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
Pregnancy category: C; D in 3rd trimester
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.