Amisulpride, an unusual "atypical" antipsychotic: a meta-analysis of randomized controlled trials

OBJECTIVE: The "atypical" profile of the new antipsychotics clozapine, olanzapine, quetiapine, and risperidone has been linked to combined antagonism of serotonin 2 (5-HT(2)) and dopamine 2 (D(2)) receptors. Although amisulpride is a highly selective D(3)/D(2) receptor antagonist, it is assumed to have atypical properties as well. The purpose of this article was to compare the atypical profile of amisulpride with that of the 5-HT(2)/D(2) antagonists. METHOD: Randomized controlled trials that compared amisulpride with conventional antipsychotics or placebo for patients with schizophrenia were identified and included in a meta-analysis. The mean effect sizes found for amisulpride were compared with those of an updated meta-analysis of the 5-HT(2)/D(2) antagonists. RESULTS: Eighteen randomized controlled trials of amisulpride (N=2,214) were found. In 11 studies of acutely ill patients it proved to be consistently more effective than conventional antipsychotics for global schizophrenic symptoms (measured with the Brief Psychiatric Rating Scale) and negative symptoms. Amisulpride is to date the only atypical antipsychotic for which several studies of patients suffering predominantly from negative symptoms have been published. In four such studies amisulpride was significantly more effective than placebo. Three small studies with conventional antipsychotics as comparators showed only a trend in favor of amisulpride in this regard. Amisulpride was associated with clearly lower use of antiparkinsonian medication and with fewer dropouts due to adverse events than conventional antipsychotics. CONCLUSIONS: These results cast some doubt on the notion that combined 5-HT(2)/D(2) antagonism is the reason that the newer antipsychotic medications are effective for negative symptoms and have fewer extrapyramidal side effects.     

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

Atypical antipsychotics are generally thought to be more effective than conventional agents in treating the negative symptoms of schizophrenia; however, there have been few direct comparisons among atypicals. We therefore investigated risperidone and quetiapine with respect to their efficacy against negative symptoms in a 12–week,double–blind, comparative pilot study involving 44 patients with schizophrenia with predominantly negative symptoms, as defined by Positive and Negative Syndrome Scale (PANSS) scores. Other efficacy measures included the Scale for the Assessment of Negative Symptoms (SANS) and the Clinical Global Impression (CGI) rating scale. Antipsychotic tolerability was assessed using the Simpson–Angus Scale (SAS) and various laboratory measures. Mean doses were 589.7 mg/ day quetiapine and 4.9 mg/day risperidone (observed cases). Both antipsychotics produced significant decreases in PANSS total, positive and negative scores, and SANS scores. Patients receiving risperidone were significantly more likely to experience extrapyramidal symptoms (EPS) [p <0.05], or to require anticholinergic medication (p <0.05), and had significantly higher prolactin levels (p <0.001) than quetiapine–treated patients. In conclusion, there is no significant difference in efficacy between quetiapine and risperidone in alleviating the negative symptoms of schizophrenia. Quetiapine is also well tolerated, with a lower incidence of EPS and prolactin increase than risperidone.     

Treatment of schizophrenia with long-acting injectable risperidone: a 12-month open-label trial of the first long-acting second-generation antipsychotic

BACKGROUND: The long-term safety and efficacy of long-acting injectable risperidone, the first long-acting second-generation antipsychotic, were evaluated in stable patients with schizophrenia. METHOD: After a 2-week run-in period during which patients with DSM-IV schizophrenia received flexible doses of 1 to 6 mg of oral risperidone, patients received injections of 25 mg, 50 mg, or 75 mg of long-acting risperidone every 2 weeks for 12 months. Severity of extrapyramidal symptoms was assessed with the Extrapyramidal Symptom Rating Scale (ESRS), and efficacy was assessed with the Positive and Negative Syndrome Scale (PANSS). This study was conducted from March 29, 1999 to July 19, 2000. RESULTS: The subjects were 615 patients with schizophrenia who received at least 1 injection of long-acting risperidone. The 12-month trial was completed by 65% of patients. Treatment was discontinued because of adverse events in 5% of patients. Extrapyramidal symptoms as adverse events were reported by 25% of the patients. Severity of extrapyramidal symptoms (according to ESRS scores) was low at baseline and decreased in each of the groups during the 12 months. The other most common adverse events were anxiety in 24%, insomnia in 21%, psychosis in 17%, and depression in 14% of the patients. Little pain was associated with the injections. Severity of symptoms of schizophrenia was improved in each group, with significant reductions in PANSS total scores (p <.01) and positive (p <.01) and negative (p <.001) factor scores. CONCLUSION: In terms of both safety and efficacy, symptomatically stable patients with schizophrenia benefit from being switched to long-acting injectable risperidone.     

