Drug treatment of schizophrenia in the 1990s. Achievements and future possibilities in optimising outcomes

Rational pharmacotherapy in early psychosis

Background

An increased focus in research specific to first-episode schizophrenia has provided a rapidly growing body of evidence that can be directly translated to clinical practice.

Aims

To provide clinical recommendations specific to effective pharmacotherapy of first-episode schizophrenia.

Method

Evidence from clinical trials focused on the first-episode population is combined with data from other areas of investigation.

Results

In first-episode psychosis, when to initiate treatment is not always clear, being intimately linked to challenges regarding early detection and diagnosis. There may be differences in antipsychotic dosing, patterns of response and sensitivity to side-effects. Adherence appears to be even more problematic at this stage.

Conclusions

Clinicians currently treating early psychosis have considerably more information to guide their decision-making. However, the speed at which the field is growing is a reminder totreatthis knowledge as a work in progress.

Atypical antipsychotics in the treatment of early-onset schizophrenia

Atypical antipsychotics (AAPs) have been successfully used in early-onset schizophrenia (EOS). This review summarizes the randomized, double-blind, controlled studies of AAPs in EOS, including clozapine, risperidone, olanzapine, aripiprazole, paliperidone, quetiapine, and ziprasidone. No significant differences in efficacy between AAPs were found, with the exception of clozapine and ziprasidone. Clozapine demonstrated superior efficacy in treatment-resistant patients with EOS, whereas ziprasidone failed to demonstrate efficacy in the treatment of EOS. Our review also focuses on the onset of action and weight gain associated with AAPs. The data on onset of action of AAPs in pediatric psychiatry are scanty and inconsistent. Olanzapine appears to cause the most significant weight gain in patients with EOS, while ziprasidone and aripiprazole seem to cause the least.

Chronic effects of clozapine administration on insulin resistance in rats: evidence for adverse metabolic effects

Chronic treatment with the atypical antipsychotics clozapine has been associated with an increased risk for deterioration of glucose homeostasis, leading to hyperglycemia and insulin resistance diabetes. The present study mainly aimed to investigate possible mechanisms underlying clozapine-induced hyperglycemia. Male Wistar albino rats were randomly divided into two groups (each consists of 12 rats). The first group received clozapine orally at a dose of 10mg/kg body weight daily for 6 weeks, while the other group received the drug vehicle only and served as the control group. At the end of the six weeks, hyperglycemia, hyperinsulinemia and insulin resistance, as indicated by Homeostatic model assessment of insulin resistance (HOMA-IR), were observed in the clozapine group as compared with the control group. This disturbance in glucose regulation was associated with non-significant changes in body weight, serum cortisol level, and hepatic glycogen content. The Clozapine group showed a significant increase in hepatic phosphorylase activity and in the gene expression level of hepatic glucose-6-phosphatse (G6Pase) enzymes compared to the control group. It can be concluded that clozapine-induced hyperglycemia and insulin resistance occur in a manner mostly independent of weight gain, and may be attributed to an increase in hepatic phosphorylase activity and increased expression level of G6Pase.

Delivering the choice agenda as a framework to manage adverse effects: a mental health nurse perspective on prescribing psychiatric medication

The article describes the clinical management of a patient referred, with a diagnosis of schizophrenia, who experienced adverse effects associated with an elevated prolactin level. A reflective model was adopted to inform the new learning which emerged from the clinical scenario. It highlights that Mental Health Nurse Supplementary Prescribers need to develop a prescribing value base underpinned by choice in addition to advanced technical skills to manage unhelpful effects of medication.

Tardive dyskinesia: eliminated, forgotten, or overshadowed?

PURPOSE OF REVIEW

The present review focuses on atypical antipsychotics and tardive dyskinesia.

