There are other established therapies for the treatment of bipolar disorder. These include drugs that were initially used for the treatment of epilepsy and are referred to as mood stabilizers when used in psychiatry. Carbamazepine and valproic acid are the two best studied agents and they have found use in aggressive behaviours, eating disorders, alcohol withdrawal, anxiety disorders, and behavioural disturbances in the developmentally disabled. Valproic acid and carbamazepine both work to decrease the kindling pre-synaptically.
Valproic acid is a sodium channel blocker but the true mechanism of carbamazepine is unknown. It is thought to augment the activity of GABA and decrease DA and NE turnover. Both drugs have an impact on the cytochrome P 450 system and thus have many drug interactions. Valproic acid inhibits the metabolism of other drugs in the liver and as such will increase the serum concentrations of other drugs. Carbamazepine is an enzyme inducer, and thus will lower the serum concentrations of other drugs (and itself over time).
Both carbamazepine and valproic acid can cause drug interactions. How?
Extra info: It is important to remember that carbamazepine can lower the serum concentrations of other drugs by inducing the enzymes and valproic acid will increase the serum concentrations of other drugs by inhibiting the enzymes.
Valproic acid and carbamazepine are often also used for the treatment of all the following EXCEPT:
Extra info: Psychosis is unlikely to respond to treatment with a mood stabilizer. There is data to support the use of these drugs for the other disorders.