Design, Synthesis, and Antibacterial Evaluation of Novel Isoindolin-1-ones Derivatives Containing Piperidine Fragments

A series of novel isoindoline-1-one derivatives containing piperidine moiety were designed and synthesized using natural compounds as raw materials, and their biological activities were tested for three bacterial and three fungal pathogens. These derivatives exhibited good against phytopathogenic bacteria activities against Pseudomonas syringae pv actinidiae (Psa) and Xanthomonas axonopodis pv.citri (Xac). Some compounds exhibited excellent antibacterial activities against Xanthomonas oryzae pv oryzae (Xoo). The dose of Y8 against Xoo (the maximum half lethal effective concentration (EC50) = 21.3 μg/mL) was better than that of the thiediazole copper dose (EC50 = 53.3 μg/mL). Excitingly, further studies have shown that the molecular docking of Y8 with 2FBW indicates that it can fully locate the interior of the binding pocket through hydrogen bonding and hydrophobic interactions, thereby enhancing its anti-Xoo activity. Scanning electron microscopy (SEM) studies revealed that Y8 induced the Xoo cell membrane collapse. Moreover, the proteomic results also indicate that Y8 may be a multifunctional candidate as it affects the formation of bacterial Xoo biofilms, thereby exerting antibacterial effects.

Tying comparative effectiveness information to decision-making and the future of comparative effectiveness research designs: the case for antipsychotic drugs

The outcome of comparative effectiveness research on antipsychotic drugs, specifically the National Institute of Mental Health-funded CATIE trial, has raised questions regarding the value of second-generation antipsychotic drugs and has sparked a debate regarding their accessibility through public insurance. We reviewed the evidence on the impact of access restrictions for antipsychotic drugs in Medicaid programs and found that such restrictions resulted in increases in overall costs and a possible decline in the quality of care. We attribute this unwanted outcome to limitations in comparative effectiveness research designs that fail to inform either clinical or policy decision-making. We enumerate these limitations and illustrate the potential for more innovative comparative effectiveness research designs that may be in line with clinical decision-making using an original analysis of the CATIE trial data. The value of genomic information in enabling better trial design is also discussed.

Carbamazepine for schizophrenia

BACKGROUND

Many people with schizophrenia do not achieve a satisfactory treatment response with just antipsychotic drug treatment and various adjunct medications are used to promote additional response. The antiepileptic carbamazepine is one such drug.

OBJECTIVES

To examine whether carbamazepine or oxcarbazepine alone is an effective treatment for schizophrenia and schizoaffective psychoses and whether carbamazepine or oxcarbazepine augmentation of neuroleptic medication is an effective treatment for the same illnesses.

SEARCH METHODS

For the original version we searched The Cochrane Schizophrenia Group's Register of Trials (December 2001), The Cochrane Library (Issue 3, 2001), MEDLINE (1966-2001), EMBASE (1980-2001), Biological Abstracts (1980-2001), PsycLIT (1886-2001) and PSYNDEX (1974-2001). For the most recent update we searched the Cochrane Schizophrenia Group's Register of Trials in July 2012. We also inspected references of all identified studies for further trials and contacted relevant pharmaceutical companies and authors for additional data.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) comparing carbamazepine or compounds of the carbamazepine family with placebo or no intervention, whether as sole treatment or as an adjunct to antipsychotic medication for the treatment of schizophrenia and/or schizoaffective psychoses.

DATA COLLECTION AND ANALYSIS

We extracted data independently. For homogenous dichotomous data we calculated fixed-effect, risk ratio (RR), with 95% confidence intervals (CIs) on an intention-to-treat basis. For continuous data, we calculated mean differences (MD). We assessed the risk of bias for included studies and created a 'Summary of findings' table using GRADE.

