Ache inhibit

Numerous studies have linked the progressive loss of cholinergic neurons and, presumably, cholinergic transmission within the cortex to the memory loss that is a hallmark symptom of Alzheimer disease. It is postulated that inhibition of acetylcholinesterase (AChE) within the CNS will improve cholinergic transmission, at least at those neurons that are still functioning. Currently, four reversible AChE inhibitors are approved for the treatment of mild to moderate Alzheimer disease. They are donepezil, galantamine, rivastigmine, and tacrin. Except for galantamine, which is competitive, all are uncompetitive inhibitors of AChE and appear to have some selectivity for AChE in the CNS as compared to the periphery. Galantamine may also be acting as an allosteric modulator of the nicotinic receptor in the CNS and, therefore, secondarily may increase cholinergic neurotransmission through a separate mechanism. At best, these compounds provide a modest reduction in the rate of loss of cognitive functioning in Alzheimer patients.