Anticoagulation, Antiplatelets

Question 1

Aspirin

Answer 1

Anti-platelet

Irreversibly inhibits formation of prostaglandin

Uses: stroke prophylaxis, MI recurrence

Adverse: GI bleeding

81 mg / day

Give to adults 50-59 if CVD risk is 10 % or greater

Still controversial with people 60-69 with a greater > 10 % CVD risk

Question 2

Cilostazol

Answer 2

Uses : intermittent claudication

Question 3

Ticlopidine, Clopidogrel, Prasugrel, Ticagrelor

Answer 3

Uses :

Clopidogrel :
prevention of ACL events, PAD, thrombosis prophylaxis in a true MI or unstable angina, PCI w/ or w/o stenting ( 300-600 loading dose)

Question 4

Dual Anti-platelet Therapy

Answer 4

Combination of ASA and a P2Y12 inhibitor

Ex. Plavix, Prasurgrel, Ticagrelor

Early uses limits platelet adhesion and aggregation in the formation of occlusive coronary artery thrombus

Question 5

DAPT duration

Answer 5

Delicate balance between decrease ischemic risk and increase bleeding risk

Consider shorter duration in low ischemic risk and high risk of bleeding

Consider longer duration in high ischemic risk and low risk of bleeding

Question 6

Plavix, Prasugrel and Ticagrelor half lives

Answer 6

Plavix - .5 h ( hold five days prior to surgery

Prasugrel - 7 hours ( hold 7 days)

Ticagrelor - 9 hours ( hold 5 days)

Question 7

Dipyrimadole

Answer 7

Off label use: stroke prevention

Question 8

Apixaban and Riveroxaban

Answer 8

Anti-coagulant

Works on the factor 10 a to inhibit platelet activation and fibrin clot formation

Uses: DVT/PE, post operative venous thromboprophyllaxisis.

Reversal: andexanet alpha

Dosing:
DVT: A: 10 mg BID for 7 days then 5 mg BID x 3 months
R: 15 mg BID for 21 days followed by 20 mg QD x 3 months

Question 9

Conversion from warfarin to A and R

Answer 9

d/c warfarin and initiate A when INR < 2

D/c warfarin and initiate as soon as INR falls to < 3

Question 10

Conversion from A and R to warfarin

Answer 10

D/c A and initiate warfarin at the at the time of the next dose of A

D/c R and initiate warfarin at the same time the next dose of R would have been given

Question 11

Dabigitran

Answer 11

Direct thrombin inhibitor that inhibits both free and fibrin bound thrombin

Uses: DVT and NVAF, and post op ( Hips)

Question 12

Unfractionated Heparin

MOA, Monitoring, watch for, advantages, disadvantages

Answer 12

Accelerates activity of antithrombin III to inactive thrombin and other clotting factors

Preferred anticoagulant during preg

Monitoring : APTT 3-4 ( normal 60-80) hours after starting , platelet count, HgB, Hct

Watch for: hemorrhage, heparin induced thrombocytopenia, hypersensitivity

Advantages: rapid onset/ off set 
Disadvantages: narrow therapuetic index 
-  thrombocytopenia
- uncontrolled bleeding 
- during and immediately after surgery of the eye, brain and spinal cord

Question 13

Low molecular weight heparins

Answer 13

Lovenox, Arixtra, fragmin

MOA: inactivation of factor Xá

Uses: preferred over PO anticoagulation for cancer pt , VTE, PE, MI

Question 14

Warfarin

Answer 14

MOA: depletes vit K reserves and reduces synthesis of clotting factors II, VII, IX and X ( has a delayed on set)

Uses: mechanic cardiac valves , NVAF, a flutter

dosing : INR goal : 2-3 or 2.5-3.5
- start lower dose for pt required w/ hepatic impairment, poor nutrition, CHF, elderly, high risk bleeding

Constant education about INR range

Question 15

Clinical pearls for Warfarin

Answer 15

Pt ed: report bleeding, accidents or falls, herbal meds, dietary changes, alcohol intake

JCAHO- pt on anticoagulants just recieved individualized care through a defined process that includes standardized ordering, dispensing , education, monitoring

INR does not measure warfarin but rather its EFFECTS

Anticoagulation is attained not when serum levels of warfarin are achieved but when the level of coagulation factor deplete . Could take up to 5 days.