Anticoagulants Flashcards
Heparin-induced thrombocytopenia
- potentially fatal
- caused by antibody development
- reduce platelet counts
- paradoxical increase in thrombotic events
Heparins adverse effects
Bleeding
Localized bruising,petichiae, purpura
Nose bleeds, gum bleeding
Black tarry stool
Systemic hemorrhage
-tachycardia, hypotension
Heparin adverse effects
Low platelet count
Thrombocytopenia
Heparins contraindications
- Thrombocytopenia
- uncontrollable bleeding
- surgery on eye, brain or spinal cord
- spinal puncture/epidural
Heparins general info. How to give…
- Give it subcutaneous not IM
- inject in fatty areas- abdomen
- rotate sites
- don’t give injections within 2” of incisions, umbilicus,scars etc.
- don’t aspirated or massage injection site
Massaging or aspirating injection sites for heparins causes
Hematoma formation
Heparin IV doses are double checked with…
Another nurse
Labs run for heparin to monitor…
Coagulation effects
Normal Coagulation values are
25-35 seconds
Coagulation values goal w/ heparin…
1.5-2.5 times the norm. 45-70 sec.
What is the antidote for excessive anti coagulation?
Protamine
Prototype low-molecular-weight heparins
Enoxaparin ( Lovenox )
How is Enoxaparin ( Lovenox ) given?
1-2x/day subcutaneous
Does Enoxaparin require labs?
No. Can be given at home.
General info on Enoxaparin
Synthetic Heparin
Provides a more predictable response than Heparin.
Inactivates Xa(10a), less able to inactivate thrombin
What is hemostasis?
The process that halts bleeding.
How many stages to hemostasis?
2
Hemostasis stage 1 is
Formation of platelet plug
-platelet aggregation
Stage 2 hemostasis
Coagulation
- intrinsic coagulation
- extrinsic coagulation
Result of coagulation system
Fibrin… A clot forming substance
Conditions that cause clot (thrombus) formation
Stroke
MI
Deep vein thrombosis
Pulmonary embolism
What are the coagulation modifier drugs?
Anticoagulants
Antiplatelets
Thrombolytics
What are the different Anticoagulants?
Heparin
Low Molecular Weight Heparin
-Enoxaparin (Lovenox)
Selective Factor Xa(10a) Inhibitors
-Fondaparinux (Arixtra)
Warfarin(Coumadin)
Direct Thrombin Inhibitors
-Dibigatran (Pradaxa)
Direct Factor Xa (10a) Inhibitors
-Rivaroxaban (Xarelto)Low molecular weight heparin drug…
Enoxaparin (Lovenox)
Selective factor Xa drug
Fondaparinux (Arixtra)
Direct thrombin inhibitors drug
Dibigatran (Pradaxa)
Direct factor Xa inhibitors
Rivaroxaban (Xarelto)
Heparin (Unfractionated) mechanism of action
Inhibits clotting action IIa & Xa which enhances antithrombin and inhibits the formation of fibrin
Heparins indications
Prevention & Treatment of Low dose therapy postoperatively Deep vein thrombosis Pulmonary embolism Stroke MI Unstable angina Atrial fibrillation Mechanical devices like valves
Basic info on Heparin unfractionated
Rapid acting
Half life only 1-2hrs
Effects seen immediately
IV or SC only
Reversal agent for Heparin
Protamine Sulfate
It binds with Heparin given IV
Fondaparinux general info
Indirectly enhances activation of antithrombin
It suppresses coagulation
Given SC once a day
Fondaparinux does not affect
Prothrombin time, aPTT, bleeding time or platelet aggregation
General info in Warfarin
Inhibits vitamin K synthesis
Inhibits vitamin K-dependent clotting factors
Therapeutic uses of Warfarin
Prevention of clot formation
Not useful in emergencies due to slow onset
-half life 6hrs-2.5 days
Warfarin adverse effects
Bleeding
Warfarin contraindications
Pregnancy cat X
Thrombocytopenia
Eye, brain,spinal cord surgery
Vitamin K deficiency, liver disorder
Warfarin interactions-anticoagulant effects increased
Acetaminophen, sulfonamides, cephalosporins,heparin, aspirin….these all increase anticoagulant effects
Warfarin interactions-decreased anticoagulant effects
Phenobarbital, carbamazepine, phenytoin, rifampin, oral contraceptives, vitamin k
Labs to monitor for warfarin
Prothrombin time (PT)
- normal: 11-13 sec
- goal: 18 sec
INR
- normal:1
- goal: 2-3.5
Give ________for warfarin toxicity or OD.
