Donepezil

Donepezil is a prescription medication used to treat Alzheimer's disease. Donepezil belongs to a group of drugs called cholinesterase inhibitors. This medication works by stopping a specific enzyme from breaking down acetylcholine in the brain. Acetylcholine is important in many brain functions, including memory, attention, reason, and language.

Donepezil is a prescription medicine to treat mild, moderate, and severe Alzheimer's disease. Donepezil can help with mental function and with doing daily tasks. 

Donepezil may be found in some form under the following brand names:

• Aricept

• Aricept ODT

Donepezil may cause serious side effects. See "Drug Precautions" section.

The most common side effects of donepezil are:

• nausea
• diarrhea
• not sleeping well
• vomiting
• muscle cramps
• feeling tired
• not wanting to eat

These side effects may get better after the patient takes donepezil for a while. This is not a complete list of side effects with donepezil. For more information, ask the doctor or pharmacist.

Tell your doctor about all of the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you are taking:

• aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Advil, Motrin) or naproxen (Aleve). If you take NSAIDs together with donepezil it may make it more likely you will develop stomach ulcers.
• drugs such as phenytoin, carbamazepine, dexamethasone, rifampin, and phenobarbital could decrease the effectiveness of donepezil.
• ipratropium bromide (Atrovent), oxitropium bromide (Oxivent), tiotropium (Spiriva), and Glycopyrrolate (Robinul) may be less effective if taken with donepezil
• donepezil may increase the effectiveness of bethanecol

Because donepezil may cause side effects when taken with certain medicines used for anesthesia, tell your doctor or dentist that you are taking donepezil if you:

• will have surgery or medical procedures
• will have dental surgery or procedures

Donepezil may cause the following serious side effects:

• slow heartbeat and fainting. This happens more often in people with heart problems. Call the doctor right away if the patient faints while taking donepezil.
• more stomach acid. This raises the chance of ulcers and bleeding. 
• worsening of lung problems in people with asthma or other lung disease.
• seizures.
• difficulty passing urine.

Call the doctor right away if the patient has:

• fainting.
• heartburn or stomach pain that is new or won't go away.
• nausea or vomiting, blood in the vomit, dark vomit that looks like coffee grounds.
• bowel movements or stools that look like black tar.
• new or worse asthma or breathing problems.
• seizures.
• difficulty passing urine.

Do not take donepezil if you are allergic to any of the ingredients in donepezil or to medicines that contain piperidines. 

Donepezil can cause dizziness, drowsiness, and blurred vision. Do not drive or operate heavy machinery until you know how donepezil affects you.

Medicines can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of donepezil there are no specific foods that you must exclude from your diet when receiving donepezil.

Tell the doctor about all of your medical conditions including:

• irregular, slow or fast heartbeat or other heart problems
• asthma or breathing problems
• seizures
• difficulty passing urine
• liver or kidney problems
• trouble swallowing tablets
• if you are pregnant or breastfeeding
• if you have or have had stomach ulcers

Tell your doctor about all of the medicines you are currently taking or plan to take including prescription and non-prescription medicines, vitamins, and herbal products. Because donepezil may cause side effects when taken with certain medicines used for anesthesia, tell your doctor or dentist that you are taking donepezil if you:

• will have surgery or medical procedures
• will have dental surgery or procedures

It is not known if donepezil can be used in pregnancy or if it will harm an unborn baby. Donepezil should be used during pregnancy only if the potential benefit justifies the potential risk to the unborn child.

It is not known whether donepezil is excreted into human breast milk or if it will harm a nursing child.

Donepezil comes as a tablet and an orally disintegrating tablet (donepezil ODT) to be taken by mouth with or without food. It is usually taken once a day at bedtime. Donepezil orally disintegrating tablets melt on the tongue. After the ODT melts, drink some water.

If you are taking the 23 mg tablet, Do not split, crush or chew the tablet, because this may increase its rate of absorption.

• If you miss a dose of donepezil, just wait. Take the next dose at the usual time. Do not take 2 doses at the same time.
• If donepezil is missed for 7 days or more, talk with the doctor before starting again.

Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Do not take more or less of it or take it more often than prescribed by your doctor.

• In mild to moderate Alzheimer's Disease the dosages of donepezil shown to be effective are 5 mg and 10 mg taken by mouth once a day.
• For moderate to severe Alzheimer’s Disease donepezil has been shown to be effective at doses of 10 mg and 23 mg (this strength is only available as brand name Aricept) taken by mouth once daily. 

If you take too much donepezil, call your doctor or local Poison Control Center right away.