Donepezil (Oral)

Donepezil is a medication used in the treatment of dementia associated with Alzheimer's disease. It is not a cure.

Donepezil is also known by US brand name Aricept, and although not a cure or preventative for dementia, it is reported to help some dementia patients with their ability to think.

Overview

Donepezil is used in the treatment of dementia (mental changes and memory loss) associated with mild, moderate and severe Alzheimer's disease. This drug will not cure Alzheimer's disease, and it will not stop a patient suffering from the disease from deteriorating. However, it can improve some patients' ability to think. This drug improves the function of nerve cells in the brain and works by preventing the breakdown of a chemical known as acetylcholine. This medication is only available via prescription from your doctor and is available in the dosage form of a tablet and disintegrating tablet.

Condition(s) treated?

  • Mild to Moderate Alzheimer's Type Dementia

Type of medicine?

  • Tablet

Side Effects

Along with its intended effects, the consumption of Donepezil can cause unwanted side effects. Not all of these may be present at one time; however, if they are present, you may need medical assistance.

Let your doctor know if you suffer from any of the following side effects whilst taking donepezil.

More common side effects

  • Loss of appetite

Less common side effects

Rare side effects

  • Tarry, black, stools

Incidence not known

  • Leg, back or stomach pains

Symptoms of overdose

  • Convulsions (seizures)

Not all side effects are listed. Some may also occur which are not listed above, if you notice anything unusual, then contact your healthcare professional or doctor.

Remember you can report all side effects to the FDA on 1-800-FDA-1088.

Dosage

The final dose of any medication will depend on a variety of different factors. This can include your age, weight, height and the condition that is being treated. Your doctor will also take into account any current and past medications you are on and any other medical conditions that you suffer from, including any medical conditions that run in your family's history. Do not alter, change or stop taking medication without consulting your doctor first. The following doses are to be taken as a reference point as each dose is tailored to each patient.

Typical Adult Dose for Alzheimer's Disease

An initial dose of 5 mg should be given orally once daily, in the evening prior to retiring to bed.

For mild to moderate Alzheimer's disease:

A maintenance dose of 10 mg should be given orally once daily after the patient has been given the initial dose of 5 mg once a day for around four to six weeks.

For moderate to severe Alzheimer's disease:

A maintenance dose of 23 mg should be given orally once daily after the patient has been on a regular dose of 10 mg once daily for at least a three-month period.

A higher dose of 10 mg could provide a statistically significantly greater clinical benefit than a 5 mg dose, but in other cases, it may not. The final dose should be based on preference and individual response to the medication.

Interactions

Drug interactions can cause unwanted side effects and alter the effectiveness of either drug. To help limit the risk of drug interactions occurring, you should make a list of all the current and past medications you are taking and give it to your doctor or a healthcare professional. This list should include all herbal remedies, vitamins and prescription and nonprescription drugs. You should also let your doctor know of any other medical conditions you suffer from or any other conditions that run in the family.

The use of this medication with any of the following medications is not recommended. Your doctor may avoid treating you with this medication altogether or change some of the medications you are taking.

  • Amifampridine

Using this medication with any of the following medications is not usually recommended, but in some cases, it may be necessary. If both medications are given together, your doctor may alter the dose of the medication or how often you one or the other.

  • Acetophenazine

Vinflunine

  • Vilanterol

The use of this medication alongside any of the following medications may cause an increased risk of some side effects, but sometimes it's the best treatment for you. If both medications are prescribed together, your doctor may alter the dose or how often you use one or both of the medications.

  • Ramelteon

The presence of other medical conditions can affect the use of this medication. Ensure you inform your doctor if you have any other medical conditions, especially:

  • Lung disease, history of

Other Interactions

Certain medications should not be used around the time of eating food since it increases the chance of interactions. Using alcohol or tobacco with some specific medications can produce interactions.

The use of this medication with any of the following is usually not recommended, but in some cases, it may be unavoidable. If used together, your doctor may alter the dose or frequency of the medication.

