Donepezil (Aricept) Flashcards

Donepezil Overview

• Therapeutic Class: Alzheimer's disease drug
• Pharmacologic Class: Cholinesterase inhibitor

Actions and Uses

• Donepezil improves memory in mild to moderate Alzheimer's dementia.
• Functions as an AChE inhibitor, enhancing acetylcholine effects in intact neurons.
• Assess maximum benefits after at least 6 months of pharmacotherapy.
• Early memory improvement may occur within 1 to 4 weeks.
• Therapeutic effects are often modest and short-lived.
• Advantageous long half-life allows for once-daily administration.

Administration Alerts

• Administer medication before bedtime for optimal effectiveness.
• Maintain a regular dosing schedule.
• Classified as pregnancy category C.

Pharmacokinetics

• Onset of action: less than 20 minutes.
• Peak plasma concentration occurs in 3 to 4 hours.
• Duration of effects varies significantly.

Adverse Effects

• Common side effects include vomiting and diarrhea.
• Less common: abnormal dreams, fainting, dark urine.
• CNS effects may involve insomnia, syncope, depression, headache, irritability.
• Musculoskeletal issues may lead to muscle cramps, arthritis, fractures.
• General side effects include headache, fatigue, chest pain, increased libido, hot flashes, urinary incontinence, dehydration, and blurred vision.
• No hepatotoxicity has been reported.
• Monitor patients with bradycardia, hypotension, asthma, hyperthyroidism, or active peptic ulcer disease carefully.

Contraindications

• Contraindicated for patients with gastrointestinal bleeding and jaundice.

Drug-Drug Interactions

• Anticholinergic drugs will be less effective when used with donepezil.
• Synergistic effect with bethanechol; caution advised.
• Phenobarbital, phenytoin, dexamethasone, and rifampin can speed donepezil elimination.
• Quinidine and ketoconazole may inhibit donepezil metabolism.
• Other cholinergic drugs should not be used concurrently.

Treatment of Overdose

• Anticholinergics like atropine are used as an antidote for donepezil overdose.
• Initial recommended IV dose of atropine sulfate is 1 to 2 mg, with subsequent doses based on clinical response.

Other Drugs in Class

• Alternatives include galantamine (Razadyne) and rivastigmine (Exelon).