A nurse administered prochlorperazine (Compazine) IV to a client two hours ago. Which of the following signs should the nurse recognize as a complication of this medication?

A. Nausea is a common symptom of the condition being treated with prochlorperazine (such as nausea from chemotherapy), but it is not a complication of the medication itself. B. Anxiety is not a common complication of prochlorperazine. It is a dopamine antagonist, and while it may cause sedation, it is not known for causing anxiety. C. Prochlorperazine is associated with cardiac side effects such as a prolonged QT interval, which can lead to arrhythmias. This is a serious complication and requires monitoring. D. Vomiting is not a typical side effect of prochlorperazine; in fact, prochlorperazine is used to prevent nausea and vomiting.