Alzheimer's Disease Medications

Two drug classes treat Alzheimer's disease, each targeting a different neurotransmitter system. Cholinesterase inhibitors — donepezil, rivastigmine, galantamine — block the enzyme that breaks down acetylcholine, boosting levels of this memory-related neurotransmitter in the brain. They are first-line for mild-to-moderate Alzheimer's; donepezil is also FDA-approved for severe disease. Because they increase acetylcholine systemically, expect cholinergic side effects: nausea, diarrhea, bradycardia, and weight loss. Always check the heart rate before administration — bradycardia is a real risk, especially if the client is on beta-blockers. Donepezil is given at bedtime to minimize GI effects. Memantine works differently: it blocks excess glutamate at NMDA receptors, preventing excitotoxic neuronal damage. It is approved for moderate-to-severe Alzheimer's and can be combined with a cholinesterase inhibitor. Memantine does not cause cholinergic side effects; watch instead for dizziness, headache, and constipation. Neither class reverses damage already done — the goal is to maintain current function as long as possible.