Which of the following drugs does not act by blocking GP 2b/3a receptors
## **Core Concept**
The question tests understanding of antiplatelet drugs, specifically those that target the glycoprotein (GP) 2b/3a receptor on platelets. GP 2b/3a receptors play a critical role in platelet aggregation by binding fibrinogen, which facilitates platelet-to-platelet bridging. Drugs that block these receptors inhibit platelet aggregation.
## **Why the Correct Answer is Right**
Tirofiban is a non-peptide tyrosine derivative that acts as a reversible antagonist of the GP 2b/3a receptor. It prevents fibrinogen from binding to platelets, thereby inhibiting platelet aggregation. This mechanism is crucial in acute coronary syndromes and during percutaneous coronary interventions.
## **Why Each Wrong Option is Incorrect**
* **Option A:** Abciximab is a monoclonal antibody that irreversibly blocks the GP 2b/3a receptor. Its action prevents platelet aggregation, making it useful in acute coronary syndromes and during angioplasty.
* **Option B:** Eptifibatide is a synthetic peptide that reversibly inhibits the GP 2b/3a receptor. It is used to prevent platelet aggregation in patients undergoing coronary interventions.
* **Option D:** Prasugrel is a P2Y12 receptor inhibitor, not a GP 2b/3a receptor blocker. It works by irreversibly inhibiting the P2Y12 receptor on platelets, which prevents ADP-mediated platelet activation and aggregation.
## **Clinical Pearl / High-Yield Fact**
A key clinical point to remember is that while GP 2b/3a inhibitors (like abciximab, eptifibatide, and tirofiban) are used in acute settings such as during coronary interventions, P2Y12 inhibitors (like prasugrel, clopidogrel, and ticagrelor) have a broader role in long-term antiplatelet therapy, especially in patients with coronary artery disease.
## **Correct Answer:** D. Prasugrel