Alzheimer's Medicines: What Exists, What Each One Does
The standard Alzheimer's medicines do not cure, but they may modestly ease symptoms for a time. What donepezil, rivastigmine, galantamine, and memantine do.
Prepared with AI assistance and checked against the linked sources. The update date records an editorial revision; it does not certify physician review.
- → The standard Alzheimer's medicines do not cure and do not stop the underlying disease — but they may modestly ease symptoms for a time.
- → Cholinesterase inhibitors (donepezil, rivastigmine, galantamine) raise a brain chemical involved in memory and attention.
- → Memantine works differently and is often added in moderate-to-severe stages.
- → Side effects are usually mild — nausea and appetite loss for cholinesterase inhibitors, dizziness and constipation for memantine — but they deserve a conversation, not a shrug.
- → Benefit is measured in daily life — clearer conversation, steadier routine — not in a lab value, and it varies from person to person.
When Joan, 76, was diagnosed with Alzheimer's, her son asked the doctor a direct question: "Is there a pill that fixes this?" The doctor's answer was honest, and it helped more than a false promise would have. "No pill fixes it," she said. "But there are pills that may help her think a little more clearly and hold her routine a little longer. We try one, we watch, and we decide together whether it is earning its place." That is the right frame for this page.
Here is what exists, what each medicine does, and what to watch for.
Cholinesterase inhibitors: donepezil, rivastigmine, galantamine
In Alzheimer's, a brain chemical called acetylcholine — involved in memory and attention — becomes scarce. Cholinesterase inhibitors slow the breakdown of acetylcholine, leaving more of it available. They do not make new brain cells, and they do not remove plaques or tangles. What they may do is modestly improve memory, attention, and daily function for a time, or slow the worsening of symptoms.
- Donepezil. A once-daily tablet, usually started at a low dose and raised gradually. The most widely used of the three.
- Rivastigmine. Available as a capsule or a skin patch. The patch can suit people who struggle with tablets or who have nausea from capsules.
- Galantamine. A capsule, also started low and raised gradually. Less commonly used than donepezil, but similar in effect.
These medicines are used mainly in Alzheimer's disease, and sometimes in Lewy body dementia and Parkinson's disease dementia, where cholinesterase problems also play a role. They are not generally used for frontotemporal dementia, where they may worsen behavior.
Common side effects: nausea, reduced appetite, loose stools, vivid dreams, and muscle cramps. Less commonly, they can slow the pulse, which matters for people with heart rhythm problems or fainting — tell the doctor about any dizziness or fainting. Side effects are often worst when the dose rises and may settle; a slower rise or a switch (for example, to the patch) can help.
Memantine: a different mechanism
Memantine works on a different brain system — it dampens overactivity of glutamate, another brain chemical that, in excess, can damage brain cells. It is used mainly in moderate-to-severe Alzheimer's, often added to a cholinesterase inhibitor rather than replacing it. Some people notice steadier attention and daily function; others notice little change.
Common side effects: dizziness, headache, constipation, and sometimes confusion. It is usually taken as a tablet, once or twice daily depending on the formulation, and the dose is raised gradually. Kidney function affects dosing, so the doctor checks it.
What these medicines do not do
Three honest limits, stated plainly:
- They do not cure. No current standard medicine reverses Alzheimer's or restores lost memory.
- They do not stop the disease. The underlying biology continues. Benefit, when it comes, is a matter of easing symptoms or slowing their worsening for a time.
- They do not help everyone. Some people notice a real difference; some notice none. A trial period with a clear review date is the sensible approach — not an open-ended prescription nobody revisits.
If a medicine is not helping, or side effects outweigh any benefit, stopping is a reasonable decision to discuss with the doctor — doses are usually lowered gradually rather than stopped abruptly, and the doctor can advise on that.
Choosing, starting, and reviewing
- Starting: low dose, raised slowly over weeks. A medicine list review comes first, since some common medicines (for example, certain bladder or allergy medicines) can blunt thinking and work against these drugs.
- Reviewing: after a few weeks to a few months, the doctor asks: is conversation clearer? Is the routine steadier? Are side effects acceptable? Family observations matter as much as test scores here.
- Combining: a cholinesterase inhibitor plus memantine is a common combination in moderate-to-severe stages.
- Not the same as infusions: these standard medicines ease symptoms. Anti-amyloid infusions are a different class — they target amyloid biology itself, suit only some people with early disease, and carry different risks. See the infusions page for that pathway.
For clinicians
Cholinesterase inhibitors produce a modest average symptomatic benefit in mild-to-moderate Alzheimer's (cognition, global function, activities of daily living) with a well-characterized adverse-effect profile dominated by gastrointestinal effects and bradycardia risk; the Cochrane review remains the standard synthesis. Memantine shows a small benefit in moderate-to-severe Alzheimer's, including as add-on therapy to a cholinesterase inhibitor. Effect sizes are small at the group level and heterogeneous individually — counsel in terms of a trial with a defined review point, not a guaranteed response. Avoid cholinesterase inhibitors in frontotemporal dementia, where they may worsen behavioral symptoms. Review anticholinergic burden before attributing poor response to disease progression.
References.
- Birks J. Cholinesterase inhibitors for Alzheimer's disease. Cochrane Database of Systematic Reviews. 2006.
- McShane R, et al. Memantine for dementia. Cochrane Database of Systematic Reviews. 2019.
- Jack CR Jr, et al. Revised criteria for diagnosis and staging of Alzheimer's disease (NIA-AA). Alzheimer's & Dementia. 2024.
Frequently asked questions
Do these medicines cure Alzheimer's?
No. They may modestly ease symptoms or slow worsening for a time, but they do not cure and do not stop the underlying disease.
Which one is best?
There is no clear winner among the cholinesterase inhibitors for most people. Choice often comes down to formulation (tablet vs patch), side effects, other health problems, and cost. Donepezil is the most commonly used.
How long until they work?
Weeks rather than days, since doses rise gradually. The doctor usually reviews benefit after a few weeks to a few months.
What if side effects appear?
Tell the doctor rather than stopping suddenly. Nausea and appetite loss often ease with slower dose rises or a formulation switch; pulse slowing or fainting needs prompt review.
Can the medicine be stopped?
Yes, as a discussed decision — usually tapered rather than stopped abruptly. If benefit is unclear and side effects are real, stopping is reasonable.
Do they help other types of dementia?
Sometimes. They may help Lewy body dementia and Parkinson's disease dementia. They are generally not used for frontotemporal dementia.
Takeaways
- Standard Alzheimer's medicines may modestly ease symptoms for a time — they do not cure or stop the disease.
- Cholinesterase inhibitors (donepezil, rivastigmine, galantamine) and memantine work differently and are often combined in later stages.
- Judge them by daily life, review them at a set date, and stop or switch if they are not earning their place.
This article is for education only and is not medical advice. Medicine decisions belong with the treating clinician, who knows the full history. For sudden confusion, weakness, or rapid change, seek urgent care; call 911 for emergencies.
Book a memory assessment — if medicines, side effects, or next steps need a review, bring the full medicine list to the appointment.
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