Xanomeline is a muscarinic receptor agonist, with preference for the M1
receptor subtypes [2
]. It also has antagonist activity at 5-HT2
receptors, and agonist activity at 5-HT1
]. Xanomeline was investigated for potential to improve cognition in Alzheimer's disease (AD) patients, but activation of muscarinic receptors in the gastrointestinal tract caused severe nausea and diarrhoea, and this adverse effect led to discontinuation of xanomeline's clinical development for AD.