Olanzapine: a review of its use in the treatment of bipolar I disorder

The effect of olanzapine on spatial memory impairment, depressive-like behavior, pain perception, and BDNF and synaptophysin expression following childhood chronic unpredictable mild stress in adult male and female rats

Chronic unpredictable mild stress (CUMS) method has been introduced as a rodent model of depression. On the other hand, olanzapine, as an antipsychotic, can induce antidepressant and antipsychotic effects. Also, olanzapine may improve cognitive functions. Both CUMS and olanzapine can also affect the expression level of brain-derived neurotrophic factor (BDNF) and synaptophysin, the molecular factors involved in synaptic function, and learning and memory. In this study, we investigated the effect of olanzapine on locomotor activity (using open field test), pain threshold (using hot plate), depressive-like behavior (using forced swim test), spatial learning and memory (using Morris water maze), and BDNF and synaptophysin hippocampal expression (using real-time PCR) in both male and female CUMS rats. CUMS was performed for three consecutive weeks. Olanzapine was also injected intraperitoneally at the dose of 5 mg/kg. Our data showed that olanzapine can reverse the effects of CUMS on behavioral functions and BDNF and synaptophysin expression levels in the hippocampus of both males and females. It was also shown that olanzapine effects on spatial memory, pain perception, and BDNF and synaptophysin level were stronger in females than males. In conclusion, we suggested that the therapeutic effects of olanzapine in CUMS rats may be closely related to the function of BDNF and synaptophysin. Also, the therapeutic effects of olanzapine may be stronger in females. Therefore, and for the first time, we showed that there may be a sex difference in the effects of olanzapine on behavioral and molecular changes following CUMS.

Improved biopharmaceutical performance of antipsychotic drug using lipid nanoparticles via intraperitoneal route

This study aims to develop, characterize, and examine olanzapine-loaded solid lipid nanocarriers (OLAN-SLNs) for effective brain delivery. OLAN has poor water solubility and low penetration through blood-brain barrier (BBB). Herein, OLAN-SLNs were fabricated using high-pressure homogenization (HPH) method followed by their investigation for particle properties. Moreover, in vitro release and in vivo pharmacokinetics profiles of OLAN-SLNs were compared with pure drug. Anti-psychotic activity was performed in LPS-induced psychosis mice model. Furthermore, expressions of the COX-2 and NF-κB were measured trailed by histopathological examination. The optimized formulation demonstrated nanoparticle size (149.1 nm) with rounded morphology, negative zeta potential (-28.9 mV), lower PDI (0.334), and excellent entrapment efficiency (95%). OLAN-SLNs significantly retarded the drug release and showed sustained release pattern as compared to OLAN suspension. Significantly enhanced bioavailability (ninefold) was demonstrated in OLAN-SLNs when compared with OLAN suspension. Behavioral tests showed significantly less immobility and more struggling time in OLAN-SLNs treated mice group. Additionally, reduced expression of COX-2 and -NF κB in brain was found. Altogether, it can be concluded that SLNs have the potential to deliver active pharmaceutical ingredients to brain, most importantly to enhance their bioavailability and antipsychotic effect, as indicated for OLAN in this study.

Effect of Co-Treatment of Olanzapine with SEP-363856 in Mice Models of Schizophrenia

Olanzapine is a commonly used drug in the treatment of schizophrenia, but its clinical application has been restricted by metabolic-related side effects. In order to mitigate the weight gain side effects caused by olanzapine, other drugs with different targets were selected for combined use and evaluated in animal models of schizophrenia. SEP-363856 is a novel psychotropic agent which is under phase III clinical trials for schizophrenia treatment. The aim of the research was to evaluate whether co-administration of olanzapine and SEP-363856 exerts synergistic anti-schizophrenic effects in the apomorphine (APO)-induced climbing test, the MK-801-induced hyperactivity test, and the Morris water maze test, and therefore reduces the weight gain side effects induced by olanzapine. Through isobolographic analysis, the results showed a synergistic interaction in the climbing test; the experimental ED30 (3 mg/kg) was significantly smaller (p < 0.05) than the theoretical ED30 (5 mg/kg). Additionally, such potentiating effects appeared additive in the MK-801 challenge experiment. Co-treatment with an effective dose of olanzapine and a low dose of SEP-363856 reversed MK-801-induced cognitive impairment symptoms in mice. Moreover, combination treatment with olanzapine and SEP-363856 controls sustained weight gain in mice with chronic exposure to olanzapine. These results support further clinical trials to test the effectiveness of co-treatment of olanzapine and SEP-363856 for controlling symptoms and weight gain in patients with schizophrenia during antipsychotic treatments.

Olanzapine-Induced Therapeutic Hypothermia Attenuates Renal Injury in Rats after Asphyxial Cardiac Arrest and Resuscitation

Return of spontaneous circulation (ROSC) through cardiopulmonary resuscitation (CPR) after cardiac arrest (CA) causes post-cardiac arrest syndrome (PCAS) due to dysfunction in various organs, which provokes acute kidney injury because of renal ischemia-reperfusion injury. Therapeutic hypothermia (TH) can reduce PCAS after CA and ROSC. However, it needs to be more sophisticated and effective. Hence, we aimed to elucidate the protective effects of olanzapine-induced TH against renal injury in asphyxial CA-induced rats. Every rat’s body temperature was maintained at 33 °C for 6 h after administering olanzapine post-CA and ROSC. Olanzapine-induced TH dramatically increased the survival rate of the rats and ameliorated renal tissue damage. Moreover, it suppressed oxidative stress responses through preservation of mitochondrial function and endoplasmic reticulum stress as the main contributor of oxidative stress. Notably, these actions of olanzapine-induced TH were mediated through the Sirt3-related signaling pathway, including the maintenance of Sirt3 and FOXO3a protein expression and the activation of AMPKα and superoxide dismutase 1 (SOD2, a mitochondrial antioxidant). This study is the first to disclose the protective effects of olanzapine-induced TH against renal injury after CA and ROSC, suggesting that olanzapine-induced TH could be utilized for treating CA followed by ROSC.

Nanostructured Lipid Carriers for Intranasal Administration of Olanzapine in the Management of Schizophrenia

BACKGROUND

Olanzapine belongs to a new class of dual spectrum antipsychotic agents. It is known to show promise in managing both the positive and negative symptoms of schizophrenia. Drug delivery systems based on nanostructured lipid carriers (NLC) are expected to provide rapid nose-to-brain transport of this drug and improved distribution into and within the brain.

