What medications are approved for dementia?

Two main classes have been approved for decades: cholinesterase inhibitors (donepezil, rivastigmine, galantamine) and memantine. These provide modest symptomatic benefits for many people with Alzheimer's disease. In 2023 and 2024, two newer medications — lecanemab (Leqembi) and donanemab (Kisunla) — were approved as the first disease-modifying therapies for early Alzheimer's. They slow progression modestly in carefully selected patients but carry real risks including brain swelling and bleeding.

Do cholinesterase inhibitors actually work?

Their benefit is modest and variable. On average, they produce small improvements in cognition and function — often described as stabilizing for six to twelve months, with the underlying disease continuing to progress underneath. Many patients experience noticeable benefit; many do not. They are worth a trial in most cases of mild-to-moderate Alzheimer's disease, with a clear plan to reassess after three to six months. If there is no apparent benefit and side effects are a problem, stopping is reasonable.

What's the difference between donepezil, rivastigmine, and galantamine?

All three are cholinesterase inhibitors and work by the same mechanism — reducing breakdown of acetylcholine in the brain. They differ in side effect profile, dosing, and formulation. Donepezil is once daily and often best tolerated. Rivastigmine comes as a pill or a transdermal patch (the patch reduces gastrointestinal side effects). Galantamine is twice daily. Most patients start on donepezil because of simplicity; rivastigmine patch is often preferred when gastrointestinal side effects are limiting.

What does memantine do?

Memantine is used in moderate-to-severe Alzheimer's disease, usually added to a cholinesterase inhibitor rather than replacing it. It works by a different mechanism — modulating glutamate signaling. Its benefit is modest. It is often better tolerated than the cholinesterase inhibitors, with fewer gastrointestinal side effects, though it can cause dizziness or confusion in some patients. Namzaric is a combination pill containing memantine and donepezil.

What are lecanemab and donanemab, and should I take them?

They are monoclonal antibodies that target amyloid plaques — the proteins that accumulate in Alzheimer's disease. Unlike older medications, they are disease-modifying, meaning they slow the underlying progression rather than just treating symptoms. Clinical trials showed a modest slowing of decline — roughly 27 to 35 percent over 18 months, depending on outcome measured. They are approved for early Alzheimer's disease (mild cognitive impairment due to AD or mild AD) with confirmed amyloid pathology. They carry risks including brain swelling (ARIA-E) and microhemorrhages (ARIA-H), which can occasionally be severe. Whether to take them is a decision to make with a neurologist who can assess eligibility, risks, and your specific clinical picture.

Are there medications that should be avoided in dementia?

Yes, several categories. Anticholinergic medications — common in over-the-counter sleep aids (diphenhydramine, Tylenol PM), some bladder medications, many older antidepressants — can worsen cognition acutely. Benzodiazepines (lorazepam, diazepam, alprazolam) worsen cognition, increase fall risk, and are generally avoided as first-line for anxiety or sleep in older adults. Many antipsychotics, particularly haloperidol, carry serious risks in people with Lewy body dementia and have black-box warnings for increased mortality in older adults with dementia generally. The American Geriatrics Society Beers Criteria list specific medications to avoid in this population.

Do supplements help with dementia?

The evidence for supplements is limited. Omega-3 fatty acids, vitamin E, vitamin D, B vitamins, ginkgo biloba, and various 'brain health' proprietary blends have all been studied with mostly disappointing results. Vitamin B12 deficiency, if present, should be corrected because it can cause cognitive symptoms that mimic dementia. Vitamin D deficiency correction is reasonable for many older adults. Beyond addressing actual deficiencies, no supplement has strong evidence for treating or preventing dementia. Money and attention are better spent on the modifiable risk factors with stronger evidence — physical activity, hearing aids, blood pressure control.

December 9, 20259 min read

Dementia Medications: What Actually Helps, Explained

Creator: Mai Shimada, MD
Published: Tue Dec 09 2025 00:00:00 GMT+0000 (Coordinated Universal Time)

By Mai Shimada, MD, Emergency medicine-trained physician, Founder of Tokei Health

The medication landscape for dementia has changed meaningfully in the last two years, after decades of limited options. This article is a plain-English summary of what medications actually do — the older symptomatic treatments that have been the mainstay since the 1990s, the newer disease-modifying therapies approved since 2023, and the medications that should typically be avoided in people with dementia.

None of this replaces a clinician's judgment about a specific situation. It is meant to help families and patients know what questions to ask.

The older medications — symptomatic treatment

Before 2023, every approved dementia medication in widespread use was symptomatic — meaning it aimed to ease symptoms without changing the underlying disease course. These remain widely prescribed and have a real, though modest, role.

