Aricept (donepezil)


Please consult the full data sheet before prescribing ARICEPT ARICEPT* Donepezil hydrochloride 5 mg tablets 10 mg tablets

Presentation: Film coated, round tablets, containing either 5 mg or 10 mg donepezil hydrochloride equivalent to 4.56 mg or 9.12 mg donepezil free base respectively. The tablets are marked with "ARICEPT" on one side, and "5" and "10" respectively on the other side. ARICEPT tablets are packaged in blister packs of 28.

Indications: ARICEPT is indicated for the treatment of mild to moderately severe Alzheimer's Dementia and vascular dementia (dementia associated with cerebrovascular disease).

Dosage and Administration: Treatment is initiated at 5mg once-a-day, taken orally in the evening just prior to retiring. Maintain dose for at least one month in order to assess the earliest clinical responses to treatment at steady-state. The dose may then be increased to 10 mg once-a-day, A similar dose schedule can be followed for patients with renal or mild to moderate hepatic impairment.

Contraindications: ARICEPT is contraindicated in patients with a known hypersensitivity to donepezil hydrochloride: piperidine derivatives, or to any excipients used in the formulation.

Warnings and Precautions: Clinical benefits should be reassessed on a regular basis. Discontinuation should be considered when evidence of a therapeutic effect is no longer present.

ARICEPT, as a cholinesterase inhibitor, may:

  • exaggerate succinylcholine-type muscle relaxation during anaesthesia
  • lead to bradycardia. Caution in "sick sinus syndrome" or other supraventricular cardiac conduction conditions
  • increase gastric acid and thus patients at increased risk of developing ulcers should be monitored
  • cause bladder outflow obstruction
  • cause generalised convulsions. However, seizure activity is a manifestation of Alzheimer's disease

Cholinesterase inhibitors should be prescribed with care to patients with a history of asthma or obstructive pulmonary disease. Coadministration of ARICEPT with other inhibitors of acetylcholinesterase, agonists or antagonists of the cholinergic system should be avoided.

Pregnancy: There are no adequate studies in pregnant women. Use only if the potential benefit justifies the potential risk to the foetus. Lactation:There are no studies in lactating women.

Paediatric use: Not recommended.

Driving, and use of machinery: Dementia may cause, impairment of driving performance or compromise the ability to use machinery. ARICEPT can cause fatigue, dizziness and muscle cramps, mainly when initiating or increasing the dose. The treating physician should routinely evaluate the ability of patients to continue drivjng or operating complex machines.

Adverse effects: Most adverse events are mild in severity and transient in nature. The most common (incidence> 5% and twice the frequency of placebo) were diarrhoea, muscle cramps, fatigue, nausea, vomiting and insomnia. Other common adverse events (incidence> 5% and > placebo) were headache, pain, accident, common cold, abdomina1 disturbance and dizziness. Cases of syncope, bradycardia, sinoatrial block and atrioventricular block were observed. No notable abnormalities in laboratory values associated with treatment were observed.

Interactions: ARICEPT and/or any of its metabolites do not inhibit the metabolism of theophylline, warfarin, cimetidine or digoxin in humans. Inhibitors of CYP3A4 and CYP2D6, such as ketoconazole and quinidine respectively, may inhibit donepezil metabolism. Conversely, enzyme inducers of these cytochromes (eg rifampicin, phenytoin, carbamazepine and alcohol) may reduce the levels of ARICEPT. ARICEPT has the potential to interfere with medications having anticholinergic activity. It may also demonstrate synergistic activity with concomitant treatment involving medication that affects cardiac conduction.

Overdosage: Can result in cholinergic crisis characterised by severe nausea, vomiting, salivation, sweating, bradycardia, hypotension, respiratory depression, collapse and convulsions. Increasing muscle weakness is a possibility and may result in death if respiratory muscles are involved. Treat with general supportive measures and consider tertiary anticholinergics such as atropine as an antidote.

Package Quantities: Tablets: 5 mg x 28 10 mg x 28.

Name and Address: Pfizer New Zealand Ltd PO Box 3998 Auckland NEW ZEALAND
Phone Toll Free: O800 736 363.

Date of Preparation: 7 November 2003
* Registered trademark of Eisai Co. Ltd.

References: 1. Winblad B. Neurology 2001; 57: 489-495. 2. Mohs RC.:Neurology 2001; 57: 481-488. 3. Feldman H. Neurology 2001; 57: 613-620. 4..Gauthier S. et al: Curr Med Res Opin 2002;18(6):347-354. 5. Data on file.