  • Grapefruit juice

Warnings

Allergies

Let your doctor or a healthcare professional know if you have suffered from an allergic reaction to this medication in the past or any other reactions or other medicines. You should also let them know of any other allergies you suffer from, including dyes, preservatives, animals, and foods.

Use in pediatric population

Studies have not been conducted on the relationship of age to the effects of this drug on the younger population. Therefore, efficacy and safety have not yet been established.

Use in geriatric population

Studies performed to date have not indicated a geriatric-specific problem that could limit the effectiveness of this drug in the older population.

Use in pregnancy and breastfeeding

This drug is under FDA pregnancy category C. There are no well-controlled or adequate studies in pregnant women. Therefore, the use of this drug during pregnancy should only be approved if the national benefits outweigh the potential risk to the fetus.

With regards to breastfeeding, it's not known whether donepezil is passed into human milk. You should exercise caution when using this drug if you are a woman who is breastfeeding. Always let your doctor know if you are pregnant or breastfeeding.

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

Before you have any kind of dental treatment, surgery or emergency treatment, let your doctor or dentist know that you are taking this medication. Taking this drug alongside other medications that are used during surgery or dental treatments can increase the effects of those medications and increase the risk of unwanted side effects.

This medication may cause some people to feel drowsy or dizzy or to experience blurred vision, or to have problems with unsteadiness or clumsiness. Ensure you know how you react to this medication before you use machinery, drive or do anything else that could require you to be alert.

Some people who have taken this medication have developed problems such as severe vomiting, nausea, loss of appetite, weight loss and diarrhea. Speak with a healthcare professional or doctor before using this medication if you have any questions or queries.

Let your doctor or healthcare professional know immediately if you have any black or bloody tarry stools, severe stomach pain, constipation or vomiting of a material that looks similar to ground coffee. These may be symptoms of bowel or stomach bleeding.

If you believe that you or someone else may have taken an overdose of this medication, seek emergency help. An overdose of this medication can cause convulsions or other serious effects on your breathing or heart.

Don't take other medications unless they have been discussed with a healthcare professional or doctor.

If you do not take this drug for a week or more in a row, you need to speak with your doctor about starting the dose again. You may need to begin with a lower dose to decrease your risk of side effects.

To get the full benefit from this medication, you need to use it regularly at a similar time each day. To help you remember, use an alarm. You should not stop taking this medication unless your doctor has instructed you to. It can take several weeks before you experience the full benefit of this medication.

This use of this drug can cause QT prolongation which is a condition that affects the heart rhythm. This can rarely cause serious problems such as fast/irregular heartbeat and other symptoms (such as severe fainting or dizziness which require urgent medical attention.

The risk of QT prolongation can be increased if you have certain medical issues or are taking other drugs which increase your risk of QT prolongation. Before using this drug, inform your doctor or healthcare professional of all the drugs you are taking and if you suffer from certain heart problems (slow heartbeat, heart failure) or a family history of certain heart problems.

Low levels of magnesium or potassium in the blood can also put you at risk of QT prolongation. If you use certain drugs such as water pills or diuretics, you can increase this risk. If you suffer from vomiting, diarrhea or nausea, this can also increase your risk. Speak with your doctor or healthcare professional for advice.

Proper use

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

Follow this advice for proper use:

  • Make sure your hands are dry.

If you miss a dose of this medication, skip the dose you missed and revert back to the original dosing schedule. Under no circumstances should you double a dose to make up for a missed dose.

Storage

Store at 68° to 77°F (20° to 25°C) and keep medication in a tight container. Keep medication away from direct light, heat, and moisture. Make sure it's kept out of the reach of children. Do not keep medication that is no longer needed or has gone out of date. You should contact your local pharmacist for advice on the best way to dispose of unused medication.

Summary

When used correctly, donepezil is successful in helping to aid those patients' ability to think who suffer from dementia associated with Alzheimer's disease. Due to a large number of interactions possible with this drug, it is vital that you let your doctor know of all the current medication you are taking. This drug should not be used during breastfeeding or pregnancy. You should let your doctor know if you are pregnant or currently breastfeeding. This medication may be taken with or without food. You should let your doctor know if your condition becomes worse as your dose may need to be altered.