Aspirin

Indications

Aspirin is used for: Fever, Headache, Pain/inflammation, Acute coronary syndrome, TIA, MI, Stroke

Adult Dose

PO Prophylaxis of myocardial infarction Adult: 75-300 mg once daily. Lower doses should be used in patients receiving ACE inhibitors. Stent implantation Adult: 300 mg 2 hr before procedure followed by 150-300 mg/day thereafter. Mild to moderate pain and fever Adult: 150-300 mg repeated every 4-6 hr according to response. Max: 4 g/day. Pain and inflammation associated with musculoskeletal and joint disorders Adult: Initial: 2.4-3.6 g/day in divided doses. Usual maintenance: 3.6-5.4 g/day. Monitor serum concentrations. Hepatic impairment: Severe liver disease: Not recommended

Child Dose

PO Juvenile rheumatoid arthritis Child: <25 kg: 60-100 mg/kg/day PO divided q6-8hr (maintain serum salicylate at 150-300 mcg/mL) >25 kg: 2.4-3.6 g/day Pain & Fever <12 years 10-15 mg/kg PO q4hr, up to 60-80 mg/kg/day

Renal Dose

Renal impairment CrCl >10 mL/min: Dose adjustment not necessary CrCl <10 mL/min: Not recommended

Administration

Should be taken with food.

Contra Indications

Hypersensitivity (attacks of asthma, angioedema, urticaria or rhinitis), active peptic ulceration; pregnancy (3rd trimester), children <12 yr, patients with haemophilia or haemorrhagic disorders, gout, severe renal or hepatic impairment, lactation.

Precautions

Patients with history of asthma, angioedema, urticaria or rhinitis, nasal polyp, severe renal or hepatic impairment, lactation. Lactation: Drug enters breast milk; decision should be made regarding whether to discontinue nursing or to discontinue drug, taking into account importance of drug to mother.

Pregnancy-Lactation

Pregancy Avoid chronic or intermittent high doses during pregnancy; may affect maternal and newborn hemostasis mechanisms, leading to an increased risk of hemorrhage High doses may also increase perinatal mortality by intrauterine growth restriction and teratogenic effects Near term, aspirin may prolong gestation and labor Premature closure of the ductus arteriosus may occur if used near term with use of full-dose aspirin Lactation Drug enters breast milk; a decision should be made regarding whether to discontinue nursing or to discontinue drug, taking into account importance of drug to mother

Interactions

Alcohol, corticosteroids, analgin, phenylbutazone and oxyphenbutazone may increase risk of GI ulceration. Aspirin increases phenytoin levels. May antagonize actions of uricosurics and spironolactone. Potentially Fatal: May potentiate effects of anticoagulants, methotrexate and oral hypoglycaemics.

Adverse Effects

Side effects of Aspirin : GI disturbances; prolonged bleeding time, rhinitis, urticaria and epigastric discomfort; angioedema, salicylism, tinnitus; bronchospasm. Potentially Fatal: Gastric erosion, ulceration and bleeding; severe, occasionally fatal exacerbation of airway obstruction in asthma; Reye's syndrome (children <12 yr). Hepatotoxicity; CNS depression which may lead to coma; CV collapse and resp failure; paroxysmal bronchospasm and dyspnoea.

Mechanism of Action

Aspirin is an analgesic, anti-inflammatory and antipyretic. It inhibits cyclooxygenase, which is responsible for the synthesis of prostaglandin and thromboxane. It also inhibits platelet aggregation.