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)

Amisulpride (Solian), a substituted benzamide derivative, is a second-generation antipsychotic that preferentially binds to dopamine D2/D3 receptors in limbic rather than striatal structures. High dosages preferentially antagonise postsynaptic D2/D3 receptors, resulting in reduced dopamine transmission, and low dosages preferentially block presynaptic D2/D3 receptors, resulting in enhanced dopamine transmission. Amisulpride (200-1200 mg/day) was at least as effective as haloperidol and as effective as risperidone or olanzapine, in studies of up to 1 year in patients with schizophrenia manifesting predominantly positive symptoms. Amisulpride (50-300 mg/day) was significantly more effective than placebo in studies of up to 6 months in patients manifesting predominantly negative symptoms. Quality of life was also improved significantly more in patients receiving amisulpride than in those receiving haloperidol in 4- and 12-month studies in patients with predominantly mixed symptoms. Amisulpride was generally well tolerated in clinical trials. In patients with predominantly positive symptoms, amisulpride appeared to be better tolerated than haloperidol and was tolerated as well as risperidone and olanzapine. The incidence of extrapyramidal adverse effects with amisulpride was lower than with haloperidol but was generally similar to risperidone or olanzapine. Weight gain with amisulpride was less than that with risperidone or olanzapine and, unlike these agents, amisulpride does not seem to be associated with diabetogenic effects. Plasma prolactin levels are increased during amisulpride therapy and amenorrhoea occurs in about 4% of women. The incidence of adverse events with low dosages of amisulpride (< or = 300 mg/day) in patients with predominantly negative symptoms was similar to that observed with placebo. In conclusion, oral amisulpride (200-1200 mg/day) is at least as effective as haloperidol, and as effective as risperidone or olanzapine, in the treatment of patients with schizophrenia manifesting predominantly positive symptoms. In the treatment of patients manifesting predominantly negative symptoms, low dosages of amisulpride (50-300 mg/day) are significantly more effective than placebo. Amisulpride appears to be better tolerated than haloperidol, causing a lower incidence of extrapyramidal adverse effects and an improved quality of life. Compared with risperidone or olanzapine, amisulpride is more likely to cause hyperprolactinaemia, but has a lower propensity to cause weight gain and does not seem to be associated with diabetogenic effects. Thus, amisulpride is an effective and well tolerated option for the first-line treatment of patients with acute schizophrenia as well as for those requiring long-term maintenance therapy.
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PMID:Amisulpride: a review of its use in the management of schizophrenia. 1552 94

Considerable interest has arisen in identifying antipsychotic agents with improved efficacy against negative symptoms, such as social withdrawal. In rats, a social interaction deficit can be induced by the NMDA antagonist phencyclidine (PCP). Here, we examined the effects of antipsychotics, reported to exert dual 5-HT(1A)/D(2) actions, on PCP-induced social interaction deficits. Drugs were administered daily for 3 days in combination with either vehicle or PCP (2.5mg/kg, SC) and social interaction was measured on the last day of drug treatment. Pairs of unfamiliar rats receiving the same treatment were placed in a large open field for 10 min and the number of social behaviors were scored. The results indicate that: (1) PCP significantly reduced social interaction by over 50% compared with vehicle-treated controls; (2) haloperidol (0.0025-0.16 mg/kg, SC) and clozapine (0.04-10mg/kg, IP) did not reverse PCP-induced social interaction deficits; (3) the substituted benzamide remoxipride reversed PCP-induced deficits at 0.63 and 2.5mg/kg (4) the 5-HT(1A) agonist 8-OH-DPAT was inactive (at 0.01-0.63 mg/kg, SC); (5) among compounds reported to exert dual 5-HT(1A)/D(2) actions, SSR181507 (at 0.16 mg/kg, SC) and aripiprazole (at 0.04 and 0.16 mg/kg, IP), but not ziprasidone (0.04-2.5mg/kg, IP), SLV313 (0.0025-0.16 mg/kg, SC) or bifeprunox (0.01-0.63 mg/kg, IP), significantly reversed PCP-induced social interaction deficits; and (6) the 5-HT(1A) receptor antagonist WAY100635 blocked the effects of SSR181507 and aripiprazole. These findings indicate that the balance of activity at 5-HT(1A) and D(2) receptors profoundly influences the activity of antipsychotics in this model of social withdrawal, and their potential benefit on at least some of the negative symptoms of schizophrenia.
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PMID:Effects of novel antipsychotics with mixed D(2) antagonist/5-HT(1A) agonist properties on PCP-induced social interaction deficits in the rat. 1600 87

