Anticoags

Question 0

Indirect Factor Xa inhibitor

Answer 0

Fonadparinux

• binds antithrombin with high specific activity, resulting in inactivation of factor Xa, inhibition and reduced size of clotting
• given SQ once daily
• used for prevention and tx of DVE and PE
• AE: bleeding, dont use in pts with renal problems, and preg

Question 1

Indirect Thrombin Inhibitors

Answer 1

Heparin: UFH, LMWH (enoxaparin)
Accelerates the action of antithrombin III. Binds to antithrombin III which undergoes change and neutralizes activated clotting factors.
LMWH inhibits activated factor Xa. given SQ. Used prophylaxis of DVT post op, tx of ischemic stroke and acute coronary stroke
UFH given IV or SQ - used to tx nd prevent DVT and pulmonary embolism, percutaneous coronary intervention, and relief from CP in unstable angina
-AE: bleeding, reversible low platelet count, osteoporosis (3+ mo of tx)
- elevation in plasma K+, could be problem in pt taking ACE

Question 2

Direct Thrombin inhibitors

Answer 2

alternative to heparin therapy
Bivalirudin, lepirudin, argatroban
- inhibit clot-bound and circulating thrombin factor IIa
-inhibit and reduced size of clotting
-given IV
can be used in place of heparin, or pts with heparin-induced thrombocytopenia
AE: bleeding

Question 3

Oral Anticoag

Answer 3

Warfarin (Coumadin)
-antagonize Vit K recycling, depleting vit K. decreases synthesis of vit K dependent coag clotting factors
-inhibition of clotting
-given orally
-1st line, used long term
AE: bleeding, fetal tox, liver and kidney tox, can be revered thru vit K admin
lots of drug/drug interactions inhibiting effect: abx, antiepileptic, antipsychotics, bile-acid binding, antacids steroids, OCP, vit C and K, St. John wort
Potentiating effect: acid-neutralizing agent, analgesics, abx, antidepressants, antifungals, statins, alcohol, cranberries, vit E

Question 4

thrombolytic agents

Answer 4

Streptokinase, anistreplaase and urokinse
TPAs: alteplase and reteplase
-MOA: cause the activation of plasmin from plasminogen, induces fibrinolysis
-Given IV
-Degrade existing thrombi in cases of MI, stroke, PE, DVT
AE: Bleeding, cerebral bleeding

Question 5

Anti-platelet Agents

Answer 5

• Aspirin: Inhibits platelet aggregation, prophylaxis or tx of stroke or MI, used after vascular surgery to prevent thrombosis. AE: bleeding, GI upset
• dipyridamole: inhibits platelet release, available in combo w/ aspirin for prevention of cerebrovascular ischemia, potentiate effect of ASA AE: vasodilation – flushing, HA, dizzy and hypotension
• Clopidogrel and Ticlopidine: inhibit ADP-induced platelet-fibrinogen binding and platelet-platelet interactions, used for pts who cant take ASA, pts having coronary stent placement, prevent MI, prevent thrombosis AE: low WBC
• Abciximab, eptifibatide, tirofiban: glycoprotein IIb/IIIa receptor antagonists, prevent platelet aggregation by competing w/ fibrinogen and willebrand factor. Blocks fibrinogen from binding platelets together. given IV. used for stent placement and angioplasty, prevent thrombosis. AE: bleeding, thrombocytopenia (abciximab)