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Wed, 24 May 2006


Effects of Antipsychotic Drugs on I(to), I (Na), I (sus), I (K1), and hERG: QT Prolongation, Structure Activity Relationship, and Network Analysis.

Crumb WJ, Ekins S, Sarazan RD, Wikel JH, Wrighton SA, Carlson C, Beasley CM

PURPOSE: To evaluate in vitro and computationally model the effects of selected antipsychotic drugs on several ionic currents that contribute to changes in the action potential in cardiac tissue. METHODS: Fourteen antipsychotic drugs or metabolites were examined to determine whether QT interval prolongation could be accounted for by an effect on one or more myocardial ion channels [I(to), I(Na), I(sus), I(K1), and human ether-a-go-go related gene (hERG)]. Using the patch clamp technique, drug effects on these human cardiac currents were tested. RESULTS: All molecules had little inhibitory effect on ion channels (blocking at concentrations >5 muM) other than hERG. A significant correlation was observed between the estimated hERG blockade and the increase in corrected QT for five of the antipsychotics. Molecular modeling identified hydrophobic features related to the interaction with hERG and correctly rank-ordered the test set molecules olanzapine and its metabolites. A network analysis of ligand and protein interactions around hERG using MetaCoretrade mark (GeneGo Inc., St. Joseph, MI, USA) was used to visualize antipsychotics with affinity for this channel and their interactions with other proteins in this database. CONCLUSION: The antipsychotics do not inhibit the ion channels I(to), I(Na), I(sus), I(K1) to any appreciable extent; however, blockade of hERG is a likely mechanism for the prolongation of the QT interval.

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An unusual case of episodic stupor.

De Silva DA, Ling LL, Yeong NB, Puvanendran K

We present a case of episodic stupor associated with a myriad of neuropyschiatric manifestations that baffled doctors until they were recognized as sleep attacks. Continuous monitoring and recognition of a cyclical pattern of symptoms and signs helped to uncover the underlying cause of a rapidly cycling bipolar disorder. The symptoms abated quickly and persistently when treated by olanzapine and lithium.

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SREBP Activation by Antipsychotic- and Antidepressant-Drugs in Cultured Human Liver Cells: Relevance for Metabolic Side-Effects?

Raeder MB, Fernø J, Vik-Mo AO, Steen VM

Drug-induced weight gain is a major problem in the treatment of psychiatric disorders, especially with some antipsychotic- and antidepressant drugs. We have recently demonstrated that antipsychotic- and antidepressant drugs activate the SREBP (sterol regulatory element-binding proteins) transcription factors in human- and rat glial cells, with subsequent up-regulation of downstream genes involved in cholesterol- and fatty acid biosynthesis. Since stimulation of cellular lipogenesis in the liver could be of relevance for the metabolic side effects of these drugs, we have now investigated the effects of antidepressants, antipsychotic- and mood-stabilizing drugs on cell cultures of human liver cells. For several of the drugs being strongly associated with weight gain (clozapine, imipramine, and amitriptyline), we observed a very pronounced activation of SREBP. Ziprasidone and buproprion, however, which are not associated with weight gain, did hardly stimulate the SREBP system. For haloperidol, olanzapine and mirtazapine, the correspondence between metabolic side effects and SREBP stimulation in liver cells was less obvious. The mood-stabilizers did not increase SREBP activation. The results indicate a relationship between drug-induced activation of SREBP in cultured human liver cells and weight gain side-effects of antidepressant and antipsychotic drugs.

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Olanzapine differentially affects 5-HT(2Aand2C) receptor mRNA expression in the rat brain.

Huang XF, Han M, Huang X, Zavitsanou K, Deng C

This study examined regional changes in rat brain mRNA levels encoding 5-HT(2A) and 5-HT(2C) receptors following chronic olanzapine treatment. The immediate effect (2h after the last treatment) was a down-regulation of 5-HT(2A) receptor mRNA expression, predominantly in the hypothalamus, limbic system and striatum, while a rebound effect was observed 48h later. 5-HT(2C) receptor mRNA expressions were decreased in the substantia nigra. Correlations between 5-HT(2A) receptor mRNA expression and total food intake, weight gain and energy efficiency were observed.

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Atypical antipsychotics and pituitary tumors: a pharmacovigilance study.

