Which antiemetic is considered a first-line treatment for chemotherapy-induced nausea and vomiting?

Ondansetron is considered a first-line treatment for chemotherapy-induced nausea and vomiting due to its efficacy and mechanism of action. It is a selective serotonin 5-HT3 receptor antagonist that works by blocking the action of serotonin, a neurotransmitter that can trigger nausea and vomiting. This is particularly important in the context of chemotherapy, as the release of serotonin from enterochromaffin cells in the gastrointestinal tract is a key factor in inducing nausea and vomiting during chemotherapy treatments.

Clinical studies have shown that ondansetron significantly reduces the incidence of both acute and delayed nausea and vomiting associated with various chemotherapy regimens. Its high effectiveness and relatively favorable side effect profile make it a preferred choice for managing these side effects in patients receiving cancer treatment.

Other options, while also used for nausea and vomiting, do not have the same standing as first-line treatments specifically for chemotherapy-induced nausea and vomiting. Granisetron, for instance, is another 5-HT3 receptor antagonist similar to ondansetron and is also effective; however, ondansetron is more commonly recognized and utilized in clinical practice as the cornerstone of antiemetic therapy in this setting. Metoclopramide and promethazine have roles in managing nausea and vomiting but serve different clinical situations and are typically