A nurse is caring for an older adult patient who has Alzheimer disease. The patient is taking a cholinesterase inhibitor drug. Which side effects would concern the nurse?

A. Dizziness and headache are possible mild side effects of cholinesterase inhibitors, but they are less concerning than gastrointestinal or cardiac effects. B. Confusion and memory impairment are symptoms of Alzheimer’s disease, not typically caused by cholinesterase inhibitors. These would not be the primary side effects of concern when monitoring for drug-related complications. C. Nausea, vomiting, and diarrhea are common gastrointestinal side effects of cholinesterase inhibitors (e.g., donepezil, rivastigmine, galantamine). These can lead to dehydration, electrolyte imbalances, and weight loss, especially in older adults, so they require monitoring. D. Slowed heart rate (bradycardia) and lightheadedness are potential cardiac side effects of cholinesterase inhibitors due to increased parasympathetic activity. These effects can increase the risk of falls, syncope, and injury in older adults, making them clinically significant.