Indication for treatment and management of seizure disorders, mania, and prophylactic treatment of migraine headache. in epileptics, valproic acid is used to control absence seizures, tonic-clonic seizures (grand mal), complex partial seizures, and the seizures associated with lennox-gastaut syndrome.mechanism of action valproic acid dissociates to the valproate ion in the gastrointestinal tract and then binds to and inhibits gaba transaminase. the drug s anticonvulsant activity may be related to increased brain concentrations of gamma-aminobutyric acid (gaba), an inhibitory neurotransmitter in the cns, by inhibiting enzymes that catabolize gaba or block the reuptake of gaba into glia and nerve endings. valproic acid may also work by suppressing repetitive neuronal firing through inhibition of voltage-sensitive sodium channels. it is also a histone deacetylase inhibitor. valproic acid has also been shown to be an inhibitor of an enzyme called histone deacetylase 1 (hdac1).