Chapter 52: Anticoagulants, Antiplatelet drugs, Thrombolytic Drugs Flashcards
Anticoagulants are used to treat what? Antiplatelets are used to treat what? What are thrombolytic drugs used to treat?
Anticoagulants: This is a class of drugs used to prevent thrombosis in both the venous system and atria. They also treat arterial thrombi, DVT, and PE
Antiplatelets: Used to prevent arterial thrombosis
Thrombolytic drugs: Used to dissolve newly formed thrombi.
What does heparin treat? Who is at risk for these conditions?
This is an anticoagulant that is used to treat PE and DVT. It is also used in patients who are undergoing open heart surgery and renal dialysis. It prevents coagulation in devices of extracorporeal circulation and post op thrombosis. It treats disseminated intravascular coagulation (DIC) and is used as adjunct treamtent with MI.
Pts at increased risk for developing these conditions: Patients who are/have immobility, broken bones, trauma, engage in sitting for long periods, pregnancy, use of BC pills, family hx of clotting disorders, inflammatory bowel disease, cancer, or heart disease. smoking, obesity, over 60yoa,
What does DVT look like?
pitting edema, pain, warmth in one leg, venous stasis ulcers, venous varicosities, signs of chronic venous insufficiency, one calf is 3-4cm larger than other.
How does PE present?
Dyspnea, hemoptysis, cough, wheezing, tachypnea, pulmonary crackles, chest pain, palpitations, tachycardia, lightheadedness, fever, neck vein distention, low pulse oximetry. **sudden severe hypotension and syncope, severe hypoxemia, or sudden cardiac arrest
What lab value needs to be monitored with heparin? What is the therapeutic range? What is the antidote for heparin overdose?
Activated partial prothromboplastin time (aPPT). Normal aPPT is 40 seconds. Therapeutic range: 60-80 sec. Initially, this needs to be monitored q4-6h until an effective dose is established. Daily measurement after this.
Antidote: Protamine Sulfate
Which patients are at risk for serious bleeding from heparin therapy?
Patients with hemophilia, increases capillary permeability, dissecting aneurysm, peptic ulcer disease, severe hypertension, or threatened abortion.
When is heparin use contraindicated?
immediately following and during surgery of the eye, brain, or spine. It is also contraindicated in patients who have a low platelet count, had regional anesthesia, or lumbar puncture.
What is heparin-induced thrombocytopenia? What are its S/S? What are appropriate interventions?
Immune-mediated disorder characterized by reduced platelet counts and increased thrombotic events.
S/S: low platelet counts, presence of thrombi while on anti-coagulant therapy, pain/swelling in legs, chest pain, dyspnea, anxiety, sweating, rapid; irregular heart beat.
Treatment: D/C heparin, starting a new anticoagulant.
What are the Low Molecular Weight Heparins (LMW)? How are they different from unfractionated heparin?
LMWs or fractionated Heparin (enoxaparin, daltaparin, and tinaparin) are different from unfractionated Heparin in that they do not require aPTT monitoring, can be administered at home by subQ injection. The rate of LMW dosage is fixed. Unfractionated heparin requires regular monitoring and must be given IV or subQ.
Which heparin costs more: unfractionated heparin or enoxaparin?
Unfractionated heparin: $3.00/day
Enoxaparin: $35.00/day (being able to administer at home and does not require monitoring offsets much the cost.) LMWs also have an extended half-life; reducing dosing to 1-2 times per day.
What are sites and route for each type of heparin?
Unfractionated heparin: subQ, IV
LMW heparins: SubQ
Sites: abdomen, anterior thigh, upper outer aspect of arm
What is the concern of giving patients enoxaparin post op DVT who have an epidural in place?
Heparin use is contraindicated with patients who have had lumbar puncture or spinal anesthesia. You would need to be hyper vigilant regarding neurological impairment as this may cause long and short term paralysis.
What is Warfarin (coumadin)
Vitamin K antagonist. It suppresses coagulation by decreasing production of four clotting factors. it is used for long term prophylaxsis of thrombosis. It binds readily to albumin, crosses membranes, long half life. Prothrombin Time (PT) used to monitor. NOw called INR.(international normalized ratio) 2-3 recommended range
How is it different from Heparin?
Heparin helps antithrombin inactivate clotting factors, Warfarin does not impact clotting factors in circulation. It decreases PRODUCTION of clotting factors. Warfarin can be taken at home PO. Warfarin has a much longer half-life.
Why would a patient who just developed a large DVT get heparin and not warfarin
Heparin is fast acting.
