Hematology: Coagulation Modifying Agents Flashcards
What is the therapeutic range for Partial Thromboplastin Time (PTT)?
40-70 seconds
What is the therapeutic range for Prothrombin Time (PT)?
18 seconds
What is the therapeutic range for International Normalized Ration (INR)?
2-3
What do anticoagulants do? What is it used for?
- Inhibit the action or formation of clotting factors
- Uses vary: prevent clot formation to prevent the extension of an established clot
What do antiplatelet drugs do?
Inhibit platelet adhesion at the site of blood vessel injury; essentially, stopping your platelets from sticking together
What do thrombolytic drugs do?
Lyse (break down) existing clots in the coronary arteries; reestablishes blood flow to the heart muscle
What do antifibrinolytic / hemostatic drugs do?
- All varying MOAs, but all prevent the lysis of fibrin
- Promote blood coagulation
Describe anticoagulants. What are they used to prevent?
- Also known as antithrombotic drugs
- Prevent intravascular thrombosis by decreasing blood coagulability
- Used prophylactically to prevent
~ Clot formation (thrombus)
~ An embolus (dislodged clot)
» Brain vessel -> stroke
» Coronary artery -> myocardial infarction (MI)
» Lungs -> pulmonary embolism
» Vein in the leg-> deep vein thrombosis (DVT)
List examples of older anticoagulant drugs.
- Heparin (Unfractionated)
- Warfarin
What is a common nursing consideration among all anticoagulants?
Assess for symptoms of bleeding and blood loss
What is a common patient education point among all anticoagulants?
Report any symptoms of unusual bleeding or bruising to HCP
What are some considerations when administering a subcutaneous anticoagulant injection?
- Administer subcut; do NOT expel the air bubble
~ Inject the entire needle at 45 or 90 degree angle (depending on what you can pinch)
~ Do NOT aspirate or massage
~ Do NOT administer IM (danger of hematoma)
What is a common patient education point for anticoagulants and antiplatelets?
Advise client to notify HCP of medication regimen prior to
treatment or surgery
How do you administer heparin for DVT prophylaxis?
5000 units subQ/subcut two or three times a day; aPPT does not need to be monitored when used for prophylaxis (or IV catheters)
What are some considerations for when heparin is used therapeutically as a continuous IV infusion?
- Measurement of aPTT (usually every 4-6 hours until therapeutic effects are seen; then daily once achieved)
- Antidote for overdose/toxicity is protamine sulfate
Heparin indication?
Prophylaxis & tx of various thromboembolic disorders
Heparin adverse effects?
Hem: BLEEDING, heparin induced thrombocytopenia (HIT), thrombocytopenia, hematoma, anemia
Heparin drug interactions?
Aspirin & NSAIDS (decreased platelet activity); Oral anticoagulants, antiplatelet drugs, and thrombolytics (additive effects)
Describe heparin-induced thrombocytopenia (HIT).
- Immune mediated adverse drug reaction caused by the emergence of antibodies that activate platelets in the presence of heparin
- May reduce platelets counts to as low as 5000/mm3
- May lead to increased resistance to heparin therapy
Heparin nursing considerations?
- Monitor aPTT and hematocrit prior to and periodically during therapy
- Subcut: observe injection sites for hematomas, ecchymosis, or inflammation
- For an overdose, protamine sulfate is the antidote
Heparin patient education?
- Instruct patient to avoid medications that contain aspirin or NSAIDs
- Caution patient to avoid IM injections and activities leading to injury
- Advise patient to use a soft toothbrush, not to floss and to us an electric razor during heparin therapy
- Educate patient on the importance of carrying an identification card or a medical alert bracelet or necklace at all times
Warfarin drug profile?
- Most commonly prescribed oral anticoagulant; PO only
- Careful monitoring of the prothrombin time/international normalized ratio (PT/INR)
- A normal INR (without warfarin) is 1.0, but a therapeutic INR (with warfarin) ranges from 2 to 3
- Dietary considerations- vitamin K consistent diet
- Antidote for overdose/toxicity is Vitamin K
Warfarin indication?
- Prophylaxis & tx: venous thrombosis, pulmonary embolism, a-fib
- Management of MI
- Prevention of thrombus formation after prosthetic valve replacement
Warfarin adverse effects?
- Hem: BLEEDING
- Derm: purple toes (rare, affects 1 in 5000 clients)
Warfarin nursing considerations?
- Monitor stool and urine for occult blood before and periodically during therapy
- Monitor PT and INR
- Monitor CBC, renal, and liver enzymes before and periodically throughout therapy
Warfarin patient education?
- Avoid cranberry juice or products during therapy
- Avoid IM injections, use a soft toothbrush, avoid flossing, and shave w/ an electric razor during therapy
- Do not to drink alcohol or take Rx, OTC, herbal products or start or stop any new medications during warfarin therapy w/o advice of their HCP
- Carry identification describing medication regimen at all times
List an example of a Low-molecular weight heparin (LMWHs). [Anticoagulant]
Enoxaparin
Enoxaparin drug profile?
- Higher degree of bioavailability and longer elimination half-life
- More predictable anticoagulant response, lab monitoring is not necessary
- Injectable form
- Used for prophylaxis and treatment
- “Bridge therapy”
- Pre-filled syringes
~ Do not expel air bubble
Enoxaparin indication?
- Prevention/Prophylaxis of venous thromboembolism (VTE), DVT, and/or PE
- Treatment of DVT w/ or w/o PE (with warfarin)
Enoxaparin contraindication?
patients w/ an indwelling epidural catheter
Enoxaparin adverse effects?
Hem: BLEEDING, thrombocytopenia, hematoma, anemia
Enoxaparin drug interactions?
- Risk of bleeding may increase by concurrent use of drugs that affect platelet function and coagulation:
~ Warfarin
~ Aspirin
~ NSAIDs
~ Clopidogrel
Enoxaparin nursing considerations?
- Monitor CBC, platelet count at the beginning and periodically throughout therapy
~ They can be restarted on any LMWH 2 hours AFTER the indwelling epidural catheter is removed - Administer subcut; do NOT expel the air bubble
- The ONLY time this medication is given IVP is for a STEMI
Enoxaparin patient education?
- Instruct patient in correct technique for self-injection care, and disposal of equipment (if using at home)
- Do not to take aspirin, naproxen, and/or ibuprofen w/o first discussing w/ their provider while on enoxaparin therapy
- Notify HCP of therapy before dental or medical treatments or surgery
Describe “Bridge Therapy.”
- “Bridging” refers to the use of short-acting anticoagulants (heparin or LMWH) during the interruption of warfarin
~ Warfarin is stopped 5-6 days before surgery to allow its anticoagulation effects to wane
~ Bridging w/ either heparin or LMWH is started 3 days before surgery w/ the last dose given 24 hours before surgery
~ Bridging is resumed no earlier than 24 hours after surgery
List examples of Direct Thrombin Inhibitors. [Anticoagulant]
- Dabigatran
- Argatroban
Dabigatran drug profile?
- First oral direct thrombin inhibitor approved for prevention of strokes and thrombosis in patients with nonvalvular atrial fibrillation
- Prodrug that becomes activated in the liver
- Antidote of overdose/toxicity is idarucizumab
Dabigatran indication?
Decreased risk of stroke (associated w/ a-fib)
Dabigatran adverse effects?
Hem: BLEEDING with increased GI Bleed
Misc: Fever, shortness of breath, urticaria (r/t hypersensitivity reaction)
Dabigatran drug interactions?
- Risk of bleeding may increase by concurrent use of anticoagulants and antiplatelet
- Rifampin and St. John’s wort can cause decreased drug effect