The safety and lack of efficacy of vinpocetine in Alzheimer's disease.

Fifteen Alzheimer patients were treated with increasing doses of vinpocetine (30, 45, and 60 mg per day) in an open-label pilot trial during a one-year period. Patients were assessed seven times both on and off drug with: the Buschke Selective Reminding Task, a letter fluency test, a category fluency test, the Boston Naming Test, a cognitive capacity screening examination, and a clinical global impression. Vinpocetine failed to improve cognition on psychometric testing or overall functioning, as measured by the clinical global impression, at any dose tested. Patients showed significant decline in most measures during the course of the study, at the same rate as a matched control group, consistent with progressive dementia. There were no significant side effects from drug therapy. We conclude that vinpocetine is ineffective in improving cognitive deficits and does not slow the rate of decline in individuals with Alzheimer's disease.