Improvement of schizophrenic patients with primary negative symptoms treated with amisulpride. Amisulpride Study Group

OBJECTIVE: The goal of this placebo-controlled study was to evaluate the efficacy and safety of low doses of amisulpride, an atypical antipsychotic of the benzamide class with high affinity for D2 and D3 dopamine receptors, in the treatment of schizophrenic patients with predominantly primary negative symptoms. METHOD: After completion of a 4-week washout period, schizophrenic patients with primary negative symptoms participated in a 12-week, multicenter double-blind trial of placebo (N = 83), amisulpride, 50 mg/day (N = 84), or amisulpride, 100 mg/day (N = 75). They were evaluated with the Scale for the Assessment of Negative Symptoms, the Scale for the Assessment of Positive Symptoms, the Brief Psychiatric Rating Scale, and the Montgomery-Asberg Depression Rating Scale. RESULTS: Both amisulpride treatment groups showed significantly greater improvement in negative symptoms than the placebo group. Positive symptom scores were low at baseline and changed minimally during the study, suggesting that the improvement in negative symptoms was independent of improvement in positive symptoms. The safety of amisulpride was comparable to that of placebo, and extrapyramidal symptoms were infrequent. Comparable efficacy and safety results were observed with either dose of amisulpride. CONCLUSIONS: These findings confirm and extend those of earlier placebo-controlled studies of low-dose amisulpride in the treatment of patients with predominantly negative symptoms of schizophrenia.     

Evaluation of the clinical efficacy of risperidone for untreated and treated cases of schizophrenia from various aspects

The present study used a diversified approach to the evaluation of the clinical efficacy of the atypical antipsychotic risperidone, and the most appropriate method of switching the medication of patients undergoing alternative therapies; particularly, the widely used typical antipsychotic haloperidol. A study group of 120 patients with CYP2D6*1/*1 was subdivided into an untreated group of 20 (group A) and two groups of 50 previously treated patients (groups B and C) with haloperidol only, for more than 5 years. All patients began risperidone therapy at 2 mg/day b.i.d., increasing in increments of 2 mg to a maximum of 8 mg/day b.i.d., according to their respective PANSS score after each psychiatric evaluation. Group B underwent a tapered changeover in treatment, while group C was abruptly transferred to the new regimen. The results demonstrated that risperidone was effective in 81% of patients, regardless of previous treatment or the method of switching. Twenty patients interrupted their switch treatment for reasons of symptom aggravation. Risperidone was immediately effective against positive and negative symptoms in untreated patients; however, in the previously treated groups, it was initially effective against negative symptoms only; after a 2-week interval, positive symptoms also improved. The previously treated patients required the concomitant administration of an anticholinergic drug. The results of this study provide evidence that risperidone has a favorable profile with regard to efficacy and safety, which makes it a suitable treatment for schizophrenia. Risperidone therapy at the earliest possible stage shows optimal improvement in schizophrenia.     

Beyond the dopamine receptor: novel therapeutic targets for treating schizophrenia

All current drugs approved to treat schizophrenia appear to exert their antipsychotic effects through blocking the dopamine D2 receptor. Recent meta-analyses and comparative efficacy studies indicate marginal differences in efficacy of newer atypical antipsychotics and the older drugs, and little effects on negative and cognitive symptoms. This review integrates findings from postmortem, imaging, and drug-challenge studies to elucidate a corticolimbic "pathologic circuit" in schizophrenia that may be particularly relevant to the negative symptoms and cognitive impairments of schizophrenia. Potential sites for pharmacologic intervention targeting glutatatergic, GABAergic, and cholinergic neurotransmission to treat these symptoms of schizophrenia are discussed.     