OBJECTIVE

The present study deals with the preparation and evaluation of olanzapine loaded NLC via the intranasal route for schizophrenia.

METHODS

Olanzapine-NLC were formulated through the solvent injection method using isopropyl alcohol as the solvent, stearic acid as solid lipid, and oleic acid as liquid lipid, chitosan as a coating agent, and Poloxamer 407 as a surfactant. NLC were characterized for particle size, polydispersity index, entrapment efficiency, pH, viscosity, X-ray diffraction studies, in-vitro mucoadhesion study, in- vitro release and ex-vivo permeation studies. The shape and surface morphology of the prepared NLC was determined through transmission electron microscopy. To detect the interaction of the drug with carriers, compatibility studies were also carried out.

RESULTS

Average size and polydispersity index of developed formulation S6 was 227.0±6.3 nm and 0.460, respectively. The encapsulation efficiency of formulation S6 was found to be 87.25%. The pH, viscosity, in-vitro mucoadhesion study, and in- vitro release of optimized olanzapine loaded NLC were recorded as 5.7 ± 0.05, 78 centipoise, 15±2 min, and 91.96%, respectively. In ex-vivo permeation studies, the percent drug permeated after 210 min was found to be 84.03%.

CONCLUSION

These results reveal the potential application of novel olanzapine-NLC in intranasal drug delivery system for the treatment of Schizophrenia.

Blockade of the orexin 1 receptors in the nucleus accumbens' shell reversed the reduction effect of olanzapine on motivation for positive reinforcers

Effort-based choice of high reward requires one to decide how much effort to expend for a certain amount of reward. Orexin is a crucial neuropeptide in the physiological aspect especially a variety of affective and cognitive processes. The nucleus accumbens (NAc) is a region of the neural system that serves effort-related high reward choices andthe Orexin 1 receptor (OX1R) is distributed extensively throughout the nucleus accumbens shell (AcbS). Olanzapine (OLZ), a typical antipsychotic drug, has a high affinity to D2 as an antagonist, and also partial agonistic-like action at D2 receptors has been reported. We examined the interaction of OLZ with the orexinergic receptor 1 in AcbS on effort- related high reward choice when two goal arms were different in the amount of accessible reward. The animals had to pass the barrier for receiving a high reward in one arm (HRA) or obtain a low reward in the other arm without any cost. Before surgery, all animals were selecting the HRA on almost every trial.During test days, the rats received local injections of either DMSO 20% /0.5 µl, as vehicle or SB334867 (30, 100, 300 nM/0.5 µl), as selective OX1R antagonist, within the AcbS. Other group received OLZ (32 µM/0.5 µl DMSO20%) / vehicle alone or 5 min after administration of SB334867 (300 nM/0.5 µl). The results showed that administration of OLZ in the AcbS alters rat's preference for high reward. On the other hand, blocked of the OX1R (300 nM/0.5 µl) in this region could reverse the effect of OLZ, however, administration of the OX1R antagonists alone in the AcbS led to decreasing rat's preference for high reward. This result indicates that the orexin-1 antagonist might affect some effects of antipsychotic drugs.

Challenging identification of polymorphic mixture: Polymorphs I, II and III in olanzapine raw materials

Olanzapine (OLZ), a drug for the treatment of schizophrenia, presents in more than 60 crystal forms. Polymorphs I, II and III were reported, however, the preparation conditions for pure II and III have not been reported. Polymorph IV was reported but this form is actually polymorph II described at different temperature. The diversity of solid forms of OLZ, the change in the nomenclature found in the literature and the presence of polymorphic mixture in samples, increase the difficulty for a correct solid state characterization. Therefore, the goal was the polymorphic identification of three OLZ raw materials, highlighting the limitation of conventional techniques (typically used in analytical control) and the necessity to use a combination of advanced ones to solve this challenge. The samples were studied by conventional techniques such as powder X-ray diffraction, thermoanalytical techniques, infrared spectroscopy. In apart from that, synchrotron powder X-ray diffraction (SPXRD) and solid state nuclear magnetic resonance (ss-NMR) were used. All samples were in accordance with the pharmacopoeia criteria. However, the conventional techniques were not specific for the complete polymorphic identification. Therefore, a combination of advanced techniques (SPXRD and ss-NMR) was necessary to identify the mixture of polymorphs (I, II and III) in all samples.

Enhanced Degradation of Lactide-co-Glycolide Polymer with Basic Nucleophilic Drugs

The purpose of this study was to examine the degradative effect of weakly basic nucleophilic drugs on a lactide-co-glycolide (PLGA) polymer in a microsphere formulation. Biodegradable PLGA microspheres of two second-generation atypical antipsychotics, Risperidone and Olanzapine, were manufactured using a solvent extraction/evaporation technique. The effect of drug content, buffer pH and temperature on polymer molecular weight and degradation, were examined via a series of experiments and compared against a control (Placebo PLGA microspheres). In comparison to Placebo microspheres, significant polymer molecular weight reduction was observed upon encapsulation of varying levels of either Risperidone or Olanzapine. There was excellent correlation between the extent of molecular weight reduction during manufacture and the amount of encapsulated drug in the microspheres. Subsequent studies on polymer degradation showed: the following (a) the Placebo and Olanzapine microspheres followed pseudo first order kinetics, (b) Risperidone microspheres exhibited biphasic degradation profiles, and (c) polymer degradation was dependent on temperature, not pH. The findings of these studies show that encapsulation of weakly basic nucleophile type drugs into PLGA can accelerate the biodegradation of the PLGA and have major implications on the design of polymeric microsphere drug delivery systems.

Intranasal drug delivery of olanzapine-loaded chitosan nanoparticles

The aim of this study was to investigate olanzapine (OZ) systemic absolute bioavailability after intranasal (i.n.) administration in vivo to conscious rabbits. Furthermore, the study investigated the potential use of chitosan nanoparticles as a delivery system to enhance the systemic bioavailability of olanzapine following intranasal administration. Olanzapine-loaded chitosan nanoparticles were prepared through ionotropic gelation of chitosan with tripolyphosphate anions and studied in terms of their size, drug loading, and in vitro release. The OZ nanoparticles were administered i.n. to rabbits, and OZ plasma concentration at predetermined time points was compared to i.n. administration of OZ in solution. The concentrations of OZ in plasma were analyzed by ultra performance liquid chromatography mass spectroscopy (UPLC/MS). OZ-loaded chitosan nanoparticles significantly (p < 0.05) enhanced systemic absorption with 51 ± 11.2% absolute bioavailability as compared to 28 ± 6.7% after i.n. administration of OZ solution. The results of the present study suggest that intranasal administration of OZ-loaded chitosan nanoparticles formulation could be an attractive modality for delivery of OZ systemically.

