Tiagabine in the treatment of acute affective episodes in bipolar disorder: efficacy and acceptability

Topiramate for acute affective episodes in bipolar disorder in adults

BACKGROUND

Bipolar disorder is a common recurrent illness with high levels of chronicity. Previous trials have suggested that the anticonvulsant topiramate may be efficacious in bipolar disorder. This is an update of a previous Cochrane review (last published 2006) on the role of topiramate in bipolar disorder.

OBJECTIVES

To assess the effects of topiramate for acute mood episodes in bipolar disorder in adults compared to placebo, alternative pharmacological treatment, and combination pharmacological treatment as measured by treatment of symptoms on specific rating scales for individual episodes.

SEARCH METHODS

We searched the Cochrane Depression, Anxiety and Neurosis Controlled Trials Register to 13 October 2015, which includes records from the Cochrane Central Register of Controlled Trials (CENTRAL) all years; MEDLINE 1950-; EMBASE 1974-; and PsycINFO 1967-.We performed handsearching, reviewing of grey literature and reference lists, and correspondence with authors and pharmaceutical companies.

SELECTION CRITERIA

Randomised controlled trials comparing topiramate with placebo or with active agents in the treatment of acute mood episodes in adult male and female patients with bipolar disorder.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed data extraction and methodological quality assessment. For analysis, we used odds ratio (OR) for binary efficacy outcomes and mean difference (MD) for continuously distributed outcomes.

MAIN RESULTS

This review included six studies with a total of 1638 male and female participants, of all ethnic backgrounds in both inpatient and outpatient settings. In five studies, participants were experiencing a manic or mixed episode, and in the other study the participants met the criteria for a depressive phase. Topiramate was compared with placebo and alternative pharmacological treatment as both monotherapy and as adjunctive treatment.Moderate-quality evidence showed topiramate to be no more or less efficacious than placebo as monotherapy, in terms of mean change on Young Mania Rating Scale (YMRS) (range 0 to 60), at endpoint 3 weeks (MD 1.17, 95% confidence interval (CI) -0.52 to 2.86; participants = 664; studies = 3; P = 0.17) and at endpoint 12 weeks (MD -0.58, 95% CI -3.45 to 2.29; participants = 212; studies = 1; P = 0.69; low-quality evidence). For the same outcome, low-quality evidence also showed topiramate to be no more or less efficacious than placebo as add-on therapy (endpoint 12 weeks) (MD -0.14, 95% CI -2.10 to 1.82; participants = 287; studies = 1; P = 0.89) in the treatment of manic and mixed episodes. We found high-quality evidence that lithium was more efficacious than topiramate as monotherapy in the treatment of manic and mixed episodes in terms of mean change on YMRS (range 0 to 60) (endpoint 12 weeks) (MD 8.46, 95% CI 5.86 to 11.06; participants = 449; studies = 2; P < 0.00001).For troublesome side effects experienced of any nature, we found no difference between topiramate and placebo as monotherapy (endpoint 12 weeks) (OR 0.68, 95% CI 0.33 to 1.40; participants = 212; studies = 1; P = 0.30; low-quality evidence) or as add-on therapy (endpoint 12 weeks) (OR 1.10, 95% CI 0.58 to 2.10; participants = 287; studies = 1; P = 0.76; low-quality evidence). In terms of participants experiencing side effects of any nature, we found no difference between topiramate and an alternative drug as monotherapy (endpoint 12 weeks) (OR 0.87, 95% CI 0.50 to 1.52; participants = 230; studies = 1; P = 0.63; low-quality evidence) or as add-on therapy (endpoint 8 weeks) (OR 1.57, 95% CI 0.42 to 5.90; participants = 36; studies = 1; P = 0.50; very low-quality evidence).We considered five of the studies to be at low risk of selection bias for random sequence generation, performance, detection, attrition, and reporting biases, and at unclear risk for allocation concealment and other potential sources of bias. We considered the McIntyre 2000 study to be at high risk of performance bias; unclear risk of bias for random sequence generation, allocation concealment, blinding of outcome assessment, and other potential sources of bias; and at low risk for attrition bias and reporting bias.

AUTHORS' CONCLUSIONS

It is not possible to draw any firm conclusions about the use of topiramate in clinical practice from this evidence. The only high-quality evidence found was that lithium is more efficacious than topiramate when used as monotherapy in the treatment of acute affective episodes in bipolar disorder, and we note that this evidence came from only two studies. Moderate-quality evidence showed that topiramate was no more or less efficacious than placebo as monotherapy when a 3-week endpoint was used, but the quality of the evidence for this outcome at a 12-week endpoint dropped to low. As we graded the quality of the evidence for the other findings as low and very low, it was not possible to draw any conclusions from the results.To best address this research question, if investigators see the indication in so doing, more double-blind randomised controlled trials could be conducted that are more explicit with regard to methodological issues. In particular, investigators could compare placebo, alternative, and combination treatments (including a wide range of mood stabilisers), atypical antipsychotics for manic and mixed episodes, and antidepressants in combination with mood stabilisers or atypical antipsychotics for depressive episodes.