2-Chloro-N-S-phenyl 2S-piperidin-2-yl methyl]-3-trifluoromethyl benzamide, monohydrochloride (SSR504734) is a potent and selective inhibitor of the glycine transporter type 1, which increases central N-methyl-D aspartate glutamatergic tone. Since glutamate has been shown to play a role in the regulation of the dopaminergic system in dopamine-related disorders, such as schizophrenia, we investigated the possibility that SSR504734 may modify the basolateral amygdala-elicited stimulation of dopamine release in the nucleus accumbens via an augmentation of glutamate receptor-mediated neurotransmission. First, our data confirmed that SSR504734 is an inhibitor of GlytT1. In the nucleus accumbens of anesthetized rat, SSR504734 (10 mg/kg, i.p.) induced an increase of extracellular levels of glycine as measured by microdialysis coupled with capillary electrophoresis with laser-induced fluorescence detection. Second, the data demonstrated that SSR504734 (10 mg/kg, i.p.) enhanced the facilitatory influence of glutamatergic afferents on dopamine neurotransmission in the nucleus accumbens. Using an electrochemical technique, we measured dopamine release in the nucleus accumbens evoked by an electrical stimulation of the basolateral amygdala. SSR504734 facilitated dopamine release evoked by a 20 or a 40 Hz frequency basolateral amygdala stimulation. This facilitatory effect was dependent on glutamatergic tone, as intra-nucleus accumbens application of 6-7-dinitroquinoxaline-2,3-dione (10(-3) M) or DL-2-amino-5-phosphonopentanoic acid (10(-3) M), alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid and N-methyl-D aspartate receptors antagonists, respectively, inhibited dopamine release evoked by basolateral amygdala stimulation. Furthermore DL-2-amino-5-phosphonopentanoic acid co-administrated with SSR504734 hampered the dopamine-evoked release facilitation. These data underline the in vivo implication of the glycine uptake mechanism in the control of subcortical glutamate/dopamine interactions.
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PMID:2-Chloro-N-[(S)-phenyl [(2S)-piperidin-2-yl] methyl]-3-trifluoromethyl benzamide, monohydrochloride, an inhibitor of the glycine transporter type 1, increases evoked-dopamine release in the rat nucleus accumbens in vivo via an enhanced glutamatergic neurotransmission. 1628 93

The beneficial effect of sulpiride augmentation of clozapine therapy for treatment-resistant schizophrenia patients is enhanced by its antisalivatory effect on clozapine-induced hypersalivation (CIH). Amisulpride, similar to sulpiride, is a substitute benzamide derivative with higher selective binding to the D2/D3 dopamine receptor. We hypothesized that add-on amisulpride would also be beneficial in controlling CIH. In a randomized, double-blind, placebo-controlled cross-over study, 20 clozapine-treated schizophrenia (DSM-IV criteria) inpatients with CIH were randomly initially assigned to add-on amisulpride (nine patients; 400 mg/day up-titrated from 100 mg/day over 1 week) or placebo (11 patients). Primary outcome was change in the five-point Nocturnal Hypersalivation Rating Scale (NHRS). Other measures included the Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression scale (CGI) and Simpson-Angus Scale (SAS). Mean NHRS indices were considerably lower with amisulpride (1.79 +/- 1.25) than with placebo (2.63 +/- 1.33) [F(1,38) = 5.36, P < 0.05]. With amisulpride treatment, there was a significant improvement on the negative symptoms subscale of the PANSS [F(3,57) = 3.76, P < 0.05], but not on the SAS, CGI or other subscales of the PANSS (all F < 1). Short-term amisulpride augmentation has a strong ameliorating effect on CIH. A long-term, large-scale study with a broader dose range is warranted to evaluate the stability of this effect across time.
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PMID:Amisulpride treatment of clozapine-induced hypersalivation in schizophrenia patients: a randomized, double-blind, placebo-controlled cross-over study. 1642 61

