Aspirin

Question 1

Aspirin - Drug Class

Answer 1

Antiplatelet

Question 2

Aspirin - Pharmacology

Answer 2

Aspirin inhibits platelet aggregation by irreversibly inhibiting cycle-oxygenase, reducing the synthesis of thromboxane A2 (an inducer of platelet aggregation) for the life of the platelet. This action forms the basis of preventing platelets from aggregating to exposed collagen fibres at the site of vascular injury.

Question 3

Aspirin - Metabolism

Answer 3

Aspirin is converted to salicylic acid in many tissues, but primarily in the GI mucosa and liver. It is excreted by the kidneys.

Question 4

Aspirin - Indications

Answer 4

• Suspected ACS

- Acute carcinogenic pulmonary oedema

Question 5

Aspirin - Contraindications

Answer 5

• KSAR or hypersensitivity to Aspirin or other NSAID’s
• Chest pain associated with psychostimulant overdose
• Bleeding or clotting disorders (e.g. haemophilia)
• Current GI bleeding or peptic ulcers
• Patients < 18yo

Question 6

Aspirin - Precautions

Answer 6

• Possible aortic aneurysm or other condition that may require surgery
• Pregnancy
• History of GI bleeding or peptic ulcers
• Concurrent anticoagulant therapy (e.g. warfarin)

Question 7

Aspirin - Side effects

Answer 7

• Epigastric pain / discomfort
• Nausea and / or vomiting
• Gastritis
• GI bleeding
• NSAID induced bronchospasm

Question 8

Aspirin - Presentation

Answer 8

Tablet (white). 300mg aspirin.

Question 9

Aspirin - Onset, duration & half-life

Answer 9

Onset - 10 mins
Duration - 1 week (anti platelet)
Half-life - 3.2 hours (300-650mg)

Question 10

Aspirin - Schedule

Answer 10

S2 (therapeutic poisons)

Question 11

Aspirin - Routes of administration

Answer 11

PO per oral

Question 12

Aspirin - Adult dose - Suspected ACS

Answer 12

> 18 yrs - 300mg chewed and followed by a small sip of water

Question 13

Aspirin - Adult dose - Acute cardiogenic pulmonary oedema

Answer 13

> 18 yrs - 300mg chewed and followed by a small sip of water

Question 14

Aspirin - Paediatric dose

Answer 14

N/A

Question 15

Aspirin - Special Notes

Answer 15

• In suspected ACS or ACPO aspirin should be administered following GTN dose.
• Aspirin is indicated for ACS and ACPO even if pain free
• Patients who have had <300mg Aspirin in the previous 24 hours and who present with suspected ACS or ACPO should be administered a dose of aspirin that equates to a total daily dose of 300-450mg.