Mood Stabilizers: Risperidone for Treating Bipolar Disorders in Adults

Risperidone is a benzisoxazole derivative atypical antipsychotic drug that is available as solid oral tablet, oral solution, orally dissolvable tablet, and risperidone long-acting injectable (RLAI) formulations. For adults, oral risperidone has regulatory approval in the USA both as a monotherapy and as an adjunct to lithium or valproate for treating acute manic episodes and mixed episodes as they were previously defined in DSM-IV-TR, in patients with bipolar I disorder. RLAI is also approved in the USA as a monotherapy, or an adjunctive therapy to lithium or divalproex, for maintenance treatment in patients with bipolar I disorder. However, the efficacy profile of oral risperidone for the acute treatment of bipolar depressive episodes is unclear, and, in double-blind studies, RLAI appeared to be more effective for preventing manic or mixed episodes than depressive episodes. The efficacy profile of risperidone for clinically important subtypes of bipolar disorders, including bipolar II disorder and patients with rapid cycling, is also uncertain. Although risperidone appeared to be well-tolerated across short-term and longer-term studies, dose-related extrapyramidal side effects, prolactin elevation, and weight gain during long-term treatment are common adverse effects.