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.

Oxcarbazepine for acute affective episodes in bipolar disorder

BACKGROUND

Oxcarbazepine, a keto derivative of the 'mood stabiliser' carbamazepine, may have efficacy in the treatment of acute episodes of bipolar disorder. Potentially, it may offer pharmacokinetic advantages over carbamazepine.

OBJECTIVES

To review the efficacy and acceptability of oxcarbazepine compared to placebo and other agents in the treatment of acute bipolar episodes including mania, mixed episodes and depression.

SEARCH METHODS

Electronic databases were searched up to 2 September 2011. Specialist journals and conference proceedings were handsearched. Authors, experts in the field and pharmaceutical companies were contacted requesting information on published and unpublished trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) which compared oxcarbazepine with placebo or alternative agents, where the stated intent of intervention was the acute treatment of bipolar affective disorder were sought. Participants with bipolar disorder of either sex and of all ages were included.

DATA COLLECTION AND ANALYSIS

Data were extracted from the original reports individually by two review authors. For dichotomous data, odds ratios (ORs) were calculated with 95% confidence intervals (CI). Continuous data were analysed using standardised mean differences (with 95% CI).

MAIN RESULTS

Seven studies were included in the analysis (368 participants in total). All were on mania, hypomania, mixed episodes or rapid-cycling disorder. Overall, their methodological quality was relatively low.There was no difference in the primary outcome analysis - a fall of  50% or more on the Young Mania Rating Scale (YMRS) - between oxcarbazepine and placebo (N=1, n=110, OR =2.10, 95% CI 0.94 to 4.73) in one study, conducted in children; no studies were available in adult participants.In comparison with other mood stabilisers, there was no difference between oxcarbazepine and valproate as an antimanic agent using the primary outcome (50% or more fall in YMRS, OR=0.44, 95% CI 0.10 to 1.97, 1 study, n=60, P=0.273) or the secondary outcome measure (differences in YMRS between the two groups, SMD=0.18, 95% CI -0.24 to 0.59, 2 studies, n=90, P=0.40). No primary or secondary efficacy outcome measures were found comparing oxcarbazepine with lithium monotherapy.As an adjunctive treatment to lithium, oxcarbazepine reduced depression rating scale scores more than carbamazepine in a group of manic participants on the Montgomery-Åsberg Depression Rating Scale (MADRS) (SMD=- 1.12, 95% CI -1.71 to -0.53, 1 study, n=52, P=0.0002) and on the Hamilton Depression Rating Scale (HDRS) (SMD=- 0.77, 95% CI -1.35 to -0.20, 1 study, n=52, P=0.008).There was a higher incidence of adverse effects, particularly neuropsychiatric, in participants randomised to oxcarbazepine compared to those on placebo (1 study, n=115, 17% to 39% of participants on oxcarbazepine had at least one such event compared to 7% to 10% on placebo).There was no difference in adverse events rates between oxcarbazepine and other mood stabilisers or haloperidol.

AUTHORS' CONCLUSIONS

Currently, there are insufficient trials of adequate methodological quality on oxcarbazepine in the acute treatment of bipolar disorder to inform us on its efficacy and acceptability. Studies predominantly examine the treatment of mania: there are data from subgroup analysis on mixed affective, hypomania and rapid-cycling states.From the few studies included in this review, oxcarbazepine did not differ in efficacy compared to placebo in children and adolescents. It did not differ from other active agents in adults. It may have a poorer tolerability profile compared to placebo. No data were found on outcomes relevant to patients and clinicians, such as length of hospital admission.  There is a need for adequately powered randomised controlled trials of good methodological quality to inform us of the therapeutic potential of oxcarbazepine across the spectrum of acute episodes in bipolar disorder.

Tiagabine in the maintenance treatment of bipolar disorder

BACKGROUND

Tiagabine, an anticonvulsant, has been reported to have efficacy in prophylactic treatment of bipolar disorder in case reports and in case series.

OBJECTIVES

To assess the efficacy and acceptability of tiagabine, relative to placebo, and other agents in the prevention or attenuation, or both, of episodes of bipolar disorder in adults. The efficacy and acceptability of tiagabine were considered in terms of mood symptoms, mortality, general health, social functioning, adverse effects and overall acceptability to participants.

SEARCH METHODS

The Cochrane Collaboration Depression, Anxiety and Neurosis review group's specialised registers (CCDANCTR-Studies and CCDANCTR-References) were searched to 1 October 2011. These registers contains relevant randomised controlled trials from: The Cochrane Library (all years to date), EMBASE, (1974 to date) MEDLINE (1950 to date) and PsycINFO (1967 to date). Reference lists of relevant papers and major textbooks of affective disorder were examined. Authors, other experts in the field and pharmaceutical companies were contacted for knowledge of suitable published or unpublished trials. Specialist journals and conference proceedings were handsearched.

