Description
Donepezil is another “nonclassic,” centrally acting, reversible, noncompetitive AChEI that was approved in 1997 for treatment of mild-to-moderate AD and dementia. Its selectivity for AChE is 570- to 1,250-fold that for butyrylcholinesterase, and it also exhibits greater affinity for
brain AChE than for AChE in the periphery.
Uses
Acetylcholine is a neurotransmitter involved in neural signaling throughout the body. Donepezil is a reversible acetylcholinesterase inhibitor that readily crosses the blood-brain barrier to reduce the breakdown of acetylcholine. It has a half-life in circulation of about 70 hours. As acetylcholine modulates plasticity, excitability, and arousal in the central nervous system, donepezil is commonly used in the treatment of Alzheimer’s disease to improve cognition, memory, and behavior. In this way, it is intended to prevent or reverse dementia. Studies on these effects have been equivocal, indicating that more research into the therapeutic potential of donepezil is warranted.[Cayman Chemical]
Definition
ChEBI: Donepezil is a centrally acting reversible acetyl cholinesterase inhibitor. Its main therapeutic use is in the treatment of Alzheimer's disease where it is used to increase cortical acetylcholine.
Brand name
Aricept (Eisai Medical Research).
General Description
Donepezil, (±)-2,3-dihydro-5,6-dimethoxy-2-[[1-(phenylmethyl)-4-piperidinyl]methyl]-1H-inden-1-one (Aricept), commonly referred to in the literature asE2020, is a reversible inhibitor of AChE. It is indicated forthe treatment of symptoms of mild-to-moderate Alzheimerdisease. Donepezil is approximately 96% bound to plasmaproteins, with an elimination half-life of 70 hours. It is metabolizedprincipally by the 2D6 and 3A4 isozymes of theP450 system.
Metabolism
When compared to tacrine, donepezil exhibits greater CNS AChE selectivity, longer elimination
half-life (70–104 hours in subjects older than 55 years) and little or no potential for hepatotoxicity. Donepezil is metabolized by CYP2D6 and
CYP3A4 via demethylation, debenzylation, hydroxylation, oxidation to the cis-N-oxide, and glucuronidation. The 6-O-desmethyl metabolite
accounts for 11% of a dose, and it exhibits AChE inhibitory activity comparable to that of the parent compound.