The association of the histone deacetylase (HDAC) inhibitor valproate (VPA) with atypical antipsychotics has become a frequent treatment strategy for schizophrenia and bipolar disorder. Because the VPA doses administered are elevated, one cannot assume that the benefits of the VPA plus antipsychotic treatment are exclusively related to the covalent modifications of nucleosomal histone tails. We compared the actions of N-(2-aminophenyl)-4-[N-(pyridin-3-yl-methoxycarbonyl)aminomethyl]benzamide derivative (MS-275), which is a potent HDAC inhibitor in vitro, with the actions of VPA for their ability to (i) increase the acetylated status of brain nucleosomal histone tail domains and (ii) to regulate brain histone-RELN and histone-GAD(67) promoter interactions. MS-275 increases the content of acetylhistone 3 (Ac-H3) in the frontal cortex. Whereas this response peaks after a s.c. injection of 15 micromol/kg, the increase in Ac-H3 content in the hippocampus becomes significant only after an injection of 60 micromol/kg, suggesting that MS-275 is 30- to 100-fold more potent than VPA in increasing Ac-H3 in these brain regions. In contrast to VPA, MS-275, in doses up to 120 micromol/kg, fails to increase Ac-H3 content in the striatum. Chromatin immunoprecipitation shows that MS-275 increases Ac-H3-RELN and Ac-H3-GAD(67) promoter interaction in the frontal cortex. These results suggest that MS-275 is a potent brain region-selective HDAC inhibitor. It is likely that, in addition to MS-275, other benzamide derivatives, such as sulpiride, are brain-region selective inhibitors of HDACs. Hence, some benzamide derivatives may express a greater efficacy than VPA as an adjunctive to antipsychotics in the treatment of epigenetically induced psychiatric disorders.
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PMID:The benzamide MS-275 is a potent, long-lasting brain region-selective inhibitor of histone deacetylases. 1643 98

Neuroleptic malignant syndrome is a rare but potentially lethal, rare reaction to neuroleptics which is characterized by altered levels of consciousness, extrapyramidal effects, autonomic instability, hyperthermia, and elevated serum creatine phosphokinase levels. The most serious complication of neuroleptic malignant syndrome is acute renal failure. We investigated six cases of neuroleptic malignant syndrome associated with myoglobulinemic acute renal failure due to rhabdomyolysis and effect of hemodialysis or hemodiafiltration. The patients were five males and one female with a mean age of 43.5 yr. All of the patients, who developed acute renal failure induced from rhabdomyolysis, had previously received butyrophenone (haloperidol), phenothiazine, benzamide, iminomide, benzisoxazole, antidepressants, and hypnotics (benzodiazepine and barbiturate) for the treatment of schizophrenia. The clinical manifestations of neuroleptic malignant syndrome were characterized by altered consciousness, muscle rigidity and weakness, fever, and excessive perspiration. The peak laboratory data were blood urea nitrogen 102 +/- 26 (mean +/- SD) mg/dL, serum creatinine 9.1 +/- 2.1 mg/dL, serum creatine phosphokinase 229,720 +/- 289,940 IU/L, and all of them developed oliguric acute renal failure. Dantrolene sodium administration was given to five cases and hemodialysis or hemodiafiltration was performed in all of them. The serum creatinine level after hemodialysis or hemodiafiltration was 1.4 +/- 1.0 mg/dL. All patients were successfully cured of acute renal failure by hemodialysis or hemodiafiltration. As a result, myoglobulinemic acute renal failure associated with neuroleptic malignant syndrome was successfully treated by hemodialysis or hemodiafiltration.
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PMID:Successful treatment of six patients with neuroleptic malignant syndrome associated with myoglobulinemic acute renal failure. 1652 19

