Donepezil Hydrochloride

Pronunciation

Donepezil hydrochloride 10mg (ARICEPT 10mg)

Donepezil hydrochloride 5mg (ARICEPT 5mg)

Introduction

Donepezil hydrochloride, is a reversible inhibitor of acetylcholinesterase. It is used for the treatment of mild to moderate dementia in Alzheimer’s disease.

Generic Name 藥名	HA Code 藥物代碼	Classification藥物分類
Donepezil HCL Tablet 5mg	DONE01	P1S1S3
Donepezil HCL Tablet 10mg	DONE02	P1S1S3
Donepezil HCL Orodispersible Tablet 5mg	DONE03	P1S1S3

Mechanism of Action

Acetylcholinesterase inhibiting drug

Dosage

By Oral: initially 5 mg once daily at bedtime, increased if necessary, after one month to max. 10 mg daily.

Clinical benefit should be assessed on a regular basis. Up to half the patients will show a slower rate of cognitive decline. Donepezil should be discontinued in those not responding.

Side Effects

Common side effects include

• Nausea and vomiting
• difficulty sleeping
• aggression
• Loss of appetite
• Diarrhoea
• Feeling tired
• Muscle cramps

These effects usually last 1 – 3 weeks and then lessen

Serious side effects may include:

• Abnormal heart rhythms
• Difficulty emptying urine from the bladder
• seizures

Donepezil, like other acetylcholinesterase inhibitors, can cause nightmares due to enhanced activation of the visual association cortex during REM sleep. Taking donepezil in the morning can reduce the frequency of nightmares.

Pharmacokinetics

Oral bioavailability	By mouth: the initial oral dose is 300 mg on day 1, then 300mg twice daily on day 2, then 300mg 3 times daily on day 3. Alternatively, 300 mg three times daily on day 1; then increased according to response in steps of 300 mg every 2 -3 days. Usual dose: 0.9 – 3.6 g daily in 3 divided doses (Max. 4.8 g daily) Doses in children, for use as adjunctive therapy in children aged 6 years and over, and as monotherapy in those aged 12 years or over. 6-12 years (adjunctive therapy): initially 10 mg/kg (max. 300 mg) once daily on day 1, then 10 mg /kg (max. 300mg) twice daily on day 2, then 10mg mg/kg (max. 300 mg) 3 times daily on day 3; Usual dose 25 – 35 mg/kg daily in 3 divided doses; Max. 70 mg/kg daily in 3 divided doses.
Neuropathic Pain	By mouth: 300 mg once daily on day 1, then 300 mg twice daily on day 2, then 300 mg 3 times daily on day 3. Alternatively, 300 mg 3 times daily on day 1, then increased according to response in steps of 300mg (in 3 divided doses) every 2-3 days up to max. 3.6 g daily.
Migraine prophylaxis	By mouth: initially 300 mg daily, increased according to response up to 2.4 g daily in divided doses.