Antipsychotic dose-sparing effect with addition of memantine

To describe a case of an antipsychotic-sparing effect achieved after the addition of memantine to the regimen of a patient with severe Alzheimer's disease and aggressive behavioral disturbances.

A 78-year-old white man with severe Alzheimer's disease was receiving risperidone 2 mg 3 times daily for persistent aggressive and dangerous behavioral disturbances. Memantine was initiated, and the dose was titrated to 10 mg twice daily. The patient's response included improvement in functional status and resolution of problematic behaviors, allowing repeated reduction of the risperidone dose and ultimate discontinuation.

Antipsychotics are often employed to treat behavioral disturbances for patients with Alzheimer's disease; however, the adverse effect potential of these agents remains a significant concern. Adjunctive medications that maintain or improve behavioral symptoms yet allow an antipsychotic-sparing effect are attractive. Such experiences have previously been described with other drug classes, but clinical experience is evolving with memantine. For this patient, the effect of this agent on behavioral symptoms and risperidone requirements is one example of such an antipsychotic-sparing effect.

Response to memantine therapy may include behavioral improvements allowing a dose-sparing effect of antipsychotic medication. Changes in psychoactive drug burden may be a valuable surrogate marker of memantine's effects on behavior.