The effects of the second generation antipsychotics and a typical neuroleptic on collagen-induced platelet aggregation in vitro

Objective. Antipsychotics are widely used in psychiatry, and consequently a lot of their side effects have been reported. One of them is cardiovascular disease leading to increased risk of stroke, thrombosis, pulmonary, embolism, in which hyperactivation of blood platelets is involved. The purpose of the present study was to examine the effects of the second generation antipsychotics (SGAs) such as clozapine, risperidone, and olanzapine, and a typical neuroleptic – haloperidol – on the one step of platelet activation–platelet aggregation induced by collagen in vitro. Blood was collected into buffered sodium citrate (3.8%) and centrifuged to get platelet-rich plasma (PRP). In PRP (2×10⁸ platelets/ml) obtained from healthy volunteers that was incubated with antipsychotics (clozapine, risperidone, olanzapine, haloperidol; 30 min) aggregation of blood platelets was measured using a Chrono-Log Lumi-aggregometer. Aggregation of platelets was measured after stimulation of platelets with 1 µl of collagen (2 µg/ml). Results. Clozapine, like haloperidol reduced platelet aggregation induced by collagen (inhibition of platelet aggregation reached about 20%) (P=1×10^?5 and P=0.003, respectively). Risperidone had also a weak antiaggregatory effect (P=0.05). Among tested antipsychotics only olanzapine had no effect on collagen-stimulated platelet aggregation (P>0.05). Conclusion. The obtained results indicate that the difference in action of tested drugs on platelet aggregation may dependent on the various chemical structures of these drugs. Clozapine, risperidone and haloperidol are structurally diverse, and they all significantly reduce platelet aggregability induced by collagen. On the other hand, a close structural analog of clozapine – olanzapine – did not inhibit platelet aggregation. However, mechanism of antipsychotics action on blood platelets is not clear. Moreover, it seems that clozapine, risperidone and haloperidol treatment due to antiaggregatory action may have even some antithrombotic effects.     

Clozapine, olanzapine, risperidone, and haloperidol in the treatment of patients with chronic schizophrenia and schizoaffective disorder

OBJECTIVE: The authors compared the efficacy and safety of three atypical antipsychotics (clozapine, olanzapine, and risperidone) with one another and with haloperidol in the treatment of patients with chronic schizophrenia or schizoaffective disorder. METHOD: In a double-blind trial, 157 inpatients with a history of suboptimal treatment response were randomly assigned to treatment with clozapine, olanzapine, risperidone, or haloperidol for 14 weeks (an 8-week escalation and fixed-dose period followed by a 6-week variable-dose period). RESULTS: Clozapine, risperidone, and olanzapine (but not haloperidol) resulted in statistically significant improvements in total score on the Positive and Negative Syndrome Scale. Improvements seen in total and negative symptom scores with clozapine and olanzapine were superior to haloperidol. The atypical drugs, particularly olanzapine and clozapine, were associated with weight gain. CONCLUSIONS: The effects of atypical antipsychotics in this population were statistically significant but clinically modest. The overall pattern of results suggests that clozapine and olanzapine have similar general antipsychotic efficacy and that risperidone may be somewhat less effective. Clozapine was the most effective treatment for negative symptoms. However, the differences among treatments were small.     

The effect of chronic treatment with typical and atypical antipsychotics on working memory and jaw movements in three- and eighteen-month-old rats

The effects of chronic treatment with typical and atypical antipsychotics on acquisition, working memory, motor activity, and rat tardive dyskinesia (TD) were studied in 3- and 18-month-old Sprague-Dawley rats. Acquisition and working memory were studied in eight-arm radial mazes. TD liability of antipsychotic drugs (APD) was evaluated in rat model of TD in which spontaneous repetitive jaw movements (RJM) occur during withdrawal from neuroleptic treatment. Motor behavior was assessed using the traverse beam test. D1 and D2 receptor occupancy was determined in the rat brain during treatment with typical and atypical antipsychotics. Chronic administration of clozapine, haloperidol, and risperidone impaired acquisition of the eight-arm radial maze in both young and aging rats while olanzapine had no effect. Retention tests showed that aging rats made more errors than the adults and that the antipsychotics haloperidol and risperidone significantly impaired retention in both age groups. Evaluation of motor behavior revealed that typical and atypical antipsychotics used in comparable doses in young rats had no effect on motor behavior, whereas in aging rats performance was impaired by clozapine, haloperidol, and risperidone but not by olanzapine. RJM responses were increased during washout from haloperidol treatment in young and aging rats whereas olanzapine, clozapine, and risperidone had no effect. D2 receptor occupancy in haloperidol- and risperidone-treated rats was above 70% while olanzapine and clozapine receptor occupancy was below 70%, which is the threshold for the appearance of extrapyramidal syndrome (EPS) and TD.     