Olanzapine in Chinese patients with schizophrenia or bipolar disorder: a systematic literature review

BACKGROUND

Despite the burden of schizophrenia and bipolar disorder in the Chinese population, country-specific data to guide practitioners regarding antipsychotic therapy are lacking. The primary aim of this systematic review was to examine evidence of the efficacy, effectiveness, and safety of olanzapine in Chinese populations.

METHODS

A systematic literature search was conducted using databases covering international and Chinese core journals using search terms related to schizophrenia and bipolar disorder, specified countries (People's Republic of China, Hong Kong, Taiwan), and olanzapine treatment. Following initial screening, inclusion and exclusion criteria were applied to the search results to identify relevant studies from which data were extracted.

RESULTS

A total of 489 publications were retrieved and 61 studies were identified for inclusion. Most studies were related to schizophrenia (n=54), with six studies related to bipolar disorder and one study related to both conditions. The quality of study methods and reporting in international journals was noticeably better than in Chinese language journals. Most studies included relatively small patient populations and were of short duration. The efficacy of olanzapine in Chinese populations was confirmed by multiple comparative and noncomparative studies that found statistically significant reductions in symptom measures in studies conducted for ≥6 weeks (schizophrenia) or ≥3 weeks (bipolar disorder). Findings related to effectiveness (treatment discontinuation, quality of life, and neurocognitive improvements) were generally consistent with those observed in non-Chinese populations. No new safety signals specific for Chinese populations were raised for olanzapine.

CONCLUSION

Chinese and non-Chinese populations with schizophrenia or bipolar disorder treated with olanzapine display broadly similar responses. Differences between these populations, especially in relation to the relative efficacy of olanzapine versus other antipsychotics, may warrant further investigation via studies incorporating both populations. Use of local data to provide evidence for practice guidelines should be encouraged, and may promote ongoing improvements in the quality of research and study reporting.

Preparation, Characterization, and In Vivo Evaluation of Olanzapine Poly(D,L-lactide-co-glycolide) Microspheres

The aim of this study was to prepare injectable depot formulations of Olanzapine using four poly(D,L-lactide-co-glycolide) (PLGA) polymers of varying molecular weight and copolymer composition, and evaluate in vivo performance in rats. In vivo release profiles from the formulations were governed chiefly by polymer molecular weight and to a lesser extent, copolymer composition. Formulations A and B, manufactured using low molecular weight PLGA and administered at 10 mg/kg dose, released drug within 15 days. Formulation C, prepared from intermediate molecular weight PLGA and administered at 20 mg/kg dose, released drug in 30 days, while Formulation D, manufactured using a high molecular weight polymer and administered at 20 mg/kg dose, released drug in 45 days. A simulation of multiple dosing at 7- and 10-day intervals for Formulations A and B revealed that steady state was achieved within 7-21 days and 10-30 days, respectively. Similarly, simulations at 15-day intervals for Formulations C and D indicated that steady state levels were reached during days 15-45. Overall, steady state levels for 7-, 10-, or 15-day dosing ranged between 45 and 65 ng/mL for all the formulations, implying that Olanzapine PLGA microspheres can be tailored to treat patients with varying clinical needs.

Comparing tolerability of olanzapine in schizophrenia and affective disorders: a meta-analysis

BACKGROUND

Olanzapine is prescribed for a number of psychiatric disorders, including schizophrenia, bipolar mania, and unipolar and bipolar depression. Olanzapine treatment is associated with tolerability issues such as metabolic adverse effects (e.g. weight gain, increase in blood glucose, triglycerides and total cholesterol levels), extrapyramidal symptoms [EPS] (e.g. parkinsonism, akathisia, tardive dyskinesia) and sedative adverse effects. Metabolic issues lead to some long-term consequences, which include cardiovascular diseases (CVD) and type 2 diabetes mellitus, and these complications cause high rates of mortality and morbidity among patients with severe mental illnesses. The expanded indications of olanzapine in psychiatry suggest a need to investigate whether there is a difference in the incidence and severity of adverse effects related to category diagnosis. Are the adverse effects expressed differently according to phenotype? Unfortunately, there are no reported studies that investigated these differences in adverse effects associated with olanzapine treatment in psychiatric patients with different phenotypes.

OBJECTIVE

The aim of the present meta-analysis is to separately examine olanzapine-induced cardiometabolic adverse effects and EPS in patients with schizophrenia and affective disorders.

DATA SOURCES

A search of computerized literature databases PsycINFO (1967-2010), PubMed (MEDLINE), EMBASE (1980-2010) and the clinicaltrials.gov website for randomized clinical trials was conducted. A manual search of reference lists of published review articles was carried out to gather further data.

STUDY SELECTION

Randomized controlled trials were included in our study if (i) they assessed olanzapine adverse effects (metabolic or extrapyramidal) in adult patients with schizophrenia or affective disorders; and (ii) they administered oral olanzapine as monotherapy during study.

DATA EXTRACTION

Two reviewers independently screened abstracts for choosing articles and one reviewer extracted relevant data on the basis of predetermined exclusion and inclusion criteria. It should be mentioned that for the affective disorders group we could only find articles related to bipolar disorder.

DATA SYNTHESIS

Thirty-three studies (4831 patients) that address olanzapine monotherapy treatment of adults with schizophrenia or bipolar disorder were included in the analysis. The primary outcomes were metabolic adverse effects (changes in weight, blood glucose, low-density lipoprotein, total cholesterol and triglyceride levels). The secondary outcomes of our study were assessing the incidence of some EPS (parkinsonism, akathisia and use of antiparkinson medication). The tolerability outcomes were calculated separately for the schizophrenia and bipolar disorder groups and were combined in a meta-analysis. Tolerability outcomes show that olanzapine contributes to weight gain and elevates blood triglycerides, glucose and total cholesterol levels in both schizophrenia and bipolar disorder patients. However, olanzapine treatment produced significantly more weight gain in schizophrenia patients than in bipolar disorder patients. In addition, increases in blood glucose, total cholesterol and triglyceride levels were higher in the schizophrenia group compared with the bipolar disorder group, even though these differences were not statistically significant. Based on our results, the incidence of parkinsonism was significantly higher in the schizophrenia group than in the bipolar disorder group. Subgroup analysis and logistic regression were used to assess the influence of treatment duration, dose, industry sponsorship, age and sex ratio on tolerability outcome.

