Pharm 6 Thrombi pt2

Question 1

All antiplatelets are taken __ and reach peak concentration in how much time?

Answer 1

Orally

Quick (1-2 hours)

Question 2

Antiplatelet drugs (aspirin) works how?

Answer 2

Work at the ADP receptor on cell sites on platelets or RBC.

Question 3

Apparently God screwed up by not letting humans have __ naturally in their body.

Answer 3

aspirin

Question 4

Aspirin’s (ASA) Mechanism of Action

Answer 4

Aspirin prevents conversion of arachidonic acid to prostaglandin H2
Irreversably inactivates COX (1 and 2)
Aka: Irreversibly inhibits platelet aggregation for the life of the platelet (usu. ~7-10 days)

Question 5

What are the 2 COX isoforms? Whwere do they exist?

What does COX stand for?

Answer 5

COX-2 is an inducible enzyme increased in many settings (inflammation, infection)
Only COX-1 is in platelets (no areas of inflammation)
COX = Cyclooxygenase

Question 6

What happens to you after you take One baby aspirin?

Answer 6

1-2 hours after swallowing, all your platelets will be irreversibly affected. You won’t clot again normally for 5-7 days. At this point you have created new platelets to return the normal clotting ability.

Question 7

If aspirin must be discontinued for a procedure, how many days ahead of time do you stop?

Answer 7

5 days prior

Question 8

Patient is takes aspirin, but must get a tooth pulled. What do you do?

Answer 8

don’t stop the drug. Instead, apply pressure. Procedure is too miniscule.

Question 9

Patient takes aspirin, must have orthopedic joint replaced (knee/hip) after they had an MI!
What do you do?

Answer 9

Put off the joint replacement until later.

Question 10

Patient takes aspirin and must get a Colonoscopy. What do you do?
What if you find a polyp?

Answer 10

Do a virtual colonoscopy with a CT (there’s a risk of bleeding with a regular colonoscopy)
If I find a polyp then I’ll decide when to pull you off the drug, do the procedure, then restart the drug the next day.

Question 11

___ can be measured in serum within 5-30 minutes of oral admin of Aspirin

Answer 11

Salicylate

Question 12

Aspirin analogy: Railroad cars

Answer 12

Aspirin makes it so you can’t push those railroad cars together (prevents coupling of platelets)

Question 13

Simplified dosing info for Aspirin.

Answer 13

usually 81 mg

Only time you use more than 81 mg is when they’re having acute MI. Then they get 325 mg.

Question 14

2 issues with aspirin

What’s the most consistent form of aspirin?

Answer 14

Resistance - Increasing the dose works
Insensitivity - Increasing dose won’t help
Taking uncoated aspirin (recommended) has increased consistency over the enteric-coated aspirin.

Question 15

Clopidogrel
Mechanism of action?
How long does it take to work?

Answer 15

Inhibits ADP-induced expression of platelet GPIIb/IIIa and fibrinogen binding to activated platelets resulting in platelet “de-coupling”
Works within 4 days, fully effective in 10 days

Question 16

Antiplatelet therapy for an AMI

Answer 16

give aspirin to prevent platelets from clumping. Then Clopidogrel to get any platelets that still clump (or already clumped) to de-couple.

Question 17

Compare how aspirin and clopidogrel work, in simple terms:

Answer 17

Aspirin: prevents platelet aggregation
Clopidogrel: de-couples already clumped platelets

Question 18

FDA-approved indications of Cloopidogrel (6)

Answer 18

you want to decouple platelets for the following:
S/P MI
S/P CVA
PAD
Non-ST-segment elevation ACS (unstable angina, non-Q-wave AMI)
ST-segment elevation AMI
S/P PTCA with stent

Question 19

How is PAD diagnosed?

Answer 19

Ankle Brachial Index

Question 20

List these 3 in order from Lowest bleeding risk - Highest bleeding risk
ASA 81mg, ASA 325 mg, Clopidogrel

Answer 20

ASA 81 mg
Clopidogrel
ASA 325 mg

Question 21

If antiplatelet drugs (Clopidogrel) increase risk of bleeding where are you at highest risk to bleed?

Answer 21

into Stomach

Question 22

Clopidogrel’s drug interaction

Answer 22

Clopidogrel has variable metabolism when combined with some PPI’s

Question 23

Thrombolytics are ___ activators, a pre-cursor to __ which does what?

Answer 23

plasminogen, plasmin

Plasmin dissolves otherwise stable and formed clots

Question 24

Thrombolytic drugs convert __ to __, which in turn:

Answer 24

plasminogen to plasmin

lyses thrombi, fibrinogen and other plasma proteins

Question 25

Thrombolytics are the drug of choice to break down newly formbed thrombi.
When are they most effective? (duh)
How long can they be used?

Answer 25

Most effective immediately after thrombosis

Can be used up to 6 hours after onset of symptoms

Question 26

When are thrombolytics truly used?

Answer 26

Thrombolytics are only used when you can’t get to a Cath lab in time.

Question 27

Why are thrombolytics the most dangerous of all the drugs in this powerpoint?

Answer 27

Break up/bust clots. Do so indiscriminately. Any clot in the body will be lysed.
The ambulance bumps around and it takes multiple tries and there’s plenty of incisions from the needles. You get to the hospital and get poked with more needles. Then you get the thrombolytic and you’d bleed like a pig.

Question 28

1st Generation thrombolytic/fibrinolytic
Example
Unique CI
Who gets it?

Answer 28

Streptokinase - a non-enzymatic protein derived from beta-hemolytic streptococcus indirectly activates plasminogen
Unique CI: Recent Strep Throat.  They’ll go into anaphylaxis & probably die.
Older patients (>70) get Streptokinase.

Question 29

FDA approved use for thrombolytics

When can you not give thrombolytics?

Answer 29

ST-segment elevation MI

If the patient does not have ST elevation, they CANNOT get thrombolytics.

Question 30

Multiple CI of Thrombolytics (8)

Answer 30

recent hemorrhagic CVA, recent surgery (especially ocular/brain surgery), CPR > 10 minutes, AAA, uncontrolled HTN, some malignancies, non-compressible arterial punctures, etc

Question 31

What do you give if thrombolytics cause bleeding, or are overdosed?

Answer 31

Antifibrinolytic drugs and Fresh Frozen Plasma

Question 32

What is Urokinase for?

Answer 32

Localized thrombi that you thread a catheter to, then drip Urokinase into the catheter to break the thrombus up. For a localized thrombus that you’re using a high dose thrombolytic at this particular site, as opposed to the others that are systemic.