How does this medication work? What will it do for me?

Donepezil belongs to the class of medications called cholinesterase inhibitors. It works to increase the level of the chemical messenger acetylcholine in the brain, which may help relieve the symptoms of Alzheimer's disease.

This medication is used for the treatment of symptoms for people with mild-to-severe Alzheimer's disease. Donepezil does not cure Alzheimer's disease. It works in the brain to improve thinking, memory, attention, and the ability to do simple tasks.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

What form(s) does this medication come in?

5 mg
Each white, round film coated tablet, debossed with "DP" on one side and "5" on the other side contains 5 mg of donepezil hydrochloride, equivalent to 4.56 mg of donepezil free base. Nonmedicinal ingredients: hypromellose, hydroxypropyl cellulose, lactose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, and titanium dioxide.

10 mg
Each yellow, round, coated tablet, debossed with "DP" on one side and "10" on the other side contains 10 mg of donepezil hydrochloride, equivalent to 9.12 mg of donepezil free base. Nonmedicinal ingredients: hypromellose, hydroxypropyl cellulose, iron oxide yellow, lactose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, and titanium dioxide.


How should I use this medication?

The recommended initial dose of donepezil is 5 mg once daily. If the response is not adequate after 4 to 6 weeks, your doctor may increase the dose to 10 mg daily, which is the recommended maximum daily dose. For senior women with a low body weight, it is recommended that the dose of donepezil not exceed 5 mg daily. Donepezil can be taken with or without food at the same time every day, in the morning or evening.

The tablet should be swallowed whole with water. The rapidly disintegrating tablet should be placed on the tongue and allowed to dissolve before swallowing with water.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important that this medication be taken on a regular schedule as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Do not take donepezil if you:

  • are allergic to donepezil or any ingredients of the medication
  • are allergic to piperidine-type medications (e.g., rifabutin, methylphenidate, bupivacaine, paroxetine)

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • diarrhea
  • loss of appetite
  • muscle cramps
  • nausea
  • trouble sleeping
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • vomiting

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

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

  • fainting
  • mood or mental changes, including abnormal crying, aggression, agitation, delusions, irritability, nervousness, or restlessness
  • signs of muscle damage (e.g., muscle pain, tenderness or weakness, or brown or discoloured urine), especially if you also have a fever or a general feeling of being unwell

Stop taking the medication and seek immediate medical attention if any of the following occur:

  • signs of bleeding in the stomach (e.g., bloody, black, or tarry stools, spitting up of blood, vomiting blood or material that looks like coffee grounds)
  • symptoms of neuroleptic malignant syndrome (e.g., muscle pain, tenderness or weakness, or joint pain accompanied by a fever or very dark urine)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

HEALTH CANADA ADVISORY

January 21, 2015

Health Canada has issued new restrictions concerning the use of Aricept (donepezil). To read the full Health Canada Advisory, visit Health Canada's web site at www.hc-sc.gc.ca.

Asthma and lung conditions: If you have lung conditions such as asthma or chronic obstructive pulmonary disease, discuss with your doctor how this medication may affect your medical condition, and whether any special monitoring is needed. Donepezil could cause symptoms of these conditions to worsen.

Chronic illness: In general, people with chronic medical conditions should be cautious when taking donepezil because of the increased risk of side effects. The benefits of taking the medication must be carefully weighed against the risks.

Epilepsy: There is a possibility that donepezil may increase the risk of seizures for susceptible people. If you have a history of seizure disorder, speak to your doctor about the risks and benefits of taking donepezil.

Heart disease: If you have heart disease such as active coronary artery disease or congestive heart failure, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Donepezil has the potential to slow the heart rate. People with cardiac conduction abnormalities (e.g., heart rhythm problems such as sick sinus syndrome) should not take donepezil.

Liver function: Liver disease or reduced liver function may cause this medication to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Muscle effects: In rare cases, serious muscle damage has been associated with the use of donepezil. Report any unexplained muscle pain, tenderness, weakness or cramps, or any brown or discoloured urine to your doctor immediately, particularly if you are also experiencing malaise (a general feeling of being unwell) or fever.

Neuroleptic malignant syndrome (NMS): Donepezil, can rarely cause a potentially fatal syndrome known as neuroleptic malignant syndrome (NMS). If you notice the symptoms of NMS, get immediate medical attention. Symptoms include high fever, muscle stiffness, confusion or loss of consciousness, sweating, racing or irregular heartbeat, and fainting.

Stomach problems: Donepezil has the potential to cause an increase in the amount of acid that the stomach produces. If you have a history of ulcers or are at increased risk of developing stomach ulcers, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Pregnancy: The safety of donepezil for use during pregnancy has not been established. This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if donepezil passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children.

What other drugs could interact with this medication?

There may be an interaction between donepezil and any of the following:

  • aclidinium
  • amiodarone
  • antihistamines (e.g., cetirizine, doxylamine, diphenhydramine, hydroxyzine, loratadine)
  • antipsychotics (e.g., chlorpromazine, clozapine, haloperidol, olanzapine, quetiapine, risperidone)
  • atropine
  • azelastine
  • barbiturates (e.g., phenobarbital)
  • belladonna
  • benztropine
  • beta-adrenergic blockers (e.g., atenolol, propranolol, sotalol)
  • bethanechol
  • corticosteroids (e.g., budesonide, dexamethasone, hydrocortisone, fluticasone, prednisone)
  • cyclobenzaprine
  • digoxin
  • dipyridamole
  • disopyramide
  • flavoxate
  • glycopyrrolate
  • ipratropium
  • ketotifen
  • octreotide
  • orphenadrine
  • oxybutynin
  • peginterferon Alfa-2b
  • pilocarpine
  • scopolamine
  • tiotropium
  • tolterodine
  • tranylcypromine
  • tricyclic antidepressants (e.g., amitriptyline, clomipramine, desipramine, trimipramine)
  • verapamil

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.