Depakote & Phenobarbital
Just a quick note/reminder. Valproic acid can cause an increase in the concentration of phenobarbital and should be used with caution in those already on phenobarbital.
The use of valproic acid with other antiepileptic medications can also cause a decrease in the level of valproic acid itself because enzyme-inducing antiepileptic medications, such as carbamazepine, phenytoin, phenobarbital, and primidone, will increase the metabolism of valproate.