anticoagulants Flashcards
Normal hemostasis
anticoagulant agents
use if someone has arrythmias
ischemic stroke
post op pts –> highest risk of afibb
unfractioned heparin
used mostly in OR
direct thrombin inhibitor
used more for ECMO
use if patient is allergic to heparin
Heparin
inactives Thrombin and activated factor X (factor Xa) thorugh an antithrombin (AT) - dependent mechanism - has an effect on thrombin
protamine
reverses heparin and low moleucular weight heparin
Heparin
HALF LIFE IS SHORT
excreted through kidneys, 50% unchanged and 50% changed
Prevention and treatment of venous thromboembolic disease, arterial thrombosis, and prevention of thrombosis in arterial or cardiac surgery
IV bolus, IV infsuion
HIT
Heparin-induced Thrombocytopenia
A systemic hypercoagulable state that occurs in 1-4% of patients
Risk is higher in surgical patients and lower in those treated with LMW heparins
direct thrombin inhibitorssss Drugs
Exert their effect by directly binding to active site of thrombin inhibiting its downstream effect
Direct thrombin inhibitors (DTI) used in clinical practice:
Bivalirudin
Argatroban
Bivalirudin (Angiomax)
when in OR Ex: bolus –> has the most data comparing to argatroban
always give infusion
20% clearance relies on kidneys
NO REVERSAL AGENT
monitor platelets
does not cause thrombocytopenia
argatroban
only binds to active site of thrombin
treatment for HIT
IV bolus and followed by continuous infusion
short half life
can use for clotting
does not get affected by argatroban
warfarin
only give when patent has mechanical valve
Prophylaxis and treatment of venous thromboembolism, artificial heart valves, atrial fibrillation or flutter, left ventricular thrombus, cardioembolic stroke, thromboprophylaxis, HIT
half lives goes from 20 - 60 hours
metabolism: hepatic
Excretion urine: 92% metabolites, minimal as unchanged drug
SLIDE 27
protein C
natural anticoagulant
warfarin**
Slide 28
Has LONG HALF LIFE
half lives goes from 20 - 60 hours
metabolism: hepatic
Excretion urine: 92% metabolites, minimal as unchanged drug
Warfarin Reversal
Vitamin K (phytonadione)
giving once is not going to be enough and will kick in for about 2 hours
full reversal in 24 hours
emergency reversal of warfarin
Risk of intracranial hemorrhage doubles for every 0.5 INR increase over 4.5
Reversal involves de novo synthesis of affected factors
–> Watch for long duration of warfarin effect
Half life: ~40 hours
Duration of effect: 2 – 5 days
FVII replenished before FII
FFP –> fresh frozen plasma
dose: 10-15 ml/kg
blood bank product –> risk of infection we usually stay away from it
FFP has clotting factors in it
prothrombin
Feiba
antiplatelet agents
aspirin
ADP-P2y inhibitors
clopidogrel
prasugrel
ticagrelor
ticlopidine
Phosphodiesterase inhibitors
Cilostazol
Dipyridamole
GP IIb/IIIa antagonists
factor VII
only time we use it for someone that is factor VII deficient may see it sometimes
dabigatran (Pradaxa)
indications: Non-valvular atrial fibrillation, venous thromboembolism (VTE)
Oral administration
half life 12-17 hours
renal impairment can increase half life
excretion: urine
aspirin mechanism of action
Inhibits synthesis of thromboxane A2 by irreversibly acetylation of cyclooxygenase (COX)
INdications:
Primary prevention of atherosclerotic cardiovascular disease in adults 40-70 at high risk, but not at an increased risk of bleeding
Aspirin pharmacokinetics
Administration: Oral
- Pharmacokinetics
Onset: Immediate
Half-life: 15–20 minutes
Duration: 4–6 hours, but platelet inhibitor effect lasts the lifetime of the platelet (~can last up to 10 days)
Excretion: urine
Monitoring: CBC
Adverse effect: Bleeding (specifically GI)
P2Y12 inhibitors
Mechanism of action: Reduce platelet aggregation by irreversibly blocking the ADP P2Y12 receptor on platelets
Clopidogrel
Clopidogrel
Indications:
Unstable angina, myocardial infarction, percutaneous coronary intervention, stroke, or peripheral artery disease
Dose:
Loading dose 300–600 mg once, maintenance dose 75 mg daily
Administration: Oral
Pharmacokinetics
Onset: dose-dependent 2 hours to 1 day
Half-life: 6 hours
Duration: 7–10 days
Excretion: urine + feces
Monitoring: CBC
Adverse effects: bleeding, thrombotic thrombocytopenic purpura
Prasugrel
Prasugrel
Indications:
Acute coronary syndrome managed by percutaneous coronary intervention
Dose:
60 mG loading dose followed by 5-10 mG daily
Administration: Oral
Pharmacokinetics
Onset: <30 minutes after loading dose
Half-life: 7 hours
Duration: 5–9 days
Excretion: urine + feces
Monitoring: CBC
Adverse effects: bleeding (higher bleeding risk than clopidogrel)
Contraindicated in patients with a history of TIA or stroke
cangrelor
Use most commonly on ECMO pts
Cangrelor is a parenteral P2Y12 inhibitor
Indications: Coronary interventions in patients without previous ADP P2Y12 inhibitor therapy and used for bridging therapy prior to cardiac surgery
Pharmacokinetics: Platelet inhibition occurs within 2 minutes and returns to normal within 2 hours after discontinuation
Desmopressin
uses for ASPIRIN REVERSAL
improves platelt function
