Donepezil

Better Known as: Aricept

• Marketed By: Eisai & Pfizer
  
• Major Indication: Alzheimer's Disease
  
• Drug Class: Acetylcholinesterase Inhibitor
• Date of FDA Approval (Patent Expiration): 1996 (2008)
  
• 2006 Sales: $1.4 Billion^[1]
• Importance: One of the most effective treatments for the symptoms of Alzheimer's Disease, although no definitive proof exists as to whether it alters the progression of the disease.
• See: Pharmaceutical Drugs for more information about other drugs and disorders

Mechanism of Action

Donepezil is a potent Acetylcholinesterase (AChE) inhibitor to the active site of . By inhibiting AChE, the important neurotransmitter, acetylcholine, is degraded at a slower rate, helping reverse the marked decrease in neuronal function evident in Alzheimer's Disease patients. Donepezil binds along the active-site gorge, extending from the anionic subsite to the peripheral anionic site . Interestingly, it does not directly interact with the catalytic triad of acetylcholinesterase nor the oxyanion hole. Further, donepezil does not form any direct hydrogen bonds with AChE nor electrostatic interactions, but rather only interacts via aromatic stacking and solvent mediated interactions. It with Glu 199, His 440, Phe 330, Trp 84, Tyr 334, Tyr 121, Phe 331, Phe 288, Ser 286, Phe 290, Arg 289, Trp 279, & Leu 282 to tightly bind to AChE^[2]. More details can be seen at Aricept_Complexed_with_Acetylcholinesterase.

Pharmacokinetics

References

1. ↑ Irena Melnikova, Therapies for Alzheimer's disease, Nature Reviews Drug Discovery 6, 341-342 (May 2007)
2. ↑ Kryger G, Silman I, Sussman JL. Structure of acetylcholinesterase complexed with E2020 (Aricept): implications for the design of new anti-Alzheimer drugs. Structure. 1999 Mar 15;7(3):297-307. PMID:10368299