ABSTRACT
This chapter discusses a wide variety of repurposing cases for Alzheimer's and Parkinson's disease that illustrates the diversity of ways a repurposing candidate can take toward ultimate success or failure. It also discusses the more remote possibilities available, only the clinically most interesting therapeutic classes of repurposing candidates for Alzheimer's disease. The redevelopment history of galantamine has recently been reviewed in great detail, including the nonscientific and nonmedical hurdles that a drug repurposing project can face even if clinical development for the new therapeutic indication goes smoothly. The chapter suggests that galantamine as the first-ever repurposing candidate for Alzheimer's disease. As with Alzheimer's disease, longer-term use of nonsteroidal anti-inflammatory drugs (NSAIDs) appears to exert some protection against the development of Parkinson's disease. It was a classic case of repurposing by serendipity: a patient with Parkinson's disease had noticed relief in her motor symptoms after taking amantadine for influenza.
