Anti-Coagulants & Anti-Platelets Flashcards
Drugs that inhibit platelet aggregation to prevent thrombus formation.
Anti-Platelets
What are Anti-Platelets primarily used for?
Prevention of Arterial Thrombosis
Medication that irreversibly inhibits Cyclooxygenase-1 (COX-1) and Thromboxane A2
Aspirin
Medications that inhibit the P2Y12 receptor and block ADP-induced platelet aggregation.
Clopidogrel (Plavix)
Ticagrelor
GPIIb/IIIa Inhibitors
Abciximab
Eptifibatide
Medications that inhibits phosphodiesterase and adenosine uptake.
Dipyridamole
Cilostazol
Aspirin is used for the primary prevention of what pathology?
Myocardial Infarction
Adverse effect of Aspirin that occurs in pediatric populations.
Reye’s Syndrome
(Liver + Brain Swelling)
What are the signs and symptoms of Aspirin overdose?
Tinnitus
Vertigo
Nausea, Vomiting, Diarrhea
Hyperventilation
Respiratory Alkalosis
Metabolic Acidosis
Hypokalemia
Hypoglycemia
A Salicylate level of what would indicate Aspirin overdose?
> 40mg/dL
How do you treat Aspirin overdose?
ABCs
Activated Charcoal
Sodium Bicarbonate
Dialysis
Irreversible inhibitors of P2Y12 or ADP receptor.
Clopidogrel
Prasgurel
What are the indications for Clopidogrel (Plavix)
Unstable Angina
NSTEMI
STEMI
Stroke
Peripheral Arterial Disease
What is an adverse event that can occur due to Clopidogrel?
Thrombotic Thrombocytopenic Purpura
(Blood clots in small blood vessels)
What medications can Clopidogrel interact with?
CYP-2C19 Inhibitors
Omeprazole
If a patient has an allergy to Aspirin, what medication can be used as an alternative?
Plavix
Medication that is more potent and than Plavix and is preferred in ACS when strong anti-platelet action is required.
Prasugrel (Effient)
How is Prasugrel metabolized?
Prodrug
What is Prasugrel a substrate of?
CYP-2C19
What medication should be avoided with Prasugrel (Effient)
Omeprazole
What is the indication for Prasugrel (Effient)
STEMI
When is Prasugrel (Effient) contraindicated?
History of TIA or Stroke
What patients should you be very cautious with when using Prasugrel (Effient)
Elderly (75+)
Only if Diabetic or prior MI
Patients below what weight need a reduced dose of Prasugrel?
< 60kg
Medication that is a reversible inhibitor of P2Y12 or ADP.
Ticagrelor (Brilinita)
When is Ticagrelor used?
Acute Coronary Syndrome + Aspirin
(Maximum Aspirin dose of 100mg)
What drugs does Ticagrelor interact with?
CYP3A4 Inhibitors
5x increase with Anti-Fungal!
When is Ticagrelor contraindicated?
History of Intracranial Hemorrhage
Medications that bind to and irreversibly Inhibits GPIIb/IIIa receptors and block platelet aggregation.
GPIIB/IIIA Antagonists
(Abciximab + Eptifibatide & Tirofiban)
When are GPIIB/IIIA antagonists used?
Percutaneous Coronary Intervention
Acute Coronary Syndromes
What patients should you be cautious with when prescribing GPIIb/IIIa antagonists?
Renal Dysfunction (reduce dose)
What are some adverse drug reactions of Abciximab?
Anaphylaxis
Thrombocytopenia
What are some adverse drug reactions of Eptifibatide & Tirofiban?
Anaphylaxis
Thrombocytopenia
Renal Dysfunction
Medication that inhibits platelet function by inhibition adenosine uptake and cGMP phosphodiesterase activity (PDE3 Inhibitor)
Dipyridamole
When is Dipyridamole used?
With another Agent
(Aspirin or Warfarin)
What are the adverse effects of Dipyridamole (PDE3 Inhibitor)
Headaches
GI Distress
Dizziness
PDE3 Inhibitor that is used for Intermittent Claudication.
Cilostazol (Pletal)
What can cause interactions with Cilostazol (Pletal)
High Fat Diet = ↑ Level
Grapefruit = ↑ Level via CYP3A4
Medications used for prevention of Venous Thromboembolism and stroke prevention in A-Fib.
Anti-Coagulants
What are the three factors that contribute to the formation of blood clots in Virchow’s Triad?
Endothelial Injury
Hypercoagulability
Stasis
Vitamin K Antagonist that inhibits Vitamin K epoxide reductase.
