ASPIRIN (ASA)

Class

Platelet inhibitor/Anti-inflammatory

Pharmacology and Actions

1. ASA inhibits blood clotting. It inhibits the formation of thromboxane A2, a platelet aggregating, vasoconstricting prostaglandin. ASA in low doses, however, inhibits the production of thromboxane A2 in the platelet more than it does the production of prostacyclin in the endothelial cells.
2. Platelet aggregation has been implicated in the pathogenesis of atherosclerosis contributing to the acute episodes of TIA's, unstable angina, and acute myocardial infarction.
3. Unstable angina is precipitated by a sudden fall in coronary blood flow. One possible mechanism is platelet aggregation.
4. ASA has been shown to be beneficial in decreasing sudden cardiac death and myocardial infarction in patients with unstable angina.
5. ASA has been shown to be of added benefit in maintaining vessel patency after thrombolytic therapy.

Indications

1. Patients with chest pain or other symptoms, which may be of cardiac origin.
2. ASA is not to be used for analgesia (i.e. headache).

Contraindications

1. Children under 12 years of age
2. Known hypersensitivity to drug, especially allergy induced asthma
3. Current ulcer or GI bleed

Administration

1. Chew four 81 mg ASA chewable tablets (324 milligrams total) if the patient is able to swallow voluntarily.

Side Effects and Special Notes

1. ASA is one of the few interventions that has been shown to improve mortality and therefore should be considered early in the care of the patient.
2. Patients taking Coumadin may receive aspirin.