MAPT and Alzheimer disease: These inhibitors act on one or more targets with additive or synergistic effects, aiming to increase efficacy, prolong therapeutic effects, minimize side effects, and lower drug doses.68,69,525 Compared with combined therapies, they further reduce the risk of drug-drug interactions and simplify administration, making treatment safer, more effective, and more convenient for patients.524,525 From a biochemical standpoint, growing evidence supports a link between cholinergic abnormalities and other pathophysiological features of AD, including abnormal Aβ and tau.