Eight-year follow-up of olanzapine therapy in a previous treatment-refractory schizophrenic patient: a case report

The introduction of atypical antipsychotic drugs during the 1990s represented a great step forward in the treatment of schizophrenia and other psychoses. These drugs might more effectively prevent relapse because of their effectiveness against a wider range of schizophrenic symptoms, as well as their improved tolerability, which leads to improved medication compliance. Olanzapine, a thienobenzodiazapine, is an antipsychotic drug with high affinity for the serotonergic receptors 5-HT 2 and 5-HT 6 and high affinity for dopaminergic receptors, mainly D2, D3 and D4, and with a lower propensity to cause extrapyramidal symptoms or increasing prolactin levels. The long-term efficacy and safety of olanzapine for treating treatment-refractory schizophrenia is still being investigated. The authors present a case of a 43-year-old man suffering from chronic treatment-resistant schizophrenia with both positive and negative symptoms, who was successfully treated with olanzapine for 8 years. (Int J Psych Clin Pract 2002; 6: 211-214 )     

A 12-week, double-blind, placebo-controlled trial of donepezil adjunctive treatment to risperidone in chronic and stable schizophrenia

There is considerable incentive to develop new treatment strategies that effectively target cognitive deficits in schizophrenia. One of the theoretically promising novel treatment candidates is acetylcholinesterase inhibitors that increase the synaptic levels of cholinergic, nicotinic, and muscarinic receptor activity. The purpose of this study was to assess the efficacy of donepezil as an adjuvant agent in the treatment of chronic schizophrenia in particular for cognitive impairments. This investigation was a 12-week, double-blind study of parallel groups of patients with stable chronic schizophrenia. Thirty patients were recruited from inpatient and outpatient departments, age ranging from 22 to 44 years. All participants met DSM-IV-TR. diagnostic criteria for schizophrenia. To be eligible, patients were required to have been treated with a stable dose of risperidone as their primary antipsychotic treatment for a minimum period of 8 weeks. The subjects were randomized to receive donepezil (10 mg/day) or placebo, in addition to risperidone (4–6 mg/day). Clinical psychopathology was assessed with Positive and Negative Syndrome Scale (PANSS). Cognition was measured by a cognitive battery. Patients were assessed by a psychiatrist at baseline and after 8, and 12 weeks after the medication started. The PANSS scores and cognitive performance were used as the outcome measures. The donepezil group had significantly greater improvement in the negative symptoms over the 12-week trial. There were no differences between the donepezil and placebo groups on any neurocognitive assessments at endpoint (week 12). The present study indicates donepezil as a potential adjunctive treatment strategy for negative symptoms of chronic schizophrenia.     

What have we learned from CATIE about the pharmacologic treatment of schizophrenia?

The Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) study sponsored by the National Institute of Mental Health compared the effectiveness of four second-generation antipsychotics (olanzapine, risperidone, quetiapine, and ziprasidone), and one first-generation antipsychotic (perphenazine) in 1460 individuals with chronic schizophrenia. A hybrid of effectiveness and efficacy study design, the primary outcome was antipsychotic “effectiveness,” as measured by discontinuation of the assigned antipsychotic because of inadequate efficacy, inadequate tolerability, patient decision, or other reason. Most (64% to 82%) patients discontinued the phase-I antipsychotic before 18 months of treatment (approximately two-thirds subjects continued treatment with a different antipsychotic in phase 2). The five antipsychotics varied significantly in effectiveness, efficacy, and side-effect profiles. CATIE baseline results also find the general health of individuals with chronic schizophrenia to be poor, highlighting concerns about added risk from metabolic side effects of some antipsychotics. Analysis of comparative cost effectiveness, impact on cognition, rates of recovery, phase 2 results, and many other analyses are forthcoming, and the cumulative findings from the CATIE study will provide an evidence base for clinicians, health care administrators, patients and their families to make pharmacologic treatment choices.     

