Aspirin

How it works

It irreversibly inhibits platelet cyclo-oxygenase-1, reducing thromboxane-A2-mediated aggregation for the lifespan of the platelet.

Prescribing in practice

• Gastrointestinal irritation and bleeding occur — consider gastroprotection in at-risk patients.
• It can trigger bronchospasm in aspirin-sensitive asthma.
• Avoid in children under 16 (Reye's syndrome) except for specific indications; bleeding risk rises with other antithrombotics.

Monitoring

Watch for gastrointestinal symptoms and bleeding.

Counselling the patient

• Take it with or after food.
• Report indigestion, black stools or unusual bleeding.
• Do not give aspirin to children unless specifically told to.

Evidence & guidelines

Established for secondary cardiovascular prevention; routine primary prevention is no longer generally recommended.