Donepezil is used to treat dementia (memory loss and mental changes) associated with mild, moderate, or severe Alzheimer's disease. Donepezil will not cure Alzheimer's disease, and it will not stop the disease from getting worse. However, it can improve thinking ability in some patients.

This medicine is available only with your doctor's prescription.

Take this medicine exactly as directed by your doctor in order to improve your condition as much as possible. Do not take more of it or less of it, and do not take it more or less often than your doctor ordered.

Donepezil should be taken at bedtime unless otherwise directed by your doctor. It may be taken with or without food, on a full or empty stomach.

Swallow the tablet whole. Do not crush, break, or chew it.

For patients using the oral disintegrating tablet form of this medicine:

Make sure your hands are dry.
Do not push the tablet through the foil backing of the package. Instead, gently peel back the foil backing and remove the tablet.
Immediately place the tablet on top of the tongue.
Do not swallow the tablet whole. The tablet will dissolve in seconds, and you may swallow it with your saliva. You should drink a glass of water after the tablet has dissolved.
For patients taking the oral solution form of this medicine:

Shake the bottle well before measuring the dose.
Use a specially marked measuring spoon, a plastic syringe, or a small marked measuring cup to measure each dose accurately. The average household teaspoon may not hold the right amount of liquid.
If your dose is 5 mg, you should take 5 mL of this medicine.
If your dose is 10 mg, you should take 10 mL of this medicine.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

More common

Diarrhea

loss of appetite

muscle cramps

nausea

trouble in sleeping

unusual tiredness or weakness

vomiting

Less common

Abnormal dreams

constipation

dizziness

drowsiness

fainting

frequent urination

headache

joint pain, stiffness, or swelling

mental depression

pain

unusual bleeding or bruising

weight loss

Rare

Black, tarry stools

bloating

bloody or cloudy urine

blurred vision

burning, prickling, or tingling sensations

cataract

chills

clumsiness or unsteadiness

confusion

cough

decreased urination

difficult or painful urination

dryness of mouth

eye irritation

fever

flushing of skin

frequent urge to urinate

high or low blood pressure

hives

hot flashes

increase in sexual desire or performance

increased heart rate and breathing

increased sweating

increased urge to urinate during the night

irregular heartbeat

itching

loss of bladder control

loss of bowel control

mood or mental changes, including abnormal crying, aggression, agitation, delusions, irritability, nervousness, or restlessness

nasal congestion

pain in chest, upper stomach, or throat

problems with speech

runny nose

severe thirst

shortness of breath

sneezing

sore throat

sunken eyes

tightness in chest

tremor

troubled breathing

wheezing

wrinkled skin

Incidence not known

Back, leg, or stomach pains

bleeding gums

chest pain or discomfort

coma

convulsions

dark urine

difficulty breathing

fast or irregular heartbeat

fatigue

general body swelling

general tiredness and weakness

high fever

increased thirst

indigestion

light-colored stools

muscle pain or cramps

nausea and vomiting

nosebleeds

pains in stomach, side, or abdomen, possibly radiating to the back

pale skin

rash

seeing, hearing, or feeling things that are not there

seizures

severe muscle stiffness

severe nausea

slow or irregular heartbeat

stomach pain

sweating

swelling of face, ankles, or hands

tiredness

unusually pale skin

upper right abdominal or stomach pain

yellow eyes and skin

Symptoms of overdose

Convulsions (seizures)

increased sweating

increased watering of mouth

increasing muscle weakness

low blood pressure

severe nausea

severe vomiting

slow heartbeat

troubled breathing

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

It is important that your doctor check your progress at regular visits. This is necessary to allow dose adjustments and to reduce any unwanted effects.

Before you have any kind of surgery, dental treatment, or emergency treatment, tell the medical doctor or dentist in charge that you are using this medicine. Taking donepezil together with certain medicines that are used during surgery or dental or emergency treatments may increase the effects of those medicines and cause unwanted effects.

This medicine may cause some people to become dizzy or drowsy, to have blurred vision, or to have problems with clumsiness or unsteadiness. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are not alert, well-coordinated, and able to see clearly.

Some people who have used this medicine developed problems such as nausea, severe vomiting, loss of appetite, diarrhea, and weight loss. Talk with your doctor before using this medicine if you have any concerns.

Tell you doctor right away if you have bloody or black tarry stools, constipation, severe stomach pain, or vomiting of blood or material that looks like coffee grounds. These may be symptoms of stomach or bowel bleeding.

If you think that you or someone else may have taken an overdose of this medicine, get emergency help at once. Taking an overdose of this medicine may cause convulsions (seizures) or serious effects on your heart and your breathing. Signs of overdose include increased watering of mouth, increased sweating, low blood pressure, muscle weakness, severe nausea, severe vomiting, slow heartbeat, and troubled breathing.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.