearance (CL/F), volume of apparent distribution in center (V(1)/F), and the first-order absorption rate constant (Ka) of blonanserin under fasting was 1230 L/h, 9500 L, and 3.02 h(-1), respectively. Food intake decreased Ka of blonanserin to 0.78 h(-1). The relative bioavailability between fasting and food intake estimated by the final model was 55%. No clinically significant safety issues were identified.

CONCLUSION

This is the first study assessing the PK profile of blonanserin with population PKs method. The results can be used for simulation in further clinical trial and optimize individual dosage regimens using a Bayesian methodology in patients.

Blonanserin for schizophrenia: systematic review and meta-analysis of double-blind, randomized, controlled trials

BACKGROUND

There is uncertainty about the efficacy and tolerability of blonanserin in schizophrenia.

METHOD

PubMed, the Cochrane Library databases, PsycINFO, and Google Scholar were searched up to September 2012. A systematic review and meta-analysis of individual patient data from randomized, controlled trials comparing blonanserin with other antipsychotics were conducted. The risk ratio (RR), 95% confidence intervals (CI), numbers-needed-to-harm (NNH), and weighted mean difference (WMD) were calculated.

RESULTS

Four studies (total n = 1080) were identified (vs. risperidone studies [n = 508], vs. haloperidol studies [n = 572]). Comparing blonanserin with other pooled antipsychotics, there were no significant differences in the Positive and Negative Syndrome Scale (PANSS) total score (p = 0.75), PANSS positive (p = 0.41), PANSS negative (p = 0.09), and PANSS general psychopathology subscale scores (p = 0.96), and response rate (p = 0.72). However, blonanserin showed greater efficacy in PANSS negative subscale scores compared with haloperidol (WMD = -1.29, CI = -2.29 to -0.30, p = 0.01, I(2) = 0%). No significant differences were found in discontinuation rates between blonanserin and other pooled antipsychotics (due to any cause: p = 0.29, inefficacy: p = 0.32, adverse events: p = 0.56). Blonanserin had a 0.31 lower risk of hyperprolactinemia than the other pooled antipsychotics (CI = 0.20-0.49, NNH = not significant). While dizziness (RR = 0.47, CI = 0.23-0.93, NNH = not significant) and akathisia (RR = 0.54, CI = 0.32-0.90, NNH = 7) occurred significantly less often with blonanserin than with haloperidol, blonanserin had a 1.62 higher risk of akathisia than risperidone (CI = 1.18-2.22, NNH = 8) [corrected].

CONCLUSION

Our results suggest that although blonanserin has a more beneficial effect on negative symptoms than haloperidol, there was a significant difference in the adverse events profile between blonanserin and other antipsychotics.

Profile of blonanserin for the treatment of schizophrenia

Blonanserin was developed as an antipsychotic drug in Japan and approved for the treatment of schizophrenia. It belongs to a series of 4-phenyl-2-(1-piperazinyl)pyridines and acts as an antagonist at dopamine D2, D3, and serotonin 5-HT2A receptors. Blonanserin has low affinity for 5-HT2C, adrenergic α1, histamine H1, and muscarinic M1 receptors, but displays relatively high affinity for 5-HT6 receptors. In several short-term double-blind clinical trials, blonanserin had equal efficacy as haloperidol and risperidone for positive symptoms in patients with chronic schizophrenia and was also superior to haloperidol for improving negative symptoms. Blonanserin is generally well tolerated and has a low propensity to cause metabolic side effects and prolactin elevation. We recently reported that blonanserin can improve some types of cognitive function associated with prefrontal cortical function in patients with first-episode and chronic schizophrenia. Taken together, these results suggest that blonanserin may be a promising candidate for a first-line antipsychotic for acute and maintenance therapy for schizophrenia. Further comparative studies are warranted to clarify the benefit/risk profile of blonanserin and its role in the treatment of schizophrenia.

Efficacy and tolerability of blonanserin in 48 patients with intractable schizophrenia

Takaki M, Okahisa Y, Kodama M, Mizuki Y, Sakamoto S, Ujike H, Uchitomi Y. Efficacy and tolerability of blonanserin in 48 patients with intractable schizophrenia.

Background: Blonanserin is effective for the treatment of schizophrenia in Korea and Japan.

Methods: We administered blonanserin to 48 Japanese patients with schizophrenia for whom other atypical antipsychotics were not sufficiently effective or tolerated.