Effectiveness and safety of antipsychotics in early onset psychoses: a long-term comparison

The effectiveness and safety of various antipsychotics was evaluated in a long-term study on 47 patients, 29 with schizophrenia and 18 with schizoaffective disorder, aged 10 to 17 years (mean 15.5) at onset. Follow-up ranged from 3 years (all 47 patients) to 11 years (19 patients). Data were collected on the following antipsychotics: haloperidol, risperidone, olanzapine, quetiapine, aripiprazole and clozapine. Cases with positive response were significantly more frequent with clozapine as compared to haloperidol, risperidone and olanzapine. Risperidone was significantly better than haloperidol at the 3-year follow-up. A comparison of the degree of clinical improvement evaluated with PANSS and CGI in patients treated with drugs in subsequent periods showed clozapine led to significantly greater improvement as compared to haloperidol, risperidone and olanzapine, and risperidone as compared to haloperidol. Data on long-term functioning significantly favored clozapine as compared to all the other drugs. Discontinuation due to side effects involved 20% patients with clozapine, lower percentage with the other drugs. The results of this study on early-onset schizophrenic and schizoaffective disorders confirm that even in the long-term, clozapine is more effective than haloperidol, risperidone and olanzapine. Despite a relevant incidence of adverse effects, clozapine seems to have unique effectiveness in treating children and adolescents with early-onset schizophrenic disorders.     

The effects of novel antipsychotics on glucose and lipid levels

BACKGROUND: The novel antipsychotics are extensively used based on their favorable extrapyramidal side effect profiles. However, accumulating evidence suggests that these agents, particularly clozapine and olanzapine, have serious side effects of their own, including weight gain and elevated glucose and triglyceride levels. The goal of this study is to compare the effects of novel antipsychotics clozapine, olanzapine, risperidone, and quetiapine and typical antipsychotics haloperidol and fluphenazine on glucose and lipid levels. METHOD: The charts of 590 patients were retrospectively reviewed. Of those, 215 patients had adequate laboratory data for inclusion. Glucose and lipid level data from 2 1/2 years before and after initiation of the target antipsychotic were included. Covariates, including patients' age, the duration of antipsychotic treatment, other medications that may affect glucose or lipid levels, and the initial laboratory values, were controlled for in the analyses. RESULTS: Glucose levels were increased from baseline for patients treated with clozapine, olanzapine, and haloperidol. There were statistically and clinically significant differences among the medications' effects on lipid profiles (p < .05). Those receiving clozapine and olanzapine demonstrated statistically significant increases in triglyceride levels compared with the other groups. Over one third of patients treated with any of the novel antipsychotics had clinically meaningful triglyceride elevations. CONCLUSION: It has been shown that novel antipsychotics are associated with weight gain. This risk factor along with others, such as elevated glucose and triglyceride levels, compounds the risk for coronary artery disease. Routine monitoring of glucose and lipid levels during treatment with novel antipsychotics should be advocated.     

Neuroendocrine responsivities of the pituitary dopamine system in male schizophrenic patients during treatment with clozapine, olanzapine, risperidone, sulpiride, or haloperidol

