Conditions: Alzheimer Disease Psychotic Disorders Agitation Aggression
Keywords: Risperidone treatment, psychosis, agitation, aggression, discontinuation, placebo
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 180
Healthy volunteers: no

Brief summary:
In patients with Alzheimer's disease (AD) who respond to antipsychotic treatment of psychosis and/or agitation/aggression, the relapse risk after discontinuation is not established. AD patients with psychosis and/or agitation/aggression receive 16 weeks of open risperidone treatment (Phase A). Responders are then randomized, double-blind, to one of three arms in Phase B: (1) continuation risperidone for 32 weeks, (2) risperidone for 16 weeks followed by placebo for 16 weeks, (3) placebo for 32 weeks. The primary outcome is time to relapse of psychosis/agitation.

Detailed description:
This multicenter study (6 academic sites and 2 non-academic sites) involves treating AD patients (assisted living or nursing home patients, and outpatients) using an atypical antipsychotic, risperidone. In Phase A, 180 AD patients with psychosis and/or agitation/aggression receive open treatment with risperidone for 16 weeks. Responders are randomized, double-blind, to one of three arms in Phase B: (1) continuation risperidone for the next 32 weeks, (2) risperidone for the next 16 weeks followed by placebo for 16 weeks, or (3) placebo for the next 32 weeks. The primary hypothesis is that in the first 16 weeks of Phase B, relapse risk will be lower with continuation risperidone (Arms 1 + 2) compared to discontinuation on placebo (Arm 3). The secondary hypothesis is that in the second 16 weeks of Phase B, relapse risk will be lower with continuation risperidone (Arm 1) compared to discontinuation on placebo (Arm 2). For both randomized time periods, the proportions who relapse will be compared for interpretive support. This design provides useful data on the efficacy and side effects of longer term treatment with risperidone, and, in particular, critical information about the time to relapse and likelihood of relapse in patients switched from risperidone to placebo. This information is essential to guide the clinician toward optimal use of such medications in one of the most challenging types of patients: the AD patient with psychosis and/or agitation/aggression. The results of this study will also help to address Federal regulations urging early antipsychotic discontinuation in nursing homes.

Arms:
arm 1: Risperidone for 16 weeks followed by risperidone for 16 weeks arm 2: Risperidone for 16 weeks followed by placebo for 16 weeks arm 3: Placebo for 16 weeks followed by placebo for 16 weeks

Interventions: intervention 1: risperidone
Intervention descriptions: intervention 1: Risperidone open label flexible dose 0.25 to 3 mg daily for first 16 weeks; dose at 16 weeks then fixed for randomized trial

Protocol document: