Cognitive enhancers cholinesterase inhibitors

Tacrine has been found to be somewhat effective in patients with mild-to-moderate symptoms of this disease for improvement of cognitive functions. The drug is primarily a reversible cholinesterase inhibitor that increases the concentration of functional ACh in the brain. However, the pharmacology of tacrine is complex the drug also acts as a muscarinic receptor modulator in that it has partial agonistic activity, as well as weak antagonistic activity on muscarinic receptors in the CNS. In addition, tacrine appears to enhance the release of ACh from cholinergic nerves, and it may alter the concentrations of other neurotransmitters such as dopamine and NE. 

In this chapter, we use the term cognitive enhancers to refer to two classes of pharmacological agents used in the treatment of Alzheimer s disease the cholinesterase inhibitors and the A-methyl-D-aspartate (NMDA) receptor antagonists. 

Stahl, S.M. (1998) Enhancing cholinergic neurotransmission with the new cholinesterase inhibitors implications for Alzheimer s disease and cognitive disorders. Hospital Practice 33(11), 131-6. 

Friedman J. Cholinergic targets for cognitive enhancement in schizophrenia focus on cholinesterase inhibitors and muscarinic agonists. Psychopharmacology 2004 174 45-53. 

Q6 Cholinesterase inhibitors block the action of the enzyme acetylcholinesterase (which normally hydrolyses acetylcholine) and so terminate its activity. These drugs increase the life of released acetylcholine at the synapse, leading to an enhancement of acetylcholine activity. Drug treatment for Alzheimer s disease is supervised in specialist clinics where the patient s cognitive function can be assessed at approximately three-monthly intervals. About half the patients treated show a decreased rate of cognitive decline while receiving this type of drug. 

Cholinesterase inhibitor (selective acetylcholinesterase inhibitor) cognitive enhancer... 

---