MAIN RESULTS

The updated search did not reveal any further studies that met our inclusion criteria. The number of included studies therefore remains at 10 with the number of participants randomised still 283.One study comparing carbamazepine with placebo as the sole treatment for schizophrenia was abandoned early due to high relapse rate with 26 out of 31 participants relapsing by three months. No effect of carbamazepine was evident with no difference in relapse between the two groups (1 RCT n = 31, RR 1.07 CI 0.78 to 1.45). Another study compared carbamazepine with antipsychotics as the sole treatment for schizophrenia. No differences in terms of mental state were found when comparing 50% reduction in Brief Psychiatric Rating Scale (BPRS) scores (1 RCT n = 38, RR 1.23 CI 0.78 to 1.92). A favourable effect for carbamazepine was found when more people who received the antipsychotic (perphenazine) had parkinsonism (1 RCT n = 38, RR 0.03 CI 0.00 to 0.043). Eight studies compared adjunctive carbamazepine versus adjunctive placebo, we were able use GRADE for quality of evidence for these results. Adding carbamazepine to antipsychotic treatment was as acceptable as adding placebo with no difference between the numbers leaving the study early from each group (8 RCTs n = 182, RR 0.47 CI 0.16 to 1.35, very low quality evidence). Carbamazepine augmentation was superior compared with antipsychotics alone in terms of overall global improvement, but participant numbers were low (2 RCTs n = 38, RR 0.57 CI 0.37 to 0.88). There were no differences for the mental state outcome of 50% reduction in BPRS scores (6 RCTs n = 147, RR 0.86 CI 0.67 to 1.12, low quality evidence). Less people in the carbamazepine augmentation group had movement disorders than those taking haloperidol alone (1 RCT n = 20, RR 0.38 CI 0.14 to 1.02). No data were available for the effects of carbamazepine on subgroups of people with schizophrenia and aggressive behaviour, negative symptoms or EEG abnormalities or with schizoaffective disorder.

AUTHORS' CONCLUSIONS

Based on currently available randomised trial-derived evidence, carbamazepine cannot be recommended for routine clinical use for treatment or augmentation of antipsychotic treatment of schizophrenia. At present large, simple well-designed and reported trials are justified - especially if focusing on people with violent episodes and people with schizoaffective disorders or those with both schizophrenia and EEG abnormalities.

Heterogeneity in action: the role of passive personalization in comparative effectiveness research

Despite the goal of comparative effectiveness research (CER) to inform patient-centered care, most studies fail to account for the patient-centeredness of care that already exist in practice, which we denote as passive personalization (PP). Because CER studies describe the average effectiveness of treatments rather than heterogeneity in how individual patients respond to therapies, clinical or coverage policies that respond to CER results may undermine PP in clinical practice and generate worse outcomes. We study this phenomenon empirically in the context of use of antipsychotic drugs in Medicaid patients with schizophrenia using novel instrumental variable methods. We find strong support for PP in clinical practice and demonstrate that the average effects from a CER study cannot be replicated in practice because of the presence of PP. In contrast, providing physicians with evidence to further personalize treatment can produce significant benefits.

Pimozide for schizophrenia or related psychoses

BACKGROUND

Pimozide, formulated in the 1960s, continues to be marketed for the care of people with schizophrenia or related psychoses such as delusional disorder. It has been associated with cardiotoxicity and sudden unexplained death. Electrocardiogram monitoring is now required before and during use.

OBJECTIVES

To review the effects of pimozide for people with schizophrenia or related psychoses in comparison with placebo, no treatment or other antipsychotic medication.A secondary objective was to examine the effects of pimozide for people with delusional disorder.

SEARCH METHODS

We searched the Cochrane Schizophrenia Group's Register (28 January 2013).

SELECTION CRITERIA

We sought all relevant randomised clinical trials (RCTs) comparing pimozide with other treatments.

DATA COLLECTION AND ANALYSIS

Working independently, we inspected citations, ordered papers and then re-inspected and assessed the quality of the studies and of extracted data. For homogeneous dichotomous data, we calculated the relative risk (RR), the 95% confidence interval (CI) and mean differences (MDs) for continuous data. We excluded data if loss to follow-up was greater than 50%. We assessed risk of bias for included studies and used GRADE to rate the quality of the evidence.