Background Atypical antipsychotic drugs, in clinical doses, occupy 5-HT2 receptors near saturation, while D2 dopamine receptors, assessed usually in striatum by SPECT or PET methods, are occupied to different degrees. We hypothesized that these differences in D2 receptor occupancies may also be evaluated by a neuroendocrine approach, namely by measuring the plasma prolactin responses to i. m. administered haloperidol, since the expected elevations depend mainly on the free remaining D2 receptors in the tuberoinfundibular tract. Methods We measured the plasma prolactin levels at 0, 30, 60, 90, and 120 minutes after administration of 5 mg haloperidol i. m. in six groups of male patients with schizophrenia: a) 33 patients in a drug-free state, b) 15 patients on treatment with clozapine (range 200–600 mg/day), c) 15 patients on olanzapine (10–30 mg/day), d) 14 patients on risperidone (8–16 mg/day), e) 23 patients on haloperidol (10–40 mg/day), f) 14 patients on sulpiride (600–1600 mg/day). Data were also obtained from a group of 14 healthy male control subjects. The differences in baseline prolactin levels and in the responses to acute haloperidol of the seven groups were compared. Results The baseline prolactin levels did not differ significantly in the groups of controls (8.3±3.8 ng/ml), drug-free patients (8.0±3.6) and patients treated with clozapine (7.7±3.8), they were moderately elevated in patients treated with olanzapine (16.8±8.9), elevated in patients on haloperidol (34.4±17.3), and they were even higher in the groups of patients treated with risperidone (54.9±22.4) or sulpiride (58.8±27.0). All groups of patients gave attenuated prolactin responses to i. m. haloperidol compared to healthy controls. During treatment with haloperidol, risperidone, or sulpiride, no significant prolactin increases after i. m. haloperidol were observed. The group treated with olanzapine gave significant prolactin increases, which were lower than those obtained in the group of patients treated with clozapine, who gave responses similar to that of the drug-free patients. Conclusions Plasma prolactin levels and responses to i. m. haloperidol of patients on treatment with antipsychotic drugs, reflect the prolactin release potencies of the drugs, which are related, but not restricted, to their affinities to D2 dopamine receptors. According to the prolactin baseline levels and responses to i. m. haloperidol, the drugs of this study can be categorized for their potency to the pituitary dopamine system that controls prolactin release, as follows: sulpiride > risperidone > haloperidol > olanzapine > clozapine. This categorization is similar to that obtained by binding studies in striatal D2 dopamine receptors using brain imaging techniques. Received: 26 March 2001 / Accepted: 21 June 2001     

Long-term Effects of JL 13, a Potential Atypical Antipsychotic,on Ionotropic Glutamate Receptors

Changes in ionotropic glutamate (Glu) N-methyl-d-aspartic acid (NMDA), and 2-amino-3-(3-hydroxy-5-methyl-isoxazol-4-yl)propionic acid (AMPA) receptors in rat forebrain regions were autoradiographically quantified after continuous infusion of JL 13 [(5-(4-methylpiperazin-1-yl)-8-chloro-pyrido[2,3-b][1,5]benzoxazepine fumarate] for 28 days using osmotic minipumps, and compared to the effects of representative typical (haloperidol) and atypical (clozapine, olanzapine, and risperidone) antipsychotic drugs from previous studies. Similar to other atypical and not typical antipsychotics, JL 13 decreased labeling of NMDA receptors in medial and lateral caudate-putamen (CPu; by 40%). These findings indicate that down-regulation of NMDA receptors by JL 13 and other atypical antipsychotic agents in CPu may contribute to their low risk of extrapyramidal side effects. In addition, and similar to olanzapine and risperidone, JL 13 increased AMPA receptor binding in CPu (by 42%). Changes in AMPA receptors may contribute to psychopharmacological properties of JL 13 and other atypical agents. Similar to clozapine, JL 13 did not alter levels of NMDA and AMPA receptors in hippocampus and entorhinal cortex. Long-term effects of JL 13 on ionotropic Glu receptors, as well as on other dopamine and serotonin receptors, support the atypical antipsychotic profile of this novel agent.     

Effect of atypical antipsychotics on phencyclidine-induced expression of arc in rat brain

The effect of atypical antipsychotics on the immediate-early gene, arc (activity-regulated cytoskeleton-associated gene), expression was investigated in phencyclidine (PCP)-treated rats using RT-PCR. Administration of PCP (10 mg/kg) increased arc mRNA levels in the prefrontal cortex, nucleus accumbens and posterior cingulate cortex. Pretreatment with clozapine (20 mg/kg), olanzapine (10 mg/kg) and risperidone (2 mg/kg), but not haloperidol (2 mg/kg), prevented PCP-induced arc expression in the prefrontal cortex and nucleus accumbens. Pretreatment of haloperidol increased the striatal arc mRNA levels. Clozapine, olanzapine and haloperidol inhibited the PCP-induced arc expression in the posterior cingulate cortex. These results suggest that the effects of antipsychotic drugs on PCP-induced arc expression in the prefrontal cortex and nucleus accumbens are useful for distinguishing atypical antipsychotic properties of the drugs.     