Pharmacotherapy 2006 Jun; 26(6): 748-58 (Read article online)
Szarfman A, Tonning JM, Levine JG, Doraiswamy PM

Study Objective. To analyze the disproportionality of reporting of hyperprolactinemia, galactorrhea, and pituitary tumors with seven widely used antipsychotic drugs. Design. Retrospective pharmacovigilance study. Data Source. United States Food and Drug Administration's Adverse Event Reporting System (AERS) database. Intervention. We initially identified higher-than-expected postmarketing reports of pituitary tumors associated with risperidone, a potent dopamine D(2)-receptor antagonist antipsychotic, by analyzing reporting patterns of these tumors in the AERS database. To further examine this association, we analyzed disproportionate reporting patterns of pituitary tumor reports for seven antipsychotics with different affinities for blocking D(2) receptors: aripiprazole, clozapine, olanzapine, quetiapine, risperidone, ziprasidone, and haloperidol. Measurements and Main Results. To conduct both of these analyses, we used the Multi-item Gamma Poisson Shrinker (MGPS) data mining algorithm applied to the AERS database. The MGPS uses a Bayesian model to calculate adjusted observed:expected ratios of drug-adverse event associations (Empiric Bayes Geometric Mean [EBGM] values) in huge drug safety databases. The higher the adjusted reporting ratio, or EBGM value, the greater the strength of the association between a drug and an adverse event. Risperidone had the highest adjusted reporting ratios for hyperprolactinemia (EBGM 34.9, 90% confidence interval [CI] 32.8-37.1]), galactorrhea (EBGM 19.9, 90% CI 18.6-21.4), and pituitary tumor (EBGM 18.7, 90% CI 14.9-23.3) among the seven antipsychotics, and one of the highest scores for all drugs in the AERS database. Some tumors were associated with visual field defects, hemorrhage, convulsions, surgery, and severe (> 10-fold) prolactin elevations. The EBGM values for risperidone for these adverse events were higher in women, but high EBGM values for these events were also seen in men and children. Moreover, the rank order of the EBGM values for pituitary tumors corresponded to the affinities of these seven drugs for D(2) receptors. Conclusion. Treatment with potent D(2)-receptor antagonists, such as risperidone, may be associated with pituitary tumors. These findings are consistent with animal (mice) studies and raise the need for clinical awareness and longitudinal studies.

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A naturalistic, 9-month follow-up, comparing olanzapine and conventional antipsychotics on sexual function and hormonal profile for males with schizophrenia.

Costa AM, de Lima MS, Faria M, Rodrigues Filho S, De Oliveira IR, Mari JD

Second generation antipsychotics have less influence on prolactin levels than conventional antipsychotics (CA), which are commonly associated with sexual dysfunction and hyperprolactinaemia. However, only a few studies have been conducted assessing these newer antipsychotics and sexual function/dysfunction. The aim of this study is to evaluate the sexual function and hormonal profile of male schizophrenic patients taking olanzapine or CA. Sixty-three inpatients with acute episodes of schizophrenia were randomly assigned to take either olanzapine, or go on conventional antipsychotic treatment. The Dickson-Glazer sexual functioning questionnaire was used to assess sexual functioning where serum prolactin, luteinizing hormone, follicle-stimulating hormone, total testosterone, free testosterone, and sex hormone-binding globulin concentrations were measured. All measurements were taken on discharge from the inpatient unit (baseline), and again at 3 and 9 months after discharge. Prolactin levels in the olanzapine group decreased more rapidly and were significantly lower than in the CA group after 3 months (12.1 +/- 6.3 microg/l, p = 0.01; 18.1 +/- 11.2 microg/l, p = 0.564, respectively). After nine months, there was a tendency toward normal levels in both groups, and the frequency of sexual complaints did not differ between the groups. This study showed no difference between olanzapine and conventional antipsychotics regarding sexual complaints in the treatment of schizophrenia, but did show a difference in the hormone level normalization rate.

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Mon, 22 May 2006


Why Do Physicians Switch From One Antipsychotic Agent to Another?: The "Physician Drug Stereotype"

J Clin Psychopharmacol 2006 Jun; 26(3): 225-231 (Read article online)
Linden M, Pyrkosch L, Dittmann RW, Czekalla J

