Objective: The efficacy and tolerability of mood stabilizers in older adults with bipolar disorder remains understudied. Authors retrospectively examined response to lamotrigine, lithium, and placebo in older (>or=age 55) adults with Bipolar I disorder (DSM-IV) who participated in two mixed-age, maintenance studies examining time to intervention for an emerging mood episode (manic/hypomanic/mixed or depressed) and drug tolerability.
Methods: In all, 588 patients received double-blind lamotrigine (LTG, 100 mg-400 mg/day), lithium (Li, 0.8 mEq/L-1.1 mEq/L), or placebo (PBO); data from 98 older adults (LTG: 33, Li: 34, PBO: 31) were examined. Mean modal total daily doses were LTG 240 mg and Li 750 mg.
Results: LTG significantly delayed time to intervention for any mood episode and for a depressive episode, compared with placebo. Li significantly delayed time to intervention for mania/hypomania/mixed compared with placebo. Back pain and headache were the most common adverse events during LTG treatment; rash: LTG, 3%; Li, 6%; and PBO, 0; no serious rash was reported. The most common adverse events (>10%) during lithium treatment were dyspraxia, tremor, xerostomia, headache, infection, amnesia, dizziness, diarrhea, nausea, and fatigue.
Conclusion: Lamotrigine and lithium may be effective and well-tolerated maintenance therapies for older adults with Bipolar I depression.