MAIN RESULTS

We included 32 studies in total: Among the five studies that compared pimozide versus placebo, only one study provided data for global state relapse, for which no difference between groups was noted at medium term (1 RCT n = 20, RR 0.22 CI 0.03 to 1.78, very low quality of evidence). None of the five studies provided data for no improvement or first-rank symptoms in mental state. Data for extrapyramidal symptoms demonstrate no difference between groups for Parkinsonism (rigidity) at short term (1 RCT, n = 19, RR 5.50 CI 0.30 to 101.28, very low quality of evidence) or at medium term (1 RCT n = 25, RR 1.33 CI 0.14 to 12.82, very low quality of evidence), or for Parkinsonism (tremor) at medium term (1 RCT n = 25, RR 1 CI 0.2 to 4.95, very low quality of evidence). No data were reported for quality of life at medium term.Of the 26 studies comparing pimozide versus any antipsychotic, seven studies provided data for global state relapse at medium term, for which no difference was noted (7 RCTs n = 227, RR 0.82 CI 0.57 to 1.17, moderate quality of evidence). Data from one study demonstrated no difference in mental state (no improvement) at medium term (1 RCT n = 23, RR 1.09 CI 0.08 to 15.41, very low quality evidence); another study demonstrated no difference in the presence of first-rank symptoms at medium term (1 RCT n = 44, RR 0.53 CI 0.25 to 1.11, low quality of evidence). Data for extrapyramidal symptoms demonstrate no difference between groups for Parkinsonism (rigidity) at short term (6 RCTs n = 186, RR 1.21 CI 0.71 to 2.05,low quality of evidence) or medium term (5 RCTs n = 219, RR 1.12 CI 0.24 to 5.25,low quality of evidence), or for Parkinsonism (tremor) at medium term (4 RCTs n = 174, RR 1.46 CI 0.68 to 3.11, very low quality of evidence). No data were reported for quality of life at medium term.In the one study that compared pimozide plus any antipsychotic versus the same antipsychotic, significantly fewer relapses were noted in the augmented pimozide group at medium term (1 RCT n = 69, RR 0.28 CI 0.15 to 0.50, low quality evidence). No data were reported for mental state outcomes or for extrapyramidal symptoms (EPS). Data were skewed for quality of life scores, which were not included in the meta-analysis but were presented separately.Two studies compared pimozide plus any antipsychotics versus antipsychotic plus placebo; neither study reported data for outcomes of interest, apart from Parkinsonism at medium term and quality of life using the Specific Level of Functioning scale (SLOF); however, data were skewed.Only one study compared pimozide plus any antipsychotic versus antipsychotics plus antipsychotic; no data were reported for global state and mental state outcomes of interest. Data were provided for Parkinsonism (rigidity and tremor) using the Extrapyramidal Symptom Rating Scale (ESRS); however, these data were skewed.

AUTHORS' CONCLUSIONS

Although shortcomings in the data are evident, enough overall consistency over different outcomes and time scales is present to confirm that pimozide is a drug with efficacy similar to that of other, more commonly used antipsychotic drugs such as chlorpromazine for people with schizophrenia. No data support or refute its use for those with delusional disorder.

Carbamazepine for schizophrenia

BACKGROUND

Many people with schizophrenia do not achieve a satisfactory treatment response with just antipsychotic drug treatment and various adjunct medications are used to promote additional response. The antiepileptic carbamazepine is one such drug.

OBJECTIVES

To evaluate the effects of carbamazepine and its derivatives for the treatment of schizophrenia and related psychoses.

SEARCH STRATEGY

For the original version we searched Biological Abstracts (1980-2001), The Cochrane Library (Issue 3, 2001), The Cochrane Schizophrenia Group's Register of Trials (December 2001), EMBASE (1980-2001), MEDLINE (1966-2001), PsycLIT (1886-2001) and PSYNDEX (1974-2001). For the current update we searched the Cochrane Schizophrenia Group's Register of Trials in March 2005 and in December 2006. We also inspected references of all identified studies for further trials and contacted relevant pharmaceutical companies and authors for additional data.

SELECTION CRITERIA

We included all randomised controlled trials comparing carbamazepine or compounds of the carbamazepine family to placebo or no intervention, whether as sole treatment or as an adjunct to antipsychotic medication for the treatment of schizophrenia and/or schizoaffective psychoses.

