Here’s a **complete and structured overview** of **antiplatelet drugs, anticoagulants, and fibrinolytic drugs**, including **mechanism, examples, clinical uses, and adverse effects** — perfect for revision or notes. --- ## 🩸 **1. ANTIPLATELET DRUGS** ### 🔹 **Mechanism of Action** They **inhibit platelet aggregation** by interfering with platelet activation pathways — used mainly in **arterial thrombosis** (where platelets play a major role). ### 🔹 **Major Classes & Examples** | Class | Drugs | Mechanism | Key Uses | | ----------------------------------- | --------------------------------------------------------------- | ------------------------------------------------------- | ------------------------------------------------------------ | | **COX Inhibitors** | **Aspirin (Acetylsalicylic acid)** | Irreversibly inhibits COX-1 → ↓ Thromboxane A₂ (TXA₂) | MI prevention, unstable angina, post-stent | | **ADP Receptor (P2Y₁₂) Blockers** | **Clopidogrel**, **Prasugrel**, **Ticagrelor**, **Ticlopidine** | Inhibit ADP binding → prevent GPIIb/IIIa activation | After PCI, ACS, stroke prevention | | **GPIIb/IIIa Receptor Blockers** | **Abciximab**, **Eptifibatide**, **Tirofiban** | Block fibrinogen binding → prevent platelet aggregation | During PCI, unstable angina | | **Phosphodiesterase Inhibitors** | **Dipyridamole**, **Cilostazol** | ↑ cAMP → ↓ platelet aggregation, vasodilation | Stroke prophylaxis (with aspirin), intermittent claudication | | **Thromboxane Synthase Inhibitors** | **Picotamide**, **Ridogrel** | Block TXA₂ synthesis/action | Experimental/rarely used | ### ⚠️ **Adverse Effects** * Bleeding (GI, intracranial) * Gastritis (esp. aspirin) * Thrombocytopenia (esp. ticlopidine, abciximab) --- ## 🧬 **2. ANTICOAGULANTS** ### 🔹 **Mechanism of Action** They **inhibit clotting factors** (mainly fibrin formation) — used in **venous thrombosis** and **embolism prevention**. ### 🔹 **Major Types & Examples** | Class | Drugs | Mechanism | Route | Monitoring | Antidote | | ------------------------------------- | ----------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------- | ------------ | -------------- | ----------------------------- | | **Heparins** | **Unfractionated Heparin (UFH)**, **Low Molecular Weight Heparin (LMWH)** e.g. Enoxaparin, Dalteparin | Activate **antithrombin III** → inhibit **Factor Xa & IIa (thrombin)** | IV, SC | aPTT (for UFH) | Protamine sulfate | | **Factor Xa Inhibitors** | **Fondaparinux**, **Apixaban**, **Rivaroxaban**, **Edoxaban** | Directly inhibit **Factor Xa** | Oral (DOACs) | Not needed | Andexanet alfa | | **Direct Thrombin Inhibitors (DTIs)** | **Dabigatran**, **Argatroban**, **Bivalirudin** | Directly inhibit **thrombin (Factor IIa)** | Oral/IV | Not needed | Idarucizumab (for dabigatran) | | **Vitamin K Antagonist** | **Warfarin** | Inhibits **Vitamin K epoxide reductase** → ↓ synthesis of Factors II, VII, IX, X | Oral | PT/INR | Vitamin K, FFP | ### ⚠️ **Adverse Effects** * **Bleeding** (major) * **Heparin-induced thrombocytopenia (HIT)** (UFH) * **Teratogenicity (Warfarin)** — contraindicated in pregnancy * **Skin necrosis (Warfarin early therapy)** ### 💉 **Clinical Uses** * DVT, PE * Atrial fibrillation * Mechanical heart valves (warfarin) * MI, unstable angina (with antiplatelets) * During surgery (thromboprophylaxis) --- ## 🧫 **3. FIBRINOLYTIC (THROMBOLYTIC) DRUGS** ### 🔹 **Mechanism of Action** They **lyse existing fibrin clots** by converting **plasminogen → plasmin**, which breaks down fibrin. ### 🔹 **Major Agents** | Drug | Source | Mechanism | Key Use | | --------------------------- | -------------------- | ----------------------------------------- | ----------------------------------------------- | | **Streptokinase** | Streptococci-derived | Activates plasminogen | MI, PE (cheap but antigenic) | | **Urokinase** | Human-derived | Directly activates plasminogen | PE, DVT | | **Alteplase (tPA)** | Recombinant | Fibrin-specific activation of plasminogen | Acute MI, ischemic stroke (within 3–4.5 hr), PE | | **Reteplase, Tenecteplase** | Modified tPA | Longer half-life, more specific | Same as above | ### ⚠️ **Adverse Effects** * **Severe bleeding** * **Allergic reactions** (streptokinase) * **Reperfusion arrhythmias** (post-MI) ### 💉 **Contraindications** * Active bleeding * Recent surgery/trauma * History of hemorrhagic stroke * Severe uncontrolled hypertension --- ## 🧾 **Quick Summary Table** | Type | Mechanism | Examples | Used For | Antidote | | ----------------- | ---------------------------- | ------------------------ | ------------------- | ---------------------------------- | | **Antiplatelet** | Inhibit platelet aggregation | Aspirin, Clopidogrel | Arterial thrombosis | None (supportive) | | **Anticoagulant** | Inhibit clotting factors | Heparin, Warfarin, DOACs | Venous thrombosis | Protamine, Vit K | | **Fibrinolytic** | Dissolve existing clots | tPA, Streptokinase | MI, Stroke, PE | Aminocaproic acid, Tranexamic acid | --- Would you like me to make this into a **colored HTML table or infographic-style page** (for presentation or website)? I can give you a **single HTML + CSS + JS file** version with all sections neatly styled.