A once-weekly transdermal formulation of the acetylcholinesterase inhibitor donepezil (Adlarity – Corium) has been approved by the FDA for treatment of mild, moderate, and severe Alzheimer's disease (AD) dementia. Donepezil is the second acetylcholinesterase inhibitor to become available in a transdermal formulation; transdermal rivastigmine (Exelon Patch), which is applied once daily, has been available for years for the same indication. Donepezil is also available in oral formulations (Aricept, and generics) for treatment of AD dementia.

View the Comparison Table: Drugs for Alzheimer's Disease

Alzheimer's disease (AD) is the most common cause of dementia, but cognitive decline is also associated with other neurological conditions such as Parkinson's disease, dementia with Lewy bodies, vascular dementia, and frontotemporal dementia.

The motor symptoms of Parkinson's disease (PD) are caused primarily by degeneration of dopaminergic neurons in the substantia nigra. The nonmotor symptoms of the disease are thought to be caused by degeneration of other neurotransmitter systems. No disease-modifying drugs are available for treatment of PD.