DATA COLLECTION AND ANALYSIS

We extracted data independently. For homogenous dichotomous data we calculated random effects, relative risk (RR), 95% confidence intervals (CI) and, where appropriate, numbers needed to treat (NNT) on an intention-to-treat basis. For continuous data, we calculated weighted mean differences (WMD).

MAIN RESULTS

The update search did not reveal any further studies that met our inclusion criteria. The number of included studies therefore remains at ten with the number of participants randomised still 258. One study comparing carbamazepine with placebo as the sole treatment for schizophrenia was abandoned early due to high relapse rate with 26 out of 31 participants relapsing by three months. No effect of carbamazepine was evident with no difference in relapse between the two groups (1 RCT n=31, RR 4.1 CI 0.8 to 1.5). Another study compared carbamazepine with antipsychotics as the sole treatment for schizophrenia. No differences in terms of mental state were found when comparing 50% reduction in BPRS scores (1 RCT n=38, RR 1.2 CI 0.8 to 1.9). A favourable effect for carbamazepine was found when more people who received the antipsychotic (perphenazine) had parkinsonism (1 RCT n=38, RR 0.03 CI 0.00 to 0.04, NNH 1 CI 0.9 to 1.4). Eight studies compared adjunctive carbamazepine versus adjunctive placebo. Adding carbamazepine to antipsychotic treatment was as acceptable as adding placebo with no difference between the numbers leaving the study early from each group (8 RCTs n=182, RR 0.5 CI 0.2 to 1.4). Carbamazepine augmentation was superior compared with antipsychotics alone in terms of overall global improvement, but participant numbers were low (2RCTs n=38, RR 0.6 CI 0.4 to 0.9, NNT 2 CI 1 to 5). There were no differences for the mental state outcome of 50% reduction in BPRS scores (6 RCTs n=147, RR 0.9 CI 0.7 to 1.1). Less people in the carbamazepine augmentation group had movement disorders than those taking haloperidol alone (1 RCT n=20, RR 0.4 CI 0.1 to 1.0). No data were available for the effects of carbamazepine on subgroups of people with schizophrenia and aggressive behaviour, negative symptoms or EEG abnormalities or with schizoaffective disorder.

AUTHORS' CONCLUSIONS

Based on currently available randomised trial-derived evidence, carbamazepine cannot be recommended for routine clinical use for treatment or augmentation of antipsychotic treatment of schizophrenia. At present large, simple well-designed and reported trials are justified especially if focusing on those with violent episodes and people with schizoaffective disorders or those with both schizophrenia and EEG abnormalities.

Pimozide for schizophrenia or related psychoses

BACKGROUND

Pimozide, formulated in the 1960s, continues to be marketed for the care of people with schizophrenia or related psychoses such as delusional disorder. It has been associated with cardiotoxicity and sudden unexplained deaths. Electrocardiogram monitoring is now required before and during use.

OBJECTIVES

To assess the clinical effects of pimozide for people with schizophrenia, non-affective psychotic mental illness and delusional disorder.

SEARCH STRATEGY

We searched the Cochrane Schizophrenia Group's Register (July 2005).

SELECTION CRITERIA

We sought all relevant randomised clinical trials comparing pimozide with other treatments.

DATA COLLECTION AND ANALYSIS

Working independently, we inspected citations, ordered papers, and then re-inspected and quality assessed the studies and extracted data. For homogeneous dichotomous data, we calculated the relative risk (RR), 95% confidence interval (CI), and, where appropriate, the number needed to treat (NNT) and the number needed to harm (NNH), on an intention-to-treat basis. We calculated weighted mean differences (WMD) for continuous data. We excluded data if loss to follow-up was greater than 50%.

MAIN RESULTS

We found 35 relevant studies (total n=1348), all including people with schizophrenia but none with delusional disorder. 123 people were randomised to pimozide versus placebo. Data suggest that pimozide prevents relapse (2 RCTs, n=66, RR 0.45 CI 0.2 to 0.9, NNT 4 CI 3 to 22). Compared with typical antipsychotic drugs, pimozide has similar efficacy for outcomes of change in global functioning, mental state, relapse and leaving the study early. People allocated to pimozide did not have a higher mortality than those taking other antipsychotic drugs. Pimozide was more likely than typical antipsychotic drugs to cause tremor in the short-term (6 RCTs, n=192, RR 1.6 CI 1.1 to 2.3, NNH 6 CI 3 to 44) and lead to need for antiparkinsonian medication (4 RCTs, n=124, RR 1.8 CI 1.2 to 2.6, NNH 3 CI 2 to 5) than other drugs. In the medium-term, however, pimozide was less likely to cause sedation (5 RCTs, n=231, RR 0.6 CI 0.5 to 0.9, NNH 6 CI 4 to 16).

