Antiplatelet Agents

Question 1

What is the drug interaction that occurs when ibuprofen is taken before aspirin?

Answer 1

Ibuprofen significantly reduces the magnitude and duration of platelet inhibition expected from aspirin

Question 2

If someone takes ibuprofen first how long should they wait to take aspirin?

Answer 2

8 hrs

Question 3

If someone takes aspirin first, how long should they wait to take ibuprofen?

Answer 3

30 minutes to 2 hours

Question 4

What is the estimated percentage of the general population estimated to be ASA non-responders?

Answer 4

20%

Question 5

Which medications increase the risk of a patient being an aspirin non-responder

Answer 5

NSAIDs and dipyridamole

Question 6

Which medication is associated with decreased risk of aspirin non-responsiveness

Answer 6

clopidogrel

Question 7

Plavix Class

Answer 7

P2Y12 antagonist / antiplatelet agent

Question 8

Plavix dosing for Ischemic stroke/ TIA

Answer 8

DAPT: 600mg once -> 75mg daily for 90 days -> dc clopidogrel and continue ASA

Question 9

Plavix dosing for STEMI/NSTEMI

Answer 9

600mg once -> 75mg daily for >/= 12 months

Question 10

Plavix altered kidney function dosing

Answer 10

no adjustment necessary

Question 11

Plavix (clopidogrel) altered liver function dosing

Answer 11

no adjustment necessary

Question 12

Plavix (clopidogrel) pediatric dosing

Answer 12

• infants and children < 24 months: 0.2 mg/kg/dose once daily
• children > 2yo and adolescents: 1 mg/kg/dose once daily

Question 13

Plavix (clopidogrel) administration instructions

Answer 13

Take by mouth with or without food, but avoid / minimize grapefruit juice

Question 14

Plavix (clopidogrel) contraindications

Answer 14

• hypersensitivity
• planned surgery (DC 24hrs to 5 days prior)

Question 15

Plavix (clopidogrel) in pregnancy and lactation

Answer 15

limited human data, probably compatible

Question 16

Plavix (clopidogrel) Serious ADE

Answer 16

• bleeding
• hypersensitivity
• Thrombotic Thrombocytopenic Purpura (TTP)
  – skin reactions
  – neuro changes (dizziness, confusion, HA, seizure)
  – fever

Question 17

Plavix (clopidogrel) common ADE

Answer 17

bleeding

Question 18

Plavix (clopidogrel) DDI

Answer 18

CYP2C19 inhibitors
- omeprazole
- azole antifungals
- SSRIs
- Carbamazepine

Question 19

Plavix (clopidogrel) MOA

Answer 19

converted to active form by CYP2C19 -> active metabolite irreversibly blocks the P2Y12 component of ADP receptors on platelet surface

Question 20

Plavix (clopidogrel) onset of action

Answer 20

Loading dose: 2 hrs
No loading dose: 2 days

Question 21

Plavix (clopidogrel) time to peak effect

Answer 21

Loading dose: 6 hrs
No loading dose: 5-7 days

Question 22

Plavix (clopidogrel) duration of action

Answer 22

5 days

Question 23

Aspirin MOA

Answer 23

irreversible inhibition of platelet cyclooxygenase -> prevents production of Thromboxane A2

Question 24

Dipyridamole MOA

Answer 24

inhibits phosphodiesterase -> increased intracellular concentration of cAMP and cGMP -> reversibly inhibit platelet aggregation

Question 25

Aggrenox (ASA/dipyridamole) indications / dosing

Answer 25

Ischemic stroke / TIA secondary prevention - 1 capsule (25mg / ER200 mg ASA/Dip) BID

Question 26

Aggrenox (ASA/dipyridamole) altered kidney function dosing

Answer 26

Avoid use in GFR < 10 mL/min

Question 27

Aggrenox (ASA/dipyridamole) hepatic impairment dosing

Answer 27

Avoid use in severe hepatic impairment

Question 28

Aggrenox (ASA/dipyridamole) administration

Answer 28

Take with or without food do not crush or chew

Question 29

Aggrenox (ASA/dipyridamole) ADE

Answer 29

- headache - abdominal pain - heart burn - nausea - diarrhea

Question 30

Aspirin Class

Answer 30

Antiplatelet agent, NSAID analgesic

Question 31

Aspirin dosing for analgesic/ antipyretic/ anti-inflammatory

Answer 31

325mg-1g Q4-6H IR

Question 32

Aspirin dosing for Stroke/TIA secondary prevention

Answer 32

75-325mg QD IR

Question 33

Aspirin dosing for STEMI/NSTEMI secondary prevention

Answer 33

81mg QD IR

Question 34

Aspirin altered kidney function dosing

Answer 34

Antiplatelet uses: no adjustment needed Analgesia/ anti-inflammatory: - CrCl < 10 avoid use

Question 35

Aspirin hepatic impairment dosing

Answer 35

avoid use in severe liver disease

Question 36

Aspirin administration

Answer 36

take with food/full glass of water to minimize GI sx

Question 37

Aspirin ADE

Answer 37

- inc risk of GI bleed or ulcer - hypersensitivity - abdominal pain - nausea/vomiting - rectal irritation (w/suppositories)