About Donepezil

Donepezil is a prescription-only drug used to treat mild to moderate Alzheimer's disease. It is marketed as Aricept in the United States and is not available as a generic drug. It was approved for use in 1996. Donepezil is the most commonly prescribed drug for the treatment of Alzheimer's disease.

Function

• Studies have shown that donezepil slows the progression of Alzheimer's disease in mild to moderate cases. People who have Alzheimer's disease have lower-than-normal levels of a chemical called acetylcholine in their brains. Acetylcholine is believed to be partially responsible for the brain's ability to think and remember information. Donezepil reduces the body's breakdown of acetylcholine, which increases the amount of this chemical that is available for the brain to use.

Dosage

• Donezepil has a relatively long half-life of 70 hours. This means that the drug's effects last for quite some time. As a result, it may be given only once per day. The standard starting dose of donezepil is 5 mg. This may be increased to 10 mg after one month, if side effects are tolerable. Donezepil may be continued for as long as it is needed, unless the patient experiences side effects severe enough to merit discontinuation.

Side Effects

• Most of the side effects caused by donezepil are not severe enough that the discomfort outweighs the benefits of the drug. The most common side effects caused by donezepil are nausea, vomiting, diarrhea, easy bruising, insomnia, muscle camps, reduced appetite and fatigue. Side effects experienced while taking donezepil may become less severe as the body becomes accustomed to the drug.

Safety

• Donezepil is considered a relatively safe drug, but it is not for everyone with Alzheimer's disease. People who have active stomach ulcers or bleeding problems should not take donezepil, due to the risk of their conditions becoming worse. Those who are at risk of developing stomach ulcers should use donezepil with caution. Rarely, donezepil may cause fainting, which can lead to injuries, especially in an elderly person. Because donezepil can cause fatigue, patients should not drive or operate heavy machinery until they know how they will react to the medication.

Considerations

• Alzheimer's disease is a progressive condition that eventually leads to death. Donezepil does not cure Alzheimer's disease nor does it halt its progression. This medication slows the rate at which a person with Alzheimer's disease declines and may temporarily improve memory and the ability to perform everyday tasks. Individuals have different levels of response to this drug, and it is not effective for all cases of Alzheimer's disease. Donezepil has not been shown to be effective in severe Alzheimer's disease or in other forms of dementia.