Lipitor is a medication used to lower cholesterol levels in the blood, and aspirin is a common medication used for pain relief and to prevent blood clots. According to the sources provided, there is no evidence that Lipitor dosage adjustment is needed when taking aspirin.

One source [1] provides information on Lipitor's patent status and generic availability. The other two sources [2][3] discuss drug interactions with Lipitor. The first [2] is a review article that mentions that aspirin can interact with other cholesterol-lowering medications, such as statins, but does not specifically mention Lipitor. The second source [3] discusses drug interactions with Paxlovid, a medication used to treat COVID-19, which includes ritonavir-boosted nirmatrelvir. The source notes that there is no evidence of a significant interaction between Lipitor and Paxlovid.

In summary, there is no evidence that Lipitor dosage adjustment is needed when taking aspirin. However, it is always important to consult with a healthcare provider before starting or changing any medication regimen.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.aafp.org/pubs/afp/issues/2007/0515/p1487.html
[3] https://www.covid19treatmentguidelines.nih.gov/therapies/antivirals-including-antibody-products/ritonavir-boosted-nirmatrelvir--paxlovid-/paxlovid-drug-drug-interactions/