ABSTRACT:: There is a lack of research on why physicians select a certain drug in an individual case and not another available alternative, although this drug selection process is important for quality assurance and cost control.Four hundred ninety-five psychiatrists documented in a standardized form patient and illness characteristics of 1711 schizophrenic outpatients who were switched for individual clinical reasons from an ongoing neuroleptic treatment to olanzapine, and of another 1654 schizophrenic outpatients whose present neuroleptic medication was continued. Physicians also filled in the "Reason for Treatment Selection Questionnaire."Patients who were switched to olanzapine were more ill and showed more preexisting extrapyramidal symptoms and less patient compliance. Reasons of psychiatrists to switch to olanzapine were the expectation of better efficacy and tolerability of the present treatment and patient preferences to continue with the present medication. The price of olanzapine is seen as a reason not to select olanzapine but has no effect on the treatment decision. The "physician drug stereotype" of olanzapine corresponds with clinical data on the efficacy and tolerability of olanzapine.The data show that medical decisions about drug selection are multidimensional, integrating knowledge about the clinical properties of the drug, personal experiences and information about the individual case. The Reason for Treatment Selection Questionnaire is an instrument that allows to objectively assess important aspects of medical decision making, to generate psychological drug profile, and to understand why physicians prefer one drug over alternatives.

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Olanzapine-Induced Weight Gain and Increased Visceral Adiposity is Blocked by Melatonin Replacement Therapy in Rats.

Raskind MA, Burke BL, Crites NJ, Tapp AM, Rasmussen DD

The atypical antipsychotic drug olanzapine increases body weight and visceral adiposity in schizophrenia. In rats, aging-associated increased body weight and visceral adiposity are reversed by administration of the pineal hormone melatonin. We asked if melatonin similarly would reverse olanzapine-induced increased weight and visceral adiposity in rats. Four groups (n=11/group) of female rats (240-250 g) were treated for 8 weeks with olanzapine, melatonin, olanzapine+melatonin, or vehicle alone in drinking water. Body weight and food and water consumption were determined weekly, locomotor activity at weeks 3 and 6, and nocturnal plasma melatonin concentration at week 7. At week 8, the rats were killed and visceral (perirenal, retroperitoneal, omental, and mesenteric) fat pads dissected and weighed. Olanzapine treatment reduced nocturnal plasma melatonin by 55% (p<0.001), which was restored to control levels by olanzapine+melatonin. Body weight increased 18% in rats treated with olanzapine alone, but only 10% with olanzapine+melatonin, 5% with melatonin alone, and 7% with vehicle control. Body weight and visceral fat pad weight increases in rats treated with olanzapine alone were greater than in each of the other three groups (all p<0.01), which were not significantly different. These results suggest that olanzapine-induced increases in body weight and visceral adiposity may be at least in part secondary to olanzapine-induced reduction of plasma melatonin levels, and that melatonin may be useful for the management of olanzapine-induced weight gain in humans.Neuropsychopharmacology advance online publication, 10 May 2006; doi:10.1038/sj.npp.1301093.

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Open-label olanzapine treatment in bipolar I disorder: clinical and work functional outcomes.

Curr Med Res Opin 2006 May; 22(5): 961-966 (Read article online)
Shi L, Juarez R, Hackworth J, Edgell ET, Haro JM, Vieta E, Tohen MF

OBJECTIVES: The objective of this study was to describe clinical and work functional outcomes associated with 6-month open-label olanzapine treatment for bipolar I disorder.METHODS: The study consisted of 249 patients entering a 6-month open label phase after 12 weeks of acute double-blind haloperidol or olanzapine treatment. Baseline for analysis was defined as the beginning of open-label treatment. The clinical outcomes were symptomatic remission defined by a Y-MRS total score

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Enhanced efficacy of both typical and atypical antipsychotic drugs by adjunctive alpha 2 adrenoceptor blockade: experimental evidence.

Wadenberg ML, Wiker C, Svensson TH

Adjunctive treatment with the selective alpha2 adrenoceptor antagonist idazoxan augments the effect of conventional antipsychotics in treatment-resistant schizophrenics comparing favourably with clozapine. Clozapine has high affinity for alpha2 adrenoceptors. Previously, we found that adjunctive idazoxan treatment to the dopamine (DA) D2/3 antagonist raclopride enhanced raclopride-induced effects in an animal model of antipsychotic activity (conditioned avoidance response, CAR) and, similarly to clozapine, reversed the disruption of working memory induced by N-methyl-D-aspartate receptor blockade in rats with a concomitant increase in prefrontal DA efflux. To further investigate the significance of alpha2 adrenoceptor affinity for antipsychotic efficacy, we here investigated, in rats, the effects of adjunctive idazoxan treatment to low doses of a typical (haloperidol) and an atypical (olanzapine) antipsychotic drug, both lacking appreciable alpha2 adrenoceptor affinity, on (i) CAR; (ii) catalepsy; and (iii) DA output in the prefrontal cortex and the nucleus accumbens using microdialysis. Adjunctive treatment with idazoxan to haloperidol or olanzapine enhanced suppression of CAR to a level predicting sufficient antipsychotic activity, increased DA output preferentially in the prefrontal cortex, and reversed haloperidol-induced catalepsy. Our data confirm and extend our previous findings as well as clinical observations, and suggest that adjunctive alpha2 adrenoceptor blockade both typical and atypical antipsychotic drugs, lacking appreciable affinity for the alpha2 adrenoceptor, may contribute to a more advantageous therapeutical profile of these drugs in schizophrenia treatment, allowing for reduced DA D2 occupancy and reduction of unwanted side-effects.