CONCLUSIONS

Our results suggest that schizophrenia patients may be more vulnerable to olanzapine-induced weight gain. The findings may be explained by considering the fact that in addition to genetic disposition for metabolic syndrome in schizophrenia patients, they have an especially high incidence of lifestyle risk factors for CVD, such as poor diet, lack of exercise, stress and smoking. It might be that an antipsychotic induces severity of adverse effect according to the phenotype.

Risperidone, quetiapine, and olanzapine adjunctive treatments in major depression with psychotic features: a comparative study

OBJECTIVES

The purpose of this study was to compare the effectiveness of novel antipsychotics in the treatment of psychotic depression.

METHOD

Consecutive patients who were admitted (n = 51) with a confirmed diagnosis of major depression with psychotic features (delusions or hallucinations or both) participated in this open-label, naturalistic study. All patients were treated with selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) (citalopram or venlafaxine extended release [XR]), and atypical antipsychotic agents were added, as tolerated, during the first week of initiating the citalopram or venlafaxine. There were patients (n = 16) who received risperidone, who received quetiapine (n = 20), and who received olanzapine (n = 15), as an adjunctive treatment to either citalopram or venlafaxine for at least 8 weeks. Outcome measures included the Clinical Global Impression-Severity subscale (CGI-S), as the primary outcome measure, as well as the Hamilton Rating Scale for Depression-21 item (HAM-D21) and the Brief Psychiatric Rating Scale (BPRS). Tolerance to treatments and weight changes were monitored over the period of the trial.

RESULTS

All patients completed the trial with no drop outs. At 8 weeks, there was a statistically significant (P < 0.001) clinical improvement in all outcome measures for both the depressive and psychotic symptoms, for all three groups of atypical adjunctive treatments. Utilizing analysis of variance (ANOVA), there were no significant differences between the three adjunctive treatment groups in outcome measures. The three antipsychotic agents were equally tolerated. At 8 weeks there was slight increase in weight in the three treatment groups, which was statistically significant (P > .01) in the olanzapine group.

CONCLUSION

Quetiapine, risperidone, and olanzapine, given as adjunctive treatment with SSRIS or SNRIs can significantly and equally improve depressive and psychotic symptoms, in the short-term treatment of major depression with psychotic features. The author recommends that large controlled trials be conducted to examine the differences in long-term efficacy and tolerance between the atypical antipsychotic agents, in the treatment of major depression with or without psychotic features.

Striatal structure and function in mood disorders: a comprehensive review

OBJECTIVES

  A large and diverse literature has implicated abnormalities of striatal structure and function in both unipolar and bipolar disorder. Recent functional imaging studies have greatly expanded this body of research. The aim of this review is to provide a comprehensive and critical appraisal of the relevant literature.

METHODS

  A total of 331 relevant articles were reviewed to develop an integrated overview of striatal function in mood disorders.

RESULTS

  There is compelling evidence from multiple studies that functional abnormalities of the striatum and greater corticostriatal circuitry exist in at least some forms of affective illness. The literature does not yet provide data to determine whether these aberrations represent primary pathology or they contribute directly to symptom expression. Finally, there is considerable evidence that bipolar disorder may be associated with striatal hyperactivity and some suggestion that unipolar illness may be associated with hypoactivation.

CONCLUSIONS

  Additional research investigating striatal function in affective disorders will be critical to the development of comprehensive models of the neurobiology of these conditions.

Phenomenology and therapeutic options for dermatotillomania

Dermatotillomania (also called psychogenic excoriation, neurotic excoriation, acne excoriée, skin picking and pathological or compulsive skin picking) is characterized by excessive scratching or picking of normal skin or skin with minor surface irregularities. Until recently, there have been few therapeutic options for patients with this disorder, which causes substantial distress and functional impairment in many patients. Recent pharmacological studies have found that some selective serotonin reuptake inhibitors may be effective in the treatment of this disorder. Furthermore, phenomenological studies have better characterized the heterogeneity of the behavior associated with dermatotillomania. Clinicians may now be able to develop more effective treatments for patients by targeting the specific behavioral symptoms of the disorder in individual patients.

Olanzapine: in adolescents with schizophrenia or bipolar I disorder

Olanzapine is an atypical antipsychotic that, in addition to its use in adults, is now indicated for the treatment of schizophrenia, and manic or mixed episodes associated with bipolar I disorder in adolescents aged 13-17 years. In a randomized, double-blind, multicentre, 6-week trial in adolescents aged 13-17 years with schizophrenia, the least squares mean reduction from baseline to 6 weeks in the Brief Psychiatric Rating Scale for Children (BPRS-C) total score (primary endpoint) was significantly greater with olanzapine than with placebo. In a randomized, double-blind, multicentre, 3-week trial in adolescents, aged 13-17 years, with manic or mixed episodes associated with bipolar I disorder, the mean reduction from baseline to 3 weeks in the Adolescent Structured Young Mania Rating Scale (YMRS) total score (primary endpoint) was significantly greater with olanzapine than with placebo. In extensions of each of the pivotal placebo-controlled trials in schizophrenia and bipolar mania, open-label treatment with olanzapine for up to 26 weeks produced significant reductions from baseline to endpoint in BPRS-C and YMRS total scores, respectively. Oral olanzapine was generally well tolerated in adolescents with schizophrenia or bipolar mania. Sedation and weight gain were the most common adverse events in placebo-controlled trials. Extrapyramidal symptoms were reported by 10% of olanzapine recipients compared with 6% of placebo recipients. Olanzapine-treated adolescents were likely to experience greater increases in bodyweight, sedation, blood lipids, serum prolactin and liver transaminase levels than olanzapine-treated adults. Therefore, careful consideration of risk-benefit is recommended before using olanzapine in adolescents.

