A retrospective analysis of changing from alternative agents to carbamazepine extended-release capsules in bipolar disorder.

BACKGROUND

Patients with bipolar disorder do not respond to the same therapy in the same way. This potentially necessitates the trial of various treatment modalities in a patient until the illness can be successfully controlled.

METHODS

Medical histories from 187 patients were reviewed to obtain information on efficacy when patients were switched from their initial drug therapy-immediate-release (IR) or extended-release (ER) carbamazepine (CBZ) tablets, valproic acid, lamotrigine, lithium, olanzapine, and oxcarbazepine-to beaded CBZ extended-release capsules (CBZ-ERC) (Shire, Wayne, PA, USA). Clinical Global Impression-Severity and Clinical Global Impression-Improvement scores were used to assess severity of illness, and response and relapse rates, respectively.

RESULTS

The overall response rate was 79.7%. The greatest percentage of responders to CBZ-ERC treatment was seen in patients originally on lithium (90.5%), followed by those initially treated with oxcarbazepine (84.8%), olanzapine (81.5%), lamotrigine (77.8%), valproic acid (75.4%), and IR or ER CBZ tablets (74.2%). The overall relapse rate was 38.2%. Patients on lithium had the highest relapse rate (52.6%), followed by those on olanzapine (50.0%), valproic acid (34.9%), IR or ER CBZ tablets (34.8%), oxcarbazepine (32.1%), and lamotrigine (28.6%). Adverse events were minimal, with nausea, dizziness, and somnolence being the most frequent.

CONCLUSIONS

The encouraging treatment response and adverse event profile observed in this retrospective analysis suggest that CBZ-ERC is an efficacious agent for the treatment of patients with bipolar disorder switched from other psychotropic agents.