Warfarin
Direct Factor Xa Inhibitors (Oral)
Apixaban (Eliquis)
Rivaroxaban (Xarelto)
Direct Thrombin Inhibitors (Oral)
Dabigatran (Pradaxa)
Medication that binds to Antithrombin III and allows for the inhibition of Thrombin and Factor Xa
Heparin
Type of Heparin that is preferred for outpatient use.
Low Molecular Weight Heparins
What clotting factors are inhibited by Warfarin? (S.N.T.T = Snot)
VII (7)
IX (9)
X (10)
II (2)
What proteins are inhibited by Warfarin?
Protein C and S
When is Warfarin indicated?
DVT + PE from Valvular and Non-Valvular A-Fib
Stroke Prophylaxis during:
- Cardioversion
- Rate Control Therapy
Reduce risk of embolism after MI
What must you bride with Warfarin until you reach a therapeutic INR?
Indirect Thrombin Inhibitor
What are some adverse effects of Warfarin?
Bleeding
Teratogenic
Skin Necrosis
CYP2C9
VKORC1
When using Warfarin, what is the goal INR?
2 - 3
What is the reversal agent for Warfarin and when is it given?
Vitamin K (orally)
INR of 4.5 - 10 or Pre-Surgery
Fresh Frozen Plasma for active bleeding
What medication can increase INR due to interacting with Warfarin?
Amiodarone
What medication can decrease INR due to interaction with Warfarin?
Rifampin
What Direct Factor Xa Inhibitor should be taken with food for doses above 10mg?
Rivaroxaban (Xarelto)
Medications that are metabolized by CYP3A4 and P-Glycoprotein. Should be avoided in patients with severe renal and hepatic impairment.
Direct Factor Xa Inhibitors
(Apixaban + Rivaroxaban)
What are the ABCs of prescribing Apixaban?
A = Age 80+
B = Body Mass ≤ 60kg
C = Creatinine 1.5+
DO NOT GIVE IF AT LEAST 2 of THESE
Direct Thrombin Inhibitors that are given Parenteral.
Bivalirudin
Argatroban
Direct Thrombin Inhibitor that is given parenterally for Percutaneous Coronary Intervention (PCI)
Bivalirudin
Direct Thrombin Inhibitor that is given parenterally for Heparin-Induced Thrombocytopenia (HIT) and PCI
Argatroban (Acova)
Direct Thrombin Inhbitor that is given orally. It does not require routine monitoring, doesn’t interact with CYP450, and has a rapid onset and offset.
Dabigatran (Pradaxa)
What are the Black Box Warnings on Dabigatran (Pradaxa)
Spinal + Epidural Hematomas
Abrupt Discontinuation
What is the reversal agent for Direct Oral Anti-Coagulants (Factor Xa) such as Eliquis and Xarelto
Andexxa
What is the reversal agent for Dabigatran?
Idarucizumab
Binds to enzyme inhibitor antithrombin III and inactivates clotting factors IIa (Fibrin) and Xa
Unfractionated Heparin
Binds to Antithrombin III but not Fibrin.
Low Molecular Weight Heparin
Synthetic Heparin
Heparin that is used primarily in the prevention of clotting in arterial and cardiac surgery and to maintain patency of IV devices and for Dialysis patients.
Unfractionated Heparin
Name three Low-Molecular Weight Heparins.
Enoxaparin
Dalteparin
Tinzaparin
When is Low-Molecular Weight Heparin preferred?
(TOP)
Trauma
Oncology
Pregnancy
Patients taking Direct Oral Anticoagulants (Eliquis + Xarelto) can have weight false reading?
Falsely Elevated PTT Levels
What is an advantage of Unfractionated Heparin?
NO RENAL DOSING
Adverse drug reactions caused by Heparin.
HIT
Platelet Factor 4-Heparin
(5-14 days after starting Heparin)
How do you treat HIT?
Stop Heparin
NO PLATELET TRANSPLANT
Replace with Fondiparinux
What is the reversal agent for Heparin?
Protamine
Medications that cause fibrinolysis by binding to fibrin in a clot and converting entrapped plasminogen to active plasmin.
Fibrinolytics
(Clot Busters)
Name three Fibrinolytics.
Alteplase
Reteplase
Tenecteplase
When do you use Fibrinolytics?
Stroke
PE
STEMI
How soon must a Fibrinolytic be given after symptom onset?
Within 3 hours
Contraindications for Fibrinolytics.
Bleeds
Stroke in last 3 months
Brain or Spine surgery in last 3 months
Serious head trauma in last 3 months
Uncontrolled Severe Hypertension
Brain lesions or aneurysm or malformation
What are some advantages of Tenecteplase over Alteplase
Better Outcomes at 90 days
Cheaper
Less bleeding
Less Adverse Drug Reactions
