Lipitor, also known as atorvastatin, is a medication used to lower cholesterol levels in the body. Aspirin, on the other hand, is a medication used to relieve pain, reduce inflammation, and prevent blood clots.

There is limited information available on the interaction between Lipitor and aspirin. According to Drug Patent Watch [1], there are no known drug interactions between Lipitor and aspirin. However, it is always important to consult with a healthcare provider before taking any new medications, including over-the-counter medications like aspirin.

A study published in the Journal of Clinical Pharmacology [3] found that atorvastatin did not affect the antiplatelet effects of aspirin in healthy volunteers. The study concluded that atorvastatin and aspirin could be used together safely in patients with cardiovascular disease.

Another study published in the Journal of Thrombosis and Haemostasis [2] investigated the effect of atorvastatin on platelet function in patients with stable coronary artery disease who were also taking aspirin. The study found that atorvastatin did not significantly affect platelet function in these patients.

In summary, based on the limited available information, there is no evidence to suggest that Lipitor affects the effectiveness of aspirin. However, it is always important to consult with a healthcare provider before taking any new medications, including over-the-counter medications like aspirin.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://pubmed.ncbi.nlm.nih.gov/16520473/
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4754966/