Aspirine

Aspirin, or acetylsalicylic acid, is a widely used nonsteroidal anti-inflammatory drug (NSAID) with analgesic, antipyretic, anti-inflammatory, and antiplatelet effects. It is used to relieve mild to moderate pain and fever and, at low doses, to reduce the risk of heart attack or stroke in some individuals with cardiovascular disease.

Mechanism of action and effects: aspirin irreversibly inhibits the cyclooxygenase enzymes (mainly COX-1 in platelets and COX-2 in inflamed tissues) by acetylation, leading to decreased synthesis of prostaglandins and thromboxane A2. The antiplatelet effect persists for the lifespan of platelets (about 7–10 days) because platelets do not have nuclei to replace the enzyme. At higher doses, aspirin provides anti-inflammatory relief through COX-2 inhibition in tissues.

Medical uses and dosing: analgesic dosing for adults is typically 325–650 mg every 4–6 hours as needed; anti-inflammatory regimens use higher doses. Low-dose regimens for cardiovascular prevention commonly range from 75–100 mg daily (often 81 mg). In children and teenagers, aspirin is generally avoided after viral illnesses due to the risk of Reye’s syndrome unless specifically advised by a clinician.

Adverse effects and contraindications: common side effects include stomach irritation, gastritis, ulcers, and an increased risk of bleeding. It can interact with anticoagulants, other NSAIDs, and alcohol, increasing bleeding risk. Aspirin should be used with caution in the elderly, people with peptic ulcers, kidney disease, or bleeding disorders. It is generally not recommended during pregnancy, particularly in the third trimester, and is excreted in breast milk.

Availability: aspirin is available over the counter in many countries, in tablet forms including plain and enteric-coated preparations, and in various combination products.