SB 277011-A (trans-N-[4-[2-(6-cyano-1,2,3,4-tetrahydroisoquinolin-2-yl)ethyl]cyclohexyl]-4-quinolinecarboxamide) and S 33084 [(3aR,9bS)-N[4-(8-cyano-1,3a,4,9b-tetrahydro-3H-benzopyrano[3,4-c]pyrrole-2-yl)-butyl](4-phenyl)benzamide] were already shown to lack cataleptogenic actions. Further to that, we report that SB 277011 exerted a dose-dependent dampening on the development of haloperidol-induced catalepsy in the dose-range of 13.5-30 mg/kg p.o. while S 33084, at the dose of 0.625 mg/kg sc. significantly inhibited catalepsy induced by haloperidol; had no effect at 1.25 mg/kg, and further augmented the effect of haloperidol after 2.5 mg/kg. The compounds also produced effective inhibition when administered 2 hours after haloperidol. The results underline that dopamine D3 receptor antagonist action may have therapeutic value in the treatment of schizophrenia.
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PMID:The selective dopamine D3 receptor antagonists, SB 277011-A and S 33084 block haloperidol-induced catalepsy in rats. 1762 35

In patients with schizophrenia who do not have an optimal response to clozapine, it remains unclear if there is an evidence base to support a second antipsychotic in combination with clozapine. The present systematic review was therefore carried out to determine the efficacy of various clozapine combination strategies with antipsychotics. Relevant studies were located by searching the Cochrane Schizophrenia Group Trials Register, Medline, and Embase (up to November 2007). Only studies randomly allocating patients to clozapine plus another antipsychotic vs clozapine monotherapy were included. The search yielded 21 studies suitable for reanalysis. In 3 trials, clozapine was combined with a phenothiazine, in 8 trials with a benzamide, and in the remaining trials with risperidone. While the majority of randomized trials were not double blind, 6 studies were double-blind placebo-controlled trials. A total of 14 randomized open studies significantly favored clozapine combination strategy in terms of mean difference (random effect standardized mean difference [SMD] = -0.80, 95% confidence interval [CI] = -1.14 to -0.46); however, data extracted from 6 randomized double-blind studies did not show a statistically significant positive effect of this combination strategy in terms of mean difference (SMD = -0.12, 95% CI = -0.57 to 0.32). In terms of percentage of patients failing to show an improvement, a total of 10 randomized open studies significantly favored clozapine combination strategy (random effect relative risk [RR] = 0.64, 95% CI = 0.42 to 0.97), but data extracted from 6 randomized double-blind studies did not show a statistically significant positive effect of this combination strategy (RR = 0.91, 95% CI = 0.75 to 1.11). We conclude that the evidence base supporting a second antipsychotic in addition to clozapine in partially responsive patients with schizophrenia is weak. This weak evidence indicates modest to absent benefit.
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PMID:Does the addition of a second antipsychotic drug improve clozapine treatment? 1985 74

