Pharmacology Quiz 2-Anti-Coagulants Flashcards
Hemophelia
The body hates clotting; factor II, VII, VIII, XI deficiency
Hypercoagulable State
The body loves clotting; could be do to cancer, trauma, DVT, pulmonary embolism, prolonged immobility,
DVT
Deep vein thrombosis; clot in the venous system; generally the legs due to poor flow
PE
Pulmonary embolism; clot in the pulmonary veins, commonly emboli from a DVT
Antithrombotic Agents
Antiplatelet OR anticoagulant agents;
Antiplatelet agent
Under the antithrombotic agents; inhibits platelet function
Anticoagulant Agents
Under the antithrombotic agents; alters clotting factors and prevents thrombus formation
Thrombolytic Agents
Helps breakdown thrombus after it has formed to restore flow
The Clotting Cascade
The “contact factor” (intrinsic) and “tissue factor” (extrinsic) are turned on due to damage to the blood vessel; this leads to a cascade of clotting factors (XII, XI, IX, X) in the intrinsic pathway and (VII, X, tissue factor) in the extrinsic factor; all lead to Xa being created; Xa converts prothrombin to thrombin, fibrinogen to fibrin, and eventually to a cross linked fibrin clot
Unfractionated Heparin: general
Along with an antithrombin, the heparin binds to thrombin and factor Xa so it can’t create the clot in the cascade; acts quickly, and doesn’t last that long; only given IV or subQ; derived from pork; more monitoring than LMWH
Heparin: therapeutic uses, monitoring, side effects
Used for ACS, atrial fibrillation, medical/surgical VTE (venous thromboembolism) prophylaxis, prosthetic heart valves, trauma, venous thromboembolism; monitor bleeding, anti-Xa levels, H/h, platelets; side effects include bleeding and thrombocytopenia; anticoagulant
Heparin Induced Thrombocytopenia
Profound drop in platelet levels secondary to heparin use; occurs between 5-10 days after heparin exposure; high rate of thrombus formation –> amputation/death; must discontinue ALL heparin use; do not initiate another type of antithrombotic agent; a “heparin allergy”
Low Molecular Weight Heparin: general
LMWH with an antithrombin bind only to factor Xa to prevent it from creating a clot; work less quickly but last longer; more predictable response; only SubQ or IV; derived from pork; not as much monitoring required; good option for VTE; more expensive; anticoagulant; enaxoparin, dalteparin
LMWH: uses, monitoring, side effects, cautions
Used for ACS, atrial fibrillation, medical/surgical VTE prophylaxis, prosthetic heart valves, trauma, and VTE; monitor sx/sy of bleeding, h/h platelets, anti-Xa levels; side effects of bleeding and thrombocytopenia; careful for renal failure/pregnancy/obesity;
Factor Xa Inhibitor
Anticoagulant; fondaparinux; factor Xa Inhibitor; used for ACS, VTE prophylaxis, VTE, valve replacement; subQ dosing once a day; could decrease risk of thrombocytopenia
Warfarin
Anticoagulant, blocked Vitamin K from being utilized in the clotting cascade (VII, IX, X, II clotting factors depend on K); used for prophylaxis of venous thrombosis, treatment of VTE, prevention of secondary embolism, acute MI, valvular heart disease, a-fib, heart valves, anti-phospholipid antibody syndrome; monitor s/sx of bleeding, H/h, and platelets; side effects= bleeding and skin necrosis; lots of contraindications! (Pregnancy, surgery, CVA, senile, alcoholic, dissecting aorta); administered orally (takes a few days before effect is seen, so start with a parenteral agent); requires close monitoring and is highly affected by diet/meds/genetics
Direct Thrombin Inhibitor
Anti-Coagulant; dabigatran (Pradaxa); used for non-valvular a-fib and treatment and secondary prevention of VTE; orally administered twice daily; monitor bleeding, h/h, renal function; side effects = bleeding, GI effects;
Oral Factor Xa Inhibitor
Rivaroxaban (xarelto), apixaban (Eliquis), edoxaban (savaysa); used for non-valvular a-fib, treatment and secondary prophylaxis for VTE; monitor s/sx of bleeding, h/h, renal function; side effects = bleeding
Aspirin
An anti-platelet; used for chronic stable/unstable angina; primary/secondary MI prevention; treatment of MI; PCI/PCTA/CABG; primary/secondary TIA/stroke prevention; atrial fib; side effects= GI intolerance and bleeding; monitor bleeding; caution with children, GI bleed, or allergy to NSAIDs
Antiplatelet Agents: P2Y12 Inhibitors
Blocks thienopyridine from becoming part of the GP-IIb and IIIa aggregation; clopidogrel (Plavix), prasugrel (Effient), and ticagrelor (Brilinta); used with aspirin for at least 1 year in patients who are post-ACS, undergoing PCI, and sometimes CABG; to use it alone, it is for secondary stroke prevention, PAD, and as an alternative to aspirin; monitor bleeding and CV events; side effects= bleeding, headache, dyspnea; cautions= active bleeding, history of stroke, patients who are elderly or less than 60kg, chronic aspirin dose;
Glycoproteins IIb/IIIa Inhibitor
An antiplatelet; Abciximab (Reopro), Eptifibatide (Integrilin), Tirofiban (Aggrastat) inhibits platelet aggregation by preventing fibrinogen from binding to the GP IIb/IIIa receptor; used for ACS; not available orally, so only administered IV; monitor s/sx of bleeding, h/h, platelets, and renal fxn; side effects= bleeding; no reversal agent;
Thrombolytics
Breakdown already formed thrombus –> re-establish blood flow; streptokinase, alteplase, reteplase, tenecteplase; tissue plasminogen activator that helps break down clots (produces a cascade that leads to clot being broken down); used for stroke, AMI, massive PE, or catheter clearance; monitor bleeding/vitals; cautions= history of CVA, GI bleed, trauma, or major surgery; HTN; aortic dissection; active bleeding; suspected ICH
Statins: mechanism of action
Atorvastatin (lipitor), fluvastatin (lescol), etc.Decrease cholesterol production in the liver, up-regulates LDL surface receptors –> LDL breakdown –> VLDL production –> decreases LDL production; has other benefits such as plaque reduction, antioxidant effects, and antithrombotic effects; HMG-CoA reductive inhibitors (the pathway that makes cholesterol); statins stop HMG-CoA from becoming mevalonate which eventually becomes cholesterol
Statins: uses, monitoring, side effects
used for dyslipidemia, post-MI, primary prevention of CV disease; monitor lipids, CPK, baseline LFTs; side effects= headache, GI, myalgia, rhabdomyolysis (rare but very serious); caution=liver disease
Fabric Acid Derivatives
Primarily used for hypertriglyceridemia alone or in conjunction with other agents; lipoprotein lipase enzyme –> decrease TG levels and VLDL breakdown; gemfibrozil (lopid) and fenofibrate (tricor);
Other Lipid Lowering Agents
Nicotinic Acid (niacin), vitamin B3, which decreases LDL synthesis, may cause flushing; bile acid sequesterants (cholestyramine-Questran); ezetimibe (zetia); bile acid and ezetimibe decreases GI absorption; use caution when combining a statin + a fabric acid;
Special Considerations of Anti-Coagulants
Be aware of increased risk of bleeding in patients on these meds (especially post-hip/knee surgery); be aware of patients with hemophilia; watch out for myopathies secondary to lipid lowering agents; help with compliance