Striatal D2/D3 receptor occupancy, clinical response and side effects with amisulpride: an iodine-123-iodobenzamide SPET study

INTRODUCTION: Amisulpride appears to be an effective atypical agent for treating schizophrenia in a dose-dependent manner. METHODS: 29 patients suffering from schizophrenia or schizoaffective disorder were treated with a broad dose range of amisulpride (50-1 200 mg/day, mean: 455.2+/-278.8 mg/day). After 2 weeks, brain single photon emission tomography (SPET) scans were performed two hours after intravenous injection of 185 MBq [ (123)I]IBZM. Clinical evaluations and ratings of extrapyramidal symptoms were performed at baseline and after steady state treatment of two weeks with amisulpride. RESULTS: In patients treated with amisulpride, specific binding of [ (123)I]IBZM to D2 receptors was significantly decreased (p<0.001) compared to healthy controls. D2 receptor blockade correlated well with administered doses and plasma concentrations of amisulpride. Extrapyramidal side effects, which had to be treated with biperiden, were observed in 31% of the patients. Clinical response was very good, without correlation between the response and striatal D2 occupancy. DISCUSSION: Within the first two weeks of treatment with the atypical antipsychotic amisulpride a significant occupancy of striatal postsynaptic dopamine D2 receptors was achieved. At the same time amisulpride shows an excellent tolerability with good efficacy.     

Treatment of negative symptoms in schizophrenia with neuroleptics

Different concepts of negative symptoms in schizophrenia are reviewed. The beneficial effects of neuroleptics are discussed. The results of a pharmacokinetic and pharmacodynamic study with Amisulpride in healthy volunteers are reported. Preliminary findings of a study with Amisulpride in schizophrenic patients with predominately negative symptoms are presented. The utility of various rating scales for documenting the clinical state of these patients during therapy, and correlations of negative symptoms with psychometric and psychophysiological data are discussed. Finally, therapeutic consequences suggested by different hypothesized etiological factors causing negative symptoms are considered.     

CYP 2D6 polymorphism and antipsychotic therapy

One of the most challenging problems in clinical psychiatry are inter-individual differences in clinical response to antipsychotic treatment. Several studies were investigating the impact of the polymorphic cytochrome P450 2D6 gene (CYP 2D6) on the psychopathological and extrapyramidal symptoms, but the results were conflicting. There is a lack of clinical studies of the impact of CYP2D6 polymorphism on therapeutic efficacy, especially in the long-term treatment of schizophrenia. The aim of the presentation was to evaluate the impact of CYP2D6 genotype on psychopathological and extrapyramidal symptoms in a group of Slovenian outpatients with schizophrenia or schizoaffective disorder in stable remission, who were receiving long-term maintenance therapy.     

Nefazodone in the adjunctive therapy of schizophrenia: an open-label exploratory study

Compared to conventional antipsychotic medications, atypical antipsychotic medications demonstrate greater central serotonin (5HT2) receptor antagonism than dopamine type 2 (D2) receptor antagonism. Nefazodone, an antidepressant medication, exhibits 5HT2 receptor antagonism; we therefore wondered if its addition to stable regimens of antipsychotic medication would increase antipsychotic efficacy, independently of a primary effect on mood, through the mechanism of augmented 5HT2 receptor antagonism. In a pilot investigation, we administered nefazodone (400 mg/d) for 6 weeks as an open-label adjunct to antipsychotic medication in 10 patients with chronic schizophrenia. The patients were moderately depressed at baseline but did not meet criteria for major depressive episode. The Brief Psychiatric Rating Scale (BPRS) and Montgomery-Asberg Depression Rating Scale scores showed statistically significant and clinically robust improvements with nefazodone treatment, which were maintained at follow-up evaluation 2 weeks after the end of nefazodone treatment. There were no adverse events. These results suggest that nefazodone may be a safe and effective adjunct to antipsychotic medications in schizophrenia and that augmentation of 5HT2 antagonism may prove to be a viable strategy for "boosting" antipsychotic efficacy and for treating depressive symptoms in schizophrenia.     