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A randomized, double-blind comparison of olanzapine/fluoxetine combination, olanzapine, fluoxetine, and venlafaxine in treatment-resistant depression.

Corya SA, Williamson D, Sanger TM, Briggs SD, Case M, Tollefson G

Based on preliminary evidence of its usefulness in treatment-resistant depression (TRD), an olanzapine/fluoxetine combination (OFC) was examined in comparison with olanzapine, fluoxetine, and venlafaxine in a TRD population. In this 12-week double-blind study, 483 subjects with unipolar, nonpsychotic TRD, with historic failure on a selective serotonin reuptake inhibitor (SSRI) and prospective failure on open-label venlafaxine, were randomized to an OFC or to an olanzapine, fluoxetine, or venlafaxine monotherapy group. Venlafaxine was continued randomly in the double-blind acute phase to explore the benefits of continuation versus switching therapy. The Montgomery-Asberg Depression Rating Scale (MADRS) total change score at end point was the primary outcome measure. The OFC group had significantly greater improvement in depressive symptoms by week 1 of treatment (MADRS mean change =-7.2, baseline =29.6), in comparison to olanzapine (-4.8, P=.03), fluoxetine (-4.7, P=.03), or venlafaxine (-3.7, P=.002) groups and maintained its statistical separation from all three monotherapy groups through week 6. At end point, the OFC group was significantly different only from the olanzapine group (-14.1 vs. -7.7, P<.001). Analysis of a subgroup of subjects who had an SSRI failure in their current depressive episode (n=334) revealed statistical separation from both olanzapine and fluoxetine (but not venlafaxine) at end point: OFC (-14.6) versus olanzapine (-9.4, P<.001) versus fluoxetine (-10.7, P=.006) versus venlafaxine (-14.7, P=.98). The OFC had a safety profile comparable to its component monotherapies (i.e., olanzapine and fluoxetine), showed a rapid onset of antidepressant effect, and was effective in this TRD sample. At the study end point, OFC, fluoxetine, venlafaxine, and low-dose OFC all appeared to be similarly effective. Depression and Anxiety 0:1-9, 2006. (c) 2006 Wiley-Liss, Inc.

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Early Predictors of Substantial Weight Gain in Bipolar Patients Treated with Olanzapine.

J Clin Psychopharmacol 2006 Jun; 26(3): 316-320 (Read article online)
Lipkovich I, Citrome L, Perlis R, Deberdt W, Houston JP, Ahl J, Hardy T

ABSTRACT:: To determine predictors of substantial weight gain (SWG) during treatment of bipolar disorder with olanzapine, data were pooled from 4 long-term randomized, multicenter studies in patients with bipolar mania or mixed mania (N = 948 at initiation of olanzapine). SWG was defined as gaining 5 kg or 7% of initial weight in 30 +/- 2 weeks. Logistic regression estimated odds ratios associated with early weight gain and baseline risk factors for predicting SWG. A classification system to identify patients at risk for SWG was constructed by recursive data partitioning. Baseline characteristics significantly associated with SWG included younger age, nonwhite ethnicity, lower body mass index (BMI), nonrapid cycling, and psychotic features. Weight gain of 2 or more kg in the first 3 weeks of therapy predicted SWG by 30 weeks (sensitivity = 57%; specificity = 71%). A classification system with thresholds for early weight gain, baseline BMI, and ethnicity further improved SWG predictability (sensitivity = 79%; specificity = 70%). In conclusion, patients with bipolar disorder who gained 2 to 3 kg during the first 3 weeks of treatment with olanzapine, SWG was predicted after 30 weeks of treatment. Patients with less pronounced early weight gain might still be at risk for later SWG if they have close to normal BMI (

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Pharmacological treatment of Alzheimer's Disease*.

