The present and future of pharmacotherapy of Alzheimer's disease: A comprehensive review

Alzheimer's disease (AD) is a generalized term used for the loss in memory and other intellectual abilities on levels serious enough to interfere with daily life. It accounts for 60-80% of dementia cases. The characteristic features include aggregation of Amyloid-Beta (A beta ) plaques and Tau Protein Tangles in the nervous tissue of brain. Another important aspect associated with development of AD is the decrease in levels of Acetylcholine (ACh) in brain. The conventional pharmacotherapy of AD employs the use of compounds that inhibit the enzyme acetylcholinesterase (e.g. donepezil, rivastigmine) thereby elevating the levels of Acetylcholine in nervous tissue of brain. Lately, another drug has come into picture for treatment of AD i.e. memantine. It is a Glutamatergic antagonist that protects the nervous tissue against glutamate mediated excitotoxicity. However, both these classes of drugs provide only the symptomatic relief. There has been a desperate need arising since the past few decades for evolution of a drug that could treat the underlying causes of AD and thereby halt its development in susceptible individuals. There are several plants and derived products which have been employed for their benefits against the symptoms and complications of AD. Some novel drugs having the potential to moderate AD are under clinical trials. This review presents a comprehensive overview of the existing and the upcoming potential treatments for AD.