Valproic acid is an anticonvulsant medication that works by changing the concentration of certain neurotransmitters in the brain. It is most commonly used in the prevention of epileptic seizures, but is also indicated for several other health conditions including bipolar disorder, prevention of migraine, neuropathic pain and attention deficit hyperactivity disorder (ADHD).
Valproate has a broad spectrum of action as an antiepileptic drug and can be used in the treatment of both generalized and focal seizures, either alone or in combination with other medications.
There is some scientific evidence supporting its use for idiopathic generalized epileptic seizures and it is considered to be more effective than alternatives such as lamotrigine or topiramate. There remains some concern, however, about the lack of appropriately designed and conducted trials for all children and adults with generalized seizures.
In the management of complex partial seizures, it is indicated for use alone or as adjunctive therapy. Similarly, it is also considered to offer a benefit as sole or adjunctive therapy for both simple and complex absence seizures.
Valproate was first introduced as a maintenance treatment for people with bipolar disorder in 1966 and has risen in use for this indication over recent decades.
Specifically, it is thought to help manage the manic episodes associated with bipolar disorder and should be used in conjunction with other medications that help to reduce depressive episodes.
However, a recent review of the available clinical data concluded that there is limited evidence available outlining the efficacy and acceptability of the drug in comparison to placebo or alternative medications for this indication. Although valproic acid is often used in bipolar disorder, further research to assess the clinical outcomes of its use is needed.
Valproic acid is indicated for the prophylactic treatment of migraine, but there is insufficient evidence to determine its effect in the relief of an acute migraine.
Preventative migraine therapy is usually considered when individuals experience frequent attacks, generally at least one per month. Currently the first-line medication options for the prevention of migraine are amitriptyline, propranolol and pizotifen, although scientific reviews have also supported the use of valproate in effectiveness and tolerability.
Occasionally valproate is also used in the relief of neuropathic pain, such as that associated with diabetic neuropathy.
However, there is limited evidence available to promote the use of valproate for neuropathic pain and is, instead, recommended to be used only when other proven treatment options have been futile.
Attention Deficit Hyperactivity Disorder
Children with ADHD that experience outbursts of aggression may also benefit from treatment with valproic acid.
It is unclear whether the benefits of using this medication to treat ADHD related aggression offset the risks associated with its use. Alternative options should, therefore, be exhausted before valproate is considered for this indication.
There are certain cases in which valproic acid should not usually be used, even if it is indicated for the condition. These include:
- Presence of family history of liver disease
- Porphyria or other disorder of urea cycle
- Women who are pregnant
- Women who are breastfeeding
Additionally, patients with impaired renal failure may require a reduced dose.