Aging Clin Exp Res 2006 Apr; 18(2): 158-62 (Read article online)
Bianchetti A, Ranieri P, Margiotta A, Trabucchi M

BACKGROUND AND AIMS: The treatment of Alzheimer's disease (AD) is a challenge for physician, families, and patients. An individualized, multimodal treatment plan addressing the treatment of cognitive, behavioural and functional decline is essential. Aim of the paper is to describe the principal components of the treatment plan of AD patients. METHODS: A review of the recent literature was performed. RESULTS: Acetylcholinesterase inhibitors (AChEIs) play an important role in the improvement of cognitive decline in mild to moderate AD, even if the improvement is not permanent. Data obtained from the CRONOS project (involving about 500 Alzheimer Evaluation Units) replicate in the real world those obtained in controlled trials, confirming that AD patients may benefit from AChEI treatment. Treatment of behavioral and psychological symptoms of dementia (BPSD) requires education of caregivers, non pharmacological interventions, identification and treatment of medical illnesses or environmental precipitating conditions, specific pharmacological treatment. Traditional neuroleptics are widely used for BPSD treatment, but limited data support their use, and side-effects are frequent and severe. Atypical antipsychotics are effective in treating BPSD, and safer than traditional neuroleptics. However, the increased risk of cerebrovascular accident in patients taking risperidone or olanzapine limited currently their use in demented subjects. The use of antidepressant drugs, as well as behavioral approach, may improve depressive symptoms frequently accompanying AD. CONCLUSIONS: Although at present there is no cure for AD, several drug treatments and care strategies may improve or stabilize cognitive and behavioral symptoms, and improve the quality of life of patients and families.

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Randomised controlled trials of conventional antipsychotic versus new atypical drugs, and new atypical drugs versus clozapine, in people with schizophrenia responding poorly to, or intolerant of, current drug treatment.

Health Technol Assess 2006 May; 10(17): 1-182 (Read article online)
Lewis SW, Davies L, Jones PB, Barnes TR, Murray RM, Kerwin R, Taylor D, Hayhurst KP, Markwick A, Lloyd H, Dunn G

OBJECTIVES: To determine the clinical and cost-effectiveness of different classes of antipsychotic drug treatment in people with schizophrenia responding inadequately to, or having unacceptable side-effects from, their current medication. DESIGN: Two pragmatic, randomised controlled trials (RCTs) were undertaken. The first RCT (band 1) compared the class of older, inexpensive conventional drugs with the class of new atypical drugs in people with schizophrenic disorders, whose current antipsychotic drug treatment was being changed either because of inadequate clinical response or owing to side-effects. The second RCT (band 2) compared the new (non-clozapine) atypical drugs with clozapine in people whose medication was being changed because of poor clinical response to two or more antipsychotic drugs. Both RCTs were four-centre trials with concealed randomisation and three follow-up assessments over 1 year, blind to treatment. SETTING: Adult mental health settings in England. PARTICIPANTS: In total, 227 participants aged 18--65 years (40% of the planned sample) were randomised to band 1 and 136 (98% of the planned sample) to band 2. INTERVENTIONS: Participants were randomised to a class of drug. The managing clinician selected the individual drug within that class, except for the clozapine arm in band 2. The new atypical drugs included risperidone, olanzapine, quetiapine and amisulpride. The conventional drugs included older drugs, including depot preparations. As in routine practice, clinicians and participants were aware of the identity of the prescribed drug, but clinicians were asked to keep their participating patient on the randomised medication for at least the first 12 weeks. If the medication needed to be changed, the clinician was asked to prescribe another drug within the same class, if possible. MAIN OUTCOME MEASURES: The primary outcome was the Quality of Life Scale (QLS). Secondary clinical outcomes included symptoms [Positive and Negative Syndrome Scale (PANSS)], side-effects and participant satisfaction. Economic outcomes were costs of health and social care and a utility measure. RESULTS: Recruitment to band 1 was less than anticipated (40%) and diminished over the trial. This appeared largely due to loss of perceived clinical equipoise (clinicians progressively becoming more convinced of the superiority of new atypicals). Good follow-up rates and a higher than expected correlation between QLS score at baseline and at follow-up meant that the sample as recruited had 75% power to detect a difference in QLS score of 5 points between the two treatment arms at 52 weeks. The recruitment to band 2 was approximately as planned. Follow-up assessments were completed at week 52 in 81% of band 1 and 87% of band 2 participants. Band 1 data showed that, on the QLS and symptom measures, those participants in the conventional arm tended towards greater improvements. This suggests that the failure to find the predicted advantage for new atypicals was not due to inadequate recruitment and statistical power in this sample. Participants reported no clear preference for either class of drug. There were no statistically significant differential outcomes for participants entering band 1 for reasons of treatment intolerance to those entering because of broadly defined treatment resistance. Net costs over the year varied widely, with a mean of pound18,850 in the conventional drug group and pound20,123 in the new atypical group, not a statistically significant difference. Of these costs, 2.1% and 3.8% were due to antipsychotic drug costs in the conventional and atypical group, respectively. There was a trend towards participants in the conventional drug group scoring more highly on the utility measure at 1 year. The results for band 2 showed an advantage for commencing clozapine in quality of life (QLS) at trend level (p = 0.08) and in symptoms (PANSS), which was statistically significant (p = 0.01), at 1 year. Clozapine showed approximately a 5-point advantage on PANSS total score and a trend towards having fewer total extrapyramidal side-effects. Participants reported at 12 weeks that their mental health was significantly better with clozapine than with new atypicals (p < 0.05). Net costs of care varied widely, but were higher than in band 1, with a mean of pound33,800 in the clozapine group and pound28,400 in the new atypical group. Of these costs, 4.0% and 3.3%, respectively, were due to antipsychotic drug costs. The increased costs in the clozapine group appeared to reflect the licensing requirement for inpatient admission for commencing the drug. There was a trend towards higher mean participant utility scores in the clozapine group. CONCLUSIONS: For band 1, there is no disadvantage in terms of quality of life and symptoms, or associated costs of care, over 1 year in commencing conventional antipsychotic drugs rather than new atypical drugs. Conventional drugs were associated with non-significantly better outcomes and lower costs. Drug costs represented a small proportion of the overall costs of care (<5%). For band 2, there is a statistically significant advantage in terms of symptoms but not quality of life over 1 year in commencing clozapine rather than new atypical drugs, but with increased associated costs of care. The results suggest that conventional antipsychotic drugs, which are substantially cheaper, still have a place in the treatment of patients unresponsive to, or intolerant of, current medication. Further analyses of this data set are planned and further research is recommended into areas such as current antipsychotic treatment guidance, valid measures of utility in serious mental illness, low-dose 'conventional' treatment in first episode schizophrenia, QLS validity and determinants of QLS score in schizophrenia, and into the possible financial and other mechanisms of rewarding clinician participation in trials.

