There is no evidence to suggest that avocado can decrease the effectiveness of Lipitor, a medication used to lower cholesterol levels in the body [1]. In fact, some studies have shown that avocado may have cholesterol-lowering properties [2]. However, it is important to note that avocado should not be used as a replacement for Lipitor or any other prescribed medication for high cholesterol. While avocado may have health benefits, it is not a substitute for medical treatment [3]. As with any medication or dietary supplement, it is always best to consult with a healthcare provider before making any changes to your treatment plan.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7023362/
[3] https://avocadotea.com/blogs/blog-1/avocado-leaf-reduces-cholesterol