When it comes to the co-administration of Lipitor (atorvastatin) and warfarin, it is crucial to follow medical advice and professional guidance due to the potential for drug interactions. According to the information provided in the articles [2][3], the recommended Lipitor dosage when taken with warfarin should be individualized based on the patient's response to treatment and clinical goals.

In general, the prescribing information for Lipitor does not provide specific dosage recommendations when used concomitantly with warfarin [1]. However, both Lipitor and warfarin are metabolized in the liver by the cytochrome P450 system, specifically by the CYP3A4 isoenzyme [2]. This shared metabolic pathway raises the potential for drug interactions, which could lead to changes in the International Normalized Ratio (INR) for patients on warfarin therapy.

Therefore, when Lipitor is prescribed to a patient already taking warfarin, or if a patient on Lipitor therapy is initiated on warfarin, it is essential to closely monitor the patient's coagulation status, as well as liver function, and adjust the warfarin dosage accordingly [2]. Healthcare providers should be vigilant for signs of bleeding or other adverse effects, and communicate closely with their patients to ensure safe and effective treatment [3].

In summary, the recommended Lipitor dosage with warfarin is individualized and requires close monitoring by healthcare professionals. Patients should consult their healthcare providers for personalized advice and recommendations.

Cited Sources:
[1] <https://www.drugpatentwatch.com/p/tradename/LIPITOR>
[2] <https://pubmed.ncbi.nlm.nih.gov/28349387/>
[3] <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8861410/>