Switching from other agents to extended-release carbamazepine in acute mania

There is a dearth of available knowledge relating to the efficacy of switching from one psychotropic agent to another in treating patients with acute mania. Methods: This is a post hoc analysis of data from two randomized, placebo-controlled trials of carbamazepine extended-release capsules (CBZ-ERC) in the treatment of mania, to evaluate the efficacy of CBZ-ERC in patients previously nonresponsive to lithium (n 5 40), olanzapine (n 5 38), or valproate (VPA, n 5 77). Results: In patients previously on lithium, Young Mania Rating Scale (YMRS) scores improved significantly from baseline to end point (27.4 6 SD 3.5 vs. 15.8 6 11.1; P 5 .0002). In patients previously on VPA or olanzapine, YMRS scores significantly improved in both CBZ-ERC- and placebo-treated groups (VPA: CBZ-ERC, P , .0001; placebo, P 5 .0002; olanzapine: CBZ-ERC, P , .0001; placebo, P 5 .0054). Improvement in YMRS was significantly greater in CBZ-ERC-treated patients versus placebo in subjects previously nonresponsive to lithium (CBZ-ERC 11.6 6 10.3 vs. placebo 4.0 6 11.2, P 5 .03), or VPA (CBZ-ERC 10.8 6 11.9 vs. placebo 5.7 6 9.2; P 5 .04), and trending to be greater for those previously nonresponsive to olanzapine (olanzapine 13.2 6 9.3 vs. placebo 7.3 6 9.7, P 5 .06). Conclusions: CBZ-ERC is an effective therapy for bipolar patients previously nonresponsive to lithium or valproate. Medication switch is frequently associated with symptom improvement.