Drug Information: Abciximab
Abciximab is an antiplatelet drug that belongs to the class of glycoprotein IIb/IIIa inhibitors. It is a monoclonal antibody fragment that binds to the glycoprotein IIb/IIIa (GP IIb/IIIa) receptor on platelets, preventing the binding of fibrinogen, von Willebrand factor, and other adhesive ligands. This action inhibits platelet aggregation, which is crucial in the formation of blood clots. Abciximab is typically used during percutaneous coronary intervention (PCI) to prevent thrombotic complications.
Category
Antiplatelet
Mechanism of Action
Abciximab functions as a potent inhibitor of platelet aggregation by targeting the glycoprotein IIb/IIIa (GP IIb/IIIa) receptor, which is found on the surface of platelets. This receptor plays a critical role in the final common pathway of platelet aggregation. When platelets are activated (e.g., by vessel injury or plaque rupture), the GP IIb/IIIa receptor undergoes a conformational change, enabling it to bind ligands like fibrinogen, von Willebrand factor (vWF), fibronectin, and vitronectin. These ligands act as bridges, connecting adjacent platelets to form a platelet plug or thrombus.
Abciximab, a monoclonal antibody fragment, irreversibly binds to the GP IIb/IIIa receptor, effectively blocking the binding of these adhesive ligands. This blockade prevents platelet cross-linking and aggregation, thereby inhibiting thrombus formation. The drug’s irreversible binding necessitates the generation of new platelets to restore normal platelet function, accounting for its relatively prolonged antiplatelet effect. The inhibition lasts for the lifespan of the treated platelets (approximately 10 days). Because Abciximab is a monoclonal antibody, it can potentially elicit an immune response.
Clinical Uses
Abciximab is primarily used in the setting of percutaneous coronary intervention (PCI) to reduce the risk of ischemic complications. Specific clinical scenarios where Abciximab is indicated include:
* **PCI in patients with unstable angina:** Abciximab helps prevent thrombotic events during and after the procedure.
* **PCI in patients with acute myocardial infarction (AMI), including ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI):** Abciximab can improve outcomes by preventing re-occlusion of the treated vessel.
* **High-risk PCI:** Used in patients undergoing PCI with complex lesions, such as those with thrombus-containing lesions or those undergoing interventions on saphenous vein grafts.
* **Facilitated PCI:** In certain situations, Abciximab may be used as a “facilitator” to help prepare the patient for PCI, particularly when delays are anticipated before the procedure can be performed.
Dosage
Abciximab is administered intravenously (IV).
* **Adults:** A typical regimen involves an initial bolus dose of 0.25 mg/kg administered 10-60 minutes before the start of PCI, followed by a continuous infusion of 0.125 mcg/kg/min (maximum 10 mcg/min) for 12 hours.
* **Pediatric:** Safety and effectiveness have not been established in pediatric patients. Use is generally not recommended.
**Important Note:** Dosage adjustments may be necessary based on individual patient factors and concomitant medications. Always refer to the prescribing information.
Indications
* Prevention of ischemic complications in patients undergoing percutaneous coronary intervention (PCI).
* Adjunct to heparin and aspirin in the treatment of unstable angina.
* Adjunct to PCI for patients with acute myocardial infarction.
Contraindications
* Active internal bleeding.
* History of stroke within the past two years.
* Significant bleeding diathesis.
* Thrombocytopenia (platelet count < 100,000/µL).
* Hypersensitivity to abciximab or any of its components.
* Major surgery or trauma within the past six weeks.
* Intracranial neoplasm, arteriovenous malformation, or aneurysm.
* Severe uncontrolled hypertension.
FAQ
* **Q: What is Abciximab used for?**
* A: Abciximab is used to prevent blood clots from forming during and after percutaneous coronary intervention (PCI), such as angioplasty or stent placement.
* **Q: How does Abciximab work?**
* A: It works by blocking the glycoprotein IIb/IIIa receptors on platelets, which prevents them from sticking together and forming clots.
* **Q: What are the common side effects of Abciximab?**
* A: The most common side effect is bleeding. Other potential side effects include thrombocytopenia (low platelet count), allergic reactions, and back pain.
* **Q: How long does Abciximab stay in your system?**
* A: The antiplatelet effect of Abciximab lasts for about 24-48 hours after the infusion is stopped, but platelet function may not return to normal for up to 10 days.
* **Q: Can I take Abciximab if I am allergic to other medications?**
* A: You should inform your doctor about any allergies you have before taking Abciximab. A history of hypersensitivity to abciximab is a contraindication.
* **Q: What should I tell my doctor before receiving Abciximab?**
* A: Tell your doctor about any bleeding disorders, recent surgeries or injuries, allergies, and all other medications you are taking, including over-the-counter drugs and herbal supplements.
* **Q: What happens if I experience bleeding while taking Abciximab?**
* A: Report any signs of bleeding to your doctor or nurse immediately. This includes unusual bruising, nosebleeds, bleeding gums, blood in your urine or stool, or coughing up blood.
* **Q: Is Abciximab safe for pregnant women?**
* A: The safety of Abciximab during pregnancy has not been established. It should only be used if the potential benefit justifies the potential risk to the fetus. Consult with your doctor.
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