Donepezil is used to treat symptomatic mild to moderately severe Alzheimer's disease and vascular dementia (associated with cerebrovascular disease). Alzheimer's disease is associated with low levels of a chemical called acetylcholine in your brain. The exact way that donepezil works is unknown. However, it is believed that donepezil prevents the breakdown of acetylcholine in your brain. Donepezil is used to improve thinking and memory in patients with Alzheimer's disease.
Before taking donepezil, tell your doctor if you have the following conditions:
a. have kidney disease, including difficulty urinating;
b. have liver disease;
c. have a history of stomach ulcers;
d. have heart disease such as a slow or irregular heartbeat;
e. take nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Motrin, Advil, Nuprin, others), indomethacin (Indocin), nabumetone (Relafen), oxaprozin (Daypro), naproxen (Naprosyn, Anaprox, Aleve),
ketorolac (Orudis, Orudis KT, Oruvail), and others, on a regular basis;
f. have seizures or a history of seizures
g. have lung problems such as asthma or chronic obstructive pulmonary disease (COPD); or
h. need to have surgery.
You may require a lower dose or special monitoring during treatment if you have any of the conditions listed above. Donepezil is in the FDA pregnancy category C. This means that it is not known whether donepezil will harm an unborn baby. It is also not known whether donepezil will harm a nursing infant. Do not take donepezil without first talking to your doctor if you are breast-feeding a baby; pregnant or planning to get pregnant.
Use caution when driving, operating machinery, or performing other hazardous activities. Donepezil may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities.
Seek emergency medical attention for symptoms of a donepezil overdose which include: severe nausea, vomiting, watering mouth, sweating, slow heartbeat, slow breathing, prolonged or severe dizziness, fainting, blurred vision, seizures, and collapse.
Stop taking donepezil and seek emergency medical attention if you experience an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives).
Continue to take donepezil and talk to your doctor if you experience the following less serious side effects: drowsiness or dizziness; nausea, vomiting, or decreased appetite; abdominal pain or diarrhea; muscle cramps; insomnia or vivid dreams; or dry mouth.
Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.
Drug interactions: Before taking donepezil, tell your doctor if you are taking any of the following medicines:
ketoconazole (Nizoral), fluconazole (Diflucan), or itraconazole (Sporanox);
quinidine (Cardioquin, Quinidex, Quinaglute, others);
dexamethasone (Decadron), methylprednisolone (Medrol), prednisone
(Deltasone, others), prednisolone (Prelone, Pediapred, others)
rifampin (Rifadin, Rifamate, Rifater) or rifabutin (Mycobutin), or
phenobarbital (Luminal, Solfoton), pentobarbital (Nembutal), secobarbital
(Seconal), or mephobarbital (Mebaral).
You may require a dosage adjustment or special monitoring during treatment if you are taking any of the medicines listed above. Drugs other than those listed here may also interact with donepezil. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines.
Donepezil hydrochloride is a white crystalline powder and is freely soluble in chloroform, soluble in water and in glacial acetic acid, slightly soluble in ethanol and in acetonitrile and practically insoluble in ethyl acetate and in n-hexane. ARICEPT is available for oral administration in film-coated tablets containing 5 or 10 mg of donepezil hydrochloride. Inactive ingredients are lactose monohydrate, corn starch, microcrystalline cellulose, hydroxypropyl cellulose, and magnesium stearate. The film coating contains talc, polyethylene glycol, hypromellose and titanium dioxide. Additionally, the 10 mg tablet contains yellow iron oxide (synthetic) as a coloring agent.
Donepezil has the following structural formula: