Donepezil

Donepezil is an indirectly cholinergic agent from the class of cholinesterase inhibitors, used for the symptomatic treatment of Alzheimer's disease.‍‍‍‍‍‍​​​‍​​​​​​ Its effects are based on the reversible inhibition of the enzyme acetylcholinesterase in the central nervous system. Donepezil is usually taken once daily in the evening immediately before bedtime. If sleep disturbances occur, it may also be administered in the morning. Donepezil is metabolized by CYP3A4 and CYP2D6. The most common possible adverse effects include gastrointestinal disturbances and headache. Donepezil (ATC N06DA02) is indirectly cholinergic and thus improves the symptoms of the disease, but has no effect on the progression of dementia. Its effects are based on the reversible and selective inhibition of acetylcholinesterase in the brain. This enzyme is responsible for the breakdown of the neurotransmitter acetylcholine into choline and acetic acid. Inhibition leads to an increase in the residence time and concentration of acetylcholine. Donepezil has a long half-life of approximately 70 hours. Mechanism of action of parasympathomimetics, click to enlarge. Illustration © PharmaWiki