AUTHORS' CONCLUSIONS

Although there are shortcomings in the data, there is enough overall consistency over different outcomes and time scales to confirm that pimozide is a drug with similar efficacy to other more commonly used antipsychotic drugs such as chlorpromazine for people with schizophrenia. There are no data to support or refute its use for those with delusional disorder.

Carbamazepine for schizophrenia and schizoaffective psychoses

BACKGROUND

Many people with schizophrenia do not achieve a satisfactory treatment response with ordinary antipsychotic drug treatment and various additional medications are used to promote additional response. The antiepileptic carbamazepine is one such drug.

OBJECTIVES

To review the effects of carbamazepine and its derivatives for the treatment of schizophrenia and schizoaffective psychoses.

SEARCH STRATEGY

We searched Biological Abstracts (1980-2001), The Cochrane Library (Issue 3, 2001), The Cochrane Schizophrenia Group's Register of Trials (December 2001), EMBASE (1980-2001), MEDLINE (1966-2001), PsycLIT (1886-2001) and PSYNDEX (1974-2001). Citations from included trials were also inspected and relevant companies and authors contacted for additional data.

SELECTION CRITERIA

All randomised controlled trials comparing carbamazepine or compounds of the carbamazepine family to placebo or no intervention, whether as sole treatment or as an adjunct to antipsychotic medication for the treatment of schizophrenia and/or schizoaffective psychoses.

DATA COLLECTION AND ANALYSIS

Citations and, where possible, abstracts were independently inspected by reviewers, papers ordered, re-inspected and quality assessed. Data were extracted independently by at least two reviewers. Dichotomous data were analysed using Peto odds ratio (OR) and the 95% confidence interval (CI) estimated. Where possible the number needed to treat (NNT) or number needed to harm statistics were calculated.

MAIN RESULTS

Ten studies with a total of 258 participants were included. One study comparing carbamazepine with placebo as the sole treatment for schizophrenia (n=31) was stopped early due to high relapse rate. No effect of carbamazepine was evident (OR relapse 1.5 CI 0.2 to 9.7). Another study (n=38) compared carbamazepine with antipsychotics as the sole treatment for schizophrenia. No differences in terms of mental state were found (OR 50% BPRS reduction 1.9 CI 0.5 to 7.2). More people who received the antipsychotic (perphenazine) had parkinsonism (OR 0.03 CI 0.01 to 0.1, NNH 1 CI 0.9 to 1.4). Eight studies compared adjunctive carbamazepine plus antipsychotics versus placebo plus antipsychotics. Adding carbamazepine was as acceptable as adding placebo (n=182, OR leaving the study early 0.4 CI 0.1 to 1.4). Carbamazepine augmentation of antipsychotics was superior compared with antipsychotics alone, but participant numbers were low (n=38, OR 0.1 CI 0.02 to 0.4, NNT 2 CI 1 to 5). There were no differences for mental state outcomes (6 RCTs, n=147, OR 50% BPRS reduction 0.99 CI 0.2 to 6.0). Less people in the carbamazepine augmentation group had movement disorders than those taking haloperidol alone (1 RCT, n=20, OR 0.15 CI 0.03 to 0.8). The effects of carbamazepine on subgroups of people with schizophrenia and aggressive behaviour, negative symptoms or EEG abnormalities or with schizoaffective disorder are unknown.

REVIEWER'S CONCLUSIONS

Based on currently available evidence from randomised trials, carbamazepine cannot be recommend for routine clinical use for sole treatment, or augmentation of antipsychotic treatment, of schizophrenia. Large, simple well-designed and reported trials are justified especially if focusing on those with violent episodes and people with schizoaffective disorders or on those with both schizophrenia and EEG abnormalities.