Results: Previous antipsychotics were replaced with blonanserin because of its effectiveness (54.2%; 26/48) or tolerability (45.8%; 22/48). Blonanserin was more effective in 65.4% (17/26) of the and better tolerated in 95.5% (21/22) of the patients. Of 48 patients, 33 continued blonanserin for 1 year. The mean Clinical Global Impression of Severity scores improved from 4.60 to 2.48. The mean Global Assessment of Functioning score improved from 29.8 to 51.7. Nineteen patients (39.6%; 19/48) had a social role. The reasons for discontinuation of blonanserin were ineffectiveness against psychosis (27.1%; 13/48) or intolerability (4.2%; 2/48). The ratio of discontinuation for intolerability versus ineffectiveness was 0.15, which was the lowest among atypical psychotics.

Conclusions: Blonanserin may be effective and safe for the treatment of intractable schizophrenia.

Pharmacological treatment of schizophrenia: a critical review of the pharmacology and clinical effects of current and future therapeutic agents

Since the introduction of chlorpromazine and throughout the development of the new-generation antipsychotic drugs (APDs) beginning with clozapine, the D(2) receptor has been the target for the development of APDs. Pharmacologic actions to reduce neurotransmission through the D(2) receptor have been the only proven therapeutic mechanism for psychoses. A number of novel non-D(2) mechanisms of action of APDs have been explored over the past 40 years but none has definitively been proven effective. At the same time, the effectiveness of treatments and range of outcomes for patients are far from satisfactory. The relative success of antipsychotics in treating positive symptoms is limited by the fact that a substantial number of patients are refractory to current medications and by their lack of efficacy for negative and cognitive symptoms, which often determine the level of functional impairment. In addition, while the newer antipsychotics produce fewer motor side effects, safety and tolerability concerns about weight gain and endocrinopathies have emerged. Consequently, there is an urgent need for more effective and better-tolerated antipsychotic agents, and to identify new molecular targets and develop mechanistically novel compounds that can address the various symptom dimensions of schizophrenia. In recent years, a variety of new experimental pharmacological approaches have emerged, including compounds acting on targets other than the dopamine D(2) receptor. However, there is still an ongoing debate as to whether drugs selective for singe molecular targets (that is, 'magic bullets') or drugs selectively non-selective for several molecular targets (that is, 'magic shotguns', 'multifunctional drugs' or 'intramolecular polypharmacy') will lead to more effective new medications for schizophrenia. In this context, current and future drug development strategies can be seen to fall into three categories: (1) refinement of precedented mechanisms of action to provide drugs of comparable or superior efficacy and side-effect profiles to existing APDs; (2) development of novel (and presumably non-D(2)) mechanism APDs; (3) development of compounds to be used as adjuncts to APDs to augment efficacy by targeting specific symptom dimensions of schizophrenia and particularly those not responsive to traditional APD treatment. In addition, efforts are being made to determine if the products of susceptibility genes in schizophrenia, identified by genetic linkage and association studies, may be viable targets for drug development. Finally, a focus on early detection and early intervention aimed at halting or reversing progressive pathophysiological processes in schizophrenia has gained great influence. This has encouraged future drug development and therapeutic strategies that are neuroprotective. This article provides an update and critical review of the pharmacology and clinical profiles of current APDs and drugs acting on novel targets with potential to be therapeutic agents in the future.

Blonanserin, a novel atypical antipsychotic agent not actively transported as substrate by P-glycoprotein

Although blonanserin, a novel atypical antipsychotic agent with dopamine D(2)/serotonin 5-HT(2A) antagonistic properties, displays good brain distribution, the mechanism of this distribution has not been clarified. P-glycoprotein [(P-gp) or multidrug resistance protein 1 (MDR1)] is an efflux transporter expressed in the brain and plays an important role in limiting drug entry into the central nervous system (CNS). In particular, P-gp can affect the pharmacokinetics and efficacy of antipsychotics, and exacerbate or soothe their adverse effects. In this study, we conducted in vitro and in vivo experiments to determine whether blonanserin is a P-gp substrate. Risperidone and its active metabolite 9-hydroxyrisperidone, both of which are P-gp substrates, were used as reference drugs. Affinity of blonanserin, risperidone, and 9-hydroxyrisperidone for P-gp was evaluated by in vitro transcellular transport across LLC-PK1, human MDR1 cDNA-transfected LLC-PK1 (LLC-MDR1), and mouse Mdr1a cDNA-transfected LLC-PK1 (LLC-Mdr1a). In addition, pharmacokinetic parameters in the brain and plasma (B/P ratio) of test compounds were measured in mdr1a/1b knockout (KO) and wild-type (WT) mice. The results of in vitro experiments revealed that P-gp does not actively transport blonanserin as a substrate in humans or mice. In addition, blonanserin displayed comparable B/P ratios in KO and WT mice, whereas B/P ratios of risperidone and 9-hydroxyrisperidone differed markedly in these animals. Our results indicate that blonanserin is not a P-gp substrate and therefore its brain distribution is unlikely to be affected by this transporter.

