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About these monographs





Platelet aggregation inhibitor, analgesic and anti-inflammatory agent


Chest pain, suspected acute myocardial infarction (AMI), acute cardiogenic pulmonary oedema

Mechanism of Action:

Irreversibly inhibits cyclooxygenase (COX) 1 and 2 enzyme leading to reduced synthesis of the platelet aggregation factor thromboxane A2 (TXA2) and prostaglandins


Onset: 1 minutes

Peak Effects: 3-6 hours

Duration: 1 week


Hypersensitivity to salicylates, chest pain associated with psychostimulant overdose, bleeding or clotting disorders, patients < 18 years

Adverse Effects:

Heartburn, gastritis, nausea, vomiting, wheezing and allergic reaction

Precautions and Facts:

Possible aortic aneurysm or any other condition that may require surgery, pregnancy, concurrent anticoagulant therapy. May also be called acetylsalicylic acid or ASA.


150 mg, 300 mg or 325 mg tablets


Route: Oral (PO)

Age: Adults only

Initial Dose: 300 to 325 mg

Dose Intervals: One dose only

Volume/Dilution: Single pill

Maximum Dose: 325 mg

Cite as: Maria, S., Colbeck, M., & Caffey, M. (Eds.). (2020). Aspirin. In Paramedic & Emergency Pharmacology Guidelines (2nd ed.). Melbourne, Victoria: Pearson.

This book is for information purposes only and is designed as a general reference for paramedics, students and healthcare professionals  No responsibility will be taken for inaccuracies, omissions or errors  The authors do not accept liability to any person or organization for the information that may result in loss or damages incurred as a result of reliance upon the material in this guide While every effort has been made to ensure that the information in this text is up to date, accurate and in accordance with current clinical recommendations and practice, the dynamic nature of healthcare and pharmaceutical information requires any student or health professional to exercise independent clinical judgement when referring, using or providing information from this book


A body of evidence for the development of this guide has been collected by the authors to support the pharmacokinetics, indication, contraindications, adverse effects and dosage behind each medication  This body reflects information provided by Australia’s Therapeutic Goods Administration, Monthly Index of Medical Specialities, the United States’ Food and Drug Administration, and both peer-reviewed studies and clinical trials demonstrating the approved efficacy, usage and current understanding of each medication  Additionally, the Australian Resuscitation Council guidelines and each state ambulance service’s clinical practice guidelines in Australia and New Zealand were reviewed and applied in order to maximize the clinical application of this reference guide  Lastly, this guide’s information is not endorsed, nor does it reflect preferences by any particular pharmaceutical company or ambulance service as this reference was compiled only to the most current and universal information available from the above listed, publicly available resources

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