Pharmacology 2.15

Question 1

What is the MOA of fibrinolytic drugs?

Answer 1

group prototype = alteplase

-activates t-PA which activates plasmin which causes fibrin degredation

Question 2

What is the therapeutic window with using alteplase in stroke treatment?

Answer 2

uses:

• catheter occlusion
• deep-vein thrombosis
• myocardial infarction
• peripheral arterial occlusion
• pulmonary embolism
• stroke
• drugs are most effective early in the stroke and safety/cost/efficacy quickly decline as time passes
• Why? older clots have more fibrin cross-linking making fibrinolytics less effective in lysing them

Question 3

What are the major contraindications for thrombolytic therapy in stoke?

Answer 3

-*any increases risk of bleeding*
EX:
-*intracranial hemorrhage*
-head trauma
-previous stroke

Question 4

What is the checklist used to assure safe use of thrombolytic drugs?

Answer 4

A way to make sure patient does not have contraindications for thrombolytic drugs

Two categories of stroke treatment windows:
1) 3-4.5 hrs of onset

4 criteria: no strokes, head injuries, oral inticoagulants, herapin use/thromboplastin time

Question 5

What are 5 drug targets and drug mechanisms for inhibiting platelet aggregation?

Answer 5

1) Block cyclo-oxygenase (COX-1): aspirin
2) Block ADP receptor (P2Y12): clopidogrel, prasugrel, (ticlopidine), ticagrelor
3) Block IIb-IIIa receptor: abciximab, tirofiban, eptifibitide
4) Block thrombin receptor (PAR-1): vorapaxar
5) Increase adenosine levels: dipyridamole

Question 6

How do aspirin and clopidogrel inhibit platelet aggregation?

Answer 6

anti-coagulants

aspirin: COX-1 inhibitor
clopidogrel: block ADP receptor (P2Y12)

Question 7

What are dosing strategies and side effects with aspirin therapy used in stroke treatment?

Answer 7

• low doses used to inhibit platelet aggregation which are not anti-inflammatory
• ADR: bleeding, gastric irritation

Question 8

What are the two anticoagulants which are commonly used for stroke?

Answer 8

1) aspirin

2) clopidrogrel (for patients allergic to aspirin)

Question 9

What is the function and MOA of prostacyclin and adenosine?

Answer 9

inhibit platelet aggregation by increasing cAMP levels in the cell

Question 10

What genetic test can be done to help choose a drug to treat stroke?

Answer 10

CYP2C19 gene can be tested in patients who may have a predisposition to CV risk; black box warning for clopidrogrel (plavix)

protn pump inhibitors should not be used due to drug interactions