Anticoagulation Drugs PDF

**Drugs That Affect Blood Clotting** ==================================== - Thrombosis: a blood clot formed within a blood vessel or the heart. This represents an abnormal or pathologic action of coagulation - Arterial thrombosis - Begins with the adhesion of platelets to th...

**Drugs That Affect Blood Clotting** ==================================== - Thrombosis: a blood clot formed within a blood vessel or the heart. This represents an abnormal or pathologic action of coagulation - Arterial thrombosis - Begins with the adhesion of platelets to the arterial wall due to the rupture of an atherosclerotic plaque or damage to the wall. - Platelet aggregation then occurs and the artery becomes occluded. - Venous thrombosis - Develops due to slowed blood flow (stagnation). - Stagnation initiates the coagulation cascade which leads to a venous thrombus. - Venous thrombus usually have a long tail-like end and break off easily creating emboli - Emboli travel through the venous system and can become lodged in distant sites such as the pulmonary arteries. - Arterial thrombus' harmful effects are localized to the area in which they form. - Injury is localized - Venous thrombus' harmful effects can occur distant to the site of formation. - Injury or embolization site can be a secondary location. **Drugs Used to Treat Clotting Disorders** ========================================== - **Three major groups** ---------------------- - ### Anticoagulants - #### Any drug interfering with a step in the clotting cascade impairs the blood's ability to clot efficiently - ### When would anticoagulants be prescribed? - ### When would anticoagulants be contraindicated? ### - ### Antiplatelets - #### Inhibit platelet aggregation - ### Thrombolytics - #### Promote lysis of fibrin and lead to dissolution of a thrombus **General Nursing Considerations** ================================== - Baseline -------- - ### VS, allergies, IV site - ### Lab Results - #### coagulation studies (aPTT, PT/INR) - #### CBC (platelets, H&H) - Presence of bleeding problems (don't give if pt is already bleeding) -------------------------------------------------------------------- - Why are we giving the drug? --------------------------- - Monitor for bleeding after administration ----------------------------------------- - Follow up after administration ------------------------------ - ### Vital Signs, patient assessment - ### Lab Results ### - Patient teaching: ----------------- - ### Signs and symptoms of bleeding - ### Medical follow-up (brusing, blood is urine or stool, syncope) - ### Take drugs as directed; no double-doses - ### Notify dentist, other doctors about therapy - ### No aspirin or NSAIDs - ### Bleeding Precautions: - #### Avoid injuries/activities that may cause bleeding - #### Soft tooth brush - #### Electric razor ### **Anticoagulants** ================== **Heparin and Heparin Derivatives** =================================== - Two type of Heparin ------------------- - ### **Unfractionated (IV or SQ)** - ### **Low molecular weight (SQ only)** **Heparin (unfractionated)** ---------------------------- - ### Enhances the activity antithrombin - ### Rapid Acting - Therapeutic uses: DVT, PE, embolic stroke, MI, arterial clots, DIC. ------------------------------------------------------------------- - Contraindicated: any signs of bleeding, low platelet, H&H, injury that could result in bleeding, during and immediately after eye/brain/spinal cord surgery. ------------------------------------------------------------------------------------------------------------------------------------------------------------ - Antidote: **protamine sulfate** ------------------------------- - Monitoring Effectiveness: ------------------------- LAB: Activated partial thromboplastin time (aPTT) ------------------------------------------------- - Normal value is 40 seconds -------------------------- - Typical therapeutic range is 60-80 seconds (IV) ----------------------------------------------- - aPTT often checked every 6 hours during initial phase of therapy -- once therapeutic range is established -- should be check daily. (for IV administration) ----------------------------------------------------------------------------------------------------------------------------------------------------------- - aPTT is not monitored with SQ administration -------------------------------------------- - Adverse effects --------------- - ### Hemorrhage - #### Risks for hemorrhage can be decreased - ###### thorough patient screening -- history, identification of risk factors - ###### tight control on dosage and frequent blood tests to evaluate clotting times ### - ### Heparin-induced thrombocytopenia (HIT) - #### Treated with: **Argatroban (IV)** ### - ### Hypersensitivity reactions - Administration Considerations: ------------------------------ - IV - Adjust infusion rate based on orders and results of aPTT ------------------------------------------------------------- - monitor infusion or injection sites for complications ----------------------------------------------------- **Low-Molecular-Weight Heparin** ================================ - **Enoxaparin (Lovenox) (SQ)** ----------------------------- - Therapeutic uses ---------------- - ### Prevention of DVT following surgery - ### Treatment of established DVT - ### Prevention of ischemic complications - #### Patients with unstable angina and myocardial infarction - Dosage based on body weight --------------------------- - ### DVT prevention dose is usually once daily (0.5 mg/kg) - ### Full anticoagulation for DVT or AMI is twice daily (1mg/kg) - Antidote for toxicity: protamine sulfate ---------------------------------------- - Adverse effects and interactions: --------------------------------- - Administration Considerations: ------------------------------ - ### SQ only - ### Monitor injection sites **Warfarin** ============ - Oral anticoagulant with delayed onset ------------------------------------- - ### Vitamin K antagonist - **Therapeutic uses:** --------------------- - ### Long-term prophylaxis of thrombosis - **Monitoring treatment:** ------------------------- - ### Prothrombin time (PT) - ### International normalized ratio (INR) - #### Therapeutic rage is 2-3.5 - **Adverse effects:** -------------------- - ### Hemorrhage - ### Warfarin-induced skin necrosis #### - Drug interactions ----------------- - ### Heparin - ### Aspirin ### - Warfarin Toxicity ----------------- - ### Vitamin K (oral or IV) - Administration Considerations: ------------------------------ - ### Category X black box warning - ### Breastfeeding Considerations - ### Patient Education: - #### Alcohol consumption: - #### Acute consumption with binge drinking decreases metabolism and can cause elevated INR value - #### Chronic consumption (daily) increases metabolism and can lower INR value - #### Acute consumption of Foods containing: - #### Vitamin K (decrease INR) (What are they at risk for?) - Examples of foods rich in Vitamin K: - #### Vitamin E (increases INR) - #### Cranberry juice ( increase INR) ### **Anticoagulants: Direct Thrombin Inhibitors** ============================================== - **Example Drugs:** ------------------ - ### **Dabigatran Etexilate** (PO) - #### **Reversal Agent: Idarucizumab (Praxbind)** - ### **Bivalirudin (IV)** - #### Prevents clot formation in patients with unstable angina who are undergoing coronary angioplasty - ##### Given in combination with aspirin ##### - ### **Argatroban (IV)** - #### Indicated for treatment of Heparin Induced Thrombocytopenia (HIT) **Anticoagulants: Factor Xa Inhibitors** ======================================== - **Example Drugs:** ------------------ - Target Specific Oral Anticoagulants (TSOAs) or Direct Oral Anticoagulants (DOACs) --------------------------------------------------------------------------------- - #### **Api[xaban]** - #### **Rivaro[xaban ]** #### **Reversal agent: Andexanet alfa (Andexxa)** Black box warning for thromboembolic risks - Advantages: less interactions than with warfarin ------------------------------------------------ - Disadvantages: -------------- - Administration Considerations: ------------------------------ - ### Patient Education (bleeding precautions) ### **FDA Approved Indications* *** =============================== Dabigatran Rivaroxaban Apixaban ------------------------------- VTE --- prophylaxis ----------- (THR, TKR) ---------- Non-valvular Afib ----------------- DVT/PE treatment \* ------------------- \*Dabigatran: approved for treatment of existing DVT/PE in patients who have been treated with a parenteral anticoagulant (heparin -- unfractionated or LMW) for 5-10 days -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- **Antiplatelet Drugs** ====================== - **Block platelet aggregation** ------------------------------ - ### Example Oral Agents - #### **Aspirin** - #### **Clopidogrel** - ### Example IV Agents - #### **Abciximab (Reopro)** - #### **Eptifibatide (Integrilin)** - #### IV agents may be used short term with Acute Coronary Syndrome, following percutaneous coronary intervention (PCI) with stent, acute ischemic stroke #### - Intended responses: prevent thrombus formation ---------------------------------------------- - Side effects: bleeding, GI upset, --------------------------------- - Adverse effects --------------- - ### Hemorrhage, allergic reactions - ### Tinnitus or salicylate poisoning (aspirin) - Administration Considerations: check labs, CBC, platelets, allergies, coagulation labs (ptt). Could be lifelong tx, pt should not drink alcohol (increases risk for GI bleed), not safe during last trimester of pregnancy/breastfeeding. ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- **Thrombolytic Drugs** ====================== - Given to treat thrombus that has already formed ----------------------------------------------- - Example drugs: -------------- - ### **Streptokinase** - ### **tPA (Activase)** ### - Used only for severe thrombotic events: AMI, DVT, PE, Acute Ischemic Stroke, Arterial occlusion ----------------------------------------------------------------------------------------------- - Major adverse effect: hemorrhaging ---------------------------------- **Thrombolytic Drugs: Administration Considerations** ===================================================== - Check before administration: ---------------------------- - ### Obtain accurate history - ### Presence of absolute or relative contraindications - ### **Absolute**: recent intracranial hemorrhage, cerebral vascular lesion, intracranial neoplasm, ischemic stroke within 3 months, aortic dissection, active bleeding - ### **Relative**: severe hypertension (\> 180 systolic or \> 110 diastolic), prolonged CPR (\> 10 minutes), previous ischemic stroke, dementia, pregnancy, active ulcer - ### Lab tests completed, IVs in place - Check after administration: --------------------------- - ### Monitor for bleeding; coagulation lab tests - ### Neuro status / patient assessment - ### Do not give any injectable drugs, start/remove IVs; avoid invasive lines or procedures - Patient teaching: ----------------- - ### Report unusual symptoms, signs of bleeding, fever or SOA **REVIEW:** **\*Page 423. Box 26.1 -- Anticoagulation Therapy and Nursing Considerations** **\*Page 426. Safety: Lab Values related to Drug Therapy** **Case Study: Safety: What Went Wrong? Heparin Therapy (Key on Sherpath)** **Patient Centered Care: Patient Teaching** **Key points** **Critical thinking exercises (Key on Sherpath)** **Colony-Stimulating Factors (not in chapter)** =============================================== - Example drugs: -------------- - ### RBC (erythrocyte growth factors) - #### **e[poetin] and darbe[poetin]** - ### WBC (granulocyte colony-stimulating factor) - #### **Filgra[stim] and pegfilgra[stim]** - Intended responses: ------------------- - Side effects ------------ - ### more viscous blood may raise BP (HTN), - ### slow movement of blood through small vessels, - ### bone pain ### - Adverse effects --------------- - ### development of emboli resulting in: stroke; MI; PE - ### spleen rupture - ### Acute Respiratory Distress Syndrome (pegfilgrastim) - ### Capillary Leak Syndrome (pegfilgrastim) - Administration Considerations: check labs, baseline v/s, monitor for allergies/reactions, not for pregnant/breastfeeding, monitor for clotting, improvement of s/s and lab results. ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- - Patient teaching: ----------------- - ### Daily weights; report gain of \>2 lb in 24 hr - ### Report any signs of abnormal clotting - ### Report to emergency department for signs of heart attack, stroke, short of air - ### Hematuria, brown urine, decreased urine output - ### Self-injection technique ###