Olanzapine/fluoxetine: a review of its use in patients with treatment-resistant major depressive disorder

Olanzapine/fluoxetine (Symbyax) is an oral, once-daily, fixed-dose combination of the atypical antipsychotic olanzapine and the selective serotonin reuptake inhibitor (SSRI) fluoxetine. It is indicated, in adult patients, for the acute treatment of depressive episodes associated with bipolar I disorder and treatment-resistant major depressive disorder. In adult patients with treatment-resistant depression (major depressive disorder in adults who do not respond to two separate trials of different antidepressants of adequate dose and duration in the current episode), olanzapine plus fluoxetine combination therapy was generally more effective than either drug as monotherapy based on an integrated analysis of clinical trials of 8-12 weeks' duration. More limited data also indicate that longer-term treatment for 76 weeks with olanzapine plus fluoxetine was efficacious in this patient group. Combination therapy was generally well tolerated, with a tolerability profile similar to that of olanzapine monotherapy, although fluoxetine monotherapy was generally better tolerated than olanzapine plus fluoxetine. The combination of olanzapine plus fluoxetine, as a fixed-dose formulation, offers a useful treatment option in this difficult-to-treat patient group.

Functional SNPs in Genes Encoding the 5-HT2A Receptor Modify the Affinity and Potency of Several Atypical Antipsychotic Drugs

Atypical antipsychotic drugs (AADs) are the standard treatment for both the acute and long-term management of schizophrenia and an augmentation to mood stabilizers for bipolar disorder (BD). Yet many individuals who take AADs do not fully respond to them, while others experience side effects that include weight gain and metabolic disorder. This in vitro pharmacogenetic study examined whether allelic variants in the 5-hydroxytryptamine (HT)2A receptor alter the in vitro pharmacology of six AADs (clozapine, olanzapine, risperidone, quetiapine, ziprasidone, and aripiprazole). We selected 4 functional single-nucleotide polymorphisms (SNPs) for investigation (Thr25Asn, Ile197Val, Ala447Val, and His452Tyr), conducted site-directed mutagenesis studies to induce variants into human HEK-293 cell lines, and screened allelic variants for their effects on 5-HT 2A receptors in the cell lines. We conducted numerous binding assays and fluorescence-based assay system (FLEX station) experiments using the six AADs. Our results indicated that three polymorphic 5-HT2A receptors (Ile197Val, Ala447Val, and His452Tyr) exhibited statistically significant, though modest, changes in atypical antipsychotic affinity. In addition, three polymorphic receptors (Thr25Asn, Ile197Val, and His452Try) altered AAD potency. Our findings support in vivo evidence that functional SNPs in genes encoding neuroreceptor drug targets could explain interindividual differences in AAD drug response and tolerability. We suggest that more in vivo pharmacogenetic studies of well-characterized patients who are prescribed AADs be indicated. Future pharmacogenetic studies of well-characterized patients will likely involve tagging SNPs and the use of haplotypes related to other genes encoding neuroreceptor drug targets.

Bipolar disorder and mechanisms of action of mood stabilizers

Bipolar disorder (BD) is a major medical and social burden, whose cause, pathophysiology and treatment are not agreed on. It is characterized by recurrent periods of mania and depression (Bipolar I) or of hypomania and depression (Bipolar II). Its inheritance is polygenic, with evidence of a neurotransmission imbalance and disease progression. Patients often take multiple agents concurrently, with incomplete therapeutic success, particularly with regard to depression. Suicide is common. Of the hypotheses regarding the action of mood stabilizers in BD, the "arachidonic acid (AA) cascade" hypothesis is presented in detail in this review. It is based on evidence that chronic administration of lithium, carbamazepine, sodium valproate, or lamotrigine to rats downregulated AA turnover in brain phospholipids, formation of prostaglandin E(2), and/or expression of AA cascade enzymes, including cytosolic phospholipase A(2), cyclooxygenase-2 and/or acyl-CoA synthetase. The changes were selective for AA, since brain docosahexaenoic or palmitic acid metabolism, when measured, was unaffected, and topiramate, ineffective in BD, did not modify the rat brain AA cascade. Downregulation of the cascade by the mood stabilizers corresponded to inhibition of AA neurotransmission via dopaminergic D(2)-like and glutamatergic NMDA receptors. Unlike the mood stabilizers, antidepressants that increase switching of bipolar depression to mania upregulated the rat brain AA cascade. These observations suggest that the brain AA cascade is a common target of mood stabilizers, and that bipolar symptoms, particularly mania, are associated with an upregulated cascade and excess AA signaling via D(2)-like and NMDA receptors. This review presents ways to test these suggestions.

Spotlight on olanzapine/fluoxetine in acute bipolar depression

Olanzapine/fluoxetine (Symbyax) is an oral once-daily fixed-dose combination of the atypical antipsychotic olanzapine and the SSRI fluoxetine that is approved in the US for the treatment of depressive episodes associated with bipolar disorder in adults. Combination therapy with olanzapine plus fluoxetine is effective in the treatment of patients with acute bipolar depression. The combination improves depressive symptoms and symptom severity in this patient population, with an efficacy greater than that of olanzapine alone or lamotrigine. Furthermore, olanzapine plus fluoxetine is generally well tolerated. Although associated with weight gain and potential elevations in glucose, lipid and prolactin levels, the combination does not increase the risk of treatment-emergent mania. Additional placebo- and active comparator-controlled studies are required in order to confirm the efficacy of olanzapine/fluoxetine in the treatment of bipolar depression and to definitively position olanzapine/fluoxetine with respect to other agents. In the meantime, fixed-dose olanzapine/fluoxetine offers an effective and generally well tolerated first-line option for the treatment of acute bipolar depression.

A double-blind, placebo-controlled trial of olanzapine for the treatment of video poker pathological gamblers

Emerging evidence suggests that dopaminergic and serotonergic functioning are altered in pathological gamblers; yet, there are no FDA-approved medications for pathological gambling and there have only been a limited number of clinical trials that have been conducted. Olanzapine was identified as a candidate medication for pathological gamblers because it modifies both dopaminergic and serotonergic function. Moreover, preliminary studies have shown that olanzapine effectively reduces impulsivity in other psychiatric disorders, a pharmacological target of interest for pathological gamblers. In this study, 21 pathological gamblers, whose primary gambling activity was video poker, were enrolled in a seven-week, double-blind, placebo-controlled trial. Outcome measures included self-reported urges for gambling, frequency of gambling behavior, and self-reported mood and anxiety levels. The results revealed that all study participants reported reduced levels of gambling urges, gambling behavior, and mood and anxiety symptoms. Olanzapine administration was not associated with an incremental effect versus placebo. While these findings suggest that olanzapine is not an efficacious treatment for video poker pathological gamblers, olanzapine may still be an effective treatment for a specific subset of pathological gamblers, including those with a co-occurring psychiatric disorder.

