Tiagabine in the maintenance treatment of bipolar disorder

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

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.

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Authors, other experts in the field and pharmaceutical companies were contacted for knowledge of suitable published or unpublished trials.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.

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 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.

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

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.