Effect of blonanserin on cognitive function in antipsychotic-naïve first-episode schizophrenia

OBJECTIVE

The purpose of this study was to evaluate the effects of blonanserin, a novel antipsychotic, on cognitive function in first-episode schizophrenia.

METHODS

Twenty-four antipsychotic-naïve patients with first-episode schizophrenia participated in the study. Blonanserin was given in an open-label design for 8 weeks. The Brief Assessment of Cognition in Schizophrenia-Japanese language version (BACS-J) was administered as the primary outcome measure at baseline and 8 weeks. Clinical evaluation included the Positive and Negative Syndrome Scale (PANSS), the Schizophrenia Quality of Life Scale-Japanese language version (SQLS-J), and the Clinical Global Impression-Severity of Illness Scale (CGI-S). To exclude the possibility of retest effects on the BACS-J, 10 age-matched patients with chronic schizophrenia treated with blonanserin were tested at baseline and after an 8-week interval.

RESULTS

Twenty first-episode patients completed the study. Repeated measures analysis of covariance revealed a significant group-by-time interaction effect on the letter fluency task due to better performance in the first-episode group, but not in the control group. Main effect of time or group-by-time interaction effect on the Tower of London task was not significant; however, the first-episode group, but not the control group, showed substantial improvement with a moderate effect size. All items on the PANSS, SQLS-J, and CGI-S significantly improved after 8 weeks of treatment.

CONCLUSIONS

These results suggest that blonanserin improves some types of cognitive function associated with prefrontal cortical function.

Blonanserin in the treatment of delirium

The purpose of the present study was to provide preliminary data on the usefulness and safety of blonanserin for patients with delirium in the intensive care unit (ICU). The charts of 32 consecutive patients with delirium in the ICU were retrospectively reviewed. These patients were treated with blonanserin. A total of 96.6% had reduction in Memorial Delirium Assessment Scale score. The proportion of patients with side-effects was 24.1%. Blonanserin may be effective and safe in the treatment of delirium in the ICU.

Emerging drugs for schizophrenia

INTRODUCTION

Since the development of clozapine, scores of antipsychotics have been introduced. These are, with one exception (aripiprazole), based on the pharmacological principle of 5-HT(2)/dopamine antagonism. Research on other treatment targets, which, in part, influence dopaminergic pathways directly or indirectly, is mounting. Managing psychotic symptoms is only one facet of successful treatment of schizophrenia. Effective remedies against negative symptoms and cognitive deficits are still an unmet clinical need.

AREAS COVERED

With the focus on the topics mentioned above, the authors briefly review the latest clinical research organized on the basis of receptor systems and other drug targets, which are discussed to be involved in the pathophysiology of schizophrenia.

EXPERT OPINION

In conclusion, although clinicians will have to have considerable patience before truly novel anti-schizophrenia treatments become obtainable, a number of interesting leads with considerable theoretical potential are being explored. As yet, it is difficult to predict which of these mechanisms will effectively augment the currently available treatments.

Fluvoxamine for blonanserin-associated akathisia in patients with schizophrenia: report of five cases

BACKGROUND

Atypical antipsychotic drugs have been reported to cause fewer incidences of extrapyramidal side effects (EPS) than typical antipsychotic drugs, but adverse events such as akathisia have been observed even with atypical antipsychotic drugs. Although understanding of the pathophysiology of akathisia remains limited, it seems that a complex interaction of several neurotransmitter systems plays a role in its pathophysiology. The endoplasmic reticulum protein sigma-1 receptors have been shown to regulate a number of neurotransmitter systems in the brain.

METHODS

We report on five cases in which monotherapy of the selective serotonin reuptake inhibitor and sigma-1 receptor agonist fluvoxamine was effective in ameliorating the akathisia of patients with schizophrenia treated with the new atypical antipsychotic drug blonanserin.

RESULTS

The global score on the Barnes Akathisia Scale in five patients with schizophrenia treated with blonanserin rapidly decreased after fluvoxamine treatment.

CONCLUSION

Doctors should consider that fluvoxamine may be an alternative approach in treating akathisia associated with atypical antipsychotic drugs.