The Overview of Drugs Used in Alzheimer’s Disease and Their Molecular Targets

Alzheimer’s disease (AD) is a progressive condition in which degeneration of neuronal cells is observed in the brain. There are many drugs approved by the FDA for the treatment of AD and it includes galantamine, donepezil, rivastigmine, memantine, and aducanumab. Among the available drugs, galantamine, donepezil, and rivastigmine are acetylcholinesterase inhibitor and they enhance cholinergic neurons in the brain. Another drug memantine is N-methyl-D-aspartate (NMDA)-type glutamate receptor antagonist. It prevents excitotoxicity and neuronal cell apoptosis. Similarly, aducanumab is a recently approved drug which attenuates the accumulation of amyloid beta protein. There are many synthetic drugs and herbal bioactives that have been reported against AD. Some of the synthetic drugs and bioactives possess low bioavailability and BBB permeability. Due to this, they show less therapeutic action at the target site for the treatment of AD. Such therapeutic moieties can be incorporated into advanced drug delivery system to enhance their bioavailability and blood–brain barrier (BBB) permeability. The chapter describes an overview of the various treatment strategies as well as the nanomedicines that have been developed so for to treat AD.