RECENT FINDINGS

We have known for many years that clozapine has a diminished risk of tardive dyskinesia compared with typical antipsychotics. The last decade has seen the introduction of a number of other atypical antipsychotics, allowing us to begin evaluating whether they too share this attribute. In addition, the opportunity to use these drugs as first-line treatment permits a more precise means of establishing risk. While longer-term data are required, the limited evidence available clearly indicates that the atypical antipsychotics have a decreased liability of tardive dyskinesia, approximately 1% compared with 5% for typical agents annually. Like clozapine, the other atypical antipsychotics also demonstrate antidyskinetic properties in individuals with preexisting tardive dyskinesia. The underlying mechanisms remain unclear, and without such information it is not possible to say what clinical conditions, if any, might diminish or even eliminate these advantages.

SUMMARY

An update is provided regarding the atypical antipsychotics and tardive dyskinesia. This information is critical in our decision-making regarding choice of antipsychotic and optimal use in the clinical setting.

The crossover approach to switching antipsychotics: what is the evidence?

Clinicians frequently use a crossover approach in switching antipsychotics, although historically there has been a lack of data addressing the question of switch strategies. To establish if there is now empiric evidence that may guide clinicians in this regard, a MEDLINE search to April 2004 was carried out to identify published, randomized and controlled trials that have addressed this topic. A total of 404 articles were identified in the search, which resulted in the identification of four reports meeting the criteria. The four studies evaluated switching strategies to one of three atypical antipsychotics: aripiprazole, olanzapine (two reports), and ziprasidone. The switching process itself could be subdivided as follows: discontinuation (abrupt vs. gradual); and, replacement (abrupt vs. gradual). Meta-analyses confirmed a lack of difference in outcome, regardless of approach. While a crossover approach does not appear to increase adverse events, the available empiric evidence does not support its clinical superiority on various outcome measures. The existing data therefore argue against the position that a crossover approach in switching antipsychotics represents a 'safer' means of preventing clinical deterioration during the switch.

Combination of "atypical" antipsychotic medication in the management of treatment-resistant schizophrenia and schizoaffective disorder

BACKGROUND

This article reviews the published clinical data on treatment-resistant schizophrenic and schizoaffective patients managed with combinations of "atypical" antipsychotic medication.

METHOD

A computerized MEDLINE literature search covering an 18-year period (1985-2003) was conducted. All pertinent papers on the subject of the use of combination "atypical" antipsychotic medication in the management of treatment-resistant schizophrenia and schizoaffective disorder were obtained with subsequent analysis and discussion of the retrieved data.

RESULTS

The search identified 29 case reports and case series reports (172 patients) and one double-blind placebo-controlled trial (28 patients) describing the use of combination "atypical" antipsychotic medication (clozapine-risperidone; clozapine-sulpiride; clozapine-olanzapine; clozapine-quetiapine; olanzapine-sulpiride; olanzapine-quetiapine; risperidone-olanzapine; risperidone-quetiapine) in the treatment of resistant schizophrenic and schizoaffective patients. An overview of results suggests that the combinations were beneficial in the described patients with reduction of positive symptoms and occasionally negative symptoms. Significant adverse effects, while rare, were reported in a few cases and did not appear to different in nature from those managed on monotherapeutic regimens.

CONCLUSION

Combinations of "atypical" antipsychotic medications are well tolerated and may be effective in the management of treatment refractory schizophrenia and schizoaffective disorder. However, further double-blind placebo-controlled trials are required in order to test and confirm these observations.

Role of aging and striatal nitric oxide synthase activity in an animal model of tardive dyskinesia

The risk of tardive dyskinesia (TD) increases with advancing age. Haloperidol increases striatal oxidative stress and inhibits nitric oxide (NO) synthase (NOS) in vitro. Biological aging is associated with increased oxidative stress and reduced brain NOS activity. This paper has explored aging and striatal NOS activity ex vivo as co-morbid factors in an animal model of TD. Young adult, mature adult and aged rats were treated with water or haloperidol (1.5 mg/kg per day) for 12 weeks. Vacous chewing movements (VCM) were monitored, as was striatal NOS activity. Aging significantly increased spontaneous VCM in mature and aged animals and progressively attenuated NOS activity in both mature adult and aged rats compared to young animals, and numerically lower in aged versus mature adult animals. Haloperidol significantly increased VCM in all age groups, while significantly reducing NOS activity in young and mature adults but not aged. Reduced NOS activity after haloperidol treatment was significantly lower in mature compared to young rats, but only numerically lower in aged rats receiving the drug, with a slight increase noted in the latter. In the current model, aging did not markedly alter haloperidol-induced VCM. Abrogated striatal nitrergic activity, therefore, underlies aging and haloperidol-induced VCM. Compensatory nitrergic mechanisms may preclude progressive NOS suppression and dyskinesia under conditions of advanced age and NOS inhibition.

