The oncology nurse reviews a call after the first fluorouracil infusion. Which findings require immediate follow-up? Highlight the findings associated with acute early or unusually severe toxicity.

Nurses' Notes 0910: The oncology nurse calls a client on treatment day 4 after the first fluorouracil infusion. The client reports that watery diarrhea occurred 8 times since midnight. The client denies blood in the stool but feels weak when standing. The nurse learns that mild nausea improved after the prescribed antiemetic. The client states that painful mouth ulcers now prevent drinking fluids. Oral intake has fallen to a few small sips since yesterday evening. The client reports that urine remains pale yellow without burning. A family member says that the client slept for 7 hours overnight. At 0920, the client has new confusion and difficulty walking across the room. The family member denies any fall or sedating medication use. The client states that the infusion-site skin remains intact without redness. The temperature is 37.2 °C, and the client can speak in complete sentences. The medication list shows that the prescribed oral rinse was used after meals. The record contains no pretreatment DPYD result because therapy was urgent. The nurse keeps the next dose on hold while contacting the oncology prescriber.