Effects of atypical antipsychotics on the syndromal profile in treatment-resistant schizophrenia

BACKGROUND: There has been considerable support for the observation that atypical antipsychotics have a broader range of therapeutic effects than traditional antipsychotics. We are exploring whether this expanded clinical efficacy can also be seen in patients with treatment-resistant schizophrenia. METHOD: The subjects were 157 treatment-resistant inpatients diagnosed with DSM-IV schizophrenia or schizoaffective disorder. They were randomly assigned to treatment with clozapine, olanzapine, risperidone, or haloperidol in a 14-week double-blind trial and rated with a standard measure of clinical antipsychotic efficacy (Positive and Negative Syndrome Scale [PANSS]). Factor analysis at baseline and endpoint together with changes in 5 PANSS-derived factors were examined. Data were gathered from June 1996 to December 1999. RESULTS: The underlying PANSS factor structure, as indicated by the factor loadings, was essentially identical at baseline and endpoint. At baseline, the excitement factor was followed by the positive, negative, cognitive, and depression/anxiety factors, explaining 49.4% of the total variance. At endpoint, the positive factor was followed by the negative, excitement, cognitive, and depression/anxiety factors, explaining 55.5% of the total variance. The endpoint data indicated statistically significant (p <.05) improvements over time on the positive factor for all 3 atypicals, but not for haloperidol. The negative factor showed significant improvement for clozapine and olanzapine, with significant worsening for haloperidol. Clozapine, olanzapine, and risperidone were superior to haloperidol on the negative factor, while clozapine was also superior to risperidone. The cognitive factor showed significant improvement for all atypicals, as did the depression/anxiety factor. Only clozapine showed improvement on the excitement factor and was superior to both haloperidol and risperidone. CONCLUSIONS: Treatment with atypical antipsychotics did not substantially change the underlying PANSS 5-factor structure. However, antipsychotic treatment with all 3 atypical medications was associated with significant improvements on 3 of 5 syndromal domains (positive, cognitive, and depression/anxiety) of schizophrenia. Clozapine and olanzapine also showed improvement on the negative factor. Only clozapine was associated with improvement on the excitement domain. This finding confirms that atypicals are associated with improvement of an expanded spectrum of symptoms in treatment-resistant patients.     

The Metabolism of Atypical Antipsychotic Drugs: An Update

This paper reviews the current literature describing the metabolism of both multi-receptor clozapine analogue atypical antipsychotic drugs (clozapine, olanzapine, and quetiapine) and serotonin-dopamine antagonist atypical antipsychotic drugs (risperidone, sertindole and ziprasidone), to highlight the significance of those data in the context of clinical practice. The former group of atypical antipsychotic drugs shares a similar tricyclic structural nucleus and are metabolized through three major categorical metabolic pathways—N ⁺-oxidation, N-glucuronidation, and phases 1 and 2 biotransformation with final glucuronidation before renal excretion. Differing in clozapine and olanzapine, quetiapine has incomplete data describing its metabolism. The latter group of atypical antipsychotic drugs has diversified chemical structures and absence of data on N ⁺-oxidation and N-glucuronidation in the literature. But their metabolic routes in phase 1 biotransformation are versatile although current data are far from completion. No apparent significant drug interactions in clinical practice are reported, although QT prolongation is implicated in all those three drugs. None of all six atypical antipsychotic drugs are identified as significant inhibitors or inducers to any co-administered medication. The author suggests the need for more research to address some pertinent clinical issues in the metabolism of those drugs.     

