A nurse is teaching the family of a client who has Alzheimer's disease about donepezil. Which of the following information should the nurse include in the teaching?

Choice A rationale Donepezil is an acetylcholinesterase inhibitor that increases the concentration of acetylcholine in the gastrointestinal tract, which typically stimulates peristalsis and gastric acid secretion. Consequently, the most common gastrointestinal side effects are diarrhea, nausea, and vomiting rather than constipation. Monitoring for constipation would be inappropriate because the pharmacological action of the drug tends to promote bowel movements. Understanding this cholinergic effect helps caregivers manage the client's nutritional and hydration status effectively during drug therapy. Choice B rationale Donepezil increases parasympathetic nervous system activity by inhibiting the breakdown of acetylcholine. This cholinergic enhancement can affect the sinoatrial node of the heart, leading to bradycardia, which is a slow heart rate, rather than tachycardia. Tachycardia is not a common side effect of this medication. Patients with underlying cardiac conduction issues must be monitored closely for significant drops in heart rate or heart block, which could lead to decreased cardiac output and subsequent dizziness. Choice C rationale Donepezil is typically administered once daily in the evening, just before the client goes to sleep. Evening administration is recommended to minimize the impact of common side effects like nausea or dizziness that may occur shortly after taking the dose. Taking the medication at bedtime allows the peak plasma levels to occur while the patient is resting, potentially improving tolerance and adherence. Administering it in the morning might increase the risk of daytime gastrointestinal distress or lightheadedness. Choice D rationale Syncope, or fainting, can occur in clients taking donepezil due to the drug's vagotonic effects on the heart rate. By increasing acetylcholine levels, the medication can induce bradycardia or even temporary heart block, leading to a sudden drop in blood pressure and cerebral perfusion. Family members must be educated to monitor for signs of low heart rate or sudden dizziness, as these episodes increase the risk of falls and related injuries in elderly patients with Alzheimer's disease.