Aspirin

Question 1

MoA

Answer 1

Aspirin (Acetylsalicylic acid) has antiplatelet, antipyretic, anti-inflammatory and analgesic effects. WFA only uses it for its antiplatelet activity.

Question 2

MoA

Answer 2

It inhibits the enzyme cyclooxygenase which results in a reduction in the formation of prostaglandins and thromboxane.

Question 3

Indications

Answer 3

STEMI, Myocardial Ischemia.

Question 4

Contraindications

Answer 4

Allergy, Third trimester of pregnancy.

Question 5

Cautions

Answer 5

• Known bleeding disorder. Aspirin worsens the risk of bleeding. generally still in favour of administering.
• Clinically significant bleeding.
• known worsening of bronchospasm with NSAIDs.

Question 6

Pregnancy

Answer 6

may cause harm. Associated with premature delivery and premature closure of the ductus arteriosus in 3rd trimester.

Unlikely for pregnant women to have clinically important myocardial ischemia. Balance is in favour of aspirin being withheld.

Breastfeeding on aspirin is not recommended.

Question 7

Dosage

Answer 7

300mg chewed or dissolved in water

Question 8

Adverse effects

Answer 8

Increased bleeding.

indigestion. gastrointestinal ulceration and bleeding are common adverse effects but they’re associated with long term use

Question 9

Pharmacokinetics

Answer 9

Absorption occurs in the small intestine.

Aspirin is predominantly metabolised in the liver.