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A Randomized Open-Label Comparison of the Impact of Olanzapine Versus Risperidone on Sexual Functioning.

J Sex Marital Ther 2006 July-September; 32(4): 315-326 (Read article online)
Knegtering H, Boks M, Blijd C, Castelein S, van den Bosch RJ, Wiersma D

The objective of this study was to compare sexual functioning in patients treated with olanzapine or risperidone. This open-label trial included 46 patients randomized to olanzapine (5-15 mg/d) or risperidone (1-6 mg/d) for 6 weeks. We used sexual dysfunction was assessed by a semistructured interview based on the items of the UKU side effect rating scale. Three olanzapine-treated patients (12.0%), compared with 11 risperidone-treated patients (52.4%), reported sexual dysfunctions (p = .008) in the semistructured interview. Only 4 patients (8.7%) spontaneously reported sexual dysfunction. The mean dose was 9.4 mg/d for olanzapine and 3.4 mg/d for risperidone. The mean (+/-SD) prolactin levels (ng/mL) in olanzapine-and risperidone-treated patients were 25.1 (+/- 23.5) and 43.5 (+/- 26.1), respectively. Less sexual dysfunction occurred in the group treated with olanzapine compared with the risperidone group. Direct questioning about sexual functioning is necessary to avoid underestimating the frequency of sexual side effects in patients with schizophrenia and related psychotic disorders.

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Olanzapine Treatment is Associated with Reduced High Molecular Weight Adiponectin in Serum: A Potential Mechanism for Olanzapine-induced Insulin Resistance in Patients with Schizophrenia.