Vitamin K
Warfarin nursing implications
Can be started while on heparin Full therapeutic effects take several days Monitor PT-INR regularly Avoid foods high in vitamin K -dark green leafy vegi -cabbage, broccoli, Brussels sprouts -mayo, canola oil, soybean oil
Dabigatran (Pradaxa) general info
Directly inhibit thrombin
Given orally twice daily
Does not require monitoring
Dibigatran indication
A fib
Dibigatran adverse effects
Bleeding
GI discomfort
Other Direct Thrombin Inhibitors
Argatroban, Bivalirudin, Lepirudin which is off the market now
Rivaroxaban general info
Directly binds with Factor Xa which inhibits thrombin production and suppresses coagulation
Does not require drug monitoring
Given orally twice a day
Rivaroxaban indication
Prevention of venous thromboembolism in adults undergoing elective hip or knee replacement
Rivaroxaban contraindications
Renal failure
Antiplatelets drugs prototypes
Aspirin Clopidogrel (plavix)
Aspirin general info
Inhibits cyclooxygenase in the platelet Prevents formation of TAX2 Reduces vasoconstriction & platelet aggregation 1 dose lasts for life of platelet-7 days 81mg/day
Clopidogrel (plavix)
ADP inhibitor
Inhibits platelet aggregation
More expensive than aspirin
Antiplatelets drug indications
Stroke prevention
TIA prevention
Reduce risk of MI
prevention of reinfarction after MI
Antiplatelet contraindications
Thrombocytopenia Active bleeding Leukemia Injury GI ulcer Brain bleed Recent stroke
Aspirin adverse effects
Dizziness, tinnitus, hearing loss GI Bleeding Thrombocytopenia Stroke
Clopidogrel adverse effects
GI
Bleeding-less than aspirin
Antiplatelet drug interactions
Drugs that cause bleeding such as
Heparin warfarin aspirin NSAIDs
Antiplatelet nursing implications
Discontinue 7 days before surgery
What do Thrombolytics do?
Clot busters
Break down Lyse clots that are already formed
Converts plasminogen to plasmin which destroys fibrin
Thrombolytic prototype drug
Alteplase (Cathflo Activase)
General info on alteplase
Given IV
Streptokinase
-increase risk of allergic reactions & hypotension
-less risk of brain bleed
Alteplase indications
Acute MI Arterial Thrombolysis DVT Pulmonary Embolus Acute ischemic stroke Occlusion of shunts or catheters
Alteplase adverse effects
Serious risk of bleeding
Nausea, vomiting, hypotension
Alteplase contraindications
Prior brain bleed Structural cerebral vascular lesion Active internal bleeding Brain tumor Suspected aortic dissection
Alteplase nursing implications
Monitor IV sites for bleeding redness pain
Bleeding from mucus membranes
Watch for increased pulse, restlessness
Risk of Coronary Heart Disease if cholesterol is higher than 300 is 3-4x greater than if less than 200
.
Cholesterol screening
Every 5 years
Total less than 200
LDL less than 100
Tri less than 150
Antilipemic treatment info
Used to lower lipid levels in combo with diet & exercise
HMG-CoA reductase Inhibitors prototype drug
Statins…Atorvastatin (Lipitor)
HMG-CoA mech of action
Inhibit HMG-CoA reductase used by liver to make cholesterol
Liver increase LDL receptors
Takes 6-8 weeks to see max results
HMG-CoA contraindications
Pregnancy-cat X
Hepatitis
HMG-CoA adverse effects
GI
Liver enzyme elevation
Muscle pain-myopathy
HMG-CoA interactions
Fibrates & oral antidiabetic drugs increase risk of Rhabdomyolysis
Grapefruit juice & Erythromycin increase levels of statins
Bile Acid Sequestrants prototype drug
Colesevelam (WelChol)
2nd line drug
Colesevelam (WelChol) mech of action
Prevent resorption of bile acids from small intestine which are necessary for absorption of cholesterol.
Liver tries to compensate by adding more LDL receptors thus less LDL in circulation
Colesevelam (WelChol) interactions
Hyperlipoproteinemia
Relief of puritis
Can be used with statins
Colesevelam (WelChol) adverse effects
Constipation
Heartburn, nausea, belching, bloating
-tend to go away in time
Colesevelam (WelChol) contraindications
Biliary or bowel obstruction
Colesevelam (WelChol) interactions
Other drugs taken at the same time
Take other drugs 1 hr before or 3-4 hrs after
Niacin general info
Nicotinic Acid
Vitamin B3
Lipid lowering requires much higher dose than vitamin
Effective, inexpensive, used in combo with other drugs
Start low initial dose and gradually increase
Niacin Indications
Lowers triglycerides & LDL
Increases HDL better than any other drugs
Niacin adverse effects
Flushing-diminishes after a few weeks, can take aspirin 30 min before Puritis GI distress Hepatotoxic Hyperglycemia Hyperuricemia
Niacin contraindications
Liver disease
Gout
Niacin interactions
HMG-CoA (statin) causes Rhabdomyolysis
Fibrates prototype drug
Gemfibrozil (Lopid)
Gemfibrozil (Lopid) Fibrates indications
Decrease triglycerides - most effective drug for this
Increase HDL by 25%
Gemfibrozil (Lopid) Fibrates adverse effects
GI distress are mild
gallstones
Myopathy-muscle pain
Hepatotoxicity
Gemfibrozil (Lopid) Fibrates contraindications
Severe liver or kidney disease
Cirrhosis
Gallbladder disease
Gemfibrozil (Lopid) Fibrates interactions
Oral anticoagulants increase risk of bleeding
Statin increase risk of rhabdomyosis
Take before eating
Cholesterol Absorption Inhibitor prototype drug
Ezetimibe
Cholesterol Absorption Inhibitor Ezetimibe general info
Inhibits absorption from the small intestine
Reduces total cholesterol, LDL & tri levels
Increases HDL
Clinical usefulness is currently questioned. New trials underway
Cholesterol Absorption Inhibitor Ezetimibe nursing implications
Before therapy:
Assess lifestyle & history, contraindications & interactions
Get baseline level labs
