Overview
Donepezil is a centrally acting reversible acetylcholinesterase inhibitor used for the treatment of dementia of the Alzheimer's type. It works by increasing acetylcholine concentrations in the cerebral cortex by slowing degradation of acetylcholine released by still intact cholinergic neurons. Clinical trials have demonstrated improvements in cognitive function and global clinical state in patients with mild to moderate Alzheimer's disease.
Mechanism of Action
Donepezil hydrochloride is a reversible inhibitor of the enzyme acetylcholinesterase, which hydrolyzes acetylcholine to choline and acetate. By inhibiting acetylcholinesterase, donepezil increases the concentration of acetylcholine available for synaptic transmission in the central nervous system, thereby enhancing cholinergic function in patients with Alzheimer's disease.
Indications
- Treatment of mild, moderate, and severe dementia of the Alzheimer's type
Common Doses
- 5 mg
- 10 mg
- 23 mg
Dosage
Initial dose: 5 mg once daily, preferably at bedtime. After 4-6 weeks, may increase to 10 mg once daily if clinically indicated. Maximum recommended dose: 10 mg daily. For severe Alzheimer's dementia, after patients have been on 10 mg daily for at least 3 months, dose may be increased to 23 mg once daily.
Contraindications
- Known hypersensitivity to donepezil hydrochloride or to piperidine derivatives
Side Effects
- Nausea
- Diarrhea
- Insomnia
- Fatigue
- Vomiting
- Muscle cramps
- Anorexia
- Headache
- Dizziness
- Syncope
- Bradycardia
- Gastrointestinal bleeding
Interactions
- Anticholinergic medications may reduce the efficacy of donepezil
- Cholinergic agonists may have additive effects with donepezil
- Succinylcholine-type muscle relaxants may have prolonged effects when used with donepezil
- Beta-blockers may increase risk of bradycardia when combined with donepezil
Counseling Points
- Take once daily at bedtime, with or without food
- Do not crush, chew, or split tablets
- Report any fainting, dizziness, slow heartbeat, or seizures to healthcare provider
- Inform all healthcare providers about all medications being taken
- Report any signs of gastrointestinal bleeding such as black, tarry stools or vomiting blood
- Do not stop taking medication without consulting healthcare provider