Solid state characterization of olanzapine polymorphs using vibrational spectroscopy

FT-Raman, infrared and near infrared investigations of two polymorphs of olanzapine are presented, establishing the main features that allow the discrimination of these crystalline forms using vibrational spectroscopic methods. Ab initio calculations on the basis of the density functional theory were used to determine the stable conformations. The calculated vibrational spectra were compared to the experimental ones in order to identify the conformers corresponding to each polymorph and to assign the vibrational bands to the internal vibrations of the olanzapine molecule. Our results support the hydrogen bonding pattern proposed by the reported crystalline structure and provide valuable information on the structural and thermodynamical relationship between the investigated polymorphs.

Spotlight on olanzapine in bipolar I disorder

Olanzapine is an atypical antipsychotic that is approved in the US and Europe for the oral treatment of acute manic episodes in patients with bipolar I disorder and for maintenance therapy to prevent recurrence in responders. Oral olanzapine is effective in the treatment of bipolar mania, both as single agent therapy and as adjunctive therapy in combination with lithium or valproate semisodium. In the treatment of acute episodes, olanzapine is superior to placebo and at least as effective as lithium, valproate semisodium, haloperidol and risperidone in reducing the symptoms of mania and inducing remission. Additional comparative studies are required to determine the efficacy of olanzapine relative to newer atypical antipsychotics such as quetiapine, ziprasidone and aripiprazole. Olanzapine is also effective at delaying or preventing relapse during long-term maintenance therapy in treatment responders and is currently the only atypical antipsychotic approved for this indication. Current evidence suggests that olanzapine may be more effective than lithium in preventing relapse into mania, but not relapse into depression or relapse overall. Olanzapine is generally well tolerated and, although it is associated with a higher incidence of weight gain than most atypical agents, it has a low incidence of extrapyramidal symptoms. Therefore, oral olanzapine is a useful first-line or adjunctive agent for both the acute treatment of manic episodes and the long-term prevention of relapse into manic, depressive or mixed episodes associated with bipolar I disorder.

Chronic lithium chloride administration to unanesthetized rats attenuates brain dopamine D2-like receptor-initiated signaling via arachidonic acid

We studied the effect of lithium chloride on dopaminergic neurotransmission via D2-like receptors coupled to phospholipase A2 (PLA2). In unanesthetized rats injected i.v. with radiolabeled arachidonic acid (AA, 20:4 n-6), regional PLA2 activation was imaged by measuring regional incorporation coefficients k* of AA (brain radioactivity divided by integrated plasma radioactivity) using quantitative autoradiography, following administration of the D2-like receptor agonist, quinpirole. In rats fed a control diet, quinpirole at 1 mg/kg i.v. increased k* for AA significantly in 17 regions with high densities of D2-like receptors, of 61 regions examined. Increases in k* were found in the prefrontal cortex, frontal cortex, accumbens nucleus, caudate-putamen, substantia nigra, and ventral tegmental area. Quinpirole, 0.25 mg/kg i.v. enhanced k* significantly only in the caudate-putamen. In rats fed LiCl for 6 weeks to produce a therapeutically relevant brain lithium concentration, neither 0.25 mg/kg nor 1 mg/kg quinpirole increased k* significantly in any region. Orofacial movements following quinpirole were modified but not abolished by LiCl feeding. The results suggest that downregulation by lithium of D2-like receptor signaling involving PLA2 and AA may contribute to lithium's therapeutic efficacy in bipolar disorder.

Service utilization and costs of olanzapine versus divalproex treatment for acute mania: results from a randomized, 47-week clinical trial

OBJECTIVE

This study examined direct treatment costs based on medication and service use data collected in a 47-week multi-center, double-blind, randomized clinical trial of olanzapine versus divalproex for patients with bipolar disorder and and experiencing acute mania.

RESEARCH DESIGN AND METHODS

Patients who completed the 3-week acute phase and entered into the 44-week maintenance phase (n = 147) of the trial were included. Service use data were collected at weeks 3, 7, 15, 23, 31, 39 and 47 of the maintenance phase. Analyses were conducted to address potential biases from discontinuation patterns and use of this patient sub-sample.

RESULTS

Overall, per patient yearly costs were similar for olanzapine- and divalproex-treated patients ($14 967 vs. $15 801). Psychiatric-related costs accounted for 95.4% and 93.6% of the total costs for olanzapine- and divalproextreated patients, respectively. Study medication costs were significantly higher for olanzapine than for divalproex ($4662 vs. $1755, p < 0.01). However, this was offset by the combined effects of numerically lower costs for several other services with olanzapine treatment. Some of the savings associated with olanzapine treatment compared with divalproex treatment resulted from differences in costs associated with emergency room services ($432 vs. $1346, p < 0.05).

CONCLUSIONS

Overall per-patient treatment costs were similar for olanzapine and divalproex. Recognizing challenges in analyzing and generalizing cost outcomes from a clinical trial setting, results provide some much-needed comparative economic information regarding these two medication options for treating mania in bipolar disorder.

