According to the provided sources, aspirin has a long-lasting effect on clotting factors in the body.

Aspirin, also known as acetylsalicylic acid, is a widely used medication that has been used for many years to relieve pain, reduce inflammation, and prevent blood clot formation. It belongs to a class of drugs called nonsteroidal anti-inflammatory drugs (NSAIDs).

One of the primary mechanisms of action of aspirin is its ability to inhibit the enzyme cyclooxygenase (COX), which plays a crucial role in the production of thromboxane A2 (TXA2). TXA2 is a potent stimulator of platelet aggregation and vasoconstriction, both of which contribute to blood clot formation [2].

The sources indicate that aspirin irreversibly inhibits COX-1, which is responsible for the production of TXA2 in platelets. This inhibition prevents the formation of new TXA2 molecules, thereby reducing platelet aggregation and clot formation [2].

The effect of aspirin on clotting factors is long-lasting due to the irreversible nature of its inhibition on COX-1. The sources suggest that the antiplatelet effect of aspirin persists for the lifespan of platelets, which is approximately 7-10 days [2][3]. This means that once aspirin has inhibited COX-1 in platelets, the effect will last until new platelets are produced.

It is important to note that the sources do not provide an exact duration for how long aspirin affects clotting factors. However, based on the information provided, it can be inferred that the effect of aspirin on clotting factors lasts for several days to a week.

In conclusion, aspirin has a long-lasting effect on clotting factors due to its irreversible inhibition of COX-1. The antiplatelet effect of aspirin persists for the lifespan of platelets, which is approximately 7-10 days. However, it is always advisable to consult with a healthcare professional for specific information regarding the duration of aspirin's effects on clotting factors.

Sources:
[1] Drug Patent Watch: ASPIRIN. Retrieved from https://www.drugpatentwatch.com/p/tradename/ASPIRIN
[2] Patrono, C., García Rodríguez, L. A., & Landolfi, R. (2007). Low-dose aspirin for the prevention of atherothrombosis. Journal of Thrombosis and Haemostasis, 5(1), 146-157. doi: 10.1111/j.1538-7836.2006.02245.x
[3] Patrono, C., & Rocca, B. (2005). Drug Insight: aspirin resistance—fact or fashion? Nature Clinical Practice Cardiovascular Medicine, 2(7), 398-407. doi: 10.1038/ncpcardio0222