J Clin Psychopharmacol 2006 Jun; 26(3): 232-237 (Read article online)
Richards AA, Hickman IJ, Wang AY, Jones AL, Newell F, Mowry BJ, Whitehead JP, Prins JB, Macdonald GA

ABSTRACT:: Treatment of schizophrenia with olanzapine and other atypical antipsychotic agents is associated with insulin resistance and diabetes mellitus. The mechanism for this is not understood. Adiponectin is an insulin-sensitizing cytokine secreted by adipocytes. It is present in serum in multimers of varying size. Trimers and hexamers are referred to as low molecular weight (LMW) adiponectin. Larger multimers (12-, 18-, and 24-mers) have been designated high molecular weight (HMW) adiponectin and seem responsible for the insulin-sensitizing action of this adipokine. The aim of this study was to examine total adiponectin and LMW and HMW multimers in serum from patients with schizophrenia treated with either olanzapine (n = 9) or other typical antipsychotics (n = 9) and compare results with 16 healthy sex-, body mass index-, and age-matched controls. The effects of olanzapine on adiponectin protein expression and secretion in in vitro-differentiated primary human adipocytes were also examined. Patients receiving olanzapine had significantly lower total serum adiponectin as compared with those on conventional treatment and controls (5.23 +/- 1.53 ng/mL vs. 8.20 +/- 3.77 ng/mL and 8.78 +/- 3.8 ng/mL; P < 0.05 and P < 0.01, respectively). The HMW adiponectin was also reduced in patients on olanzapine as compared with the disease and healthy control groups (1.67 +/- 0.96 ng/mL vs. 3.87 +/- 2.69 ng/mL and 4.07 +/- 3.2 ng/mL; P < 0.05 for both). The LMW adiponectin was not different between patient groups (P = 0.15) but lower in patients on olanzapine as compared with controls (3.56 +/- 0.85 ng/mL vs. 4.70 +/- 1.4 ng/mL; P < 0.05). In vitro, short duration (up to 7 days) olanzapine exposure had no effect on total adiponectin expression or multimer composition of secreted protein. In summary, this study demonstrates a correlation between olanzapine treatment and reduced serum adiponectin, particularly HMW multimers. This may not be a direct effect of olanzapine on adipocyte expression or secretion of adiponectin. These observations provide insights into possible mechanisms for the association between olanzapine treatment and insulin resistance.

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A Randomized, 1-Year Follow-up Study of Olanzapine and Risperidone in the Treatment of Negative Symptoms in Outpatients with Schizophrenia.

J Clin Psychopharmacol 2006 Jun; 26(3): 238-249 (Read article online)
Alvarez E, Ciudad A, Olivares JM, Bousoño M, Gómez JC

OBJECTIVE:: To evaluate the efficacy of olanzapine compared with risperidone in negative symptoms, after 1 year of treatment, in schizophrenic outpatients with prominent negative symptoms. METHODS:: This was a multicenter, randomized, monitored, open-label, parallel, dose-flexible, 1-year study of outpatients with schizophrenia (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria) with prominent negative symptoms (Scale for the Assessment of Negative Symptoms [SANS] summary score >10) previously treated with conventional antipsychotics. Patients were randomly assigned to treatment with an initial dose of olanzapine 10 mg/d or more (n = 120) or risperidone 3 mg/d or more (n = 115). The primary efficacy measure was the SANS summary score. Secondary efficacy measures included Scale for the Assessment of Positive Symptoms, Clinical Global Impression of Severity Scale, Calgary Depression Scale, and Social Functioning Scale. The response rate was defined as 30% or more of improvement in the SANS summary score. RESULTS:: The mean dose throughout the study was 12.2 mg/d (+/-5.8 mg/d) for olanzapine and 4.9 mg/d (+/-2.0 mg/d) for risperidone. At 1 year, olanzapine patients showed significantly higher improvement than risperidone patients on the SANS summary (P = 0.015) and on the affective flattening (P = 0.007) and avolition/apathy (P = 0.028) SANS subscales. There were also significant improvements in favor of olanzapine in the Scale for the Assessment of Positive Symptoms summary (P = 0.021), Clinical Global Impression of Severity (P = 0.008), and Social Functioning Scale total (P < 0.001) scores. The response rate was greater (P = 0.001) in the olanzapine cohort (69.2%) than in the risperidone cohort (48.7%). Olanzapine patients reported less extrapyramidal side effects but a higher incidence of clinically important body weight increase than risperidone patients. CONCLUSIONS:: Long-term treatment with olanzapine was associated with significantly better improvement in negative symptoms as compared with risperidone-treated schizophrenic outpatients with prominent negative symptoms.

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Tue, 16 May 2006


Acute generalized exanthematous pustulosis induced by olanzapine.

Christen S, Gueissaz F, Anex R, Zullino DF

The case of a 56 years old man is presented, who developed acute generalized exanthematous pustulosis 5 days after the introduction of olanzapine 10 mg. Multiple 1-mm pustules appeared on the whole body, concentrated especially on her neck and face. Within 2 days, the eruption was increasingly accompanied by erythema and pruritus. No fever, chills, nausea, vomiting, arthralgias or myalgias were recorded. The diagnosis was corroborated by hystopathology. After 7 days of treatment, olanzapine and valproate were stopped. Concomitantly, cetirizine 20 mg p.o. and methylprednisolone 500 mg i.v. were given once. During the following week betamethasone cream was applied, and the pustular eruption resolved completely.