Antipsychotiques et troubles bipolaires

This article is a review of the various treatments that are currently available, in particular in France, for the treatment of bipolar disorders. This article specifically addresses the use of novel antipsychotic agents as alternative therapy to a lithium therapy and/or the use of conventional antipsychotics. The prevalence of bipolar disorder over a lifetime is around 1% of the general population. Bipolar disorder consists of alternating depressive and manic episodes. It mainly affects younger subjects, and is often associated with alcohol and drug addictions. There are two main subtypes of bipolar disorder. According to the DSM IV-R, type 1 of bipolar disorder is characterised when at least one manic episode (or a mixed episode) has been diagnosed. Type 2 of bipolar disorder is related to patients enduring recurrent depressive episodes but no manic episode. Type 2 affects women more frequently as opposed to type 1 affecting individuals of both sexes. Manic-depressive disorder (or cyclo-thymic disorder) appears in relation to patients who has never suffered manic episode, mixed episode or severe depressive episode but have undergone numerous periods with some symptoms of depression and hypomanic symptoms over a two-year period during which any asymptomatic periods last no longer than two months. The average age of the person going through a first episode (often a depressive one) is 20 years-old. Untreated bipolar patients may endure more than ten manic or depressive episodes. Finally, in relation to 10 to 20% of patients, the bipolar disorder will turn into a fast cycle form, either spontaneously or as a result of certain medical treatments. Psychiatrists are now able to initiate various treating strategies which are most likely to be effective as a result of the identification of clinical subtypes of the bipolar disorder. Lithium therapy has been effectively and acutely used for patients with pure or elated mania and its prophylaxis. However, lithium medication may worsen depressive symptoms when used for a long term maintenance therapy. Additionally, mixed mania, rapid cycling type patients and bipolar disorder associated with substance abuse do not respond well to lithium therapy. In addition to the lithium therapy or in place of a lithium therapy, one can report the frequent use of antipsychotic agents in respect of patients with bipolar disorder during both the acute and maintenance phases of treatment. Antipsychotic agents have been used for almost forty years and may be used in combination with a lithium therapy. Conventional antipsychotics are effective but they may induce late dyskinesia, weight gain, sedation, sexual dysfunction and depression. These adverse side effects often lead to non compliance in particular in circumstances where antipsychotic agents are combined with a lithium therapy. A number of alternative somatic treatment approaches have been reported for patients who do not respond well or who are intolerant to lithium therapy. As such, valproate has received regulatory approval for the acute treatment of mania and carbamazepine has been indicated for this condition in a number of countries. Divalproex (Depakote) has recently obtained the authorization to market in France and may be prescribed for manic states or hypomanic states that do not tolerate lithium therapy or for which lithium therapy is contraindicated. A number of other anticonvulsants (lamotrigine, gabapentin and topiramate) are currently being tested. Because of the side effects of the conventional antipsychotic agents, atypical antipsychotic agents are currently on trial and appear to be of interest in the treatment of bipolar disorders. Currently, a number of prospective studies are available with clozapine, risperidone and olanzapine in the treatment of bipolar disorder. Most are short-term studies. Recent randomised, double-blind, placebo-controlled studies have shown clozapine, risperidone and olanzapine to be effective with antimanic and antidepressive effects, both as monotherapy and as add-on maintenance therapy with lithium or valproate. They also have a favorable side effect profile and a positive effect on overall functioning. Similarly, valproate combined with antipsychotics provides greater improvement in mania than antipsychotic medication alone and results in lower dosage of the antipsychotic medication. There is currently no double-blind study regarding the use of clozapine for bipolar disorders. However, based on the results of a number of open-label studies, clozapine appears to be effective in relation to schizo-affective and bipolar patients including those with rapid cycling or those who respond inadequately to mood stabilizers, carbamazepine, valproate or conventional antipsychotics. Clozapine seems to be more appropriate for bipolar and schizo-affective patients than schizophrenics. In particular, studies show that patients with manic and mixed-psychotic state of illness are better responders than patients with major depressive syndromes. Four open studies suggest the efficacy of clozapine in the maintenance treatment of bipolar disorder and three prospective, open-label studies show the efficacy of clozapine in the manic state of the illness. However, the number of patients in the studies was not important and these studies are not controlled. Clozapine has also adverse side affects, one of which consisting of a major risk of agranulocytosis and, potentially, death. In addition, clozapine has been shown to produce significant weight gain and sialorrhea as well as significant anticholinergic effects. As a result, clozapine should not be prescribed in the first place. As opposed to clozapine, there are open-label reports and controlled studies in respect of risperidone and olanzapine. Two recent double-blind studies of acute mania found olanzapine to be more effective than placebo. Based on these two studies, olanzapine has recently been approved for the indication of mania. The effects of olanzapine and divalproex in the treatment of mania have also been compared in a large randomized clinical trial. The olanzapine treatment group had significantly greater mean improvement of mania ratings and a significantly greater proportion of patients achieving protocol-defined remission. Significantly more weight gain and cases of dry mouth, increased appetite and somnolence were reported with olanzapine while more cases of nausea were reported with divalproex. The comparison of olanzapine with lithium for the treatment of mania has also been the subject of a double-blind randomized controlled trial. That study shows no differences between the two drugs. While these studies support the idea that olanzapine has direct acute anti-manic effects, a number of authors are of the opinion that olanzapine may have specific prophylactic mood-stabilizing properties. Olanzapine would appear to be effective in the maintenance treatment, as it exhibited both antimanic and antidepressant effects. Systematic trials have shown that risperidone may be effective and safe in the treatment of acute mania, as an add-on therapy with lithium or valproate (open studies and two controlled double-blind studies) and as monotherapy (open studies). In an open, multi-center, 6-month study, risperidone seems to be effective and safe as long-term adjunctive therapy in treatment-resistant bipolar and schizo-affective disorders, with no exacerbation of manic symptoms. Risperidone had few adverse side effects (and where there were any, they were mostly mild), mostly consisting of APS and weight gain. A naturalistic comparison of clozapine, risperidone and olanzapine in the treatment of bipolar disorder suggests that the efficacy and tolerability of the three treatments are similar. One major differentiation factor of these drugs appears to be weight gain, particularly between olanzapine and risperidone. However, this may partially be caused by the use of mood-stabilizing agents. Bipolar and schizo-affective patients now require combination therapy approach because of the cyclic nature of these disorders. Many studies report the combination of mood-stabilizing agents with conventional antipsychotics and atypical antipsychotics. Combination therapies produce a number of adverse side effects. Atypical antipsychotics (other than clozapine) are now rated as first-line agents for adjunctive treatment of mania because they produce less adverse side effects. Atypical antipsychotics are also rated as first-line agents for combined treatment of psychotic depression and they are strongly preferred when an antipsychotic is required for long-term maintenance.

Issues in the treatment of bipolar disorder

Bipolar disorder is a chronic, recurring illness that requires long-term prophylactic treatment. However, treatment is often complicated by misdiagnosis and inappropriate medication selection. A number of therapies are available for the treatment of bipolar disorder and the ultimate therapeutic choice depends on the individual patient's current symptoms, disease history, and comorbid illnesses. However, research is needed to improve the overall prognosis for patients with bipolar depression, particularly because approximately 20% of patients commit suicide. Mania is the most dramatic expression of bipolar disorder and may overshadow the impact of the depressive phase of the illness. Compared with mania, episodes of bipolar depression are more frequent, of longer duration, and are associated with higher rates of morbidity and mortality. Therefore, successful treatment and prevention of bipolar depression remains an essential treatment goal.

