ASPIRIN: Action, Uses, Routes, Dosage, Nursing considerations by Nursesnote

 ASPIRIN 

Classification 

Pharmacotherapeutic: Nonsteroidal salicylate. 

Clinical: Anti-inflammatory, antipyretic, anticoagulant. 

Action

Inhibits prostaglandin synthesis, acts on the hypothalamus heat-regulating center, interference with production of thromboxane A, a substance that stimulates platelet aggregation. 

Therapeutic effect: Reduce inflammatory response, intensity of pain, decreases fever, inhibits platelet aggregation. 

Pharmacokinetics

Route: PO

Onset: 1 hr

Peak: 2-4 hrs

Duration: 4-6 hrs

Rapidly and completely absorbed from GI tract; enteric-coated absorption delayed; rectal absorption delayed and incomplete. Protein binding: high. Widely distributed. Rapidly hydrolyzed to salicylate.

 Half-life 15-20 min(aspirin ); 2-3 hrs (salicylate at low dose); more than 20 hrs (salicylate at high dose). 

Uses

Treatment of mild to moderate pain, fever. Reduce inflammation related to rheumatoid arthritis (RA), juvenile arthritis, osteoarthritis, rheumatic fever. As platelet aggregation inhibitor in the prevention of transient ischemic attacks (TIAs), cerebral thromboembolism, MI or reinfarction. Adjunctive treatment of kawasaki's disease. 

OFF- LABEL: Prevention of pre-eclampsia; alternative therapy for preventing thromboembolism associated with atrial fibrillation where warfarin cannot be used; pericarditis associated with MI; prosthetic valve thromboprophylaxis. 

Precautions 

Contraindications: Hypersensitivity to salicylates, NSAIDs; asthma, rhinitis, nasal polyps; inherited or acquired bleeding disorders ; use in children for viral infections; pregnancy 

Cautions: platelet/bleeding disorders, sever renal/hepatic impairment, dehydration, erosive gastritis, peptic ulcer disease, sensitivity to tartrazine dyes. 

Lifespan Considerations

Pregnancy/Lactation: Readily crosses placenta; distributed in breast milk. May prolong gestation and labor; decrease fetal birth weight; increase incidence of stillbirths, neonatal mortality, hemorrhage. 

Pregnancy category: C 

Children: Caution in those with acute febrile illness (Reye's syndrome ). 

Elderly: May be more susceptible to toxicity; lower dosages recommended. 

Administration 

• PO
• Do not crush or break enteric-coated tablets.
• May give with water, milk, meals if GI distress occurs. 
• Rectal
• Refrigerate suppositories; do not freeze.
• If suppository is too soft, chill for 30 min in refrigerator or run cold water over foil wrapper.

Indications/Dosage 

Analgesia, fever: PO, Rectal:  Adults Elderly: 325-650 mg q4-6 h. Children: 10-15 mg/kg/dose q4-6 h. Maximum 4g/day.

Anti-inflammatory: PO: Adults; Elderly: Initially, 2.4-3.6 g/day in divided doses, then 3.6 - 5.4 g/day. Children: Initially, 60-90 mg/kg/day in divided doses, then 80-100 mg/kg/day.

Platelet aggregation inhibitor: PO; Adults, Elderly: 80-325 mg/day.

Kawasaki's disease: PO: children: 80-100 mg/kg/day in divided doses q6 h. After fever resolves, 3-5 mg/kg once a day.

Side effects

Occasional: GI distress, allergic reaction. 

Adverse effects/Toxic reactions

High doses of aspirin may produce GI bleeding and gastric mucosal lesions. Dehydrated, febrile children may experience aspirin toxicity quickly. Reye's syndrome may occur in children with chickenpox or flu. Low-grade toxicity characterized by tinnitus, generalized pruritus, headache dizziness, flushing, tachycardia, hyperventilation, diaphoresis, thirst. 

Nursing Consideration 

Do not give to children or teenagers who have flu or chickenpox (increase risk of Reye's syndrome ) . Assess type, location, duration of pain, inflammation.