美多巴及舒必利治疗精神分裂症阴性症状的对照研究

目的探讨美多巴、舒必利治疗精神分裂症阴性症状的效果。方法用美多巴、舒必利分别合并抗精神病药物及单用抗精神病药物对各３０例住院精神分裂症病人进行１３周的对照研究，用阴性症状量表（ＳＡＮＳ）、简明精神病量表（ＢＰＲＳ）、副反应量表（ＴＥＳＳ）于治疗前后评定。结果美多巴、舒必舒利与单用抗精神病药物对阴性病状治疗有效率分别为５０％、５３３％和２０％。结论美多巴、舒必利合并抗精神病药均能提高对阴性症状的疗效，提示精神分裂症存在生物学异质性。     

Potentiation of the NMDA receptor in the treatment of schizophrenia: focused on the glycine site

N-methyl-d-aspartate receptor (NMDAR) hypo-function theory of schizophrenia proposes that impairment in NMDAR function be associated with the pathophysiology of schizophrenia and suggests that enhancement of the receptor function may produce efficacy for schizophrenia. Consistent with this theory, for the last decade, clinical trials have demonstrated that the enhancement of NMDAR function by potentiating the glycine site of the receptor is efficacious in the treatment of schizophrenia. Full agonists of the glycine site, glycine and d-serine and a glycine transporter-1 inhibitor, sarcosine, added to antipsychotic drugs, have been shown to be effective in the treatment of negative symptoms and possibly cognitive symptoms without significantly affecting the positive symptoms of schizophrenia. A partial agonist of the glycine site, d-cycloserine, added to antipsychotic drugs, can be effective for the negative symptoms at the therapeutic doses. However, these drugs have not shown clinical efficacy when added to clozapine, suggesting that the interactions of clozapine and the glycine site potentiators may be different from those of other antipsychotic drugs and the potentiators. This article suggests that the glycine site potentiators may produce efficacy for negative and cognitive symptoms by blocking apoptosis-like neuropathological processes in patients with chronic schizophrenia and thereby can deter progressive deterioration of the disorder. This article proposes a polypharmacy of glycine site potentiators augmented with antipsychotic drugs to control positive and negative symptoms in a synergistic manner and block deterioration in schizophrenia. Since the NMDAR complex consists of multiple sites modulating receptor functions, the efficacy of glycine site potentiators for schizophrenia suggests the possibility that manipulation of other modulating sites of the NMDAR can also be efficacious in the treatment of schizophrenia.     

Repetitive transcranial magnetic stimulation for the treatment of negative symptoms in residual schizophrenia: rationale and design of a sham-controlled,randomized multicenter study

Current meta-analysis revealed small, but significant effects of repetitive transcranial magnetic stimulation (rTMS) on negative symptoms in patients with schizophrenia. There is a need for further controlled, multicenter trials to assess the clinical efficacy of rTMS on negative symptoms in schizophrenia in a larger sample of patients. The objective of this multicenter, randomized, sham-controlled, rater- and patient-blind clinical trial is to investigate the efficacy of 3-week 10-Hz high frequency rTMS add on to antipsychotic therapy, 15 sessions per 3 weeks, 1,000 stimuli per session, stimulation intensity 110% of the individual motor threshold) of the left dorsolateral prefrontal cortex for treating negative symptoms in schizophrenia, and to evaluate the effect during a 12 weeks of follow-up. The primary efficacy endpoint is a reduction of negative symptoms as assessed by the negative sum score of the positive and negative symptom score (PANSS). A sample size of 63 in each group will have 80% power to detect an effect size of 0.50. Data analysis will be based on the intention to treat population. The study will be conducted at three university hospitals in Germany. This study will provide information about the efficacy of rTMS in the treatment of negative symptoms. In addition to psychopathology, other outcome measures such as neurocognition, social functioning, quality of life and neurobiological parameters will be assessed to investigate basic mechanisms of rTMS in schizophrenia. Main limitations of the trial are the potential influence of antipsychotic dosage changes and the difficulty to ensure adequate blinding.

     

A review of the effects of nicotine on schizophrenia and antipsychotic medications.

OBJECTIVE: Research on the impact of nicotine on schizophrenia and antipsychotic medications was reviewed to determine ways to improve treatment planning for patients with schizophrenia who smoke and to evaluate smoking cessation programs for this population. METHODS: All major research databases were searched. The review focuses on reports published since 1990. RESULTS: Smoking improves processing of auditory stimuli (sensory gating) by patients with schizophrenia and may lessen negative symptoms by increasing dopamine in the nucleus accumbens and the prefrontal and frontal cortex. Use of traditional antipsychotics may result in patients' smoking more, whereas patients taking atypical antipsychotics may smoke less. Patients who smoke metabolize antipsychotics faster than nonsmoking patients. Smoking cessation programs for outpatients with schizophrenia report a success rate of about 12 percent after six months. No studies of cessation programs for chronically ill inpatients with schizophrenia have been published. Several hospitals have implemented smoking bans with equivocal results. CONCLUSIONS: Nicotine affects both schizophrenia and antipsychotic medications. Neurobiological and psychosocial factors reinforce the high use of nicotine by patients with schizophrenia     

