A nurse is caring for a 76-year-old patient with moderate Al…

A nurse is caring for a 76-year-old patient with moderate Alzheimer disease who began taking rivastigmine 1.5 mg orally twice daily 3 days ago. The patient reports nausea, has had three episodes of diarrhea today, and appears increasingly confused. Vital signs: BP 118/72 mm Hg, HR 54 bpm, RR 16 breaths/min, T 98.4°F (36.9°C). What assessment finding requires the most immediate nursing intervention?