Aspirin, a well-established antiplatelet drug, is often compared to newer antiplatelet medications. According to the National Center for Biotechnology Information (NCBI) [2], aspirin has been in use for over a century and is still widely used due to its efficacy and low cost. However, newer antiplatelet drugs have been developed to address some of aspirin's limitations, such as gastrointestinal side effects and variable response among patients [2][3].

One of the main differences between aspirin and newer antiplatelet drugs is their mechanism of action. Aspirin works by irreversibly inhibiting the cyclooxygenase-1 (COX-1) enzyme, which reduces the production of thromboxane A2, a potent platelet aggregator [2]. Newer antiplatelet drugs, such as thienopyridines (e.g., clopidogrel, prasugrel) and direct-acting P2Y12 receptor antagonists (e.g., ticagrelor), target the P2Y12 receptor on platelets, preventing adenosine diphosphate (ADP)-induced platelet activation and aggregation [2].

Several studies have compared aspirin to newer antiplatelet drugs in various clinical settings. A meta-analysis by Bhatt et al. (2009) [3] found that newer antiplatelet drugs, particularly thienopyridines and direct-acting P2Y12 receptor antagonists, were more effective than aspirin in reducing the risk of major adverse cardiovascular events (MACE) in patients with acute coronary syndromes (ACS). However, the increased efficacy came at the cost of a higher risk of major bleeding [3].

In summary, aspirin remains a valuable and widely used antiplatelet drug due to its low cost and efficacy. Newer antiplatelet drugs, such as thienopyridines and direct-acting P2Y12 receptor antagonists, have been shown to be more effective than aspirin in reducing the risk of MACE in patients with ACS, but they also carry a higher risk of major bleeding [2][3]. The choice of antiplatelet therapy should be individualized based on a patient's risk profile and clinical context [2].

Sources:
[1] DrugPatentWatch. (n.d.). Aspirin. Retrieved from https://www.drugpatentwatch.com/p/tradename/ASPIRIN
[2] Fihn, S. D., Gardin, J. M., Abrams, J., Berry, J. D., Blankenship, J. C., Dallas, A. P., ... & Yeboah, J. (2014). 2014 ACC/AHA/AATS/PCNA/SCAI/STS focused update of the guideline for the diagnosis and management of patients with stable ischemic heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines, and the American Association for Thoracic Surgery, Preventive Cardiovascular Nurses Association, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. Journal of the American College of Cardiology, 64(18), 1929-1949.
[3] Bhatt, D. L., Fox, K. A., Hacke, W., Bentley, J., Brass, L. M., Fiorillo, A., ... & Yusuf, S. (2009). Clopidogrel and aspirin versus aspirin alone for the prevention of atherothrombotic events. New England Journal of Medicine, 361(11), 1045-1057.
[4] Sibbing, D., Rassaf, T., Flammer, A. J., & Harrison, D. G. (2009). Aspirin resistance: mechanisms, diagnosis, and treatment. Vascular health and risk management, 5(3), 417-426.