Treatment of acute mania--from clinical trials to recommendations for clinical practice

Lamotrigine as a mood stabilizer: insights from the pre-clinical evidence

INTRODUCTION

Lamotrigine (LTG) is a well-established anticonvulsant that is also approved for the prevention of mood relapses in bipolar disorder. However, the mechanisms underlying LTG mood stabilizing effects remain unclear. Areas covered: Herein, the pre-clinical evidence concerning LTG's' mode of action in depression and mania is reviewed. Bottlenecks and future perspectives for this expanding and promising field are also discussed. Pre-clinical studies have indicated that neurotransmitter systems, especially serotoninergic, noradrenergic and glutamatergic, as well as non-neurotransmitter pathways such as inflammation and oxidative processes might play a role in LTG's antidepressant effects. The mechanisms underlying LTG's anti-manic properties remain to be fully explored, but the available pre-clinical evidence points out to the role of glutamatergic neurotransmission, possibly through AMPA-receptors. Expert opinion: A major limitation of current pre-clinical investigations is that there are no experimental models that recapitulate the complexity of bipolar disorder. Significant methodological differences concerning time and dose of LTG treatment, administration route, animal strains, and behavioral paradigms also hamper the reproducibility of the findings, leading to contradictory conclusions. Moreover, the role of other mechanisms (e.g. inositol phosphate and GSK3β pathways) implicated in the mode of action of different mood-stabilizers must also be consolidated with LTG.

Management of bipolar depression with lamotrigine: an antiepileptic mood stabilizer

The efficacy of lamotrigine in the treatment of focal epilepsies have already been reported in several case reports and open studies, which is thought to act by inhibiting glutamate release through voltage-sensitive sodium channels blockade and neuronal membrane stabilization. However, recent findings have also illustrated the importance of lamotrigine in alleviating the depressive symptoms of bipolar disorder, without causing mood destabilization or precipitating mania. Currently, no mood stabilizers are available having equal efficacy in the treatment of both mania and depression, two of which forms the extreme sides of the bipolar disorder. Lamotrigine, a well established anticonvulsant has received regulatory approval for the treatment and prevention of bipolar depression in more than 30 countries worldwide. Lamotrigine, acts through several molecular targets and overcomes the major limitation of other conventional antidepressants by stabilizing mood from “below baseline” thereby preventing switches to mania or episode acceleration, thus being effective for bipolar I disorder. Recent studies have also suggested that these observations could also be extended to patients with bipolar II disorder. Thus, lamotrigine may supposedly fulfill the unmet requirement for an effective depression mood stabilizer.

Misdiagnosis, duration of untreated illness (DUI) and outcome in bipolar patients with psychotic symptoms: A naturalistic study

BACKGROUND

A number of data show the negative role of duration of untreated illness (DUI) on outcome in mood disorders, but no investigation has been carried out about the impact of this variable in bipolar disorder (BD) with psychotic symptoms. Clinical experience shows that many bipolar patients with psychotic symptoms receive other diagnoses and often are chronically treated with first generation antipsychotics, with the effect to reduce duration of untreated psychosis/untreated episode with psychotic symptoms (DUP), but not DUI. Purpose of the study was to define the rate of misdiagnosis and the impact of DUP/DUI on outcome of bipolar patients with psychotic symptoms.

METHOD

Clinical information (DUP, DUI, first received diagnosis) about bipolar outpatients with psychotic symptoms (N=240) were extrapolated through a retrospective review of the clinical charts, Lombardy database and, if necessary, through clinical interviews with patients and their relatives. Outcome measures included psychiatric and substance abuse comorbidity, occupational status, Global Assessment of Functioning (GAF), number of hospitalizations and of suicidal attempts, number of depressive/manic recurrences. Patients were divided in two groups according to the DUP (1 year) and DUI (8 years) median, and the groups were compared through analyses of variance (ANOVAs) for continuous variables or χ(2) tests for dichotomous ones. Multivariate analysis of variance (MANOVA) with duration of illness as covariate was then performed to eliminate the effect of this variable. Finally, binary logistic regressions were performed considering age at onset, DUI, DUP as independent variables and outcome variables as dependent ones (presence of hospitalizations/suicidal attempts, GAF scores<50, occupational status).

RESULTS

Most of patients (61.5%) received a first diagnosis different from BD with the most frequent DSM-diagnosis being delusional disorder (17.9%). Patients with longer DUP were not different in outcome measures with respect to patients with shorter DUP. Patients with a DUI >8 years presented higher number of hospitalizations (F=6.04, p=0.015), higher number of manic recurrences (F=5.25, p=0.023), higher number of depressive recurrences (F=7.13, p=0.008) and lower GAF scores (F=17.74, p<0.001). Statistical significance persisted for number of hospitalizations (p<0.001) and GAF scores (p=0.003) after MANOVA. Finally binary logistic regression showed that a longer DUI was predictive of GAF scores<50 (F=17.74, p<0.001).