Neurocognitive effects of clozapine,olanzapine, risperidone,and haloperidol in patients with chronic schizophrenia or schizoaffective disorder

OBJECTIVE: Newer antipsychotic drugs have shown promise in ameliorating neurocognitive deficits in patients with schizophrenia, but few studies have compared newer antipsychotic drugs with both clozapine and conventional agents, particularly in patients who have had suboptimal response to prior treatments. METHOD: The authors examined the effects of clozapine, olanzapine, risperidone, and haloperidol on 16 measures of neurocognitive functioning in a double-blind, 14-week trial involving 101 patients. A global score was computed along with scores in four neurocognitive domains: memory, attention, motor function, and general executive and perceptual organization. RESULTS: Global neurocognitive function improved with olanzapine and risperidone treatment, and these improvements were superior to those seen with haloperidol. Patients treated with olanzapine exhibited improvement in the general and attention domains but not more than that observed with other treatments. Patients treated with risperidone exhibited improvement in memory that was superior to that of both clozapine and haloperidol. Clozapine yielded improvement in motor function but not more than in other groups. Average effect sizes for change were in the small to medium range. More than half of the patients treated with olanzapine and risperidone experienced "clinically significant" improvement (changes in score of at least one-half standard deviation relative to baseline). These findings did not appear to be mediated by changes in symptoms, side effects, or blood levels of medications. CONCLUSIONS: Patients with a history of suboptimal response to conventional treatments may show cognitive benefits from newer antipsychotic drugs, and there may be differences between atypical antipsychotic drugs in their patterns of cognitive effects.     

Effects of clozapine, olanzapine, risperidone, and haloperidol on hostility among patients with schizophrenia.

OBJECTIVE: This study compared the specific antiaggressive effects of clozapine with those of olanzapine, risperidone, and haloperidol. METHODS: A total of 157 inpatients with schizophrenia or schizoaffective disorder and a history of suboptimal treatment response were randomly assigned to receive clozapine, olanzapine, risperidone, or haloperidol in a double-blind 14-week trial. The trial was divided into two periods: eight weeks during which the dosage was escalated and then fixed, and six weeks during which variable dosages were used. The hostility item of the Positive and Negative Syndrome Scale (PANSS) was the principal outcome measure. Covariates included the items that reflect positive symptoms of schizophrenia (delusions, suspiciousness or feelings of persecution, grandiosity, unusual thought content, conceptual disorganization, and hallucinations) and the sedation item of the Nurses Observation Scale for Inpatient Evaluation (NOSIE). RESULTS: Patients differed in their treatment response as measured by the hostility item of the PANSS. The scores of patients taking clozapine indicated significantly greater improvement than those of patients taking haloperidol or risperidone. The effect on hostility appeared to be independent of the antipsychotic effect of clozapine on other PANSS items that reflect delusional thinking, a formal thought disorder, or hallucinations and independent of sedation as measured by the NOSIE. Neither risperidone nor olanzapine showed superiority to haloperidol. CONCLUSION: Clozapine has a relative advantage over other antipsychotics as a specific antihostility agent.     

Weight gain and antipsychotic medication: differences between antipsychotic-free and treatment periods.