Induction of hyperglycemia in mice with atypical antipsychotic drugs that inhibit glucose uptake

Many antipsychotic drugs disturb the regulation of glucose metabolism in patients treated for schizophrenia. The goal of the present studies was to determine if these antipsychotic drugs produce hyperglycemia in mice in relation to their ability to interfere with glucose uptake and utilization. Male C57BL/6 mice were injected with a panel of typical and atypical antipsychotic drugs and blood glucose levels were determined periodically over a 3- to 6-h time interval. The atypical drugs, clozapine, desmethylclozapine, quetiapine, and loxapine, and the original antipsychotic, chlorpromazine, induced significant hyperglycemia in the mice in accordance with their effects on glucose transport. By contrast, haloperidol and sulpiride, which have little effect on glucose uptake, did not induce hyperglycemia. Risperidone produced a modest elevation of blood glucose levels, but only at a low dose of the drug. Cytochalasin B, a specific inhibitor of the glucose transporter (GLUT) protein, produced significant hyperglycemia in the mice. Overall, there was a strong correlation between the ability of a drug to inhibit glucose transport in vitro and its ability to induce hyperglycemia in vivo. Finally, the drugs that produced hyperglycemia in mice have been linked to the development of diabetes in patients.

Dose-related effects of amisulpride on five dimensions of psychopathology in patients with acute exacerbation of schizophrenia

The present analysis investigated symptom-specific dose-response relationships of the atypical antipsychotic amisulpride (AMI) in schizophrenic patients. The effects of different AMI doses on five different symptom dimensions of the Brief Psychiatric Rating Scale (BPRS) were analyzed. Results on global efficacy and safety parameters have been previously published. Four AMI doses (100 mg/day [AMI100], 400 mg/day [AMI400], 800 mg/day [AMI800], 1200 mg/day) were compared with 16 mg haloperidol (HAL16) in a multicenter, double-blind, randomized, parallel-group, 4-week trial. A total of 319 patients with acute exacerbation of schizophrenia (DSM-III-R) were included. AMI100 was compared with the other AMI doses, and HAL16 was compared with all AMI dosage groups. Response on BPRS factors defined as > or = 40% improvement and ORs were computed. An optimal AMI dose was calculated for each BPRS factor based on linear and quadratic regression. For all BPRS factors, inverted u-shaped dose-response curves emerged (r2 > 95%). The estimated AMI dose optimum for the BPRS factors activation/ agitation (760 mg), thought disturbances (716 mg), and hostility/suspiciousness (694 mg) was higher than that for anergia/negative symptoms (584 mg) and depression/anxiety (672 mg). Significant differences (p < 0.05) were found for AMI400/800 versus AMI100 (thought disturbances, hostility/ suspiciousness), for AMI400/800 versus HAL16 (depression/anxiety, thought disturbances, hostility/suspiciousness), and for AMI400 versus HAL16 (anergia/negative symptoms). ORs for response of the BPRS factors depression/anxiety, anergia/negative symptoms, and hostility/suspiciousness were highest under treatment with AMI400 compared to AMI100 and HAL16. For the BPRS factors thought disturbances and activation/agitation, the highest response chance emerged under AMI800 compared to AMI100 or HAL16. AMI seems to show the best clinical efficacy in acutely schizophrenic patients in a moderate dose (400-800 mg/day), with a somewhat lower dose optimum for negative than for positive symptoms. The present finding of distinct dose-response relationships of AMI regarding the BPRS dimensions is in accordance with studies on the mechanism of action of AMI and provides a useful rationale for the clinical treatment of schizophrenic patients with AMI.

