Lipitor (atorvastatin) is a medication used to lower cholesterol levels in the blood, while Warfarin is an anticoagulant medication used to prevent blood clots. According to DrugPatentWatch [1], there are no known drug interactions between Lipitor and Warfarin. However, caution should be exercised when taking these two medications together, as they can both have an effect on blood clotting.

In a study published in the Journal of Pharmacy Practice and Research [2], it was found that there is a low risk of drug interactions between Lipitor and Warfarin. The study concluded that Lipitor can be safely used in patients taking Warfarin, as long as their blood clotting levels are closely monitored.

Drugs.com [3] also suggests that the combination of Lipitor and Warfarin may increase the risk of bleeding, and advises patients to monitor for signs of bleeding, such as unusual bruising or bleeding from the gums.

In summary, while there are no known drug interactions between Lipitor and Warfarin, caution should be exercised when taking these two medications together. Patients should closely monitor their blood clotting levels and watch for signs of bleeding. It is important to speak with a healthcare provider before starting any new medications or making changes to existing medication regimens.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8861410/
[3] https://www.drugs.com/drug-interactions/lipitor-with-warfarin-276-128-2311-0.html