Amisulpride vs. risperidone in the treatment of acute exacerbations of schizophrenia. Amisulpride study group

Amisulpride, a substituted benzamide with high selectivity for dopamine D3 and D2 receptors, was compared with the antipsychotic risperidone in patients with acute exacerbations of schizophrenia. The study was double-blind and involved 228 patients allocated, after a 3-6-day wash-out period, to amisulpride 800 mg (n = 115) or risperidone 8 mg (n = 113) for 8 weeks. Both treatments produced a marked improvement in schizophrenic symptomatology. Decreases in mean BPRS total score were 17.7 +/- 14.9 for amisulpride and 15.2 +/- 13.9 for risperidone, and all of the individual factors on the BPRS showed a numerically greater improvement in the amisulpride than in the risperidone patients. Both treatments were equally effective against positive symptoms on the PANSS positive syndrome subscale; however, there was a trend in favor of greater improvement in negative symptoms assessed on the PANSS negative subscale in patients receiving amisulpride with a decrease of 6.9 +/- 7.5 vs. 5.3 +/- 6.6 for risperidone (P = 0.09). Both drugs demonstrated good safety profiles, and scores on neurological scales (SAS, AIMS, and BAS) did not increase during treatment. A comparable proportion of patients received antiparkinsonian medication, 30 and 23% in the amisulpride and risperidone groups, respectively (P = 0.21). Patients receiving risperidone experienced an increase in body weight, which was significantly greater than for amisulpride (P = 0.026).     

Risperidone response and 5-HT6 receptor gene variance: genetic association analysis with adjustment for nongenetic confounders

Previous genetic-response studies, usually without considering environmental factors, encountered great difficulties in replication of results. Although atypical antipsychotics are becoming the mainstay for schizophrenia treatment which makes an antipsychotic "atypical" remains unclear. Risperidone (a widely used atypical antipsychotic agent) and several other atypicals have high affinities for 5-HT6 and 5-HT7 receptors. This study investigated the effects of the T-->C 267 polymorphism in the 5HT6 receptor gene and two rare Pro279Leu and Thr92Lys substitutions in the 5HT7 receptor gene on risperidone efficacy after rigorous control for nongenetic confounders. We found an association between the T-->C 267 polymorphism of the 5HT6 receptor gene and response to risperidone in 123 acutely ill schizophrenia inpatients after adjustment for confounders. Compared to patients with the T/C 267 genotype, those with T/T 267 showed less severe positive symptoms (p=0.006) and general psychopathology (including anxiety, depression, and cognitive dysfunctions) (p=0.005). The T-->C 267 polymorphism had no influences on negative symptoms. The two rare polymorphisms in the 5HT7 receptor gene were not observed in our sample. In conclusion, the 5HT6 receptor gene variant can affect risperidone response to positive symptoms and general psychopathology (but not negative symptoms) after control for nongenetic factors.     

Hypermetabolic pattern in frontal cortex and other brain regions in unmedicated schizophrenia patients

We report results of a FDG–PET study in 10 patients with schizophrenia (6 unmedicated, 4 never medicated) and 12 healthy age–matched controls. The patients met ICD–10 and DSM–IV criteria for schizophrenia and all reported psychotic, "positive" symptoms when tested. Schizophrenic patients had higher absolute CMRGlu values in almost all quantified regions compared to normal subjects. Using the occipital cortex as the reference region patients showed a hyperfrontal metabolic pattern. Other significant regional differences were found with respect to thalamus, striatum and temporal cortex. The finding of a hyperfrontality in un– and never medicated psychotic schizophrenic patients must be discussed in the light of the psychopathological symptoms of patients when tested, a possible disruption of cortico–striato–thalamic feedback loops and recent findings of a hyperfrontality in experimentally induced psychosis (ketamine– and psilocybin–model of schizophrenia).