Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036341 (schizophrenia)
 60,220 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Remoxipride is a substituted benzamide that acts as a weak but very selective antagonist of dopamine D2 receptors. It was introduced by Astra (Roxiam) at the end of the eighties and was prescribed as an atypical antipsychotic. This article reviews its putative selective effects on mesolimbic versus nigrostriatal dopaminergic systems. In animals, remoxipride has minimal cataleptic effects at doses that block dopamine agonist-induced hyperactivity. These findings are predictive of antipsychotic activity with a low likelihood of extrapyramidal symptoms. Remoxipride also appears to be effective in more recent animal models of schizophrenia, such as latent inhibition or prepulse inhibition. In clinical studies, remoxipride shows a relatively low incidence of extrapyramidal side effects and its effects on prolactin release are short-lasting and generally mild. The clinical efficacy of remoxipride is similar to that of haloperidol or chlorpromazine. Although its clinical use was severely restricted in 1993, due to reports of aplastic anemia in some patients receiving remoxipride, this drug has been found to exhibit relatively high selectivity for dopamine D2 receptors making remoxipride an interesting tool for neurochemical and behavioral studies.
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PMID:Pharmacology of the atypical antipsychotic remoxipride, a dopamine D2 receptor antagonist. 1160 43

In this paper the historical and scientific background that led to the use of substituted benzamides in two apparently unrelated clinical conditions namely dysthymic disorder and schizophrenia will be reviewed, in order to understand if a common mechanism of action may support this dual therapeutic indication. The dopaminergic antidepressant action of substituted benzamides such as sulpiride, has been proposed, since the late 1970s, by several authors and extensively explored in preclinical experiments by our group. In Italy the first marketing authorization obtained for the new substituted benzamide amisulpride, was with the sole indication of dysthymia and therefore a solid clinical experience exists in the use of substituted benzamides in mild forms of depression, with more than 1 000 000 patients being treated in the last 7 years. The proposed mechanism of action of substituted benzamides implies a selective modulation of the dopaminergic system in the mesocorticolimbic area, important for cognitive processing of internal and external cues, related to survival. The selective antagonism of dopamine D2-D3 receptors has been evoked to explain, in small to moderate doses (ie 50-100 mg day(-1)), the antidepressant effect and, in moderate to medium doses (100-400 mg day(-1)), the reported efficacy on negative symptoms of schizophrenia. Thus, substituted benzamides could represent the first class of atypical antipsychotics successfully employed for both depressive states and schizophrenia. Interestingly, recent evidence in the literature suggests that depressive episodes belonging to the bipolar spectrum are among "alternative indications" of other atypical antipsychotics such as olanzapine and risperidone.
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PMID:The substituted benzamides and their clinical potential on dysthymia and on the negative symptoms of schizophrenia. 1192 Jan 52

Amisulpride is a second-generation antipsychotic, a substituted benzamide. It appears to be an effective agent in treating schizophrenia for what are characterised as positive and negative symptoms. The recommended doses are between 400 mg/day and 800 mg/day. Amisulpride demonstrates a good global safety profile, particularly when compared with first-generation antipsychotics, such as haloperidol. There are interesting studies that point towards amisulpride's antidepressant effect in dysthymia speculative on possible roles in affective psychoses and chronic fatigue syndrome.
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PMID:Focus on amisulpride. 1209 19

The aim of the study was to examine the action of low-dose amisulpride (100 mg/d), an atypical antipsychotic from the benzamide class with a high affinity for the D2 and D3 dopamine receptors, given for 4 weeks in 19 schizophrenic patients with the deficit syndrome, in terms of clinical response, modifications in their cognitive performance and changes in brain perfusion values. A secondary objective was to distinguish between primary and secondary deficit, according to Carpenter's definition. Both efficacy and a relatively low rate of side effects of low-dose amisulpride in the deficit forms of schizophrenia were found as expected from earlier placebo-controlled studies. Our study found significant changes in the cerebral blood flow, before and after treatment, more marked in the frontal area and particularly in the dorso-lateral frontal area. A significant improvement of cognitive function was found after treatment, without a link to any particular changes in a loco-regional perfusion value. Finally, a distinction between primary and secondary deficit showed a higher percentage of clinical improvement in the patients with a secondary deficit. The psychometric and cerebral perfusion changes were no different in the two groups.
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PMID:SPECT imaging, clinical features, and cognition before and after low doses of amisulpride in schizophrenic patients with the deficit syndrome. 1216 66

