Question

Aprepitant, a drug used to prevent late-onset chemotherapy-induced nausea and vomiting, acts through which of the following mechanisms?

• A. NK-1 antagonist
• B. NK-1 agonist
• C. NK-3 antagonist
• D. NK-2 antagonist

Hint:

Aprepitant is an NK-1 antagonist, effective in preventing chemotherapy-induced nausea and vomiting by blocking the action of substance P.

Answer 1

The Correct Option is A

Aprepitant is a NK-1 receptor antagonist, and it works by blocking substance P binding to the NK-1 receptor in the brain. This helps prevent nausea and vomiting, which are common side effects of chemotherapy, especially those involving highly emetogenic agents. By inhibiting substance P’s action on the NK-1 receptor, Aprepitant effectively reduces these symptoms, particularly in the late phases of chemotherapy-induced nausea and vomiting.
- Option (1) is correct as Aprepitant is an NK-1 antagonist. - Option (2) is incorrect because Aprepitant does not activate the NK-1 receptor but rather blocks it.
- Option (3) is incorrect because NK-3 antagonists are not used in this setting. NK-3 receptors are involved in different signaling pathways unrelated to nausea prevention.
- Option (4) is incorrect as NK-2 antagonists are not relevant to the action of Aprepitant.