1. Understanding Anti Thrombotic
Drugs
Steven Podnos MD

2. Arterial and Venous Thrombi are
Different
• Arterial Thrombi are composed of platelets
bound by fibrin
• Venous thrombi are composed of fibrin and
trapped red blood cells, with rare platelets

3. What Drugs Work for Arterial vs.
Venous Thrombi
• Anti Platelet agents help with prevention and
treatment of Arterial (but not Venous)
Thrombosis
• Anticoagulants help with prevention of BOTH
Arterial and Venous Thrombosis

4. Anti Platelet Drugs
• Used primarily for Primary and Secondary
Prevention and Treatment of Acute Coronary
Syndrome (angina, non STEMI, STEMI, PCI)

5. Anti Platelet Drugs -ASA
• ASA-irreversible. Reduces risk of MI and death
by 15-25% in patients with ACS
• Slight benefit in prevention of MI in men and
stroke in women as primary Rx.

6. Anti Platelet Drugs -Persantine
• Dipyridamole-combined with ASA (Aggrenox)
prevents vascular events in patients after
TIA/minor stroke
• High incidence of HA
• Not better than Plavix alone

7. Thienopyridines-Plavix/Effient
• Both irreversible blockers of platelet
aggregation. Both have delayed onset
• Plavix (Clopidogrel)-some genetic variability in
metabolism
• Effient (Prasugrel)-more effective than
Plavix, but more bleeding, especially in older
patients

8. Ticagrelor (Brilinta)
• Reversible binding
• May be slightly more effective than Plavix if
used with small doses of ASA

9. Glycoprotein 2b/3a Receptor
Antagonists
• Abciximab (Reopro)
• Eptifibatide (Integrilin)
• Tirofiban (Aggrastat)
• All given IV
• Can see bleeding at puncture sites, can see
serious Thrombocytopenia

10. Anticoagulants
• Heparin-advantages-quick reversal, cheap, not
cleared by kidneys. Disadvantages-need
monitoring, more HIT
• LMWH-enoxaparin (Lovenox) and dalteparin
(Fragmin). At least as safe and effective as
Heparin in ACS. Also effective for Venous
thrombosis prevention and Rx.

11. Anticoagulants
• Fondaparinux-(Arixtra)
• As effective as LMWH in ACS except PCI
• Once a day
• Limited in renal insufficiency
• Less likely to cause HIT

12. Oral Anticoagulants
• Warfarin (Coumadin)
• Vitamin K antagonist-Factors 2,7,9,10
• Effective in VT, stroke prevention with A fib
(more than anti platelet drugs)
• Needs monitoring, can reverse with FFP and
Vit K

13. Oral Anticoagulants-Pradaxa
• Dabigatran
• No monitoring
• Irreversible, once a day (long acting)
• Effective for VT and A fib
• Direct Thrombin Inhibitor

14. Oral Anticoagulants-Xarelto
• Rivaroxaban
• Once daily
• Irreversible, no monitoring
• Seems at least as effective as Warfarin for VT
and A fib
• Direct Thrombin Inhibitor

15. Oral Anticoagulants-Eliquis
• Apixaban
• Yet to be approved by FDA
• Maybe better than Warfarin in Afib and
Lovenox in VT
• May not help with ACS
• Direct Thrombin Inhibitor

16. Direct Thrombin Inhibitors
• Bivalirudin (Angiomax)
• IV, short half life
• Used instead of Heparin/LMWH in PCI. ?
Maybe more effective with less bleeding

17. Issues
• Cost
• Lack of Monitoring
• Study outcomes for ACS, PCI, VT prevention
and Rx