One of the most stimulating problems posed by second generation antipsychotics is the question of whether their ability to act on the negative, as well as the positive, symptoms of schizophrenia relies on the same neurochemical mechanisms as those responsible for their lack of extrapyramidal symptoms (EPS). Amisulpride is a substituted benzamide antipsychotic, which is known to be efficacious against both the positive and the negative symptoms of schizophrenia and to have a lower propensity to induce EPS than conventional antipsychotics. Amisulpride preferentially blocks the D2 and D3 subtypes of dopamine receptors, both presynaptically in the frontal cortex, enhancing dopaminergic transmission, and postsynaptically in subcortical areas such as the nucleus accumbens, so reducing dopaminergic transmission. Given that dopaminergic under-activity in the frontal cortex is thought to produce negative symptoms, and over-activity in the limbic system to produce positive symptoms, it is proposed that these are the mechanisms by which amisulpride produces its atypical profile.
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PMID:Clinical implications of dopamine research in schizophrenia. 1241 5

Amisulpride, a substituted benzamide derivative, is a second-generation (atypical) antipsychotic and is effective as maintenance therapy in patients with schizophrenia. For toxicological purpose, a rapid RP-HPLC assay was developed for the determination of amisulpride in human plasma. A linear response was observed over the concentration range 100-1000 ng/ml. A good accuracy (< or =5%) was achieved for all quality controls, with intra- and inter-day variation coefficients equal or inferior to 4.9%. The lower limit of quantification was 20 ng/ml, without interferences of endogenous components. This rapid method (run time <5 min) was used to monitor eight intoxications involving amisulpride.
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PMID:Rapid high-performance liquid chromatographic measurement of amisulpride in human plasma: application to manage acute intoxication. 1272 48

Striatal dopamine D2 receptor density is an important indicator of many neuropsychiatric disorders and also of motor activity. This study examined the relationship between a fine motor task (finger tapping test, FTT) and striatal D2 dopamine receptor density by examining 20 healthy volunteers and 20 schizophrenic patients. Striatal D2 receptor density was determined with single photon emission computed tomography using [123I]IBZM (iodo-benzamide). The correlation between the FTT score and striatal D2 receptor density was statistically significant not only in the patient group but also in healthy controls. The FTT scores and striatal D2 receptor density were lower in medicated patients than that in healthy controls. Compared with the Simpson-Angus Scale scores, the FTT scores were more strongly associated with striatal D2 receptor density. The use of neuroleptic medication seemed to influence the associations between FTT scores and striatal D2 receptor density in the patient group. The FTT scores and striatal D2 receptor density were age-sensitive in healthy controls. FTT may be a more sensitive tool for detecting neuroleptic-induced motor impairment in patients with schizophrenia. The sensitivity of the FTT to age and neuroleptic effects may be explained in part by a decline in dopamine D2 density.
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PMID:Correlation between fine motor activity and striatal dopamine D2 receptor density in patients with schizophrenia and healthy controls. 1292 7