Pimozide for schizophrenia or related psychoses

BACKGROUND

Pimozide was first formulated in the late 1960s and marketed for the care of those with schizophrenia or related psychoses such as delusional disorder.

OBJECTIVES

To assess the effects of pimozide for people with schizophrenia, non-affective psychotic mental illness and delusional disorder in terms of clinical, social and economic outcomes.

SEARCH STRATEGY

Electronic searches of Biological Abstracts (1982-1995), The Cochrane Schizophrenia Group's Register, EMBASE (1980-1995), Janssen-Cilag UK's register of studies (1999), MEDLINE (1966-1995), PsycLIT (1974-1995), hand-searching the references of all included studies and contacting the manufacturers of the compound.

SELECTION CRITERIA

All randomised trials relating to people with schizophrenia, or similar disorders comparing pimozide to other drug treatments were sought. Studies where randomisation was implied rather than stated were included if they did not change the results. Primary outcomes were clinically significant change in global function, mental state, relapse, hospital admission, death, adverse events and acceptability of treatment.

DATA COLLECTION AND ANALYSIS

Studies were selected, rated and data extracted. For dichotomous data Relative Risks (RR) based on a random effects model with the 95% confidence intervals (CI) were estimated. The number needed to treat statistic (NNT) was calculated where indicated. Analysis was by intention-to-treat.

MAIN RESULTS

This review currently includes 34 studies focusing on those with schizophrenia, none on people with delusional disorder. Few people have been randomised to pimozide versus placebo, but data from three longer term studies does suggest that the active drug prevents relapse (RR 0.59 CI 0.4-0.8, NNT 4 CI 2-13). Pimozide has similar efficacy to that of typical antipsychotic drugs for the outcomes of change in global functioning, mental state, relapse and leaving the study early. People allocated to pimozide did not have a higher mortality than those taking other antipsychotics. Pimozide was more likely to cause parkinsonian tremor (RR 1.6 CI 1.1-2.3, NNH 6 CI 3-44) and lead to a requirement for antiparkinsonian medication more frequently (RR 1.8, CI 1.2-2.6, NNH 3 CI 2-5) than other drugs. It was, however, less likely to cause sedation (RR 0.38 CI 0.2-0.7, NNH 6 CI 4-16).

REVIEWER'S CONCLUSIONS

Although there are shortcomings in the data there is enough overall consistency, over different outcomes and time scales, to confirm that pimozide is a drug with similar efficacy to other more commonly used antipsychotics such as chlorpromazine for those with schizophrenia. There are no data to support or refute its use for those with delusional disorder.

Analogues of the potential antipsychotic agent 1192U90: amide modifications

Analogues of 2-amino-N-(4-(4-(1,2-benzisothiazol-3-yl)-l-piperazinyl) -butyl)benzamide hydrochloride (1192U90) were prepared and evaluated in receptor binding assays for the dopamine D2, serotonin 5-HT1a, and serotonin 5-HT2 receptors. Eight compounds have been synthesized in which the amide group of 1192U90 has been replaced with a variety of functional groups (i.e. ester, ketone, thioamide, butyramide, butyranilide, sulfonamide, alkoxyamide and hydrazide). These compounds exhibited moderate to potent affinities (0.55-200 nM) for all three receptors. Several analogues exhibited improved selectivity for the 5-HT2 receptor with D2/5-HT2 binding ratios greater than 1192U90.

Clozapine: current status and role in the pharmacotherapy of schizophrenia

OBJECTIVE

This study evaluates clozapine and its present role in the pharmacotherapy of schizophrenia.

METHOD

Clozapine's current clinical status is reviewed, as is its position with respect to other treatment options.

RESULTS

Clozapine represents the prototype of "atypical" neuroleptics, with evidence of clinical efficacy in both positive and negative symptoms, as well as a diminished risk of extrapyramidal side effects. It is the only neuroleptic to date that has established itself as having little, if any, risk of tardive dyskinesia. More recent research has focused on its potential for overall savings in health care costs, as well as possible benefits in the area of neuropsychological functioning.

