Certified Neuroscience Registered Nurse (CNRN) Practice Exam

Which medication should not be used for rescue therapy in PONV?

1. Metoclopramide

2. Ondansetron

3. Dexamethasone

4. Prochlorperazine

The correct answer is: Ondansetron

Ondansetron is primarily used as a prophylactic medication for the prevention of postoperative nausea and vomiting (PONV) rather than as a rescue therapy after symptoms have developed. This medication is a serotonin 5-HT3 receptor antagonist that works effectively to prevent nausea in high-risk patients, particularly when given before surgery or at the onset of nausea. In contrast, the other medications listed, such as metoclopramide, dexamethasone, and prochlorperazine, can be employed for rescue therapy after PONV has occurred. These medications have the capability to alleviate symptoms once they present, making them suitable options for managing PONV after it has already started. So, while ondansetron is effective in preventative measures, its role is not within immediate rescue therapy, hence making it the medication that should not be used in that context.