A nurse is caring for a client who has been prescribed ondansetron (Zofran) for postoperative nausea and vomiting. Which of the following is a complication associated with this medication?

A. Prolonged QT interval – This is correct. Ondansetron can cause prolongation of the QT interval, increasing the risk of arrhythmias, including torsades de pointes. This is a serious complication that requires monitoring, particularly in clients with cardiac risks. B. Extrapyramidal symptoms – This is incorrect. Ondansetron does not typically cause extrapyramidal symptoms, which are more associated with dopamine antagonists like metoclopramide or prochlorperazine. C. Nausea – This is incorrect. Ondansetron is specifically used to treat nausea and vomiting, not to cause them. If nausea persists, it may indicate treatment failure or another underlying issue. D. Vomiting – This is incorrect. Ondansetron is an antiemetic and works to prevent vomiting. Vomiting would not be a complication of this medication under proper use.