Duration and stability of the rapid-cycling course: a long-term personal follow-up of 109 patients

BACKGROUND

Recognition by the DSM-IV of rapid cyclicity as a course specifier has raised the question of the stability and long-term outcome of rapid-cycling (RC) patients. Data on this topic is sparse and often inconsistent. To our knowledge, these are the first personally followed patients over the long term, dealing directly with the issue of the duration of the RC course.

METHODS

We examined the evolution of the course of 109 RC patients (68 women and 41 men) followed for a minimum of 2 years and up to 36 years, beginning with the index episode when the RC course was diagnosed by the authors (A.K., G.P.M., P.G., L.P., D.R.). Patients were included in the study if they met criteria for RC as defined by>or=4 affective episodes per year (Dunner and Fieve, 1974). The follow-up period varied from 2-5 years for 25 patients, 6-10 years for 24 patients, 11-15 years for 24 patients, 16-20 years for 19 patients, 21-25 years for 13 patients, 30-36 years for four patients.

RESULTS

In 13 patients (12%), RC emerged spontaneously and in 96 patients (88%), it was associated with antidepressant and other treatments. In 19 women (28% of all women) RC course started in perimenopausal age (45-54 years). The mean duration of RC during the follow-up period was 7.86 years (range 1-32) and its total duration (including RC course prior to the follow-up period) was 11 years (range 1-40). The total duration of the affective disorder, from the first episode to the end of the follow-up, was 21.78 years (range 1-70). At the end of the follow-up, 36 patients (33%) had complete remission for at least the past year, 44 (40%) stayed rapid cycling with severe episodes (six of this group committed suicide), while 15 (14%) were rapid cycling but with attenuated episodes. The other 14 patients (13%) became long cyclers, eight with severe episodes and six with milder ones. The main distinguishing features between those who remitted from and those who persisted in the RC course were: (1). the initial cycle pattern: patients with Depression-Hypomania(mania)-Free interval cycles (53 patients) had a worse outcome: 26.4% remitted and 52.8% persisted in the RC course through to the end of the follow up period. The Mania/Hypomania-Depression-Free interval cycles (22 patients) had a significantly better outcome, with 50% remitted and 27.2% persisting RC; and (2). the occurrence of the switch process from depression to hypomania/mania and the occurrence of agitated depressions made the prognosis worse. Continuous treatment was more effective against mania/hypomania than against depression, yet in all persisting RC cases the mania/hypomania remitted only partially.

LIMITATIONS

These data derive from clinics known for their expertise in mood disorders, and they may have attracted and retained patients with a more severe course. Treatment was uncontrolled and consisted more of lithium than divalproex, lamotrigene and olanzapine, recently shown to be beneficial in subgroups of patients with rapid-cycling.

CONCLUSIONS

Our findings suggest that rapid cyclicity, spontaneous or induced, once established, becomes for many years a stable rhythm in a substantial proportion of patients, linked to endogenous and environmental factors. The suggestion is made to consider as rapid-cyclers, at least for research purposes, those patients who have had a rapid cycling course for at least 2 years, borrowing the duration criterion currently employed for other chronic disorders such as Dysthymia and Cyclothymia. That our patients had poorer prognosis than some other cohorts in the literature is probably due to the shorter duration of "rapid-cycling" at entry in the latter cohorts. A true understanding of the nature of rapid-cycling will require a rigorous definition of not only duration, but also pole-switching and course patterns at entry into study.

Valproate for acute mood episodes in bipolar disorder

BACKGROUND

Bipolar disorder is a common debilitating illness, characterised by acute affective episodes with full or partial inter-episode remission. Effective and acceptable treatment of acute episodes is required. Valproate has become a leading adjunctive and alternative mood stabilising treatment to lithium in bipolar disorder.

OBJECTIVES

To determine the efficacy and acceptability of valproate in the treatment of acute episodes of bipolar disorder.

SEARCH STRATEGY

The search included the Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Registrar (CCDANCTR), the Cochrane Controlled Clinical Trials Register (CCTR), reference lists of relevant papers and books, and contact with authors of trials, experts and pharmaceutical companies.

SELECTION CRITERIA

Randomised controlled trials comparing valproate with placebo, other mood stabilisers and antipsychotic medication in the treatment of any bipolar affective episode. Participants were of both sexes, of all ages, with a diagnosis of bipolar affective disorder approximating to ICD 10 Code F31 and DSM IV 296.

DATA COLLECTION AND ANALYSIS

Methodological quality was assessed independently by two reviewers blind to the authorship and source of papers. Ten randomised controlled trials were found comparing valproate with other interventions in mania. None was found examining its use in depression or mixed affective episodes. Data were extracted on the main outcome 'failure to respond by the end of the study' assessed by a less than 50% reduction in the Young Mania Rating Scale or the SADS-S mania scale. Three trials (316 participants) compared valproate with placebo. Three trials (158 participants) compared valproate with lithium. Two trials (363 participants) compared valproate with olanzapine. One trial (36 participants) compared valproate with haloperidol. Two trials (59 patients) compared valproate with carbamazepine. Acceptability of treatment was estimated using the outcome measure 'total number of subjects withdrawing from the study'. Three trials (321 patients) contributed to the comparison between valproate and placebo, two studies (144 patients) contributed to the comparison with lithium. One study (30 patients) provided data on this outcome in the comparison between valproate and carbamazepine. Pooled relative risks (with 95% confidence intervals) were calculated using fixed effect approaches.

MAIN RESULTS

Valproate was more efficacious than placebo (RRR 38%; RR 0.62; 95% C.I. 0.51 to 0.77) in the treatment of mania. There was no significant difference between valproate and lithium (RRI 5%; RR 1.05; 95% C.I. 0.74-1.50) or between valproate and carbamazepine (RRR 34%; RR 0.66; 95% C.I. 0.38 to 1.16). Valproate was less effective than olanzapine (failure to achieve clinical response; RRI 25%; RR 1.25, 95% C.I. 1.01 to 1.54; average of 2.8 point less change on the Mania Rating Scale (95% CI 0.83 to 4.79). There were no significant differences in acceptability as measured by total number of subjects withdrawing from the study. There were significant differences in the side effect profiles of valproate and olanzapine, with more sedation and weight gain on olanzapine.

REVIEWER'S CONCLUSIONS

There is consistent, if limited, evidence to suggest that valproate is an efficacious treatment for acute mania. Valproate may be less effective than olanzapine but may cause less sedation and weight gain. More well designed, randomised controlled trials investigating the relative efficacy and acceptability of valproate in the treatment of the full range of acute affective episodes occurring in bipolar disorder are required.