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Year 3 - Pharmacology > Antiplatelets > Flashcards

Flashcards in Antiplatelets Deck (8)
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1
Q

describe the MOA of aspirin

A

Irreversibly inhibits COX-1, preventing conversion of arachidonic acid to prostaglandins… no production of thromboxane A2… no platelet aggregation.

2
Q

name common indications for aspirin

A
  1. secondary DVD prevention: 75 mg
  2. acute management of UA, NSTEMI, STEMI, suspected TIA: 300 mg
  3. management of TIA (with dipyridamole): 75 mg
  4. following coronary by-pass surgery: 75-300 mg
  5. mild to moderate pain or pyrexia: 300-900 mg every 4 hrs as required (max 4g/day)
3
Q

contra-indications for aspirin?

A
  • <16 yrs
  • current or previous peptic ulcer
  • haemophilia and other bleeding disorders
  • severe HF
    Caution:
  • asthma
  • G6PD deficiency
4
Q

ADRs of aspirin?

A
  • haemorrhage, inc. GI or intracranial bleed, menorrhagia
  • bronchospasms, dyspnoea
  • dyspepsia, GI ulceration
5
Q

why is aspirin contra-indicated in children?

A

Risk of Reye syndrome: rapidly progressive encephalopathy + hepatitis. Risk of death or permanent brain damage.

6
Q

describe the MOA of clopidogrel

A

Antagonises P2Y12 ADP receptor, inhibiting platelet activation.

7
Q

suggest indications for clopidogrel

A
  1. acute management of NSTEMI or STEMI (with aspirin): 300 mg, then 75 mg for at least 4 wks
  2. secondary CVD prevention in PAD, within 35 days of MI or 6 mths of ischaemic stroke: 75 mg
8
Q

do aspirin and clopidogrel need to be stopped before surgery?

A

Aspirin: no, unless high bleeding risk procedure.

Clopidogrel: stop 7 days before elective surgery.