<P> Valproate (VPA), and its valproic acid, sodium valproate, and valproate semisodium forms, are medications primarily used to treat epilepsy and bipolar disorder and to prevent migraine headaches . It is useful for the prevention of seizures in those with absence seizures, partial seizures, and generalized seizures . It can be given intravenously or by mouth . Long and short acting formulation of tablets exist . </P> <P> Common side effects include nausea, vomiting, sleepiness, and a dry mouth . Serious side effects can include liver problems and regular monitoring of liver function tests is therefore recommended . Other serious risks include pancreatitis and an increased suicide risk . It is known to cause serious abnormalities in the baby if taken during pregnancy . Because of this it is not typically recommended in women of childbearing age who have migraines . </P> <P> It is unclear exactly how valproate works . Proposed mechanisms include affecting GABA levels, blocking voltage - gated sodium channels, and inhibiting histone deacetylases . Valproic acid is a branched short - chain fatty acid (SCFA) made from valeric acid . </P> <P> Valproate was first made in 1881 and it came into medical use in 1962 . Valproate is included in the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system . It is available as a generic medication . The wholesale cost in the developing world is between 0.14 and 0.52 USD per day . In the United States, it costs roughly $0.90 USD per day . It is marketed under the brand names Depakote and Epilim among others . </P>

Mechanism of action of valproic acid in epilepsy
find me the text answering this question