FREQUENTLY ASKED QUESTIONS ABOUT ASPIRIN

The active ingredient in aspirin is acetyl-salicylic acid.

Aspirin is a medication that has two main actions in the body: an anti-prostaglandin (anti-inflammation, fever-reducing, pain reliever) and an anti-platelet (‘blood thinner’) action.  Both of these actions are the result of the effect of aspirin on an enzyme in the body called cyclo-oxygenase, or COX. When the body is injured, inflammation occurs as part of the natural healing process. Inflammation is facilitated by a number of cells, mediators and enzymes including cyclo-oxygenase (COX). COX is responsible for the formation of a group of inflammatory mediators known as prostaglandins. Aspirin inhibits COX, in turn stopping the formation of prostaglandins; hence aspirin acts as an anti-inflammatory agent in this process.

COX also plays a role in cessation of bleeding. Blood clotting is the result of a complex mechanism which involves many different cells, including a type of blood cell known as platelets. When blood vessels are damaged or are diseased, platelets clump together to facilitate repair. COX activates a chemical known as thromboxane A2 that causes platelets to stick together to form a ‘plug’ over the damaged area. The aggregation of platelets (forming a platelet plug), in concert with the clotting process, results in a fibrin clot which stops bleeding and aids repair of the blood vessel. Aspirin inhibits COX and reduces the ability of the platelets to form a plug. This is why aspirin is known as a ‘blood thinner’ or anti-platelet agent.

This is a dose that has blood thinning (anti-platelet) actions with low side effects from bleeding. This dose is lower than that usually taken for pain relief and for reducing fever. It is the same dose prescribed for people who need aspirin for secondary prevention, e.g. to prevent a second heart attack or stroke.

All medications have the potential to cause adverse effects, and aspirin is no exception. Aspirin has risks related to its actions on chemicals in the body called prostaglandins and on platelets, a type of cell in the blood responsible for blood clotting.

Some prostaglandins cause fever, inflammation and pain, while other prostaglandins form a layer on the stomach wall to protect it from harsh stomach acid. Aspirin inhibits the production of prostaglandins, which will reduce fever, pain and inflammation, but it will also put the stomach at risk of this layer thinning. If the layer becomes too thin stomach acid can erode the wall of the stomach and form an ulcer. Watch video here.

Others side effects of aspirin are related to its action on platelets. Aspirin’s anti-platelet or blood thinning effect leads to a delay in blood clotting. This means that if you bleed and are taking aspirin, the bleeding may take longer to stop. Symptoms of this longer bleeding time may include bruises, blood in the stools (due to gastrointestinal bleeding), or in the worst case, a bleed into the brain (cerebral haemorrhage or a bleeding stroke). These adverse effects are risks. Although some people unfortunately experience side-effects, not everyone that takes aspirin will experiences adverse effects.

ASPREE is the first study in the world to determine the balance of the benefit of aspirin versus the risk of side-effects in healthy older people.

Prolonged use of aspirin at higher doses can cause stomach ulcers, and can also prolong bleeding time. The low-dose form of aspirin (100mg) used in the ASPREE study reduced the risk of developing stomach ulcers from aspirin, while also having the potential to provide therapeutic benefit.  ASPREE is the first study in the world to determine the balance of potential benefit versus the risk of aspirin for primary prevention of disease. The ASPREE Clinical Trial officially concluded in January 2018.

ASPREE-XT (eXTension) is a follow up observational study of possible long term effects of aspirin in older people, which commenced in January 2018.  There are indications that taking aspirin for a period of time may reduce the incidence and spread of some cancers, such as bowel cancer, however this may not be evident until may years later.

There is NO evidence that low-dose aspirin (100mg) causes tinnitus. There is evidence that long term, high dose aspirin (>500mg daily) can cause tinnitus in some people and this is reversible once the treatment is stopped or the dose is lowered.

Yes. Aspirin can interact with the following drugs: acetazolamide, corticosteroids, ibuprofen, probenecid, sodium valproate and warfarin. The significance of the interaction between aspirin and these medications varies depending upon the person taking them.

Aspirin belongs to a class of drugs called non-steroidal anti-inflammatory drugs (NSAIDs). If you take a number of NSAIDs at the same time the side effects can be cumulative. If you have any concerns about any medications, please seek medical advice.

Yes. Salicylic acid is found in certain vegetables, fruits, nuts, seeds and herbs in various amounts. Acetyl salicylic acid in aspirin, is a modified version of salicylic acid.