Cholinesterase inhibitors

Three medications, all working by the same mechanism:

Donepezil (Aricept) — once daily
Rivastigmine (Exelon) — twice-daily capsule or once-daily transdermal patch
Galantamine (Razadyne) — twice daily or extended-release once daily

How they work. Alzheimer's disease reduces the brain's levels of a neurotransmitter called acetylcholine. Cholinesterase inhibitors reduce the breakdown of remaining acetylcholine, partially compensating. This is a substitution rather than a cure — the underlying disease continues.

What to expect. On average, these produce modest improvements in cognition, function, and sometimes behavior. Some patients experience clear benefit and their families notice it. Others experience little to no benefit. A three-to-six-month trial is standard, with reassessment to decide whether to continue. Long-term benefit, if initial response is positive, can last years before the underlying disease overwhelms the drug's effect.

Side effects. Mainly gastrointestinal — nausea, diarrhea, loss of appetite, weight loss. These are usually dose-related and most prominent during dose increases. Starting low and going slow is standard. The rivastigmine patch bypasses the gut and often has fewer GI effects. Other side effects include muscle cramps, bradycardia (slow heart rate), sleep disturbance, and rarely syncope.

Who they are for. Approved primarily for Alzheimer's disease. Also used off-label and sometimes on-label for:

Lewy body dementia — often responds well, sometimes substantially reducing visual hallucinations. See our Lewy body dementia guide.
Parkinson's disease dementia — rivastigmine is specifically FDA-approved for this
Vascular dementia — modest benefit in mixed cases
Mild cognitive impairment — sometimes prescribed, with weaker evidence

Not for. Cholinesterase inhibitors do not help and can worsen frontotemporal dementia. See our FTD guide.

Memantine

Namenda (memantine) is a different class — an NMDA receptor antagonist that modulates glutamate signaling rather than acetylcholine.

Approved for. Moderate-to-severe Alzheimer's disease. Often used in combination with a cholinesterase inhibitor (Namzaric is a combination pill).

What to expect. Modest benefit, similar in size to the cholinesterase inhibitors. Often better tolerated, with fewer gastrointestinal side effects. Common side effects include dizziness, headache, and occasionally confusion.

The combination approach

In moderate-to-severe Alzheimer's disease, donepezil plus memantine is the most common combination. Evidence supports some additive benefit. Starting the cholinesterase inhibitor first and adding memantine when the person progresses into moderate stage is the typical sequence.

The newer medications — amyloid-targeting therapies

Two medications approved in 2023 and 2024 represent the first disease-modifying therapies for Alzheimer's disease — they slow the underlying progression of the disease rather than just treating symptoms.

Lecanemab (Leqembi) and donanemab (Kisunla)

Both are monoclonal antibodies that bind to amyloid plaques in the brain, flagging them for removal by the immune system. They differ in dosing schedule and some clinical trial specifics, but they work by the same mechanism.

Approved for. Early Alzheimer's disease — specifically mild cognitive impairment due to Alzheimer's or mild dementia stage — with confirmed amyloid pathology (by amyloid PET imaging or cerebrospinal fluid biomarkers). Not approved for moderate or severe Alzheimer's, and not useful for non-Alzheimer's dementias.

What they do. In clinical trials, both slowed decline by roughly 25 to 35 percent over 18 months, depending on the specific outcome measured. This is a meaningful effect but a modest one — the disease continues to progress, just more slowly. For an individual, what the numbers translate to in felt experience is often a few additional months of a given functional level, not a halt to decline.

Risks.

ARIA-E (edema) — brain swelling, usually asymptomatic but can cause headache, confusion, or seizures. Requires MRI monitoring during treatment.
ARIA-H (hemorrhage) — small areas of brain bleeding, usually small and asymptomatic but occasionally larger and consequential.
APOE ε4 carriers — particularly homozygotes (two copies) — have higher risk of ARIA.
Infusion reactions — fever, rash, chills during the infusion.
Rare but serious events — severe intracranial hemorrhage has been reported, particularly in patients on anticoagulation.

Who should consider them. A neurologist experienced with these medications is the right person to evaluate candidacy. The decision weighs:

Confirmed Alzheimer's pathology
Stage of disease (early only)
APOE genotype (affects risk of ARIA)
Brain MRI findings (existing microbleeds are a contraindication)
Use of anticoagulants (higher bleeding risk)
Access to infrequent infusions and regular MRI monitoring
Personal values around the trade-off of modest benefit versus real risks

Practical logistics. Both are given as intravenous infusions — lecanemab every two weeks, donanemab every four weeks. Treatment requires regular MRI monitoring for ARIA, typically several times in the first year. Treatment centers that can deliver these with proper monitoring are currently limited in availability.

