ACHE and early-onset autosomal dominant Alzheimer disease: Tacrine, a potent, selective and reversible acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitor, approved for clinical use by the U.S. Food and Drug Administration (FDA) for the treatment of mild to moderate Alzheimer’s disease (AD) in 1993, is no longer indicated for Alzheimer’s treatment due to its hepatotoxicity [41].