Aspirin is used for its antiplatelet activity in the initial treatment of cardiovascular disorders such as angina pectoris and myocardial infarction and for the prevention of cardiovascular events in a variety of conditions or procedures for patients at risk.
By decreasing platelet aggregation, Aspirin inhibits thrombus formation on the arterial side of the circulation, where thrombi are formed by platelet aggregation and anticoagulants have little effect. Aspirin is the analgesic of choice for headache, transient musculoskeletal pain and dysmenorrhoea. It has anti-inflammatory and antipyretic properties, which may be useful. Enteric coating reduces the intestinal disturbance and gastrointestinal ulceration due to aspirin.
Pain, Inflammatory diseases and as Antipyretic: Aspirin 300 mg 1-3 tablets 6 hourly with a maximum daily dose of 4 g.
Thrombotic cerebrovascular or Cardiovascular disease: Aspirin 300 mg 1 tablet or Aspirin 75 mg 4 tablets daily.
After Myocardial infarction: Aspirin 75 mg 2 tablets daily for 1 month.
Following By-pass surgery: Aspirin 75 mg 1 tablet daily.
Side effects for usual dosage of Aspirin are mild including nausea, dyspepsia, gastrointestinal ulceration and bronchospasm etc.
It should be administered cautiously in asthma, uncontrolled blood pressure and pregnant women.It is specially important not to use aspirin during the last 3 months of pregnancy unless specifically directed to do so by a doctor because it may cause problems in unborn child or complication during delivery. It should be administered with caution to patients in nasal polyp and nasal allergy. Aspirin penetrates into breast milk. So, it should be administered with caution to lactating mothers.
Salicylates may enhance the effect of anticoagulants, oral hypoglycaemic agents, phenytoin and sodium valporate. They inhibit the uricosuric effect of probenecid and may increase the toxicity of sulphonamides. They may also precipitate bronchospasm or induce attacks of asthma in susceptible subjects.
Aspirin should be avoided during the last 3 months of pregnancy. As aspirin is excreted in breast milk, aspirin should not be taken by patients who are breast-feeding.
Overdosage produces dizziness, tinnitus, sweating, nausea and vomiting, confusion and hyperventilation. Gross overdosage may lead to CNS depression with coma, cardiovascular collapse and respiratory depression. If overdosage is suspected, the patient should be kept under observation for at least 24 hours, as symptoms and salicylate blood levels may not become apparent for several hours. Treatment of overdosage consists of gastric lavage and forced alkaline diuresis. Haemodialysis may be necessary in severe cases.
Aspirin is contraindicated to the children (Reye's syndrome) under 12 years, in breast-feeding and active peptic ulcer. It is also contraindicated in bleeding due to haemophilia and other ulceration. Hypersensitivity to aspirin, hypoprothrombinaemia is also contraindicated
Store in a cool and dry place, protected from light.