Aricept (Donepezil)
Aricept is the original brand name for donepezil, an acetylcholinesterase inhibitor developed by Eisai and historically co-marketed with Pfizer. Used for mild, moderate and severe dementia of the Alzheimer's type. Tablets and orally disintegrating tablets in 5mg, 10mg and 23mg.
- Active ingredients
- Donepezil
- Manufacturer
- Eisai
- Dosage forms
- tablet , orally disintegrating tablet
- Category
- Neurological Medications
What is it?
Aricept is the original brand name for donepezil, an oral acetylcholinesterase inhibitor discovered by Eisai in Japan and approved by the FDA in 1996 for dementia of the Alzheimer's type. In the United States it was co-marketed by Eisai and Pfizer for many years, and it remains the most widely prescribed cholinesterase inhibitor worldwide. Aricept is approved for mild, moderate and severe Alzheimer's dementia, the broadest severity range in its class. It does not halt the underlying disease, but it can temporarily support memory, attention and day-to-day functioning. Authorised generic donepezil has been available since 2010, after the US patent expired.
Active ingredients
Each Aricept tablet contains donepezil hydrochloride as the active ingredient, available in 5mg, 10mg and 23mg strengths; the orally disintegrating tablet is supplied in 5mg and 10mg. Donepezil is a piperidine-based, reversible inhibitor of acetylcholinesterase, the enzyme that breaks down acetylcholine in the brain. It is highly selective for the central enzyme over peripheral butyrylcholinesterase, which is one reason its tolerability is better than that of earlier agents such as tacrine. The hydrochloride salt is water-soluble, almost completely absorbed and unaffected by food, so the tablet can be taken at any time of day.
Forms and dosages
Aricept is supplied as film-coated tablets (5mg white, 10mg yellow, 23mg reddish) and as orally disintegrating tablets (5mg and 10mg) for patients who have difficulty swallowing. Treatment starts at 5mg once daily, usually in the evening before bedtime, and may be increased to 10mg after at least 4 to 6 weeks, once early side effects have settled. The 23mg tablet, approved only in the United States for moderate to severe disease, may be considered after a patient has been stable on 10mg for at least 3 months; it must be swallowed whole, not crushed. Patients who develop insomnia or vivid dreams can switch to morning dosing after discussing it with their doctor.
Indications
Aricept is approved in the United States for the treatment of dementia of the Alzheimer's type across the mild, moderate and severe stages. In the European Union and the United Kingdom the licence covers mild to moderately severe Alzheimer's dementia, while Japan has additionally approved donepezil for dementia with Lewy bodies. Off-label, clinicians sometimes use it in vascular or mixed dementia, where the evidence is weaker. According to clinical guidelines, the diagnosis should be confirmed by a physician experienced in dementia care before treatment begins, with reassessment of benefit every 6 to 12 months and a review of cardiac history because of the risk of bradycardia and fainting.
How it works
Alzheimer's disease destroys cholinergic neurons in the basal forebrain, reducing the acetylcholine available to memory and attention circuits. Donepezil reversibly blocks acetylcholinesterase, slowing the breakdown of acetylcholine in the synapse and prolonging its action on the receptors that remain. The effect is symptomatic: it does not alter amyloid or tau pathology, and cognition usually returns to the untreated trajectory within weeks of stopping. The elimination half-life of about 70 hours supports once-daily dosing and means steady-state concentrations are reached only after roughly 2 to 3 weeks, which is why dose increases are spaced at least 4 weeks apart. Donepezil is metabolised mainly by CYP2D6 and CYP3A4.
Frequently asked questions
How long does Aricept take to work? ▾
Aricept is not a fast-acting drug. Modest gains in attention, memory and daily functioning, if they occur, usually appear over the first 6 to 12 weeks at a stable dose, and in many patients the benefit is a slower decline rather than a visible improvement. Because the half-life is about 70 hours, each dose step needs 2 to 3 weeks to reach steady state. According to the prescribing information, response is best judged after about 3 months on 10mg, ideally with a formal cognitive test, and the treating doctor then decides whether to continue.
What are the most common side effects of Aricept? ▾
The most common side effects are cholinergic and dose-related: nausea, diarrhoea, vomiting, loss of appetite, weight loss, muscle cramps, fatigue and insomnia or vivid dreams. Most settle within 2 to 3 weeks of starting or increasing the dose, which is why the step from 5mg to 10mg waits at least 4 weeks. Gastrointestinal effects are more frequent on 23mg. According to the prescribing information, unexplained weight loss, fainting or a very slow pulse should be reported to the doctor promptly.
Can Aricept be taken by someone with a heart condition? ▾
With caution. Cholinesterase inhibitors slow the heart through a vagal effect, and donepezil has been associated with bradycardia, heart block and syncope, especially in patients with sick sinus syndrome, pre-existing conduction disorders or those taking beta blockers. According to the prescribing information, a fall or fainting episode on Aricept warrants a cardiac review, and some clinicians obtain an ECG before starting. Patients with asthma, COPD, peptic ulcer disease, seizures or urinary obstruction also need their doctor's assessment, as donepezil can aggravate each of these.
What happens if Aricept is stopped or doses are missed? ▾
Donepezil does not cause a classical withdrawal syndrome, but the symptomatic benefit fades over a few weeks and cognition returns to the level expected without treatment; this loss is generally not recovered on restarting. A single missed dose should simply be skipped, not doubled the next day. According to the prescribing information, if treatment has been interrupted for more than a few days, it should be restarted at 5mg and titrated again, because tolerance to the gastrointestinal effects is lost. Any decision to stop should be made with the prescribing doctor.
Is generic donepezil the same as Aricept? ▾
Yes. Generic donepezil hydrochloride tablets and orally disintegrating tablets have been approved as bioequivalent to Aricept since 2010 and contain the same active ingredient in the same strengths. Differences lie in excipients, colour and shape, which matter mainly for patients with specific intolerances. The 23mg strength is also available generically in the United States. Most health systems now dispense generic donepezil by default; a patient who notices a change in the appearance of their tablets can ask the pharmacist to confirm the dose.
Can Aricept be combined with memantine? ▾
Yes. Memantine, an NMDA receptor antagonist, works through a different mechanism and is frequently added to donepezil in moderate to severe Alzheimer's disease; a fixed-dose combination of the two (Namzaric) is marketed in the United States. The combination does not increase cholinergic side effects, as memantine has no direct effect on acetylcholine. According to clinical guidelines, adding memantine is a decision for the treating physician based on disease stage and tolerability, and neither drug should be expected to reverse the underlying disease.
Related medications
Sources
This page is compiled from the official prescribing information for Donepezil. The links below open a search for that active ingredient in each register, so you always reach the current version of the label rather than a cached copy.
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.