Gene expression profiling with DNA microarrays: advancing our understanding of psychiatric disorders

DNA microarray transcriptome profiling of the postmortem brain opens novel horizons in understanding molecular changes associated with complex psychiatric disorders. With careful analysis and interpretation of microarray data we are uncovering previously unknown, expression patterns that maybe subject-specific and pivotal in understanding the disease process. In our recent studies, analyses of the prefrontal cortex of subjects with schizophrenia and matched controls uncovered complex changes in the expression of genes related to presynaptic secretory release, GABAergic and glutamatergic transmission, metabolic pathways, myelination, as well as cAMP and phosphoinositol second messenger systems. Our goal will be to integrate this expression data within the context of the relevant anatomical, biochemical, molecular, imaging and clinical findings.

Rapid tranquillisation: time for a reappraisal of options for parenteral therapy

BACKGROUND

When parenteral treatments are indicated for acutely disturbed behaviour, previous guidelines have recommended droperidol or haloperidol in combination with benzodiazepines. However, there has been recent concern over cardiotoxicity and sudden death associated with some antipsychotic medication and droperidol has now been withdrawn.

AIMS

To ascertain what alternatives can be recommended to replace intramuscular droperidol.

METHOD

Selective review of current guidelines and the literature pertaining to rapid parenteral tranquillisation.

RESULTS

Current guidelines recommend haloperidol as an alternative to droperidol. There is evidence of cardiotoxicity with haloperidol and it has a propensity to cause extrapyramidal side-effects that may exacerbate disturbed behaviour and reduce longer-term compliance. The rapid-acting intramuscular formulations of atypical antipsychotic agents show promise.

CONCLUSIONS

It is recommended that the mainstay of pharmacological rapid tranquillisation should be parenteral benzodiazepines used with due care.

Atypical antipsychotics: new directions and new challenges in the treatment of schizophrenia

"Atypical" antipsychotics represent a new generation of antipsychotics with a significantly lower incidence of extrapyramidal side effects (EPS), as well as little or no effect on prolactin elevation. These advantages constitute a major improvement in the treatment of patients with schizophrenia. The exact mechanisms that make these drugs atypical is not clear. However, a preferential action on serotonin 5-HT2 or D4 receptors, or a more rapid dissociation from the dopamine D2 receptor, may account for atypicality. Although the atypical antipsychotics have overcome EPS, other side effects such as weight gain and impaired glucose tolerance/lipid abnormalities have come to the fore. Thus, the challenges are far from over. The current atypicals are much more effective against the psychosis of schizophrenia than against the other, more enduring aspects of this disorder, e.g. negative symptoms and cognitive dysfunction. At present, the atypicals use a "pharmacological shotgun" strategy to treat aspects of the disease in all patients. A more sophisticated and perhaps effective approach to schizophrenia may lie in independently targeting the pathophysiological mechanisms of each clinical dimension (i.e. positive, negative, cognitive, and affective) with more selective drugs that can be combined and individually titrated to the needs of each patient.

Distribution of the methylpiperazinopyridobenzoxazepine derivative JL13, a potential antipsychotic, in rat brain

The brain uptake and distribution of the potential antipsychotic 5-(4-methylpiperazin-1-yl)-8-chloro-pyrido[2,3][1,5]benzoxazepine fumarate (JL13) was examined in rats after neuropharmacologically active doses. Plasma and brain concentrations of the compound were measured by reversed-phase HPLC with UV detection (210 nm). Clozapine was used as an internal standard. After an intraperitoneal dose of 10 mg kg(-1), the compound attained mean maximum plasma concentrations within 5 min of dosing, then declined with a mean elimination half-life of approximately 1 h. It rapidly crossed the blood-brain barrier and equilibrated with plasma, achieving mean maximum concentrations and area under the curve approximately 20-times those in plasma, with slight regional differences. Disappearance from whole brain almost paralleled its disappearance from plasma. There was a linear relationship between JL13 concentrations in plasma and brain regions, and in all tissues the concentrations of the compound increased almost linearly with the dose over the range of 5-20 mg kg(-1). It thus appears that JL13 brain pharmacokinetics parallels that in plasma, and that plasma concentrations accurately predict brain concentrations in rats.

Health care utilization in patients with schizophrenia maintained on atypical versus conventional antipsychotics

1. Patients with schizophrenia who had been stabilized on their antipsychotic medication and subsequently maintained on it for a period of at least 18 months were identified: clozapine (N=15); risperidone (N=15); depot conventional (N=18); oral conventional (N=18). 2. Groups were compared on a clinical measure as well as the use of various health care services: hospitalizations; days in hospital, emergency room visits; physician and non-physician visits. 3. No differences between groups were found for hospitalizations, days in hospital, or emergency room visits, while physician and non-physician visits were highest in the clozapine group, in keeping with the need for routine hematologic monitoring in this population. The clozapine group had the highest baseline clinical scores and greatest number of previous hospitalizations. These treatment groups may reflect different clinical populations. However, the findings suggest that in drawing conclusions regarding long-term benefits of different agents, clinical or economic, it would prove useful to include in the evaluation a comparison of patients who have been stabilized on each of the treatments.

Long-term treatment of chronic schizophrenia with risperidone: a study with plasma levels

Twenty-four chronic schizophrenic outpatients with a mean age of 37.21 years +/- 9.96 SD were treated with risperidone (RSP) at the dosage of 2-9 mg/die (mean 4.46 mg/die +/- 1.30 SD, mean 0.06 mg/kg +/- 0.01 SD) for a year. Clinical evaluation was assessed with the Brief Psychiatric Rating Scale (BPRS), Positive and Negative Symptoms Scale (PANSS), Extrapyramidal Side Effects Rating Scale (EPSE) and a checklist for Anticholinergic Side Effects (ACS) at T0, then after 1 (T1), 2 (T2), 3 (T3), 6 (T6), 9 (T9) and 12 (T12) months. RSP and 9-hydroxy-risperidone (9OH-RSP) plasma levels were determined at T12 by the HPLC method. BPRS and PANSS mean values showed a significant improvement during the study. No correlation between RSP dosage (mg/kg) and RSP, 9OH-RSP plasma levels or active moiety resulted. A positive correlation between age and active moiety was observed. A positive correlation between RSP and 9OH-RSP plasma levels was observed. A curvilinear relationship between active moiety and PANSS improvement (%) was observed. Patients with the higher PANSS amelioration showed RSP + 9OH-RSP plasma levels ranging from 15 to 30 ng/mL. RSP seems to be quite an effective drug. It seems, however, difficult to devise appropriate dose schedules and plasma level determination seems to be necessary in some cases.

Off-label use of antipsychotic drugs

Despite the fact that most antipsychotics have only been formally evaluated for the treatment of schizophreniform disorder, schizophrenia, mania, and schizoaffective disorder (defined as "classical indications"), antipsychotics are widely used for the treatment of a broad range of symptoms and disorders. In this study, 173 patients who were having their prescriptions for antipsychotics filled at local pharmacies were interviewed. In 115 patients (66.5%), an antipsychotic was prescribed for off-label indications. Patients most often stated that they took antipsychotics as a tranquilizer or an anxiolytic. Neither gender, education, duration of treatment, nor efficacy of treatment showed an influence on the prescription practices for antipsychotics. In contrast, family status and side effects showed a significant influence. A classical indication was more often found in married and widowed patients than in unmarried or divorced ones. Patients in whom antipsychotics were prescribed for the treatment of schizophrenia, schizophreniform disorder, mania, or schizoaffective disorder experienced side effects more often than others. Age was also important for the indication of antipsychotics. Classical indications of antipsychotics were most often found in patients aged 30 to 49 years. In older patients (49-70 years), antipsychotics were almost exclusively used for off-label indications. In classical indications, clozapine was used more frequently (50%) than other antipsychotics. Melperone was primarily prescribed for off-label use.

Efficacy and safety of novel antipsychotics: a critical review

Efficacy and safety of novel antipsychotic (AP) drugs (amisulpride, olanzapine, quetiapine, ziprasidone and zotepine) have been reviewed. Data on their antipsychotic efficacy and side effects profile have been evaluated only on the basis of controlled trials so far published. Overall, all these drugs have shown an antipsychotic efficacy on positive symptoms of schizophrenia similar to that of the conventional AP drugs. On negative symptoms, all novel AP drugs, except quetiapine and ziprasidone, demonstrated a better efficacy than haloperidol. Long-term efficacy of these AP drugs in the maintenance treatment of schizophrenia needs to be explored by further, better-designed, epidemiological studies. The safety profile shows that the novel AP drugs are generally well-tolerated and induce significantly less acute extrapyramidal side effects in comparison with haloperidol. Some methodological flaws in the experimental design of the clinical trials analysed are discussed. Although these novel AP drugs have potential clinical advantages, a number of relevant questions still remain to be addressed, in order to establish the impact of these drugs in the overall treatment of schizophrenia. Copyright 2000 John Wiley & Sons, Ltd.

Biotransformation of post-clozapine antipsychotics: pharmacological implications

The need to develop new antipsychotics that have fewer motor adverse effects and offer better treatment of negative symptoms has led to a new generation of drugs. Most of these drugs undergo extensive first-pass metabolism and are cleared almost exclusively by metabolism, except for amisulpride whose clearance is largely due to urinary excretion. Risperidone has metabolic routes in common with ziprasidone but shows differences in regard to other main pathways: the benzisoxazole moiety of risperidone is oxidised by cytochrome P450 (CYP) 2D6 to the active 9-hydroxyrisperidone, whereas the benzisothiazole of ziprasidone is primarily oxidised by CYP3A4, yielding sulfoxide and sulfone derivatives with low affinity for target receptors in vitro. Olanzapine, quetiapine and zotepine also have some common metabolic features. However, for the thienobenzodiazepine olanzapine a main metabolic route is direct conjugation at the benzodiazepine nucleus, whereas for the dibenzothiazepine quetiapine and the dibenzothiepine zotepine it is CYP3A4-mediated oxidation, leading to sulfoxidation, hydroxylation and dealkylation for quetiapine, but N-demethylation to the active nor-derivative for zotepine. Although the promising benzisoxazole (iloperidone) and benzisothiazole (perospirone) antipsychotics share some metabolic routes with the structurally related available drugs, they too have pharmacologically relevant compound-specific pathways. For some of the new antipsychotics we know the isoenzymes involved in their main metabolic pathways and the endogenous and exogenous factors that, by affecting enzyme activity, can potentially modify steady-state concentrations of the parent drug or its metabolite(s), but we know very little about others (e.g. amisulpride isomers, nemonapride). For yet others, information is scarce about the activity of the main metabolites and whether and how these contribute to the effect of the parent drug. Aging reduces the clearance of most antipsychotics, except amisulpride (which requires further evaluation) and ziprasidone. Liver impairment has little or no effect on the pharmacokinetics of olanzapine, quetiapine, risperidone (and 9-hydroxy-risperidone) and ziprasidone, but information is lacking for amisulpride. Renal impairment significantly reduces the clearance and prolongs the elimination half-life of amisulpride and risperidone. Again, studies are still not available for some drugs (zotepine) and have focused on the parent drug for others (olanzapine, quetiapine, ziprasidone) despite the fact that renal impairment would be expected to lower the clearance of more polar metabolites. Addressing these issues may assist clinicians in the design of safe and effective regimens for this group of drugs, and in selecting the best agent for each specific population.