BACKGROUND: We performed a retrospective analysis of data involving 121 inpatients to examine the rate of weight gain during antipsychotic-free periods and during treatment with various antipsychotic drugs. METHOD: Data were analyzed to determine differences in weekly weight change during antipsychotic-free (N = 65), typical antipsychotic (N = 51), or atypical antipsychotic (N = 130) treatment periods. Atypical antipsychotic treatment periods were further subdivided into olanzapine (N = 45), clozapine (N = 47), or risperidone (N = 36) treatment periods. A paired comparison was conducted on 65 patients who had an antipsychotic-free treatment period preceding or following a neuroleptic drug treatment period. In addition, patients were classified as either non-obese (with a body mass index [BMI] < or = 29.9 kg/ml) or obese (BMI > or = 30.0 kg/m2) to test whether the rate of weight gain during treatment periods was related to initial BMI. RESULTS: Across all treatment periods, weekly weight gain was as follows: 0.89 lb/wk (0.40 kg/wk) on atypical antipsychotic medication, 0.61 lb/wk (0.27 kg/wk) on typical antipsychotic medication, and 0.21 lb/wk (0.09 kg/wk) on no antipsychotic medications. The atypical antipsychotic versus antipsychotic-free comparison was significant (F = 3.51; df = 2,231; p = .031), while the typical antipsychotic versus antipsychotic-free comparison was not. Among the individual atypical antipsychotic medications, significantly more weight gain occurred during olanzapine treatment (1.70 lb/wk) (0.76 kg/wk) than with either clozapine (0.50 lb/wk) (0.22 kg/wk) or risperidone (0.34 lb/wk) (0.15 kg/wk) treatments (F = 7.77; df = 2,117; p = .001). In the paired analysis with patients serving as their own controls, the difference between weekly weight gain during atypical antipsychotic treatment and antipsychotic-free treatment was significant (t = -3.91; df = 44; p = .001), while the difference between weight gain during typical antipsychotic treatment and antipsychotic-free treatment was not significant. With the individual drugs. treatment with both olanzapine and clozapine caused significantly higher weekly weight gain than antipsychotic-free treatment (p = .001 and p = .036, respectively). while treatment with risperidone did not. Non-obese patients (BMI < 29.9 kg/m2) and obese patients (BMI > 30.0 kg/m2) did not differ significantly in their weight gain during typical or atypical antipsychotic treatment. CONCLUSION: Treatment with atypical antipsychotics was associated with more weight gain than treatment with typical antipsychotics. Among the atypical drugs, olanzapine was associated with more weight gain than either clozapine or risperidone. The patient's admission BMI was not associated with the amount of weight gained during subsequent antipsychotic treatment.     

Use of antipsychotic agents in Spain through 1985-2000.

OBJECTIVE: To analyze the trend of antipsychotic drug consumption in Spain from 1985 to 2000, and the impact of atypical antipsychotics on the overall consumption and on clozapine use. METHODS: Data on antipsychotic consumption were drawn from the ECOM database of the Spanish Ministry of Health, which contains the retail community pharmacies sales of medicinal products reimbursed by the National Health System. Data are presented as defined daily doses (DDDs) per 1000 inhabitants per day, for each year. To evaluate the impact of atypical antipsychotics on clozapine use, data from the Spanish "Clozapine Monitoring Program" were analyzed. Consumption data from Nordic countries were obtained from national statistics. RESULTS: The use of antipsychotics in Spain increased progressively from 1.51 DDD/1000 inhabitants/d in 1985 to 5.73 DDD/1000 inhabitants/d in 2000. The pattern of use of individual drugs changed greatly over the study period. In 1985, haloperidol, fluphenazine and thioridazine, all typical antipsychotics, were the drugs most widely used, whereas in 2000, the three drugs most frequently used were risperidone, olanzapine and haloperidol. The introduction of olanzapine in December 1996 reduced the number of new treatments with clozapine to half. Antipsychotic use is still lower in Spain than in Nordic countries, despite the prevalence of schizophrenia being similar worldwide. CONCLUSIONS: Antipsychotic agent use in Spain has increased progressively since 1985, reducing the differences between Spain and other European countries (Nordic countries). Substantial differences in the pattern of drug use from 1985 to 2000 have been observed.     

Effectiveness of antipsychotic treatments for schizophrenia: interim 6-month analysis from a prospective observational study (IC-SOHO) comparing olanzapine, quetiapine, risperidone, and haloperidol

BACKGROUND: The Intercontinental Schizophrenia Outpatient Health Outcomes (IC-SOHO) study was designed to provide information regarding use and outcome of antipsychotic treatments in a large, diverse population in real practice settings. METHOD: Outpatients with schizophrenia (ICD-10 or DSM-IV) who initiated or changed to a new antipsychotic entered this 3-year, naturalistic, prospective observational study. Four monotherapy treatment groups were defined according to the antipsychotic prescribed at baseline, namely olanzapine, risperidone, quetiapine, and haloperidol. Efficacy was assessed using the Clinical Global Impressions-Severity of Illness rating scale (CGI-S), inclusive of subscales for positive, negative, depressive, and cognitive symptoms. Tolerability was assessed by adverse event questionnaires and weight measurements. Six-month findings are described. RESULTS: At baseline, 5833 participants were prescribed monotherapy and the mean severity of illness was moderate to marked (CGI-S). At 6 months, olanzapine resulted in significantly greater improvements in overall, positive, negative, depressive, and cognitive symptoms compared with quetiapine, risperidone or haloperidol (p <.001). Improvements in overall, negative, and cognitive symptoms were significantly higher for risperidone compared with haloperidol (p <.001), whereas improvements across all symptoms were comparable for quetiapine and haloperidol. Extra-pyramidal symptoms and tardive dyskinesia decreased compared with baseline in the olanzapine, quetiapine, and risperidone groups but increased in the haloperidol group (p <.001, likelihood of extrapyramidal symptoms with haloperidol compared with olanzapine, quetiapine, or risperidone). Sexual function adverse events were most prominent in the haloperidol and risperidone treatment groups. Weight change was significantly greater for olanzapine compared with the other antipsychotics (p <.001). CONCLUSION: Our results support the previously reported positive impact of atypical antipsychotics, particularly olanzapine, in patients with schizophrenia.     

