Clotting disorders/anticoagulation Flashcards

Question

# warfarin Diagnosing hypercoagulable states in patients receiving warfarin

Answer 1

Warfarin inhibits synthesis of all Vitamin K dependent proteins, including Protein C and S Warfarin initially decreases protein C levels faster than the other coagulation factors Paradoxically increases blood's tendency to coagulate when treatment is first begun --> warfarin necrosis Why we start additional anticoagulant first Warfarin necrosis more frequent in patients with Protein C and S deficiency

Answer 2

Initiation and discontinuation of medications Antibiotics Anti-convulsants Anti-fungals Antacids Febrile illnesses Gastroenteritis Liver disease Vitamin K containing foods Enteral feeds Mango Avocado Fish Oil Soy milk Grapefruit

Answer 3

Vitamin K 2-5 mg PO, SQ or IV IV slow infusion due to anaphylaxis Fresh Frozen Plasma Stops bleeding but does not completely reverse VKAs Prothrombin Complex Concentrates Contain many Vitamin K dependent proteins at high concentration

Answer 4

Unfractionated heparin infusion/injection Low molecular weight heparin injections Fondaparinux injections

Answer 5

Naturally occurring anticoagulant **Binds reversibly to antithrombin** Increases antithrombin’s inhibition of thrombin and Factor Xa Dosing: Bolus followed by continuous infusion PTT (target range 65-80 seconds or 1.5-2.5X baseline) Sensitive to improper collection, anemia, thrombocytopenia, factor deficiencies, lupus anticoagulant, age Monitor every 4-6 hours after dose change and daily

Answer 6

Low dose: Inactivates factor Xa and inhibits conversion of prothrombin to thrombin High dose: Inactivates factors IX, X, XI, and XII and thrombin and inhibits conversion of fibrinogen to fibrin Also inhibits activation of factor VIII

Answer 7

Binds to and accelerates the activity of AT, but with a preferential and longer-lasting effect on Xa Less able to inhibit thrombin and bind to other plasma proteins Brand Names: Lovenox Another common one is Fragmin (Dalteparin) but dosed differently Dosing: 1 mg/kg SC BID or 1.5mg/kg SC daily No monitoring bloodwork for dosing needed Peak anti-Xa level is 2 to 6 hours after administration Obtain level 4-6 hours after dose Goal 0.5 to 1.0 U/ml for treatment

Answer 8

Binds and enhances activity of AT by 300-fold Does not bind to other plasma proteins No direct effect on thrombin Dosing: Weight based. Most commonly 7.5mg SC once daily Therapeutic dose lab monitoring not required Anti-Xa activity can be obtained

Answer 9

Reversibly binds to the active thrombin site of free and clot-associated thrombin. Inhibits fibrin formation; activation of coagulation factors V, VIII, and XIII; activation of protein C; and platelet aggregation. Onset: immediate Use: HIT, Heart catheterization Dosing: Weight based/min infusion- Dialyzable May be a combined effect on the INR when argatroban is used with warfarin Loading doses of warfarin should not be used The ACP suggests monitoring chromogenic factor X assay Adverse effects: Hypotension, bleeding, fever Caution with hepatic impairment

Answer 10

Use: VTE, Afib Dosing (VTE): 150 mg twice daily Avoid in moderate to severe renal impairment Adverse effects: Hemorrhage, abdominal pain, dyspepsia

Answer 11

Inhibits platelet activation and fibrin clot formation via inhibition of free and clot-bound factor Xa Comparable efficacy to VKA in adults, but with significantly lower risk of bleeding Reversal agents FDA approved A prolonged PT suggests clinically relevant serum concentrations are present, but normal PT and aPTT values cannot rule out the presence. Anti-factor Xa activity can be ordered.

Answer 12

Pregnancy: Insufficient data Monitoring: CBC, aPTT, PT, serum creatinine, and liver function tests prior to initiation and at least annually Surgeries which raise the pH of the stomach (Roux-en-Y gastric bypass) or decrease small intestine may decrease absorption of edoxaban Not recommended for patients with triple-positive antiphospholipid syndromes (lupus anticoagulant, anticardiolipin, and anti-beta 2-glycoprotein I) May have increased rates of recurrent thrombotic events compared with vitamin K antagonist therapy Avoid removal of epidural or intrathecal catheter for at least 12 hours following last edoxaban dose and avoid next dose for at least 2 hours following catheter removal due to risk of spinal or epidural hematomas.

Answer 13

Use: DVT/PE, Afib, approved for cancer patients Dosage (VTE): Patient weight >60 kg: 60 mg once daily Patient weight ≤60 kg: 30 mg once daily Use is not recommended in mod-severe hepatic and severe renal impairment Adverse effects: Hemorrhage

Answer 14

Use: VTE, Afib, prophylaxis, approved for cancer patients Dosage (VTE): 10 mg twice daily for 7 days followed by 5 mg twice daily Avoid in moderate to severe liver impairment Adverse effects: Hemorrhage

Answer 15

Use: DVT/PE (may use in active cancer), Afib, CAD, PAD, SVT Dosing (VTE): 15 mg twice daily with food for 21 days followed by 20 mg once daily with food Avoid in moderate to severe liver and severe renal impairment Adverse effects: Hemorrhage, gastroenteritis, vomiting May contain lactose

Answer 16

Activate plasminogen to form plasmin, which accelerates the lysis of thrombi Rapid clot lysis provides symptom relief and restores limb perfusion Catheter directed therapy performed by surgeon or interventional radiologist May place IVC filter at same time Drug: Tissue plasminogen activator (tPA) Dose: 0.5 to 1 mg/hour Anticoagulant therapy (typically unfractionated heparin) is generally continued before, during, and after the thrombolytic infusion Assess clinically for pulmonary embolism and any changes in neurologic or mental status Adverse effect: Bleeding <2%

Answer 17

Active major bleeding Significant potential for uncontrolled local bleeding Surgery within preceding 10 days Neurosurgery, including spinal surgery, within preceding 60 days Seizures within 48 hours Sepsis Elevated serum creatinine Uncontrolled hypertension Contrast allergy

Answer 18

Tissue plasminogen activator (tPA) is the most used thrombolytic agent Catheter-Directed Thrombolysis Placement of large-bore catheter into the vein affected by the DVT to allow slow, direct infusion of thrombolytic agent into the thrombus Systemic Thrombolysis

Answer 19

Medical leaches (hirudinea) Use dates to ancient Greece and Egypt Bloodletting to prevent disease and cure illness Medical leach farms Anesthetized and disposed off after one use Current FDA approved use Tissue graft venous congestion

Clotting disorders/anticoagulation Flashcards

(44 cards)