Alzheimer Disease: Cholinergic Involvement and Drugs
Although many neurotransmitter systems become disrupted in Alzheimer disease, cholinergic pathways become especially damaged. Functional cholinergic deficits, such as impairment in shortterm memory, become apparent even in the early stages of the disease. Medication strategies to ameliorate the decline in cholinergic function include the administration of precursors (eg, lecithin); directacting cholinergic receptor agonists; and indirectacting cholinomimetics. Indirectacting agents, specifically cholinesterase inhibitors, such as donepezil, galantamine, and rivastigmine, are currently the most commonly used. Ongoing research is investigating other potential targets, such as enzymes responsible for synthesis or degradation of Aβ or τ protein, and other postulated mechanisms responsible for the etiology or progression of the disease.