In the forebrain, synaptic glycine concentrations are regulated through the glycine transporter GlyT1. Because glycine is a coagonist of the N-methyl-D-aspartate (NMDA) receptor (NMDAR), which has been implicated in schizophrenia, inhibition of GlyT1 is thought to provide an option for the treatment of schizophrenia. In support of this hypothesis, GlyT1 inhibitors facilitate in vivo NMDAR function and demonstrate antipsychotic-like effects in animal models. Among the specific GlyT1 inhibitors, substituted N-methyl-glycine (sarcosine) derivatives (e.g., (R)-N[3-(4'fluorophenyl)-3-(4'phenyl-phenoxy)propyl]-sarcosine [NFPS], (R)-N[3-phenyl-3-(4'-(4-toluoyl)phenoxy)-propyl]sarcosine [(R)-NPTS], and (R,S)-(+/-)N-methyl-N-[(4-trifluoromethyl)phenoxy]-3-phenyl-propylglycine [Org24589]), and non-sarcosine-containing inhibitors, such as 2-chloro-N-[(S)-phenyl[(2S)-piperidin-2-yl] methyl]-3-trifluoromethyl benzamide, monohydrochloride (SSR504734), have been described. In the present study, we analyzed the mode of interaction of these compounds with GlyT1 by using electrophysiological measurements in Xenopus laevis oocytes, and with two binding assays, using [(3)H](R)-NPTS or 2-chloro-N-[(S)-phenyl[(2S)-N-methylpiperidin-2-yl]-methyl]-3-trifluoromethyl benzamide monohydrochloride ([(3)H]N-methyl-SSR504734) as radioligands. Inhibition of electrogenic glycine transport by sarcosine-based compounds was apparently irreversible and independent of glycine concentration. The latter indicates a noncompetitive mode of action. In contrast, both SSR504734 and N-methyl-SSR504734 exhibited reversible and competitive inhibition of glycine transport. In GlyT1-expressing membranes, the binding of the novel radioligand [(3)H]N-methyl-SSR504734 to a single site on GlyT1 was competitively displaced by glycine and SSR504734 but noncompetitively by sarcosine-based compounds. Inversely, [(3)H](R)-NPTS binding was competitively inhibited by sarcosine-based compounds, whereas glycine, SSR504734, and N-methyl-SSR504734 noncompetitively decreased maximal binding. Our data indicate that besides exerting an apparently irreversible or reversible inhibition, GlyT1 inhibitors differ by exhibiting either a noncompetitive or competitive mode of inhibition. The divergent modes of inhibition may significantly affect the efficacy and tolerability of these drugs.
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PMID:Inhibitors of GlyT1 affect glycine transport via discrete binding sites. 1881 13

In the search for strategies to treat schizophrenia, attention has focused on enhancing NMDA receptor function. In vitro experiments show that metabotropic glutamate 5 receptor (mGluR5) activation enhances NMDA receptor activity, and in vivo experiments indicate that mGluR5 positive allosteric modulators (PAMs) are effective in preclinical assays measuring antipsychotic potential and cognition. Here we characterized the dose-effect function of CDPPB (3-cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl)benzamide), an mGluR5 PAM, on novel object recognition memory in unimpaired Wistar Hannover rats (0, 10 or 30 mg/kg CDPPB) and animals with an MK-801-induced deficit (0, 3, 10, or 30 mg/kg CDPPB). In each experiment compound was given 30 min prior to the first exposure in order to affect acquisition/consolidation of the memory. In both cases, an inverted-U-shaped dose-effect function was observed, with lower doses improving recognition but higher doses having no effect. We then examined the effects of CDPPB (0, 3, 10, or 30 mg/kg) on markers of synaptic plasticity in prefrontal cortex and hippocampus, focusing on the expression and phosphorylation status of proteins involved in NMDA related signaling, including the NMDA receptor subunits NR1 and NR2B, the AMPA receptor subunit GluR1, alphaCa((2+))/CaM dependent Ser-Thr kinases II (alphaCaMKII), and the transcription factor CREB. Expression and phosphorylation of many of these proteins, particularly in the prefrontal cortex, were also characterized by an inverted-U-shaped dose-effect function. Taken together, these findings show that mGluR5 activation enhances NMDA receptor function and markers of neuronal plasticity commensurate with improvements in recognition memory. However, the effects of CDPPB are heavily dependent on dose, with higher doses being ineffective in improving recognition memory and producing downstream effects consistent with heightened NMDA receptor activation. These findings may have important implications for the development of mGluR5 PAMs to treat schizophrenia.
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PMID:Dose-dependent effect of CDPPB, the mGluR5 positive allosteric modulator, on recognition memory is associated with GluR1 and CREB phosphorylation in the prefrontal cortex and hippocampus. 1962 99


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