Pharmacology: Cardiovascular Drugs - Anti-clotting Medications

Introduction

Professor Hoffman discusses the different medications that interfere with coagulation, focusing on:

• Antiplatelets
• Anticoagulants
• Thrombolytics

Anticoagulants

Function

• Interfere with the clotting cascade and thrombin formation
• Prevent development of large clots or help break down early clots
• Used for DVT prevention or treatment

Examples

• Warfarin: Oral drug
• Heparin: Injection or IV
• Enoxaparin: Subcutaneous injection

Side Effects

• Main concern: Bleeding
• Monitor clotting labs: INR, PT, PTT

Patient Education

• Awareness of increased bleeding risk
• Report signs of bleeding (e.g., bleeding gums, uncontrolled bleeding from small cuts)
• Avoid NSAIDs like ibuprofen (enhance bleeding risk)

Antiplatelets

Function

• Prevent early stages of clot formation by inhibiting platelet adhesion and aggregation
• Used as preventative drugs, particularly for patients at risk of stroke or MI

Examples

• Over-the-counter: Ibuprofen, Aspirin
• Prescription drugs: Plavix, others less common now

Side Effects

• Main concern: Bleeding
• GI distress and some CNS effects possible
• Caution with bleeding disorders, recent surgery, or head injury

Thrombolytics

Function

• Enzymes that break down fibrin in clots
• Used in emergency situations (heart attack, stroke, lung embolism)

Examples

• Drugs generally ending in "-ase"

Side Effects

• Very high risk of bleeding
• Breakdown of clots can cause bleeding at previous IV sites
• Cardiac arrhythmias expected but typically short-lived
• Potential for hypotension or hypersensitivity response

Key Points to Remember

• Anticoagulants: Treat or prevent clots, monitor for bleeding, avoid NSAIDs
• Antiplatelets: Preventative, monitor for bleeding, caution with bleeding risk
• Thrombolytics: Emergency use, high bleeding risk, watch for cardiac responses