Aspirin

Aspirin is a non-steroidal anti-inflammatory drug (NSAID) with anti-platelet action used to treat and prevent heart attacks, strokes, and angina. It works by preventing platelets from sticking together, decreasing the formation of harmful blood clots.

Aspirin inhibits cyclooxygenase (COX) enzymes, reducing prostaglandin and thromboxane synthesis. By inhibiting COX-1 in platelets, it reduces thromboxane A2 production, preventing platelet aggregation and thrombus formation.

Common side effects include heartburn, nausea, vomiting, and stomach upset. Taking with food reduces stomach problems.

• Prophylaxis against arterial occlusive events: Myocardial infarction, myocardial re-infarction, after bypass surgery, acute ischaemic stroke/TIA
• Mild to moderate pain: Headache, muscle pain, dysmenorrhoea, toothache
• Osteoarthritis
• Antipyretic: Cold fever and influenza

Aspirin is a non-steroidal anti-inflammatory drug (NSAID) that irreversibly inhibits cyclooxygenase (COX-1 and COX-2) enzymes, reducing prostaglandin and thromboxane A2 synthesis.

By inhibiting COX-1 in platelets, aspirin reduces thromboxane A2 production, which prevents platelet aggregation. This decreases thrombus formation, particularly on the arterial side of circulation where thrombi are formed by platelet aggregation.

Enteric-coated aspirin reduces gastrointestinal disturbance and ulceration.

Aspirin irreversibly inhibits cyclooxygenase (COX) enzymes, reducing prostaglandin and thromboxane A2 synthesis. Thromboxane A2 promotes platelet aggregation and vasoconstriction. By inhibiting COX-1 in platelets, aspirin reduces thromboxane A2 production, preventing platelet aggregation and thrombus formation.

Pain, inflammation and fever: 300 mg 1-3 tablets every 6 hours, maximum daily dose 4 g.

Suspected acute coronary syndrome: 150-300 mg immediately (if no contraindications).

After myocardial infarction: 150 mg daily for 1 month, then 75 mg daily long-term.

Acute ischaemic stroke/TIA: Initial 150-300 mg daily, then 75 mg daily.

After bypass surgery: 75-300 mg daily starting 6 hours post-procedure.

Juvenile rheumatoid arthritis: 25 kg: 2.4-3.6 g/day.

Take with food (to reduce stomach upset). Swallow the tablet whole. Do not chew, crush, or break enteric-coated tablets.

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule. Do not double the dose.

• Heartburn
• Upset stomach
• Nausea
• Vomiting
• Increased bleeding tendency
• Gastrointestinal ulceration
• Bronchospasm
• Dyspepsia

Serious Precautions:

• Do not use in children under 12 years (Reye's syndrome risk)
• Do not use in the last 3 months of pregnancy (fetal harm and delivery complications)
• Excreted in breast milk - use with caution
• Contraindicated in active peptic ulcer, haemophilia, haemorrhagic disorders, severe renal/hepatic impairment
• Caution in asthma, uncontrolled blood pressure, nasal polyps, and allergies
• Risk of bleeding - be careful while shaving, using sharp objects
• Avoid alcohol as it increases risk of stomach bleeding

• Hypersensitivity to aspirin (asthma attacks, angioedema, urticaria, or rhinitis)
• Active peptic ulceration
• Pregnancy (3rd trimester)
• Children under 12 years (Reye's syndrome risk)
• Haemophilia or haemorrhagic disorders
• Gout
• Severe renal or hepatic impairment
• Lactation

• Anticoagulants (warfarin, heparin): Aspirin increases bleeding risk
• Oral hypoglycaemic agents: Effect may be enhanced
• Phenytoin and sodium valproate: Aspirin may increase their effects
• Probenecid: Aspirin inhibits its uricosuric effect
• Sulphonamides: Aspirin may increase their toxicity
• Other NSAIDs: Increased risk of side effects

[UNSAFE] It is unsafe to consume alcohol with Aspirin. Alcohol increases the risk of stomach bleeding.

[CONSULT YOUR DOCTOR] Aspirin is unsafe to use during pregnancy (Category C; Category D in 3rd trimester). There is definite evidence of risk to the developing baby. Do not use in the last 3 months of pregnancy. Use only under medical supervision.

[CONSULT YOUR DOCTOR] Aspirin is excreted in breast milk and may harm the baby. Use with caution and under medical supervision.

Contraindicated in children under 12 years (Reye's syndrome risk). Juvenile rheumatoid arthritis dose: 25 kg: 2.4-3.6 g/day.

Elderly patients require special caution; dose adjustment may be needed.

[CAUTION] Use with caution in kidney disease. Not recommended in severe kidney disease.

[CAUTION] Use with caution in liver disease. Not recommended in severe liver disease.

Symptoms: Dizziness, tinnitus, sweating, nausea, vomiting, confusion, hyperventilation. Severe overdose: CNS depression, coma, cardiovascular collapse, respiratory depression.

Treatment: Gastric lavage, forced alkaline diuresis. Haemodialysis may be necessary in severe cases. Monitor for at least 24 hours.

Keep out of reach of children. Store below 30°C, in a cool and dry place, protected from light.

Acetylsalicylic acid (C₉H₈O₄)