Donepezil is a medication for treating the dementia that develops as a result of Alzheimer’s disease. This anti-dementia medication treats symptoms of Alzheimer’s disease by inhibiting the activity of an enzyme called cholinesterase. Donepezil is available under the trade name Aricept®.
Alzheimer’s disease is a degenerative, incurable brain disease that generally affects people over 65 but can in rare cases appear as much as three decades earlier. The progression of this disease is not identical for every individual, but there typically are many similarities. Generally, the first symptom to be noticed is short-term memory loss, followed by mood swings, confusion, irritability, loss of long-term memory and loss of language and communication ability. Alzheimer’s disease is a terminal condition, because control of bodily functions, including breathing, eventually is lost.
Progression of Alzheimer’s disease is variable, but in general, this medication is most effective when prescribed early in the progression of the disease. This is a crucial factor because the medication cannot completely reverse symptoms that already have appeared or prevent new symptoms from occurring, but it can reduce the rate of progression. Donepezil can improve symptoms such as memory loss, cognitive impairment and personality changes, but it cannot provide a cure.
This medication is in a class of drug called anticholinesterases. These medications inhibit an enzyme called cholinesterase, which breaks down a neurotransmitter called acetylcholine. By inhibiting the activity of the enzyme, these drugs make more acetylcholine available for use in the brain. This slows the progression of Alzheimer’s disease symptoms, because acetylcholine is essential for a large number of cognitive and physical functions.
Donepezil has an extensive list of possible side effects. These side effects are highly variable in terms of severity and duration; some are temporary, and others are permanent as long as the medication is taken. Possible side effects include gastrointestinal upsets, weight loss, frequent urination, muscle cramps, joint pain, drowsiness and fatigue, headache, sleep disturbances and changes in mood and behavior. These side effects usually are temporary. Serious side effects include slow heartbeat, chest pain, blood in stools or vomit, urinary incontinence, pain or difficulty when urinating, lower back pain and seizures. Any side effects should be promptly reported to a physician.
Donepezil is often prescribed with one or more other anti-dementia agents such as memantine. Memantine works via an alternate pathway that does not involve the acetylcholine neurotransmitter. This is a useful treatment method, because prescribing multiple medications with different modes of activity improves the efficacy of both medications, helping to reduce symptoms of the disease even further.