Managing antipsychotic-induced acute and chronic akathisia

Akathisia is a frequent and common adverse effect of treatment with antipsychotic (neuroleptic) drugs. This syndrome consists of subjective (feeling of inner restlessness and the urge to move) as well as objective components (rocking while standing or sitting, lifting feet as if marching on the spot and crossing and uncrossing the legs while sitting). Antipsychotic-induced akathisia can be classified according to the time of onset in the course of antipsychotic treatment (acute, tardive, withdrawal and chronic akathisia). Reported prevalence rates vary widely between 5 and 36.8%. Numerous risk factors for acute akathisia have been described and the exact pathophysiology of akathisia is still unknown. Since akathisia is a drug-induced adverse effect, optimal management involves its prevention rather than treatment. Standardised titration and the use of novel antipsychotics are successful measures of prevention. This paper reviews different forms of therapeutic approaches for the treatment of akathisia. Based on the available literature, propranolol or other lipophilic beta-blockers seem to be the most consistently effective treatment for acute akathisia. There is nothing in the literature to guide a clinician when treatment with beta-blockers fails. Addition of benzodiazepines would appear to be a sensible next choice, especially if subjective distress persists. If all of these drugs are unsuccessful, amantadine or clonidine can be tried. Other agents that have been investigated include ritanserin, piracetam, valproic acid (sodium valproate) and tricyclic antidepressants. Evidence on the treatment of tardive akathisia is unsatisfactory.

N-Substituted (2,3-dihydro-1,4-benzodioxin-2-yl)methylamine derivatives as D(2) antagonists/5-HT(1A) partial agonists with potential as atypical antipsychotic agents

A series of N-substituted 1-(2,3-dihydro-1, 4-benzodioxin-2-yl)methylamine derivatives with D(2) antagonist/5-HT(1A) partial agonist activity has been prepared as potential atypical antipsychotic agents. Optimization of in vitro receptor binding activity and in vivo activity in rodent models of psychosis has led to compound 24, which showed good affinities for human D(2), D(3), and 5-HT(1A) receptors but significantly less affinity for human alpha(1) adrenoceptors and rat H(1) and muscarinic receptors. In rodents, 24 showed functional D(2)-like antagonism and 5-HT(1A) partial agonism. After oral dosing, 24 showed good activity in rodent antipsychotic tests and very little potential to cause extrapyramidal side effects (EPS), as measured by its ability to induce catalepsy in rats only at very high doses. In the light of this promising profile of activity, 24 has been selected for clinical investigation as a novel antipsychotic agent with a predicted low propensity to cause EPS.

Medication management: an exploratory study into the role of community mental health nurses

The recent emphasis on community care for those with mental illness has changed working patterns and modified inter-professional role boundaries within multi-disciplinary teams. Clients with serious mental illness are usually prescribed medications, which have a wide range of side effects. However, it is uncertain who is responsible for monitoring clients for the side effects of their medications, ensuring clients' and carers' understandings of their prescribed medications and optimizing compliance with medication. This paper discusses the findings of the first phase of an ongoing study designed to assess the role of community mental health nurses (CMHNs) in managing clients' medication and the provision of appropriate continuing professional education. Our respondents were 14 CMHNs, seven of whom were preparing to undertake a pharmacology module as part of a higher education diploma, and seven who were to act as comparators. Data from questionnaires, interviews and clinical observations were triangulated. All respondents felt that issues surrounding clients' medication were not accorded a sufficiently high profile and that it was, in part, their responsibility to expand their roles to meet these unmet needs of clients. Administering and managing clients' medications were considered to be the main area of 'occupational territory' which distinguished CMHNs from social workers. However, the nurses felt that their practice was limited by lack of appropriate educational preparation.

Schizophrenia

Schizophrenia is among the most severe and debilitating of psychiatric disorders. Diagnosis is currently by criterion-based systems, including positive (eg, hallucinations and delusions) and negative (eg, avolition and alogia) symptoms. The importance of negative symptoms in the course and outcome of the illness is increasingly being studied. Current research seeks to detect causal mechanisms in schizophrenia through studies of neural connectivity and function, as well as models of genetic transmission, such as polygenic models of inheritance in genetic research. Potential genes have been identified that may confer vulnerability to the illness, perhaps in conjunction with environmental factors. Neuroimaging research with magnetic resonance imaging and positron emission tomography has investigated differences in volumes and functional dysregulation in specific neural subregions. Areas studied include the frontal and temporal cortex, the hippocampus, the thalamus, and the cerebellum. Despite these advances, treatment of symptoms and psychosocial and cognitive impairments remains only partially successful for many patients.