SELECTION CRITERIA

Randomised controlled trials of tiagabine versus placebo, alternative mood stabilisers or antipsychotics, for the maintenance treatment of bipolar disorder in adults, male and female, aged 18 to 74 years.

DATA COLLECTION AND ANALYSIS

Data were to be extracted from the original reports of included studies independently by two authors. The main outcomes to be assessed were:(1) the efficacy of tiagabine treatment in preventing or attenuating further episodes of bipolar disorder, including its efficacy in rapid cycling disorder; (2) the acceptability of tiagabine treatment to participants; (3) the prevalence of side effects; and (4) mortality, if any, on tiagabine treatment.Outcomes concerning relapse or recurrence were to be analysed excluding data from studies using discontinuation protocols, which were to be analysed separately. Subgroup analyses were to be performed to examine the effects of tiagabine treatment in rapid cycling bipolar disorder and previous mood stabiliser non-responders. Data were to be analysed using Review Manager 5.

MAIN RESULTS

No randomised controlled trials of tiagabine in the maintenance treatment of bipolar disorder were found.

AUTHORS' CONCLUSIONS

There is an insufficient methodologically rigorous evidence base to draw any conclusions regarding the use of tiagabine in the maintenance treatment of bipolar disorder. There is a need for randomised controlled trials examining the therapeutic potential of this agent in bipolar disorder. There have been some reports of syncope or seizures, or both, when tiagabine has been used for the acute treatment of mania. It needs to be established if such adverse effects occur in the maintenance phase as well.

Oxcarbazepine in the maintenance treatment of bipolar disorder

BACKGROUND

Some studies have suggested that oxcarbazepine has a role in preventing episode recurrence in bipolar affective disorder. This review attempted to investigate the existing evidence from randomised controlled trials for its use in the maintenance treatment of this illness.

OBJECTIVES

To review the efficacy of oxcarbazepine, relative to placebo and other agents, in the prevention of affective episodes of bipolar affective disorder. The efficacy of oxcarbazepine was considered in terms of episode recurrence, general and social functioning. Adverse effects, overall acceptability to participants and mortality were also considered.

SEARCH STRATEGY

CCDANCTR-Studies and CCDANCTR-References were searched on 7/11/2007. Medline, CENTRAL, EMBASE and PsycINFO were searched in March 2007. Specialist journals and conference proceedings were handsearched. Reference lists of relevant papers and major textbooks of affective disorder were checked. Authors, experts in the field and pharmaceutical companies were contacted requesting information on published or unpublished trials.

SELECTION CRITERIA

Randomised controlled trials comparing oxcarbazepine with placebo or alternative agents, where the stated intent of intervention was the maintenance treatment of bipolar affective disorder were sought. Participants with bipolar disorder, male and female, of all ages, were included.

DATA COLLECTION AND ANALYSIS

Data were extracted from the original reports individually by two review authors. The methodological quality of included studies was assessed individually by two review authors. The main outcomes were the efficacy of oxcarbazepine maintenance treatment in preventing or attenuating further episodes of bipolar affective disorder (including its efficacy in rapid cycling disorder), the acceptability of oxcarbazepine treatment to participants, the prevalence of side-effects, and mortality, if any, on oxcarbazepine treatment. Where appropriate, data concerning outcome measures and adverse effects were to be extracted from the studies and analysed using Review Manager software.

MAIN RESULTS

Two randomised controlled trials were found that met the methodological criteria for inclusion in the review. However, they did not report data with sufficient clarity to allow their confident extraction for inclusion in the meta-analysis. Findings from the two studies were presented descriptively.

AUTHORS' CONCLUSIONS

There is an insufficient methodologically rigorous evidence base to provide guidance on the use of oxcarbazepine in the maintenance treatment of bipolar disorder. Given the need for more efficacious therapeutic agents, there is a need for good quality randomised controlled trials examining the therapeutic potential of this and related agents in bipolar disorder.

The effectiveness of anticonvulsants in psychiatric disorders

Anticonvulsant drugs are widely used in psychiatric indications. These include mainly alcohol and benzodiazepine withdrawal syndromes, panic and anxiety disorders, dementia, schizophrenia, affective disorders, bipolar affective disorders in particular, and, to some extent, personality disorders. A further area in which neurology and psychiatry overlap is pain conditions, in which some anticonvulsants, and also typical psychiatric medications such as antidepressants, are helpful. From the beginning of their psychiatric use, anticonvulsants have also been used to ameliorate specific symptoms of psychiatric disorders independently of their causality and underlying illness, eg, aggression, and, more recently, cognitive impairment, as seen in affective disorders and schizophrenia. With new anticonvulsants currently under development, it is likely that their use in psychiatry will further increase, and that psychiatrists need to learn about their differential efficacy and safety profiles to the same extent as do neurologists.