Different effects of centrally acting drugs on rabbit platelet aggregation: with special reference to selective inhibitory effects of antipsychotics and antidepressants

Twenty-four drugs, consisting of antipsychotics, tricyclic antidepressants, other centrally acting drugs, and related compounds, were studied for their effects on aggregation of rabbit platelets. Phenothiazine neuroleptics, haloperidol, sultopride, tricyclic antidepressants, sulpiride, atropine, and propranolol showed a selective inhibitory effect on the collagen-induced aggregation, but not on aggregations induced by arachidonic acid (AA) or adenosine diphosphate (ADP). These drugs are thought to inhibit the liberation of AA from phospholipids in platelet membranes, suggesting that they might inhibit phospholipases. Mepyramine, promethazine, phentolamine, and clozapine inhibited the aggregations evoked by collagen and AA, but failed to inhibit the ADP-induced aggregation. These drugs might inhibit the generation of prostaglandin endoperoxides or thromboxanes. Phenobarbital, phenytoin, procaine, lidocaine, flurazepam, trihexyphenydil, and lithium carbonate did not inhibit any kind of aggregation at the concentrations used. The clinical and pharmacological significance of these findings is discussed; it seems that the inhibitory effects of antipsychotics and antidepressants on platelet aggregation are closely related to the specific clinical and psychotropic effects of these drugs, but not to other actions.     

Effectiveness of clozapine, olanzapine, quetiapine, risperidone, and haloperidol monotherapy in reducing hostile and aggressive behavior in outpatients treated for schizophrenia: a prospective naturalistic study (IC-SOHO).

OBJECTIVE: Antipsychotic medications may reduce hostile and aggressive behavior in schizophrenia. This study compared the effectiveness of antipsychotics in the treatment of aggression. METHOD: The Intercontinental Schizophrenia Outpatient Health Outcomes (IC-SOHO) study compares the effectiveness of antipsychotic treatments in practice setting. Schizophrenia outpatients who initiated or changed to a new antipsychotic are followed in this non-interventional, prospective observational study for up to 3 years, with 6-months data now available on the entire cohort (N=7655). The presence or absence of verbal or physical hostility/aggression was assessed retrospectively for the period of 6 months before enrollment, and prospectively in the period of 6 months after enrollment (the study treatment period). At baseline, patients in five monotherapy treatment groups (combined N=3135) were prescribed one of the treatments: clozapine, olanzapine, quetiapine, risperidone, or haloperidol, and had complete data. RESULTS: Hostile/aggressive behavior was reduced during the treatment period. Olanzapine and risperidone were significantly superior to haloperidol and to clozapine in this respect. These results remained essentially unchanged when adjusting for baseline imbalances in age, gender, age of onset, and substance abuse. CONCLUSIONS: As monotherapy, both olanzapine and risperidone were superior to haloperidol and clozapine in reducing aggression. The relative lack of effectiveness of clozapine may be specific to this study population.     

Troubles obsessionnels compulsifs résistants et antipsychotiques : données neurobiologiques et thérapeutiques actuelles

Introduction

Forty to sixty percent of patients with obsessive compulsive disorder (OCD) are resistant to well conducted treatment with selective serotonin reuptake inhibitors (SSRIs) over 8 weeks. The data concerning effectiveness of the addition of antipsychotics in this indication is controversial.

