The most preferred acute emetic for emesis induced by anticancer drugs is
**Core Concept**
The question is testing the knowledge of antiemetic medications used in the management of chemotherapy-induced nausea and vomiting (CINV). The underlying principle is the use of serotonin 5-HT3 receptor antagonists as first-line treatment for acute emesis caused by anticancer drugs.
**Why the Correct Answer is Right**
The correct answer is based on the mechanism of action of serotonin 5-HT3 receptor antagonists, which are effective in blocking the action of serotonin at the chemoreceptor trigger zone in the central nervous system. This leads to a reduction in the incidence of acute emesis caused by anticancer drugs. Examples of serotonin 5-HT3 receptor antagonists include ondansetron, granisetron, and palonosetron.
**Why Each Wrong Option is Incorrect**
**Option A:** Metoclopramide is a dopamine antagonist and is not the preferred choice for acute emesis caused by anticancer drugs due to its side effects and limited efficacy in this setting.
**Option B:** Dexamethasone is a corticosteroid and is used as an adjunct therapy to antiemetics in the management of CINV, but it is not the preferred choice for acute emesis.
**Option C:** Opioids are not used as first-line treatment for acute emesis caused by anticancer drugs due to their side effects and risk of addiction.
**Clinical Pearl / High-Yield Fact**
When managing CINV, it is essential to use a combination of antiemetics, including a serotonin 5-HT3 receptor antagonist, a corticosteroid, and a dopamine antagonist, to achieve optimal control of symptoms.
**Correct Answer:** Ondansetron is the most preferred acute emetic for emesis induced by anticancer drugs.