Exam 3 - Platelet Inhibitors & Anticoagulants

Question 1

Arterial Thrombus

Answer 1

• platelets

- due to atherosclerosis

Question 2

Venous thrombosis

Answer 2

• fibrin and fewer platelets

- via blood stasis or inappropriate activation of coag cascade

Question 3

Thrombotic disorders

Answer 3

• MI
• Stroke
• DVT
• PE

Question 4

Resting endothelial cells

Answer 4

• release NO and prostacyclin (platelet inhibitors)
• NO/Pr bind to platelet and increase cAMP
• that decreases Ca and inhibit platelet activation
• also stabilize GP IIb/IIIa receptors and inhibit granule release

Question 5

Platelet response to injury of endothelium

Answer 5

• platelets bind to exposed collagen and activate
• trigger release of chemical mediators
• trigger platelet recruitment / aggregation
• release granules…ADP, Serotonin, TXA2, Thrombin, PAF
• this increase Ca, stimulates GP IIb/IIIa receptors, low cAMP
• stimulate fibrinogen production

Question 6

COX - cyclooxygenase

Answer 6

Mediates arachidonic acid into prostaglandin H

Question 7

Platelet inhibitor used for:

Answer 7

• occlusive cardiovascular disease
• arterial graft patency
• supplement to thrombin inhibitor

Question 8

Aspirin

Answer 8

• inactivates COX 1 by adding acetyl group
• IRRIVERSIBLE (7-10 days)
• blocks Thromboxane A2 synthesis which then blocks platelet aggregation

Question 9

Aspirin therapeutic uses

Answer 9

• anti-inflammatory
• analgesic action
• antipyretic (drop in prostaglandin)
• external application for acne, corns, warts

Question 10

Low dose aspirin

Answer 10

• 81 mg
• reduce recurrent cardiovascular events and with angina
• reduce TIA/stroke
• reduce death in revascularization
• continued inhibition of platelets

Question 11

Aspirin adverse effects

Answer 11

• GI bleeds
• ulcers
• risk of bleeding in surgery….stop one week prior
• hemorrhage stroke
• kidney damage…blocks prostaglandins…retain salt and water…drop renal flow
• avoid in < 20 yo with viral infections…reye syndrome

Question 12

Aspirin pharmokinetics

Answer 12

• turned into salicylate
• can cross BBB/placenta
• salicylates absorbed through skin and cleared by kidney

Question 13

Aspirin low dose

Answer 13

• < 2000 mg/day
• HL: 3.5 hrs
• 1st order….[ ] dependent….higher dose….higher cleared

Question 14

Aspirin high dose

Answer 14

• HL: 15+ hours

- zero order… [ ] independent

Question 15

Ticlopidine

Answer 15

• TIA and thrombotic stroke
• w/ aspirin for coronary stent thrombosis
• irreversible

Question 16

Ticlopidine adverse effects

Answer 16

• agranulocytosis (low WBC)
• Thrombotic thrombocytopenia purpura (TTP)
  
  • low platelets, systemic clotting
• hemorrhage
• aplastic anemia

Question 17

Clopidogrel

Answer 17

• plavix
• irreversible
• lasts 7-10 days
• preferred over ticlopidine
• prevent atherosclerotic events after MI, stroke, PAD
• prevent events with acute coronary syndrome
• prevent events in PCI

Question 18

Plavix adverse effects

Answer 18

• bleeding
• TTP (less than Ticlo)
• Neutropenia (less than Ticlo)

Question 19

Prasugrel

Answer 19

• like plavix
• quicker onset
• irreversible
• for acute coronary syndrome
• NO in patients with TIA/stroke
• black box warning for bleeding

Question 20

Ticagrelor

Answer 20

• ONLY reversible ADP blocker
• patients with unstable angina, acute MI, PCI
• black box for bleeding and GI (especially with aspirin)

Question 21

Abciximab

Answer 21

• Reopro
• chimeric monoclonal antibody
• binds IIb/IIIa
• blocks fibrinogen and VWF…blocks aggregation
• 2/3 human….1/3 other
• FOR PCI and acute coronary syndrome
• lasts 2-4 days

Question 22

Eptifibatide

Answer 22

• Integrilin
• cyclic peptide
• venom from rattlesnake
• prevents binding of fibrinogen

Question 23

Tirofiban

Answer 23

• Aggrastat
• non-peptide
• prevents binding of fibrinogen