Aspirin is usually sold in tablets containing 300 mg medicine. You can take it every four to six hours without risk 2-3 pills, the maximum daily dose should not, however, exceed 12 tablets, or 4 g of substance. Single ingestion 10 g (30 pills) aspirin can be life-threatening, because it over-acidifies the blood. The body tries to counteract this by violent lung action, to expel excess carbon dioxide, and by speeding up the work of the kidneys, which leads to dehydration. If the body cannot cope with acidification on its own, tissue damage occurs and can even lead to death.
How aspirin works? It acts on an enzyme that synthesizes prostaglandins. These are substances needed to regulate the digestive processes, kidney function, blood circulation and reproduction. Prostaglandins also stimulate pain signals. They are released during many injuries and diseases. This is why we suffer from inflammation, fever and pain. This was discovered in 1969 year by John Vane and a team of his associates at London's Royal College of Surgeons, who showed, that aspirin prevents the formation of prostaglandins in damaged tissues. Vane received in 1982 year – jointly with other prostaglandin researchers, Sana Bergstrome and Bengt Samuelsson from the Karolisska Institutet in Stockholm – Nobel Prize in Physiology and Medicine.
Prostaglandins are made through a series of chemical reactions. It begins with the release of a polyunsaturated fatty acid called arachidonic acid from the cell membrane. This acid reacts with oxygen, creating such relationships, like cyclic prostaglandin peroxides, initiating inflammation. Aspirin blocks the enzyme that controls this reaction and prevents the further course of events that start with a damaged cell membrane and lead to prostaglandins that are responsible for pain..