DISCUSSION

More than half of bipolar patients with psychotic symptoms receive a different diagnosis at first contact with psychiatric services. DUI (but not DUP) is a predictor of outcome in bipolar patients with psychotic symptoms. This indicates that an early diagnosis and proper treatment with a mood stabilizer (or an atypical antipsychotic with mood stabilizing effects) may improve long-term outcome of these patients. In the light of the naturalistic design of the present paper, these results have to be considered as preliminary and have to be confirmed by prospective controlled studies.

Revisiting loxapine: a systematic review

Loxapine is an antipsychotic used in psychiatry for over 40 years with a well-established profile. Loxapine is a dibenzoxazepine tricyclic antipsychotic agent, available for oral, intramuscular and inhalatory administration. In the light of the recent approval by the regulatory agencies of inhaled loxapine for use in the acute treatment of mild-to-moderate agitation in adults affected with schizophrenia or bipolar disorder, this article aims to critically review the available literature on loxapine, irrespective of its formulation. This review examines the efficacy and tolerability of the various formulations of loxapine in the treatment of agitation and aggression in patients affected with schizophrenia, bipolar disorder and other psychiatric conditions. A comprehensive and systematic literature search of PubMed/MEDLINE was conducted, and relevant pharmacodynamic and pharmacokinetic data was included. The findings from the literature were critically reviewed and synthesized. The available data suggests that the antipsychotic efficacy of loxapine is similar to the efficacy of other typical or atypical antipsychotics, with an adverse effects profile comparable to that of the typical antipsychotics at high doses for chronic treatment. As an acute treatment in agitation associated with schizophrenia or bipolar disorder, inhaled loxapine was developed as an innovative and rapid option which appears to be efficacious and tolerable.

Is the combination of a mood stabilizer plus an antipsychotic more effective than mono-therapies in long-term treatment of bipolar disorder? A systematic review

BACKGROUND

Bipolar Disorder (BD) long-term treatment is aimed to prevent relapses associated with worsening cognitive impairment and chronicity. Available mood stabilizers, including lithium, fail to prevent relapses in about 40% of bipolar patients. Purpose of the present paper is to review the available data about the efficacy and tolerability of mood stabilizer plus antipsychotic combined treatments.

METHOD

A research in the main database sources has been conducted to obtain an overview about the efficacy and tolerability of the combination of a mood stabilizer plus an antipsychotic in the long-term treatment of BD. Papers with different methodologies but having relapse prevention as main outcome have been included.

RESULTS

Despite the heterogeneity of studies in terms of methodology, almost all papers reported a major efficacy of combined treatments respect to mood stabilizer mono-therapies but lower tolerability. The antipsychotic that presents more evidence of efficacy in combination with mood stabilizers is quetiapine.

DISCUSSION

Combined treatments can be a valid option to improve relapse prevention in BD. However, the higher risk for side effects has to be taken into account and specific combinations should be preferred according to patients' medical comorbidity.

Predictive animal models of mania: hits, misses and future directions

Mania has long been recognized as aberrant behaviour indicative of mental illness. Manic states include a variety of complex and multifaceted symptoms that challenge clear clinical distinctions. Symptoms include over-activity, hypersexuality, irritability and reduced need for sleep, with cognitive deficits recently linked to functional outcome. Current treatments have arisen through serendipity or from other disorders. Hence, treatments are not efficacious for all patients, and there is an urgent need to develop targeted therapeutics. Part of the drug discovery process is the assessment of therapeutics in animal models. Here we review pharmacological, environmental and genetic manipulations developed to test the efficacy of therapeutics in animal models of mania. The merits of these models are discussed in terms of the manipulation used and the facet of mania measured. Moreover, the predictive validity of these models is discussed in the context of differentiating drugs that succeed or fail to meet criteria as approved mania treatments. The multifaceted symptomatology of mania has not been reflected in the majority of animal models, where locomotor activity remains the primary measure. This approach has resulted in numerous false positives for putative treatments. Recent work highlights the need to utilize multivariate strategies to enable comprehensive assessment of affective and cognitive dysfunction. Advances in therapeutic treatment may depend on novel models developed with an integrated approach that includes: (i) a comprehensive battery of tests for different aspects of mania, (ii) utilization of genetic information to establish aetiological validity and (iii) objective quantification of patient behaviour with translational cross-species paradigms.

Ziprasidone in the treatment of acute mania: a 12-week, placebo-controlled, haloperidol-referenced study

This 12-week, double-blind, two-part study in 438 adults with bipolar-associated acute mania began with a 3-week period comparing ziprasidone (80-160 mg/day) and placebo with haloperidol (8-30 mg/day) as active reference. Changes from baseline Mania Rating Scale (MRS) scores for ziprasidone and haloperidol were superior to placebo from day 2 (P = 0.001) to week 3 (P < 0.001); change from baseline at week 3 was greater for haloperidol than ziprasidone (P <or= 0.001). At week 3, the response rate (>or=50% decrease from baseline MRS score) was 36.9, 54.7 and 20.5% for ziprasidone, haloperidol and placebo, respectively (P <or= 0.05, active treatments versus placebo and ziprasidone versus haloperidol). In the 9-week extension phase, ziprasidone replaced placebo to examine tolerability. Maintenance of improvement was evaluated for ziprasidone (40-160 mg/day) or haloperidol (4-30 mg/day). Responses were maintained through the last visit for 88.1% receiving ziprasidone and 96.3% receiving haloperidol. More patients receiving haloperidol than ziprasidone discontinued treatment during weeks 4-12 (21.1% versus 9.6%) and had significantly higher rates of movement disorders. Mean doses of ziprasidone and haloperidol for the first 3-week and 9-week extension were 116.2 mg/day and 121.4 mg/day and 16.0 mg/day and 16.1 mg/day, respectively. Ziprasidone was shown to be effective monotherapy for acute treatment of bipolar mania. Although haloperidol showed greater efficacy, ziprasidone showed a superior tolerability profile.

