Final answer:
Ondansetron, marketed as Zofran, is an antiemetic that is a serotonin (5-HT3) antagonist used to prevent nausea and vomiting due to cancer treatments and surgery. It's a controlled substance and should be administered under medical guidance. For motion sickness, scopolamine and antihistamines like dimenhydrinate are alternative treatments.
Step-by-step explanation:
The antiemetic that is a Serotonin (5-HT3) antagonist is known as Ondansetron, commonly marketed under the brand name Zofran. It is used to prevent nausea and vomiting induced by cancer chemotherapy, radiation therapy, or surgery. Ondansetron works by selectively blocking the 5-HT3 receptors on the nerve cells, which are involved in inducing vomiting. Though effective, Ondansetron should be used under medical supervision due to it being a controlled substance. It's available in various forms, including a 4 mg intravenous injection, as shown in the reference image.
In the context of motion sickness treatments, other drugs like scopolamine can be used, which is available as a transdermal patch to prevent motion sickness. However, its use is controversial due to potential risks at higher doses. Alternatively, antihistamines like dimenhydrinate (Dramamine®) are also commonly employed as safer options for treating motion sickness.
It's important to note that while certain other substances, like phenothiazines, have antiemetic properties, they have broader applications in treating psychiatric illnesses and are distinct from serotonin antagonists like ondansetron in mechanism and clinical use.