Alzheimer’s Disease Medications

FACT SHEET

Alzheimer’s and related Dementias 

Education and Referral Center

National Institute

on Aging

Alzheimer’s Disease 

Medications — Get the Facts

 Treatment for Alzheimer’s

 Alzheimer’s Medications

 Dosage and Side Effects

 For More Information

Several prescription drugs are 

currently approved by the U.S. 

Food and Drug Administration 

(FDA) to treat people who have been 

diagnosed with Alzheimer’s disease. 

Treating the symptoms of Alzheimer’s 

can provide people with comfort, dignity, 

and independence for a longer period of 

time and can encourage and assist their 

caregivers as well. 

Most medicines work best for people in 

the early or middle stages of Alzheimer’s. 

It is important to understand that none of 

these medications stops the disease itself.

Treatment for Mild to 

Moderate Alzheimer’s

Medications called cholinesterase inhibitors are prescribed for mild to moderate 

Alzheimer’s disease. These drugs may 

help reduce some symptoms and help 

control some behavioral symptoms. 

The medications are Razadyne® (galantamine), Exelon® (rivastigmine), and 

Aricept® (donepezil).

Scientists do not yet fully understand 

how cholinesterase inhibitors work to 

treat Alzheimer’s disease, but research 

indicates that they prevent the breakdown of acetylcholine, a brain chemical 

believed to be important for memory and 

thinking. As Alzheimer’s progresses, the 

brain produces less and less acetylcholine; 

therefore, cholinesterase inhibitors may 

eventually lose their effect. 

No published study directly compares 

these drugs. Because they work in a 

similar way, switching from one of these 

drugs to another probably will not produce significantly different results. 

However, an Alzheimer’s patient may 

respond better to one drug than another. 

Treatment for Moderate 

to Severe Alzheimer’s

A medication known as Namenda®

(memantine), an N-methyl D-aspartate 

(NMDA) antagonist, is prescribed to treat 

moderate to severe Alzheimer’s disease. 

This drug’s main effect is to decrease 

symptoms, which could allow some people 

to maintain certain daily functions a 

little longer than they would without the 

medication. For example, Namenda® may 

help a person in the later stages of the 

disease maintain his or her ability to use 

the bathroom independently for several 

more months, a benefit for both the 

person with Alzheimer’s and caregivers. 

The FDA has also approved Aricept®, 

the Exelon® patch, and Namzaric®, a 

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Medications to Treat Alzheimer’s Disease

This brief summary does not include all information important for patient use and should not be used as a substitute for professional medical advice. Consult the prescribing doctor

and read the package insert before using these or any other medications or supplements.

DRUG NAME DRUG TYPE 

AND USE HOW IT WORKS COMMON SIDE EFFECTS

MANUFACTURER’S 

RECOMMENDED DOSAGE

FOR MORE 

INFORMATION

Aricept®

(donepezil)

Cholinesterase 

inhibitor prescribed

to treat symptoms of

mild, moderate, and 

severe Alzheimer’s

Prevents the breakdown 

of acetylcholine in the 

brain

Nausea, vomiting, 

diarrhea, muscle 

cramps, fatigue, 

weight loss

• Tablet*: Initial dose of 5 mg once a day; may increase dose to 10 mg/day 

after 4-6 weeks if well tolerated, then to 23 mg/day after at least 3 months

• Orally disintegrating tablet*: Same dosage as above (not available in 23 mg)

For current information about this 

drug’s safety and use, visit 

www.aricept.com.

Exelon®

(rivastigmine)

Cholinesterase 

inhibitor prescribed 

to treat symptoms 

of mild to moderate 

Alzheimer’s (patch 

is also for severe 

Alzheimer’s)

Prevents the breakdown 

of acetylcholine and 

butyrylcholine (a brain 

chemical similar to 

acetylcholine) in the brain

Nausea, vomiting, 

diarrhea, weight 

loss, indigestion, 

muscle weakness

• Capsule*: Initial dose of 3 mg/day (1.5 mg twice a day); may increase 

dose to 6 mg/day (3 mg twice a day), 9 mg/day (4.5 mg twice a day), 

and 12 mg/day (6 mg twice a day) at minimum 2-week intervals if well 

tolerated

• Patch*: Initial dose of 4.6 mg once a day; may increase dose to 9.5 mg 

once a day and 13.3 mg once a day at minimum 4-week intervals if well 

tolerated

For current information about this 

drug’s safety and use, visit 

www.fda.gov/Drugs. Click on 

“Search Drugs@FDA,” search for 

Exelon, and click on drug-name links 

to see label information.

Namenda®

(memantine)

N-methyl 

D-aspartate 

(NMDA) antagonist 

prescribed to treat 

symptoms of 

moderate to severe 

Alzheimer’s

Blocks the toxic effects 

associated with excess 

glutamate and regulates 

glutamate activation

Dizziness, headache,

diarrhea, constipation, 

confusion

• Tablet*: Initial dose of 5 mg once a day; may increase dose to 10 mg/day 

(5 mg twice a day), 15 mg/day (5 mg and 10 mg as separate doses), and 

20 mg/day (10 mg twice a day) at minimum 1-week intervals if well tolerated

• Oral solution*: Same dosage as above

• Extended-release capsule*: Initial dose of 7 mg once a day; may increase

dose to 14 mg/day, 21 mg/day, and 28 mg/day at minimum 1-week 

intervals if well tolerated 

For current information about this 

drug’s safety and use, visit 

www.namenda.com and

www.namendaxr.com. Click on 

“Full Prescribing Information” to see 

the drug label. 

