https://immattersacp.org/weekly/archives/2012/10/23/2.htm

Stopping antipsychotics in Alzheimer's patients with a sustained response may lead to increased rate, shorter time to relapse

Alzheimer's patients with psychosis or agitation that had responded to risperidone therapy for four to eight months had nearly double the risk of relapse after stopping the drug compared to placebo, a study found.


Alzheimer's patients with psychosis or agitation that had responded to risperidone therapy for four to eight months had nearly double the risk of relapse after stopping the drug compared to placebo, as well as a shorter time to relapse and an increased risk of relapse for at least another four months, a study found.

In the study, 180 patients with Alzheimer's disease and psychosis or agitation-aggression received open-label treatment with risperidone for 16 weeks. The 110 who responded were randomly assigned to one of three regimens: continued therapy for 32 weeks, therapy for 16 weeks followed by placebo for 16 weeks, or placebo for 32 weeks.

Results appeared in the Oct. 18 New England Journal of Medicine.

Relapse rates during the first 16 weeks after the initial treatment were higher in the placebo group than the two treatment groups (60% [24 of 40 patients receiving placebo] vs. 33% [23 of 70 in the two treatment groups]; P=0.004; hazard ratio [HR] with placebo, 1.94; 95% CI, 1.09 to 3.45; P=0.02).

Relapse rates were higher in the group that switched from risperidone to placebo during the next 16 weeks than in the group that continued to receive risperidone (48% [13 of 27 patients switched to placebo] vs. 15% [2 of 13 of those who continued treatment]; P=0.02; HR, 4.88; 95% CI, 1.08 to 21.98; P=0.02).

The researchers noted that while stopping risperidone was associated with a larger rate of relapse, risperidone was not highly effective in reducing psychosis and agitation in Alzheimer's patients. Also, federal regulations for nursing homes strongly urge stopping antipsychotic drugs after three to six months of treatment.

The authors concluded, “Our findings suggest that patients with psychosis or agitation-aggression who have a sustained response to antipsychotic treatment for 4 to 8 months have a significantly increased risk of relapse for at least 4 months after discontinuation, and this finding should be weighed against the risk of adverse effects with continued antipsychotic treatment.”