Drugs for cognitive loss and dementia.

The drugs currently available for the treatment of Alzheimer's disease and other dementias can provide limited symptomatic improvement. The acetylcholinesterase inhibitors donepezil, rivastigmine, and galantamine and the NMDA-receptor antagonist memantine have produced modest but apparently persistent improvements in cognition, activities of daily living, and behavior in patients with disease severity ranging from mild to severe. Among the acetylcholinesterase inhibitors, transdermal rivastigmine causes fewer gastrointestinal side effects than the oral formulation. Whether adding memantine to an acetylcholinesterase inhibitor is more effective than an acetylcholinesterase inhibitor alone remains to be established; clinical trial results have been mixed. None of these agents have been shown to stop or reverse the underlying neurodegenerative process.