[Mood stabilizers].
Mood stabilizers available in Japan include lithium, valproate, carbamazepine, and lamotrigine. These are prescribed for manic or hypomanic episodes of bipolar disorder, organic mania, and drug-induced mania. Careful dose titration is needed in consideration for serum drug level and clinical symptoms. Lithium frequently develops neurological toxicity because of its narrow therapeutic serum level. Valproate has the most favorable adverse effect profile among mood stabilizers, but gastrointestinal symptoms and weight gain can appear with a dose dependent fashion. Hyperammonemia is occasionally induced early after initiation of valproate and tends to be overlooked. Carbamazepine sometimes develops liver dysfunction and skin disorders associated with allergic mechanisms. Lamotrigine should be slowly titrated to avoid severe skin disorders such as Stevens-Johnson syndrome.