Treatment of bipolar disorder: the evolving role of atypical antipsychotics

Management of bipolar disorder (BPD) may require multiple medications, including lithium, anticonvulsants, and antipsychotics (both conventional and atypical). Updated treatment guidelines reflect an expanded role for atypical antipsychotics (AAPs) in BPD treatment. Five AAPs--olanzapine, risperidone, quetiapine, ziprasidone, and aripiprazole--are approved by the US Food and Drug Administration (FDA) as monotherapy for first-line treatment of acute manic and (except for quetiapine) mixed episodes. Two AAPs--olanzapine (in fixed-dose combination with fluoxetine) and quetiapine--are also FDA approved for bipolar depression. For long-term maintenance therapy, one option is to continue effective, well-tolerated acute phase treatment; however, only olanzapine and aripiprazole are FDA approved for maintenance, based on evidence from randomized, placebo-controlled clinical trials. Although head-to-head comparisons are scarce, meta-analysis data suggest that olanzapine, risperidone, quetiapine, ziprasidone, and aripiprazole have similar antimanic efficacy; therefore, AAP selection for this indication should be guided by other considerations such as safety, tolerability, and cost. Safety and tolerability issues to consider when selecting an AAP include metabolic dysfunction (weight gain, type 2 diabetes, and dyslipidemia); hyperprolactinemia; extrapyramidal symptoms; QTc prolongation; and pharmacokinetic drug interactions.