Aspirin is a very common over-the-counter medicine that many people take on a regular basis for everyday issues such as relieving headaches, fever, swelling and pain. However, it can also be used as part of an ongoing treatment for conditions such as heart problems. This is why it’s important to discuss any long-term aspirin use with your doctor to ensure that the medication is safe for you to continue taking.
The half-life of aspirin in blood plasma is under twenty minutes, which means it only takes about ten minutes for the drug to be completely eliminated from the body. This is much faster than other salicylic acid-based medications such as ibuprofen, which can stay in the body for up to three days.
While the exact length of time aspirin stays in the body varies from person to person, the general answer is between one and six hours. This is because the typical 81 mg dose of aspirin will be broken down in the liver and then eliminated by the kidneys. Older individuals will need to wait longer for aspirin to be cleared from their system due to declining hepatic and renal function.
Aspirin’s blood thinning qualities will remain in the body for up to 10 days, which is why doctors ask patients not to take it before surgery (including dental procedures such as extractions). Aspirin works by irreversibly inhibiting platelet aggregation through the acetylation of the platelet cyclooxygenase. Therefore, even after aspirin is no longer in the body, it can still affect the normal clotting process in the bloodstream and may result in bleeding or bruising.