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Chronic administration of olanzapine induces metabolic and food intake alterations: a mouse model of the atypical antipsychotic-associated adverse effects.

Coccurello R, Caprioli A, Ghirardi O, Conti R, Ciani B, Daniele S, Bartolomucci A, Moles A

RATIONALE: Most of atypical antipsychotics (AAPs) are highly related to a major risk of metabolic drawbacks leading to dyslipidemia and obesity. OBJECTIVE: To set up a mouse model of the AAP-associated weight gain in mice under the influence of chronic olanzapine regimen. MATERIALS AND METHODS: Female mice were housed in pairs and habituated to spontaneous feeding with a high-palatable diet (10% sucrose wet mash). Firstly, we orally administered olanzapine (0.75, 1.5 and 3 mg/kg), evaluating body weight and periuterine fat mass, as well as insulin, non-esterified fatty acids, triglycerides, and glucose levels. In a second experiment, we assessed the effect of olanzapine on energy expenditure through indirect calorimetry (IC). A third experiment was conducted to investigate the effects of olanzapine on a high fat-high sweet palatable diet (10% sucrose + 30% fat, HF-HS) in mice implanted with subcutaneous osmotic mini-pumps. Locomotor activity was also assessed. RESULTS: In experiment 1, the highest dose of chronically administered olanzapine (3 mg/kg) induced significant weight gain accompanied by augmentation of periuterine fat depots, with no changes in locomotor activity. In experiment 2, chronic administration did not alter energy expenditure, whereas, decreased respiratory quotient (RQ). In experiment 3, subcutaneously infused olanzapine evidenced a dose and time-dependent increase of body weight and HF-HS diet consumed. Notably, serum analyses revealed a hyperinsulinemia together with increased levels of triglycerides and glucose. CONCLUSIONS: In this study, we describe in female mice metabolic alterations matching the metabolic syndrome, thus resembling the clinical situation of schizophrenic patients taking AAPs.

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Mechanism of action of atypical antipsychotic drugs and the neurobiology of schizophrenia.

CNS Drugs 2006; 20(5): 389-409 (Read article online)
Horacek J, Bubenikova-Valesova V, Kopecek M, Palenicek T, Dockery C, Mohr P, Höschl C

Atypical antipsychotics have greatly enhanced the treatment of schizophrenia. The mechanisms underlying the effectiveness and adverse effects of these drugs are, to date, not sufficiently explained. This article summarises the hypothetical mechanisms of action of atypical antipsychotics with respect to the neurobiology of schizophrenia.When considering treatment models for schizophrenia, the role of dopamine receptor blockade and modulation remains dominant. The optimal occupancy of dopamine D(2) receptors seems to be crucial to balancing efficacy and adverse effects - transient D(2) receptor antagonism (such as that attained with, for example, quetiapine and clozapine) is sufficient to obtain an antipsychotic effect, while permanent D(2) receptor antagonism (as is caused by conventional antipsychotics) increases the risk of adverse effects such as extrapyramidal symptoms. Partial D(2) receptor agonism (induced by aripiprazole) offers the possibility of maintaining optimal blockade and function of D(2) receptors. Balancing presynaptic and postsynaptic D(2) receptor antagonism (e.g. induced by amisulpride) is another mechanism that can, through increased release of endogenous dopamine in the striatum, protect against excessive blockade of D(2) receptors.Serotonergic modulation is associated with a beneficial increase in striatal dopamine release. Effects on the negative and cognitive symptoms of schizophrenia relate to dopamine release in the prefrontal cortex; this can be modulated by combined D(2) and serotonin 5-HT(2A) receptor antagonism (e.g. by olanzapine and risperidone), partial D(2) receptor antagonism or the preferential blockade of inhibitory dopamine autoreceptors.In the context of the neurodevelopmental disconnection hypothesis of schizophrenia, atypical antipsychotics (in contrast to conventional antipsychotics) induce neuronal plasticity and synaptic remodelling, not only in the striatum but also in other brain areas such as the prefrontal cortex and hippocampus. This mechanism may normalise glutamatergic dysfunction and structural abnormalities and affect the core pathophysiological substrates for schizophrenia.

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