Advanced Medical‑Surgical CJE Practice Exam

Ondansetron is a serotonin 5-HT3 receptor antagonist that is specifically effective in preventing nausea and vomiting, particularly in the postoperative setting. It works by blocking the action of serotonin, a neurotransmitter that can trigger nausea in the gastrointestinal tract and the central nervous system. Postoperative nausea and vomiting can lead to significant discomfort and complications, making the use of ondansetron a common practice in surgical settings to minimize these risks.

In contrast, while metoclopramide can also be used to reduce nausea and vomiting, it primarily acts as a dopamine antagonist and has additional gastrointestinal motility effects. It is often used for acutely reducing nausea related to other causes, such as medications or gastroparesis, rather than specifically targeting postoperative nausea.

Diphenhydramine is an antihistamine that can cause sedation and is sometimes used for motion sickness or an allergic reaction, but it is not the first-line treatment for postoperative nausea and vomiting.

Topiramate is primarily an anticonvulsant medication and is not specifically indicated for nausea and vomiting, making it unlikely to be the medication of choice in this scenario.

Therefore, ondansetron stands out as the most suitable medication for the prevention of postoperative nausea and vomiting.