The atypical antipsychotic drug amisulpride is a benzamide with specific antagonistic properties, which target dopamine D(2) and D(3) receptors, preferentially in the limbic system. Amisulpride is readily absorbed from the gastrointestinal tract, distributed to all body systems with little binding to plasma proteins. Elimination occurs mainly through the kidneys as unchanged drug. In contrast, hepatic metabolism is of minor significance and primarily yields two inactive metabolites. Very little is known about the plasma concentrations of amisulpride in patients at varying oral doses or about clinically relevant interactions with co-medication. The aim of the present investigation was to elucidate the factors, which affect amisulpride levels in schizophrenic patients. The plasma amisulpride levels of 85 patients with schizophrenia or schizoaffective disorder (mean age: 34.0+/-11.4 years; 40 women, 45 men) were assessed by high-performance liquid chromatography (HPLC) with fluorometric detection. The average daily dose of amisulpride was 772.3 mg (S.D. 346.7 mg) and the mean amisulpride plasma concentration was 424.4 ng/ml (S.D. 292.8 ng/ml). The interindividual variance of the amisulpride plasma concentration was high; furthermore, the plasma concentration increased linearly with the daily oral dose (r=0.50, p<0.001). Age and gender showed a significant effect on the dose-corrected amisulpride plasma concentrations-older patients and women had higher dose-corrected amisulpride plasma concentrations than younger patients and men. However, cigarette consumption had no effect on the amisulpride plasma concentrations. Regarding co-medication with lithium and/or clozapine, significantly higher amisulpride plasma concentrations were found as compared to monotherapy, whereas other co-medications such as benzodiazepines and various conventional antipsychotics had no effect on the amisulpride plasma concentrations. The results, the possible pathomechanisms and the clinical relevance are discussed. The findings need to be confirmed in larger patient samples and with a wider range of co-medications.
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PMID:Plasma amisulpride levels in schizophrenia or schizoaffective disorder. 1505 84

Several recent studies, albeit limited in sample number, design and generalizability, have suggested that augmentation of atypical antipsychotic medication (such as clozapine and olanzapine) with sulpiride, a substituted benzamide antipsychotic medication, may play a role in the management of treatment-resistant psychotic conditions. The objective of this study was to investigate any change in clinical symptomatology or side-effect profile in treatment-resistant schizophrenia patients receiving sulpiride in addition to olanzapine. Seventeen patients with treatment-resistant chronic schizophrenia, who were receiving olanzapine monotherapy for at least 6 months before study commencement, were randomized in a 1:1 fashion to receive either adjunctive treatment with sulpiride (study group) or to continue their pre-study treatment with olanzapine with no medication augmentation (control group), each for a period of 8 weeks. Changes in measures of positive and negative symptoms, anxiety, depression and extrapyramidal symptoms were assessed at baseline and at 8 weeks. Study observations indicated no significant differences in the changes in positive or negative symptomatology between patients receiving a combined regimen of olanzapine with sulpiride (600 mg/ day) augmentation and controls. However, a significantly greater improvement of depressive symptomatology (P < 0.05; as assessed by the Hamilton Scale for Depression) was noted in the sulpiride augmentation group. These data indicate improvement in depressive symptomatology with sulpiride augmentation of olanzapine in treatment-resistant chronic schizophrenia patients.
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PMID:Sulpiride augmentation of olanzapine in the management of treatment-resistant chronic schizophrenia: evidence for improvement of mood symptomatology. 1510 66

The class of substituted benzamides includes compounds able to modulate dopaminergic neurons selectively and specifically. The first synthetic substituted benzamide was sulpiride, which has been replaced in the clinic by the more modern amisulpride. The compound is very selective for mesolimbic D2 and D3 receptors and, therefore, has a dual mechanism of action, which is associated with two different indications. At low doses (50 mg), amisulpride preferentially blocks presynaptic autoreceptors, producing an increase in dopamine release, and therefore acting as a dopaminergic compound able to resolve the dopaminergic hypoactivity that characterizes depression. At higher doses (400-1,200 mg), the drug exerts its activity on postsynaptic D3/D2 receptors located in the limbic region and prefrontal areas, producing selective dopaminergic inhibition, eliciting antipsychotic effects. In the present review, the clinical use of amisulpride in depressive syndromes is discussed, in particular in dysthymia and in schizophrenia. Based on experimental data, amisulpride is a treatment of choice for dopaminergic transmission disorders, both in depression and in schizophrenia.
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PMID:Consensus on the use of substituted benzamides in psychiatric patients. 1529 67


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