What they are not

These medications do not:

Reverse existing dementia
Stop disease progression — only slow it
Benefit non-Alzheimer's dementias
Benefit moderate or severe Alzheimer's
Replace the symptomatic medications (cholinesterase inhibitors, memantine)

They represent a meaningful but incremental change in what is available, not a cure.

Medications to avoid in dementia

A few categories of medication are worth knowing because they are commonly prescribed or available over-the-counter, and they actively worsen cognition in people with dementia.

Anticholinergic medications

This is the biggest category, and it is common. Anticholinergic drugs block acetylcholine — the exact neurotransmitter that cholinesterase inhibitors try to preserve. They measurably worsen cognition in older adults, especially those with dementia.

Common offenders:

Diphenhydramine (Benadryl, Tylenol PM, Advil PM, many sleep aids)
Oxybutynin, tolterodine — older bladder medications
Amitriptyline, nortriptyline — older tricyclic antidepressants
Promethazine — an antihistamine and antiemetic
Many over-the-counter cold and flu medications
Cyclobenzaprine — a muscle relaxant

A pharmacist-led medication review is often high-yield for older adults because anticholinergic burden adds up when several small-effect medications stack.

Benzodiazepines

Lorazepam (Ativan), diazepam (Valium), alprazolam (Xanax), clonazepam (Klonopin), temazepam (Restoril).

These worsen cognition, substantially increase fall risk, and are associated with worse outcomes in older adults with dementia. They are sometimes necessary — for severe acute anxiety, alcohol withdrawal, or specific situations — but they should not be first-line for sleep, anxiety, or agitation in dementia. Tapering chronic benzodiazepines should be done carefully with a clinician; abrupt discontinuation is dangerous.

Some antipsychotics

Antipsychotics carry an FDA black-box warning for increased mortality in older adults with dementia. This does not mean they should never be used — sometimes severe refractory psychosis or agitation requires them — but they should be at the lowest effective dose, for the shortest time, after non-medication approaches have been tried.

Specific concerns:

Haloperidol is particularly dangerous in Lewy body dementia — can cause severe neuroleptic sensitivity reactions.
Typical antipsychotics (haloperidol, chlorpromazine) are generally riskier than atypicals.
Quetiapine at low doses is sometimes used in Lewy body dementia because of a somewhat safer profile.
Pimavanserin (Nuplazid) is specifically approved for Parkinson's disease psychosis and sometimes used in Lewy body dementia.

"Z-drugs"

Zolpidem (Ambien), eszopiclone (Lunesta), zaleplon (Sonata) are non-benzodiazepine sleep medications but carry similar concerns — cognitive worsening, fall risk, and complex sleep behaviors. They are not recommended as first-line for insomnia in older adults. Cognitive behavioral therapy for insomnia has better long-term evidence.

Opioids

Not absolutely avoided — pain should be treated — but opioids worsen cognition in many older adults and should be used at the lowest effective dose with careful monitoring.

What about supplements?

The evidence for supplements in dementia is mostly disappointing. Studies of omega-3 fatty acids, vitamin E, B vitamins, ginkgo biloba, and various "brain health" blends have generally failed to show meaningful benefit.

Worth correcting if deficient

Vitamin B12 — deficiency can cause cognitive symptoms that mimic or worsen dementia. Check levels; correct if low.
Vitamin D — deficiency is common in older adults; correction is reasonable.
Folate — check and correct if low.
Thyroid hormone — not a supplement but worth mentioning; hypothyroidism can cause cognitive symptoms.

Limited evidence

Omega-3 fatty acids — modest benefit in some studies, null in others; reasonable but not transformative.
Mediterranean/MIND diets — observational evidence for reduced dementia risk; reasonable as dietary pattern even if specific supplement versions are less compelling.

Not recommended as dementia treatment

Ginkgo biloba — failed large clinical trials.
Various "brain health" branded supplements — marketing claims exceed evidence.
High-dose vitamin E — early enthusiasm did not survive rigorous trials; high doses may carry other risks.

The general rule: money spent on modifiable lifestyle factors (hearing aids, physical activity, blood pressure control) has better evidence for dementia outcomes than money spent on supplements.

Questions worth asking about any prescription

If a family member is prescribed a dementia medication — or any medication — worth asking:

What is the specific goal of this medication? Improved memory? Reduced hallucinations? Slowed progression? Each goal sets a different bar for success.
How will we know if it's working? Measurable markers matter more than general impressions, which are colored by hope and anxiety.
What are the main side effects to watch for?
How long should we try it before reassessing? Three to six months is typical for symptomatic medications.
What is the plan if it doesn't work or causes side effects?
What does this medication interact with? Particularly over-the-counter medications, supplements, and other prescriptions.

A clinician comfortable with dementia care should welcome these questions.