Efficacy and extrapyramidal side-effects of the new antipsychotics olanzapine, quetiapine, risperidone, and sertindole compared to conventional antipsychotics and placebo. A meta-analysis of randomized controlled trials

The objective of this meta-analysis is to summarize the efficacy and tolerability of the new antipsychotics risperidone, olanzapine, sertindole and quetiapine in schizophrenia compared to placebo and conventional antipsychotics. The main results are: (1) All of the 4 new drugs are more effective than placebo, but the magnitude of the effect is only moderate [mean effect size, r, of all antipsychotics vs. placebo = 0.25, with a 95% confidence interval (CI) = 0.22-0.28, n = 2477]. (2) According to the studies published to date, sertindole and quetiapine are as effective as haloperidol, and risperidone and olanzapine are slightly more effective than haloperidol in the treatment of global schizophrenic symptomatology. (3) With respect to negative symptoms, all new antipsychotics are more effective than placebo. However, contrary to widespread opinion, so is the 'conventional' antipsychotic haloperidol. Risperidone and olanzapine are slightly superior, sertindole is as effective and--according to the only study fully published to date--quetiapine is even slightly less effective than haloperidol in this regard. (4) All new antipsychotics are associated with less frequent use of antiparkinson medication than haloperidol, with risperidone appearing to have a slightly less favourable EPS-profile than the other new antipsychotics. The methodological limitations of this review, the generalizability of the results and expectations from future research are discussed.

Agonist and antagonist actions of antipsychotic agents at 5-HT1A receptors: a [35S]GTPgammaS binding study

Recombinant human (h) 5-HT1A receptor-mediated G-protein activation was characterised in membranes of transfected Chinese hamster ovary (CHO) cells by use of guanosine-5'-O-(3-[35S]thio)-triphosphate ([35S]GTPgammaS binding). The potency and efficacy of 21 5-HT receptor agonists and antagonists was determined. The agonists, 5-CT (carboxamidotryptamine) and flesinoxan displayed high affinity (subnanomolar Ki values) and high efficacy (Emax > 90%, relative to 5-HT = 100%). In contrast, ipsapirone, zalospirone and buspirone displayed partial agonist activity. EC50s for agonist stimulation of [35S]GTPgammaS binding correlated well with Ki values from competition binding (r = +0.99). Among the compounds tested for antagonist activity, methiothepin and (+)butaclamol exhibited 'inverse agonist' behaviour, inhibiting basal [35S]GTPgammaS binding. The actions of 17 antipsychotic agents were investigated. Clozapine and several putatively 'atypical' antipsychotic agents, including ziprasidone, quetiapine and tiospirone, exhibited partial agonist activity and marked affinity at h5-HT1A receptors, similar to their affinity at hD2 dopamine receptors. In contrast, risperidone and sertindole displayed low affinity at h5-HT1A receptors and behaved as 'neutral' antagonists, inhibiting 5-HT-stimulated [35S]GTPgammaS binding. Likewise the 'typical' neuroleptics, haloperidol, pimozide, raclopride and chlorpromazine exhibited relatively low affinity and 'neutral' antagonist activity at h5-HT1A receptors with Ki values which correlated with their respective Kb values. The present data show that (i) [35S]GTPgammaS binding is an effective method to evaluate the efficacy and potency of agonists and antagonists at recombinant human 5-HT1A receptors. (ii) Like clozapine, several putatively 'atypical' antipsychotic drugs display balanced serotonin h5-HT1A/dopamine hD2 receptor affinity and partial agonist activity at h5-HT1A receptors. (iii) Several 'typical' and some putatively 'atypical' antipsychotic agents displayed antagonist properties at h5-HT1A sites with generally much lower affinity than at hD2 dopamine receptors. It is suggested that agonist activity at 5-HT1A receptors may be of utility for certain antipsychotic agents.