Clinical efficacy of lamotrigine and changes in the dosages of concomitantly used psychotropic drugs in Alzheimer's disease with behavioural and psychological symptoms of dementia: a preliminary open-label trial

Aim: We investigated the clinical efficacy and changes in the dosages of concomitantly used psychotropic drugs in lamotrigine therapy in Alzheimer's disease with behavioural and psychological symptoms of dementia (BPSD). Methods: This study was a 16-week, preliminary open-label trial. The subjects were 40 inpatients. The outcome measures assessed were BPSD and cognitive function. BPSD was assessed with the Neuropsychiatric Inventory (NPI) and cognitive function was assessed with the Mini-Mental State Examination. The changes in the dosages of concomitant psychotropic drugs were also assessed. Results: Although the mean changes from baseline NPI scores and the two NPI subscales (anxiety and irritability) were significantly lower within the lamotrigine therapy group, no significant differences were found when we compared the lamotrigine therapy group to the control group. The mean decrease from baseline on the NPI agitation subscale, however, was significantly greater in the lamotrigine therapy group than in the control group (P < 0.05). Furthermore, the mean decrease from baseline in the diazepam-equivalent dose was significantly greater in the lamotrigine therapy group than in the control group (P < 0.05). Conclusions: The results of this study suggest that the administration of lamotrigine to patients with severe Alzheimer's disease with BPSD may be effective and may make it possible to avoid increasing the dosage of antipsychotic medications prescribed to elderly patients.