Valproate for maintenance treatment of bipolar disorders
Brief summary
Evidence from systematic reviews
What is the current evidence for the use of valproate in the maintenance treatment of bipolar disorders?
Valproate performs better than placebo, olanzapine and lithium in preventing relapses of bipolar disorder. All trials were performed by the pharmaceutical industry.Is there any group of patients that respond better to valproate than the others?
Primary studies included adult patients, (except one study performed in children), of both genders. Patients with substance abuse, neurological disorders or serious risk of suicide were excluded in most primary studies. In three studies more than 50% of participants were rapid cyclers.
Should valproate be used as a single or combination treatment?
Trials studied valproate as a single treatment, and compared it to placebo, olanzapine and lithium.What are the adverse events at short and long term?
It is not clear from the systematic reviews and/or the primary studies what the long term adverse effects are, as this outcome has not been measured in any studies published recently.
For how long should valproate (single or combination) be used?
Trials used valproate for 12 to 18 months.
Is valproate more efficacious than other mood stabilisers in the maintenance treatment of bipolar disorders?
From the evidence provided by the trials, valproate was more efficacious than placebo, lithium and olanzapine in the maintenance treatment of bipolar disorders.
Is the balance between harm and benefit favourable to the use of valproate?
Despite the adverse outcomes, the limited amount of data suggests that valproate has greater benefit for patients than harm.
What type of research (if any) is needed to clarify the benefits and harms of using valproate in the maintainence treatment of bipolar disorder?
Trials comparing valproate's efficacy and effectiveness with lithium and other mood stablisers are needed. Such trials should include the examination of particular clinical and course features which may predict better response to maintainence treatment by certain agents.
