ACHE and Alzheimer disease: Currently, drugs aimed to increase the levels of ACh are already in use or under clinical trials in pathologies characterized by ACh low levels; this is the case for acetylcholinesterase inhibitors in AD, selective muscarinic agonists such as alvameline and cevimeline (M1 receptor) for the treatment of AD or Sjogren's disesase, nicotinic and muscarinic receptors selective antagonists, such as darifenacin (M3 antagonist) or iprotropium (M1/M3 antagonist) have also been proposed for the treatment of overactive blabber, and chronic obstructive pulmonary disease (COPD) 12, 46.