CONCLUSION

Evidence suggesting that the course of schizophrenia can be altered by effective treatment favours a systematic approach that optimizes treatment options. While clozapine does not represent a 1st-line agent because of its risk of agranulocytosis, it has an integral role to play in treatment-resistant schizophrenia or in individuals experiencing intolerable side effects with conventional neuroleptics.

Drug strategies and treatment-resistant schizophrenia

OBJECTIVES

The aims of the paper are to review the notion of treatment resistance in schizophrenia and consider the factors important in determining non-responsiveness to standard neuroleptic treatment, and to review the strategies currently available in the treatment of such patients, including an evaluation of recently-introduced, novel drug treatments.

METHOD

A selective review of the literature relating to treatment resistance was undertaken using medline searches, followed by cross-checking for further articles identified in these references.

RESULTS

The various treatment approaches available are considered, including adjunctive treatment with lithium or carbamazepine. The risks and benefits of high dose antipsychotic treatment are discussed. The possible benefits and side-effects of new treatments, particularly the atypical neuroleptics, are also reviewed.

CONCLUSIONS

The reasons why a proportion of patients with schizophrenia fail to respond to standard neuroleptic treatment are ill-understood. Nevertheless, initial assessment should include identification of any factors that may be related to a patient's poor response, such as poor compliance, substance use or epilepsy. This may help to determine an appropriate treatment strategy. There is a need to be systematic and to ensure that patients be given an adequate trial of each treatment tested in terms of duration and dosage. The available evidence does not support the use of high doses of neuroleptics for the majority of patients. Adjunctive treatments, such as lithium, carbamazepine or benzodiazepines may be beneficial in non-responsive patients, particularly if certain target symptoms are present. Atypical neuroleptics, particularly clozapine, have proved particularly effective in non-responsive patients as well as those sensitive to the motor side-effects of standard drugs. However, the high risk of agranulocytosis with clozapine is a problem; also the drug and the necessary haematological monitoring are expensive. There are hints that some of the other, new, atypical neuroleptics have some benefit in non-responsive patients, but controlled studies are required.

Effect of linking bridge modifications on the antipsychotic profile of some phthalimide and isoindolinone derivatives

A series of phthalimide and isoindolinone derivatives bridged to 4-(1,2-benzisothiazol-3-yl)-1-piperazinyl was prepared. The compounds were evaluated in vitro at dopamine D2 and serotonin 5-HT1a and 5-HT2 receptors and in vivo for their ability to antagonize the apomorphine-induced climbing response in mice. The effects of bridge length and conformation on the biological activity of these potential antipsychotic agents are discussed. A four-carbon spacer provided optimal activity within the two homologous series. Conformational investigations of the lead compound, isoindolinone 2, were conducted in an attempt to account for the superior activity observed for the butyl derivatives. On the basis of NMR and molecular modeling studies, two types of folded structures were proposed and several conformationally restrained analogues were synthesized. In general, restrictions incorporated within the linking bridge were detrimental to activity.

Clozapine: new research on efficacy and mechanism of action

Clozapine can produce greater clinical improvement in both positive and negative symptoms than typical antipsychotic drugs in neuroleptic-resistant schizophrenic patients. The clinical response may occur rapidly in some patients but is delayed in others. Clozapine has also been reported to produce fewer parkinsonian symptoms, to involve a lower risk of producing tardive dyskinesia, and to produce no serum prolactin elevations in man. It seems likely that these effects are the result of a common biological mechanism or related mechanisms, rather than unrelated effects. Other atypical antipsychotic drugs, such as melperone and fluperlapine, share at least some of these properties. A relatively low affinity for the D-2 dopamine (DA) receptor and high affinity for the 5-HT2 receptor, producing a high 5-HT2/D-2 ratio, best distinguishes atypical antipsychotics like clozapine from typical antipsychotic drugs. Through its weak antagonist action on D-2DA receptors and a potent inhibitory effect on 5-HT2 receptors, as well as its ability to increase DA and 5-HT2 release, clozapine may be able to permit more normal dopaminergic function in the anterior pituitary, the mesostriatal, mesolimbic and mesocortical regions. The numerous advantages of clozapine over typical neuroleptics are consistent with the primary importance of DA to the pathophysiology of schizophrenia. The secondary but still significant role of 5-HT in the action of clozapine may either be direct or via the effect of 5-HT on dopaminergic mechanisms. Some aspects of schizophrenia could be due to a dysregulation of the interaction between serotonergic and dopaminergic neurotransmission.

