Heme pharm

Question 1

protamine sulfate

-MoA

Answer 1

-rapid reversal of heparin (positively charged sulfate binds to negatively charged heparin –> inactivation)

Question 2

fresh frozen plasma

Answer 2

• contains all proteins + clotting factors

- used for rapid reversal of warfarin

Question 3

“-plase” drugs (alteplase, reteplase, tenecteplase)

• MoA
• uses
• contraindications
• adverse effects

Answer 3

• thrombolytics (alteplase=tPA)
• convert plasminogen –> plasmin –> lysis of fibrin-clots in a more specific/controlled manner compared to streptokinase & urokinase
• ischemic stroke, early STEMI, severe PE
• contraindicated in patients with history of cerebral hemorrhage, recent surgery, bleeding disorders, current active bleeding
• reperfusion injury (esp. for MI and ischemic strokes), intracranial hemorrhage, GI hemorrhage

Question 4

abciximab

• MoA
• uses

Answer 4

• monoclonal antibody that binds to the glycoprotein receptor Gp2b/3a on activated platelets to prevent it from binding to fibrinogen –> no platelet aggregation
• unstable angina, especially in the setting of PCI

Question 5

agotroban, dabigatran, & bivalirudin

• MoA
• uses

Answer 5

• direct thrombin (factor 2a) inhibitors
• bivalirudin is related to anticoagulant used by leeches
• *dabigatran is the only oral agent
• used for venous thromboembolism, prophylaxis for patients with Afib, and can be used in HIT (thrombin is needed to stabilize the platelet plug; without it, the plug falls apart)
• benefit=no INR monitoring

Question 6

clopidogrel

• MoA
• uses

Answer 6

• irreversibly blocks ADP receptor (aka-P2Y12 receptor) –> prevents exposure of Gp2b/3a glycoprotein on platelet surface
• used in acute coronary syndrome (esp. in stenting) and stable angina (alternative to low-dose aspirin in patients with ulcers)

Question 7

rivaroxaban & apixaban

• MoA
• uses

Answer 7

• factor Xa inhibitors –> inhibit conversion of prothrombin (factor 2) to thrombin (factor 2a)
• used for venous thromboembolism and prophylaxis in Afib patients
• also do not require INR monitoring so can replace warfarin therapy

Question 8

enoxaparin

• MoA
• uses

Answer 8

-aka: low molecular weight heparin

• binds to anti-thrombin III with its pentasaccharide sequence to potentiate its activity but due to shorter side chain, it ONLY can help it inhibit factor Xa
• shorter side chain decreases risk of interactions that could lead to HIT
• can be used in mothers with DVT or PE (synthetic form of heparin can cross through placenta and warfarin is teratogenic)
• post-orthopedic surgery for DVT prophylaxis

Question 9

unfractionated heparin

• MoA
• uses

Answer 9

• longest form of heparin, most similar to endogenous form –> longer chain allows it to help anti-thrombin III inhibit BOTH factor Xa and thrombin!
• longer side chain increases risk of interactions –> increased risk of HIT
• pregnant mothers with DVT or PE
• post-orthopedic surgery for DVT prophylaxis