References

Birks JS, Harvey RJ. Donepezil for dementia due to Alzheimer's disease. Cochrane Database of Systematic Reviews. 2018;6:CD001190.
McShane R, Westby MJ, Roberts E, et al. Memantine for dementia. Cochrane Database of Systematic Reviews. 2019;3:CD003154.
van Dyck CH, Swanson CJ, Aisen P, et al. Lecanemab in early Alzheimer's disease. New England Journal of Medicine. 2023;388(1):9–21.
Sims JR, Zimmer JA, Evans CD, et al. Donanemab in early symptomatic Alzheimer disease: the TRAILBLAZER-ALZ 2 randomized clinical trial. JAMA. 2023;330(6):512–527.
American Geriatrics Society Beers Criteria Update Expert Panel. American Geriatrics Society 2023 Updated AGS Beers Criteria for Potentially Inappropriate Medication Use in Older Adults. Journal of the American Geriatrics Society. 2023;71(7):2052–2081.

Disclosure: Dr. Shimada is the founder of Tokei Health. This article is informational and is not a substitute for individual medical advice from your own clinician.

Frequently Asked Questions

What medications are approved for dementia?: Two main classes have been approved for decades: cholinesterase inhibitors (donepezil, rivastigmine, galantamine) and memantine. These provide modest symptomatic benefits for many people with Alzheimer's disease. In 2023 and 2024, two newer medications — lecanemab (Leqembi) and donanemab (Kisunla) — were approved as the first disease-modifying therapies for early Alzheimer's. They slow progression modestly in carefully selected patients but carry real risks including brain swelling and bleeding.
Do cholinesterase inhibitors actually work?: Their benefit is modest and variable. On average, they produce small improvements in cognition and function — often described as stabilizing for six to twelve months, with the underlying disease continuing to progress underneath. Many patients experience noticeable benefit; many do not. They are worth a trial in most cases of mild-to-moderate Alzheimer's disease, with a clear plan to reassess after three to six months. If there is no apparent benefit and side effects are a problem, stopping is reasonable.
What's the difference between donepezil, rivastigmine, and galantamine?: All three are cholinesterase inhibitors and work by the same mechanism — reducing breakdown of acetylcholine in the brain. They differ in side effect profile, dosing, and formulation. Donepezil is once daily and often best tolerated. Rivastigmine comes as a pill or a transdermal patch (the patch reduces gastrointestinal side effects). Galantamine is twice daily. Most patients start on donepezil because of simplicity; rivastigmine patch is often preferred when gastrointestinal side effects are limiting.
What does memantine do?: Memantine is used in moderate-to-severe Alzheimer's disease, usually added to a cholinesterase inhibitor rather than replacing it. It works by a different mechanism — modulating glutamate signaling. Its benefit is modest. It is often better tolerated than the cholinesterase inhibitors, with fewer gastrointestinal side effects, though it can cause dizziness or confusion in some patients. Namzaric is a combination pill containing memantine and donepezil.
What are lecanemab and donanemab, and should I take them?: They are monoclonal antibodies that target amyloid plaques — the proteins that accumulate in Alzheimer's disease. Unlike older medications, they are disease-modifying, meaning they slow the underlying progression rather than just treating symptoms. Clinical trials showed a modest slowing of decline — roughly 27 to 35 percent over 18 months, depending on outcome measured. They are approved for early Alzheimer's disease (mild cognitive impairment due to AD or mild AD) with confirmed amyloid pathology. They carry risks including brain swelling (ARIA-E) and microhemorrhages (ARIA-H), which can occasionally be severe. Whether to take them is a decision to make with a neurologist who can assess eligibility, risks, and your specific clinical picture.
Are there medications that should be avoided in dementia?: Yes, several categories. Anticholinergic medications — common in over-the-counter sleep aids (diphenhydramine, Tylenol PM), some bladder medications, many older antidepressants — can worsen cognition acutely. Benzodiazepines (lorazepam, diazepam, alprazolam) worsen cognition, increase fall risk, and are generally avoided as first-line for anxiety or sleep in older adults. Many antipsychotics, particularly haloperidol, carry serious risks in people with Lewy body dementia and have black-box warnings for increased mortality in older adults with dementia generally. The American Geriatrics Society Beers Criteria list specific medications to avoid in this population.
Do supplements help with dementia?: The evidence for supplements is limited. Omega-3 fatty acids, vitamin E, vitamin D, B vitamins, ginkgo biloba, and various 'brain health' proprietary blends have all been studied with mostly disappointing results. Vitamin B12 deficiency, if present, should be corrected because it can cause cognitive symptoms that mimic dementia. Vitamin D deficiency correction is reasonable for many older adults. Beyond addressing actual deficiencies, no supplement has strong evidence for treating or preventing dementia. Money and attention are better spent on the modifiable risk factors with stronger evidence — physical activity, hearing aids, blood pressure control.

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