Development of the Clozaril Patient Management System

The Clozaril Patient Management System (CPMS) has been developed to provide a 100% fail-safe system for monitoring white blood cell counts (WBCs) in patients being treated with clozapine (Clozaril/Leponex) in the United States and to provide comprehensive data collection on the incidence and development of agranulocytosis. CPMS provides a case administrator and a registered pharmacist. Their role is to support the physician by facilitating the determination of WBC's at a national laboratory and by distributing clozapine to the patient. Specific tasks of the case administrator include: keeping track of outpatient phlebotomy appointments, following up missed appointments, ensuring that WBCs are obtained and analyzed weekly by the national laboratory, following up the results of these tests, providing liason with the pharmacy, maintaining a data base for all patients receiving clozapine and conveying these data to the physician. Initial experience with this program in Cleveland is described in this paper. The characteristics of patients enrolled in CPMS, satisfaction with the program and its success in meeting predetermined objectives are described. Experience with 31 patients in this outpatient setting suggests that CPMS can be an effective, reliable system for assisting in blood monitoring of patients being treated with clozapine.

Clinical pharmacology of antipsychotic drugs

Antipsychotic drugs are widely used to treat abnormal behaviour particularly that related to the functional psychoses such as schizophrenia. This review discusses the pharmacokinetics and pharmacology of antipsychotic drugs like chlorpromazine. Clinical use comprises the induction of tranquillization in disturbed psychiatric patients, the treatment of acute and chronic schizophrenic symptoms, and the postponement of relapse in such patients. Unwanted effects are multifarious, involving many systems of the body. Extrapyramidal signs and symptoms are particularly noticeable, and the chronic type, tardive dyskinesia, is a major problem.

Atypical antipsychotic drugs block selective components of amphetamine-induced stereotypy

Individual items of behavior produced by 1.0 or 5.0 mg/kg d-amphetamine were monitored in rats pretreated 15 minutes earlier with vehicle or with behaviorally relevant doses of haloperidol (0.1 or 0.25 mg/kg), clozapine (1.0 or 5.0 mg/kg), or thioridazine (1.0 or 5.0 mg/kg). Unlike haloperidol, the atypical antipsychotics failed to block all components of either the low- or high-dose response to amphetamine. These drugs, however, did block selective items of amphetamine-induced stereotyped behavior. Clozapine significantly attenuated the sniffing produced by 1.0 mg/kg d-amphetamine as well as the oral behavior (licking and/or biting) produced by 5.0 mg/kg d-amphetamine. Thioridazine, at a dose of 5.0 mg/kg, also reduced oral behavior and selectively blocked repetitive head bobbing. Taken together, these results suggest that although atypical antipsychotic drugs exert some common effects on the amphetamine behavioral response, these drugs do not influence all amphetamine-induced behaviors equally.

Clozapine and haloperidol in the amygdaloid complex: differential effects on dopamine transmission with long-term treatment

Single-unit recording techniques and liquid chromatography with electrochemical detection were used to measure the effects of neuroleptic pretreatment on the efficacy of dopamine transmission in the amygdaloid complex. Rats received twice-daily injections of clozapine (10.0 mg/kg), haloperidol (1.0 mg/kg), or vehicle for 6 days. During withdrawal from haloperidol, but not clozapine, amygdaloid neurons were significantly more responsive to iontophoretic application of dopamine. Neither drug altered the neuronal response to norepinephrine or acetylcholine. Tolerance developed to the ability of haloperidol to increase the amygdaloid level of 3,4-dihydroxyphenylacetic acid (DOPAC), a major dopamine metabolite, but such an effect did not occur with clozapine. In fact, clozapine pretreatment led to a significant increase in both DOPAC and dopamine levels in the amygdaloid complex. These results suggest that a differential action of these drugs on dopamine transmission may explain their differential effects on postsynaptic dopamine receptors.