Lipitor, a brand name for atorvastatin, is a medication used to lower cholesterol levels in the blood, while blood thinners are used to prevent blood clots. Combining these two medications can potentially lead to side effects, but it depends on the individual and the dosage of the medications.

According to Drug Patent Watch [1], Lipitor can interact with certain blood thinners, such as warfarin, increasing the risk of bleeding. It is important to monitor the patient's blood clotting time if they are taking both medications. However, the website also states that there is no known interaction between Lipitor and newer blood thinners such as apixaban, dabigatran, and rivaroxaban.

A study published in the National Library of Medicine [2] found that combining atorvastatin with warfarin can lead to an increased risk of bleeding in patients with atrial fibrillation. However, the study also found that there was no significant difference in bleeding risk between patients taking atorvastatin and those not taking it.

The American Heart Association [3] lists both Lipitor and blood thinners as medications used to treat heart attacks, but they caution that combining multiple medications can increase the risk of side effects. They recommend that patients discuss their medications with their healthcare provider to ensure they are taking them safely and effectively.

In conclusion, combining Lipitor and blood thinners can potentially lead to an increased risk of bleeding, especially with older blood thinners such as warfarin. However, newer blood thinners such as apixaban, dabigatran, and rivaroxaban do not have a known interaction with Lipitor. It is important for patients to discuss their medications with their healthcare provider to ensure they are taking them safely and effectively.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8861410/
[3] https://www.heart.org/en/health-topics/heart-attack/treatment-of-a-heart-attack/cardiac-medications