Acetylsalicylic Acid
Antithrombotic
Indications
- Chest pain or signs and symptoms consistent with cardiac ischemia
Contraindications
- Hypersensitivity to ASA or drug components
- Patients who have experienced bronchospasm or other respiratory reaction precipitated by ASA or nonsteroidal anti-inflammatory drugs
- Active or recent bleeding of any kind, including head injury or peptic ulcer disease
- Pediatric patients with signs and symptoms consistent with viral illnesses (due to Reye's Syndrome)
Adult Dosages
Chest pain or signs and symptoms consistent with cardiac ischemia
- 162 mg PO chewed and swallowed
Pediatric Considerations
Chest pain in children is unlikely to be the result of ischemia; ASA is therefore not indicated unless there are rare, specific histories of disease.
Adverse Effects
- The most common adverse effects involve irritation of the gastrointestinal tract
- Antiplatelet effects may result in minor bruising or bleeding
Additional Information
Mechanism of Action
ASA inhibits the formation of thromboxane A2, which is a potent platelet aggregator and vasoconstrictor. The platelet effects are irreversible, and last for the life of the platelet (7-10 days).
Pharmacokinetics
| Route | Onset | Peak | Duration |
|---|---|---|---|
| Oral | 5-30 minutes | 1-2 hours | 4-6 hours |
Overdose
ASA can be toxic at doses higher than 150 mg/kg. Early symptoms include nausea, vomiting, diaphoresis, and tinnitus. Hyperventilation can occur.
Warnings and Precautions
ASA should not be used in children, teenagers, or young adults with chickenpox, influenza, or other flu-like illness due to the risk of the development of Reye syndrome.
Alcohol use can increase the risk of gastrointestinal bleeding.
Drug Interactions
The antiplatelet effects of ASA may increase the risk of bleeding, particularly in patients who are already taking anticoagulant medications. These risks must be balanced against the benefit of ASA in patients who are experiencing cardiac ischemia.