donepezil brands

Molecular formula: C24H29NO3

The commonly accepted cholinergic hypothesis proposes that a portion of the cognitive and behavioral decline associated with Alzheimer's are the result of decreased cholinergic transmission in the central nervous system. Donepezil selectively and reversibly inhibits the acetylcholinesterase enzyme, which normally breaks down acetylcholine. The main pharmacological actions of this drug are believed to occur as the result of this enzyme inhibition, enhancing cholinergic transmission, which relieves the symptoms of Alzheimer's dementia. In addition to the above, other mechanisms of action of donepezil are possible, including the opposition of glutamate-induced excitatory transmission via downregulation of NMDA receptors and the regulation of amyloid proteins, which have demonstrated significant effects on the disease process of Alzheimer's. Other possible targets for donepezil may also include the inhibition various inflammatory signaling pathways, exerting neuroprotective effects. Donepezil hydrochloride, a piperidine derivative, is a centrally active, reversible inhibitor of acetylcholinesterase. The drug is structurally unrelated to other anticholinesterase agents (eg, tacrine, physostigmine). The precise mechanism(s) of action of donepezil in patients with dementia of the Alzheimer's type (Alzheimer's disease) has not been fully elucidated. The drug is an anticholinesterase agent that binds reversibly with and inactivates cholinesterases (eg, acetylcholinesterase), thus inhibiting hydrolysis of acetylcholine. As a result, the concentration of acetylcholine increases at cholinergic synapses. In vitro data and data in animals indicate that the anticholinesterase activity of donepezil is relatively specific for acetylcholinesterase in the brain compared with butyrylcholinesterase inhibition in peripheral tissues. A deficiency of acetylcholine caused by selective loss of cholinergic neurons in the cerebral cortex, nucleus basalis, and hippocampus is recognized as one of the early pathophysiologic features of Alzheimer's disease associated with memory loss and cognitive deficits. Because the resultant cortical deficiency of this neurotransmitter is believed to account for some of the clinical manifestations of mild to moderate dementia, enhancement of cholinergic function with an anticholinesterase agent, such as tacrine or donepezil, is one of the pharmacologic approaches to treatment. Because widespread degeneration of multiple central neuronal systems eventually occurs in patients with Alzheimer's disease, potentially beneficial effects of anticholinesterase agents theoretically would diminish as the disease process advances and fewer cholinergic neurons remain functioning. Current theories on the pathogenesis of the cognitive signs and symptoms of Alzheimer's Disease attribute some of them to a deficiency of cholinergic neurotransmission. Donepezil hydrochloride is postulated to exert its therapeutic effect by enhancing cholinergic function. This is accomplished by increasing the concentration of acetylcholine through reversible inhibition of its hydrolysis by acetylcholinesterase. There is no evidence that donepezil alters the course of the underlying dementing process. For more Mechanism of Action (Complete) data for Donepezil (6 total), please visit the HSDB record page.

Source: PubChem (NCBI) · compound 3152