Brand Name: Aspirin
Name: Acetyl Salicylic acid
Pregnancy Category D
Mechanism of action of Aspirin
Analgesic and antirheumatic effects are attributable to aspirin's ability to inhibit the synthesis of prostaglandins, important mediators of inflammation. Antipyretic effects are not fully understood, but aspirin probably acts in the thermoregulatory center of the hypothalamus to block effects of endogenous pyrogen by inhibiting synthesis of the prostaglandin intermediary. Inhibition of platelet aggregation is attributable to the inhibition of platelet synthesis of thromboxane A2, a potent vasoconstrictor and inducer of platelet aggregation.
This effect occurs at low doses and lasts for the life of the platelet (8
d). Higher doses inhibit the synthesis of prostacyclin, a potent
vasodilator and inhibitor of platelet aggregation.
Indications of Aspirin
- Mild to moderate pain
- Inflammatory conditions-rheumatic fever, rheumatoid arthritis,
- Reduction of risk of recurrent TIAs or stroke in males with
TIA due to fibrin platelet emboli
- Reduction of risk of death or nonfatal MI in patients with
infarction or unstable angina pectoris
- Unlabeled use: prophylaxis against cataract formation with long-term use
Contraindications of Aspirin
- Allergy to salicylates or NSAIDs (more common in patients with nasal polyps, asthma, chronic urticaria);
- allergy to tartrazine (cross-sensitivity to aspirin is common);
- hemophilia, bleeding ulcers, hemmorhagic states, blood coagulation defects, hypoprothrombinemia, vitamin K deficiency (increased risk of bleeding);
- impaired or renal function;
- chickenpox, influenza (potential risk of Reye's syndrome in children and teenagers); children with fever accompanied by dehydration;
- surgery scheduled within 1 wk; pregnancy (maternal anemia, antepartal and postpartal hemorrhage, prolonged gestation, and prolonged labor have been reported; readily crosses the placenta; possibly teratogenic; maternal ingestion of aspirin during late pregnancy has been associated with the following adverse fetal effects: low birth weight, increased intracranial hemorrhage, stillbirths, neonatal death);
Adverse effects of Aspirin
- GI: Nausea, dyspepsia, heartburn, epigastric discomfort, anorexia, hepatotoxicity
- Hematologic: Occult blood loss, hemostatic defects
- Hypersensitivity: Anaphylactoid reactions to fatal anaphylactic shock
- Aspirin intolerance: Exacerbation of bronchospasm, rhinitis (in patients with nasal polyps, asthma, rhinitis)
- Salicylism: Dizziness, tinnitus, difficulty hearing, nausea, vomiting, diarrhea, mental confusion, lassitude (dose related)
- Acute aspirin toxicity: Respiratory alkalosis, hyperpnea, tachypnea, hemorrhage, excitement, confusion, asterixis, pulmonary edema, convulsions, tetany, metabolic acidosis, fever, coma, cardiovascular collapse, renal and respiratory failure (dose related 20-25 g in adults, 4 g in children).
Are you a Doctor, Pharmacist, PA or a Nurse?
Join the Doctors Lounge online medical community
Editorial activities: Publish, peer review, edit online articles.
Ask a Doctor Teams: Respond to patient questions and discuss challenging presentations with other members.