The association of the effect of lithium in the maintenance treatment of bipolar disorder with lithium plasma levels:a post hoc analysis of a double-blind study comparing switching to lithium or placebo in patients who responded to quetiapine (Trial 144)

Nolen WA, Weisler RH. The association of the effect of lithium in the maintenance treatment of bipolar disorder with lithium plasma levels: a post hoc analysis of a double-blind study comparing switching to lithium or placebo in patients who responded to quetiapine (Trial 144). Bipolar Disord 2012: 15: 100-109. (C) 2012 John Wiley & Sons A/S.Published by Blackwell Publishing Ltd. Objectives: There is no robust proof that the efficacy of lithium in the prevention of manic and depressive episodes in bipolar disorder depends on its plasma level. This analysis aimed to compare the effect of lithium within the presumed therapeutic range of 0.61.2 mEq/L and below 0.6 mEq/L with that of placebo. Methods: We carried out a post hoc analysis of a double-blind trial in which patients aged >= 18 years with bipolar I disorder (DSM-IV) who had achieved stabilization from a manic, depressive, or mixed episode during open-label treatment with quetiapine were randomized to continue quetiapine or to switch to lithium or placebo for up to 104 weeks. Of patients randomized to lithium, 201 obtained median lithium levels between 0.6 and 1.2 mEq/L, and 137 obtained median lithium levels