Memantine might improve behavioral symptoms and reduce brain deterioration in patients with mild to moderate Lewy body dementia, but not Parkinson's disease dementia, data from a randomized, placebo-controlled trial show.
The higher amount of Alzheimer's disease–like amyloid pathology that is normally observed in patients with dementia with Lewy bodies (DLB) might explain why the drug appears to provide symptomatic relief to that group but not to patients with Parkinson's disease dementia (PDD), in whom amyloid pathology is encountered less often, Dr. Murat Emre of Istanbul (Turkey) University and his colleagues reported online.
Dr. Emre and his coauthors conducted the study of memantine, which is approved in the United States for treating moderate to severe Alzheimer's disease, because previous studies had suggested that the drug might yield similar benefits in patients with Lewy body–related dementias such as PDD or DLB, which have some overlap in pathology.
The researchers randomized 78 patients with DLB and 121 patients with PDD to a 20-mg dose of memantine once daily or a placebo. Concomitant use of cholinesterase inhibitors was not allowed (Lancet Neurology 2010 Aug. 23 [doi:10.1016/S1474-4422(10)70194-0]).
Patients were assessed when they were screened, at baseline, and at weeks 4, 12, 16, and 24. The study included patients from 30 sites in Austria, France, Germany, Greece, Italy, Spain, Turkey, and the United Kingdom.
In DLB patients, memantine significantly improved scores on the ADCS-CGIC (Alzheimer's Disease Cooperative Study–Clinical Global Impression of Change) scale from baseline to 24 weeks, compared with placebo (mean change from baseline, 3.3 vs. 3.9, respectively). In addition, NPI (Neuropsychiatry Inventory) scores improved significantly more from baseline to 24 weeks in memantine-treated patients than in placebo-treated patients.
Among PDD patients, memantine did not significantly change scores with either measurement, compared with placebo. “Memantine might exert stronger beneficial effects in patients with more prominent Alzheimer's disease–type pathology,” the investigators wrote. The differences in effects between DLB and PDD patients also could be accounted for by the range in symptoms and in concomitant drug use between these two patient populations, they added.
Disclosures: The study was funded by Lundbeck, a maker and distributor of memantine. Dr. Emre and some of his coauthors disclosed financial relationships with Lundbeck and other pharmaceutical companies. One author is an employee of Lundbeck.
View on the News
Hopeful Results
The study by Dr. Emre raises the possibility that memantine could improve global function by improving mood symptoms.
More research is needed, but memantine could be part of a plan to manage DLB and PDD symptoms until definitive cognitive therapies are developed.
LAURA MARSH, M.D., is from Baylor College of Medicine in Houston. Her comments are paraphrased from an editorial (Lancet Neurology 2010 Aug. 23 [doi:10.1016/S1474-4422(10)70208-8]). Dr. Marsh has received funding from Forest Research Institute to study the effects of memantine on the treatment of dementia in Parkinson's ddisease.
Vitals