Safety of available agents used to treat bipolar disorder: Focus on weight gain

Background: Pharmacotherapeutic management of bipolar disorder has advanced considerably since the introduction of lithium therapy nearly 50 years ago. The sizable percentage of patients who do not respond adequately to lithium and/or are intolerant to its side effects has served as an impetus for identifying alternative pharmacotherapeutic agents. Recent advances in the understanding of the neurotransmitter systems and their receptors as it applies to treatment of bipolar disorder has, in part, led to progress in delineating applications of anticonvulsant/antiepileptic drugs (AEDs) in this area. Although the efficacy of many drugs has been evaluated in patients with this disorder, medication tolerability and adherence issues related to unfavorable side effect profiles are substantial impediments to the development of novel pharmacotherapies. The potential for excessive weight gain as a side effect of certain psychopharmacologic agents remains a concern to both clinicians and patients. Method: English-language literature from 1985-2001 in MEDLINE was searched for the terms bipolar disorder anticonvulsant, antiepileptic, lithium, antipsychotic, weight, and compliance. This article reviewed current therapeutic options for bipolar disorder, including newer AEDs and atypical antipsychotic drugs, with emphasis on the issue of weight gain and possible approaches to minimizing this risk. Results: Certain newer AEDs are characterized by more favorable safety and tolerability profiles that include weight loss as a desirable side effect. Because bipolar disorder is associated with unacceptably high rates of relapse, recurrence, and morbidity, the concept of pharmacotherapeutic efficacy logically not only includes symptom relief but also necessarily encompasses issues related to regimen tolerability and adherence. Conclusion: There is a need for guidelines to help physicians carefully formulate and individualize management plans to reach safe, effective, and cost-efficient patient outcomes. Monitoring the weight of patients with bipolar disorder and educating them regarding this issue should be standard components of any treatment plan.