Aims of the study

To synthesize the neurobiological mechanisms at work in order to understand the action of pharmacological treatments in this disease and to propose a systematic review of the literature on effectiveness of different antipsychotic drugs according to their pharmacological profiles, in monotherapy or in combination with SSRIs in OCD.

Method

We conducted a systematic review of the literature using the criteria according to the PRISMA research paradigm “obsessive compulsive disorder AND antipsychotic agents”. Research bases MEDLINE, Cochrane and Web of science have been explored.

Results

Unlike the classical serotonergic hypothesis, OCD may result from striatal dopaminergic hyperactivity, modulated in some patients by an underlying serotonergic hypoactivity. Most studies report effectiveness of first-generation antipsychotics (amisulpride and haloperidol) and some second-generation antipsychotics (risperidone, olanzapine, aripiprazole, quetiapine) in combination with an SSRI in the treatment of resistant OCD. Recrudescence or onset of OCD in patients with schizophrenia have been described in a relay from first generation antipsychotic to olanzapine, risperidone, aripiprazole or clozapine in case reports, but not amisulpride and quetiapine.     

Antipsychotics increase microtubule-associated protein 2 mRNA but not spinophilin mRNA in rat hippocampus and cortex

Antipsychotic (neuroleptic) drugs induce structural alterations in synaptic terminals and changes in the expression of presynaptic protein genes. Whether there are also changes in corresponding postsynaptic (dendritic) markers has not been determined. We describe the effect of 14-day treatment with typical (haloperidol, chlorpromazine) or atypical (clozapine, olanzapine, risperidone) antipsychotics on the expression of two dendritic protein genes, microtubule-associated protein 2 (MAP2) and spinophilin, using in situ hybridization, in the rat hippocampus, retrosplenial, and occipitoparietal cortices. MAP2 mRNA was increased modestly in the dentate gyrus and retrosplenial cortex by chlorpromazine, risperidone, and olanzapine and in the occipitoparietal cortex by chlorpromazine, haloperidol, and risperidone. None of the antipsychotics affected spinophilin mRNA in any area. Overall, these results show a modulation of MAP2 gene expression, likely reflecting functional or structural changes in the dendritic tree in response to some typical and atypical antipsychotics. The lack of change in spinophilin mRNA suggests that dendritic spines are not affected selectively by the drugs. The data provide further evidence that antipsychotics regulate genes involved in synaptic structure and function. Such actions may underlie their long-term effects on neural plasticity in areas of the brain implicated in the pathology of schizophrenia.     

Impact of apolipoprotein A5 (APOA5) polymorphisms on serum triglyceride levels in schizophrenic patients under long-term atypical antipsychotic treatment

Abstract

Objectives. Schizophrenic patients treated with clozapine or olanzapine often develop hypertriglyceridemia. The apolipoprotein A5 gene (APOA5), which affects VLDL production and lipolysis, has been implicated in the triglyceride (TG) metabolism. This study examined the association of common APOA5 genetic variants and TG levels in chronically institutionalized schizophrenic patients, on a stable dose of atypical antipsychotic (clozapine, olanzapine or risperidone. Methods. The TG levels in 466 schizophrenic patients treated with clozapine (n = 182), olanzapine (n = 89) or risperidone (n = 195) were measured. Patients were genotyped for the three APOA5 single nucleotide polymorphisms (SNPs) rs662799 (–1131T > C), rs651821 (3A > G) and rs2266788 (1891T > C). Results. A gene × drug interaction with TG levels was observed. In single-marker-based analysis, the minor alleles of the two polymorphisms (–1131C and –3G) were observed to be associated with increased TGs in patients treated with risperidone, but not with clozapine or olanzapine. Haplotype analysis further revealed that carriers of the haplotype constructed with the three minor alleles had higher TG levels than those who did not carry this haplotype in patients taking risperidone (CGC^(+/+) vs. = 125.4 ± 59.1 vs. 82.2 ± 65.8, P = 0.015; CGC^{(–/+ )} vs. CGC^(–/–) = 113.7 ± 80.4 vs. 82.2 ± 65.8, P = 0.012). Conclusions. Our findings extend and add new information to the existing data regarding the association between APOA5 and TG regulation during long-term atypical antipsychotic treatment.