Namzaric®

(memantine 

and donepezil)

NMDA antagonist 

and cholinesterase 

inhibitor prescribed 

to treat symptoms 

of moderate to 

severe Alzheimer’s

Blocks the toxic effects 

associated with excess 

glutamate and prevents 

the breakdown of 

acetylcholine in the brain

Headache, nausea, 

vomiting, diarrhea, 

dizziness, anorexia

• Extended-release capsule*: Initial dose of 28 mg memantine/10 mg 

donepezil once a day if stabilized on memantine and donepezil

• If stabilized on donepezil only, initial dose of 7 mg memantine/10 mg 

donepezil once a day; may increase dose to 28 mg memantine/10 mg 

donepezil in 7 mg increments at minimum 1-week intervals if well tolerated

• Only 14 mg memantine/10 mg donepezil and 28 mg memantine/10 mg 

donepezil available as generic

For current information about this 

drug’s safety and use, visit 

www.namzaric.com. Click on 

“Full Prescribing Information” to see 

the drug label.

Razadyne®

(galantamine)

Cholinesterase 

inhibitor prescribed 

to treat symptoms 

of mild to moderate 

Alzheimer’s

Prevents the breakdown 

of acetylcholine and 

stimulates nicotinic 

receptors to release more 

acetylcholine in the brain

Nausea, vomiting, 

diarrhea, decreased 

appetite, dizziness, 

headache

• Tablet*: Initial dose of 8 mg/day (4 mg twice a day); may increase dose 

to 16 mg/day (8 mg twice a day) and 24 mg/day (12 mg twice a day) at 

minimum 4-week intervals if well tolerated

• Extended-release capsule*: Same dosage as above but taken once a day

For current information about this 

drug’s safety and use, visit 

www.janssenmd.com/razadyne. 

Click on “Full Prescribing Information” 

to see the drug label. 

*Available as a generic drug.
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combination of Namenda® and Aricept®, 

for the treatment of moderate to severe 

Alzheimer’s disease.

Namenda® is believed to work by regulating glutamate, an important brain 

chemical. When produced in excessive 

amounts, glutamate may lead to brain 

cell death. Because NMDA antagonists 

work differently from cholinesterase 

inhibitors, the two types of drugs can be 

prescribed in combination.

Dosage and Side Effects

Doctors usually start patients at low drug 

doses and gradually increase the dosage 

based on how well a patient tolerates the 

drug. There is some evidence that certain 

people may benefit from higher doses of 

the cholinesterase inhibitors. However, 

the higher the dose, the more likely side 

effects are to occur. The recommended 

dosages of drugs prescribed to treat the 

symptoms of Alzheimer’s and the drugs’ 

possible side effects are summarized in 

the table (see inside). 

Patients should be monitored when a 

drug is started. Report any unusual 

symptoms to the prescribing doctor 

right away. It is important to follow 

the doctor’s instructions when taking 

any medication, including vitamins 

and herbal supplements. Also, let the 

doctor know before adding or changing 

any medications. For more information 

about Alzheimer’s medications, including 

treatment for behavioral symptoms, visit 

www.nia.nih.gov/health/how-alzheimersdisease-treated.

Testing New Alzheimer’s Drugs

Clinical trials are the best way to find out

if promising new treatments are safe and

effective in humans. Volunteers are needed 

for many Alzheimer’s trials conducted 

around the United States. To learn more, 

talk with your doctor or visit the ADEAR 

Center’s listing of clinical trials at 

www.nia.nih.gov/alzheimers/clinical-trials. 

For More Information

Alzheimer’s and related Dementias 

Education and Referral (ADEAR) 

Center

1-800-438-4380 (toll-free)

adear@nia.nih.gov

www.alzheimers.gov

The National Institute on Aging’s 

ADEAR Center offers information and 

publications for families, caregivers, and 

professionals on diagnosis, treatment, 

patient care, caregiver needs, longterm care, education, training, and 

research related to Alzheimer’s disease 

and related dementias. Staff members 

answer telephone, email, and written 

requests and make referrals to local and 

national resources. Visit the ADEAR 

website to learn more about Alzheimer’s 

and related dementias, find clinical 

trials, and sign up for email alerts. 

Alzheimer’s Association

1-800-272-3900 (toll-free)

1-866-403-3073 (TTY/toll-free)

info@alz.org

www.alz.org

Alzheimer’s Foundation of America

1-866-232-8484 (toll-free)

info@alzfdn.org

www.alzfdn.org

NIH Publication No. 18-AG-3431 April 2018

National Institute on Aging

National Institutes of Health

NIH...Turning Discovery Into Health®

U.S. Department of Health and Human Services