Predictors of switching from mania to depression in a large observational study across Europe (EMBLEM)

BACKGROUND

The risk of switching from mania to depression in bipolar disorder has been poorly studied. Large observational studies may be useful in identifying variables that predict switch to depression after mania and provide data on medication use and outcomes in "real world" patients.

METHOD

EMBLEM (European Mania in Bipolar Longitudinal Evaluation of Medication) is a 2-year, prospective, observational study of patients with a manic/mixed episode. Symptom severity measures included Clinical Global Impression-Bipolar Disorder scale (CGI-BP), Young Mania Rating Scale (YMRS) and 5-item Hamilton Depression Rating Scale. Switching was defined using CGI-BP mania and depression such that patients changed from manic and not depressed to depressed but not manic over two consecutive observations within the first 12 weeks of follow-up. Cox proportional hazards models identified baseline variables independently associated with switch to depression.

RESULTS

Of 2390 patients who participated in the maintenance phase (i.e. up to 24 months), 120 (5.0%) switched to depression within the first 12 weeks. Factors associated with greater switching to depression include previous depressive episodes, substance abuse, greater CGI-BP overall severity and benzodiazepine use. Factors associated with lower switching rates were greater CGI-BP depression, lower YMRS severity and atypical antipsychotic use.

LIMITATIONS

The definition of switching biased against patients with mixed episodes being likely to switch.

CONCLUSIONS

Strictly defined, switch to depression from mania occurs in a small proportion of bipolar patients. Clinical history, illness severity, co-morbidities and treatment patterns are associated with switching to depression. Atypical antipsychotics may protect against switch to depression.

Observational study designs for bipolar disorder - what can they tell us about treatment in acute mania?

Randomised controlled trials may have generalisability limitations when applied to the complex treatment of patients with bipolar disorder. Observational study designs can inform us about the diversity of bipolar disorder treatment in naturalistic settings. The aim of this paper was to describe the treatments prescribed for acute mania in a large prospective observational study of bipolar disorder. Patients with a manic/mixed episode were enrolled in EMBLEM (European Mania in Bipolar Longitudinal Evaluation of Medication) if they initiated or changed oral medication with antipsychotics, lithium and/or anticonvulsants. The use of monotherapy or combination therapy for treatment of acute mania, concomitant medications and rate of treatment switching during the 12-week acute treatment phase were assessed. Of the 3459 patients, 36% were treated with one drug and 64% with combination therapy. 55% of patients initiating combination therapy started on an atypical antipsychotic plus lithium or an anticonvulsant. Patients prescribed combination therapy at baseline were more clinically severe, were more often treated as inpatients and had more manic episodes in the previous year compared with the monotherapy group. Treatment switching occurred in 54.4% of patients over the 12-week acute phase. Many patients were taking at least one concomitant medication at baseline (69.4%) and week 12 (50.5%). The results of this observational study show that treatment for mania is complex with multiple combinations of treatment and frequent switching during an acute episode.

The use of atypical antipsychotics beyond psychoses: efficacy of quetiapine in bipolar disorder

BACKGROUND AND RATIONALE

Atypical antpsychotics have been sucessfully used in the treatment of bipolar disorder (BD), either as adjunctive or as monotherapy. Quetiapine is an atypical antipsychotic extensively used in the treatment of psychotic disorders. It has serotonergic and dopaminergic activity and it appears to be selective for the mesolimbic and mesocortical dopamine system. The aim of this paper was to review the recent literature on the use of quetiapine in the treatment of BD.

METHODS

The literature databases currently available online were searched for papers on quetiapine and BD. Papers and reports published between January 1995 and June 2005 were selected and reviewed critically.

RESULTS

Augmentative low dose quetiapine was found to be effective in BD partially responsive to conventional mood-stabilizers. Manic and mixed episodes have been the best studied, and quetiapine was found to be effective either as monotherapy or as adjunctive therapy in both randomized clinical trials and open-label studies. Data on the use of quetiapine in bipolar depression showed a significant efficacy and high remission rates. Maintenance data suggested a role of quetiapine as a good alternative to classical mood stabilizers in reducing recurrence rates of BD. A few studies on the efficacy in rapid cycling BD have also been published.

CONCLUSIONS

Quetiapine is an effective agent for the short- and long-term treatment of BD. The mechanism of action of quetiapine as a mood stabilizer is still unknown. Some preliminary data suggest the involvement of glutamate pathways but further studies are needed to clarify this issue.