Pharmacology · patient case question
For which condition is donepezil prescribed, and by what mechanism does it act?
Patient case: Alzheimer Disease and Consent for Care
Patient: 72-year-old male
Chief Complaint: Daughter: “He won’t let anyone near his mouth and I think his teeth are getting worse.”
Background: Moderate Alzheimer disease diagnosed 4 years ago. Trigeminal neuralgia on the right, managed medically. Disoriented to time and place; cannot reliably recall the purpose of today’s visit. His daughter holds a durable power of attorney for health care.
Medications: Donepezil 10 mg daily · Carbamazepine 200 mg twice daily
Vital Signs: BP 144/82 mmHg · HR 72 bpm · RR 16 · T 98.2°F
Findings: Generalized plaque accumulation, multiple root caries, and moderate periodontitis. Multiple restorations required. He is calm but does not follow multi-step instructions.
Show answer and explanation
Correct answer: A. Alzheimer disease — it inhibits acetylcholinesterase
- A. Correct. Donepezil is a centrally acting, reversible acetylcholinesterase inhibitor. By slowing the breakdown of acetylcholine it partially compensates for the cholinergic deficit of Alzheimer disease, producing modest symptomatic benefit without altering the underlying course.
- B. Incorrect. Serotonin reuptake inhibition describes the SSRI class, such as sertraline and fluoxetine.
- C. Incorrect. Levodopa combined with carbidopa is the dopamine precursor therapy for Parkinson disease. Donepezil has no dopaminergic action.
- D. Incorrect. Enhancement of GABAergic inhibition describes benzodiazepines, barbiturates, and several antiepileptics. Donepezil is not an anticonvulsant.
Note: Class members worth knowing: donepezil, rivastigmine, and galantamine are the cholinesterase inhibitors. Memantine works differently, as an NMDA receptor antagonist, and is used in moderate to severe disease.