Lipitor, also known as atorvastatin, is a medication used to lower cholesterol levels in the body. According to the sources provided, it is recommended to take Lipitor with or without food, but it is best to take it at the same time every day [1][2]. However, certain types of food can interfere with the effectiveness of Lipitor and increase the risk of side effects. For example, grapefruit and grapefruit juice should be avoided when taking Lipitor, as they can increase the amount of the drug in the bloodstream, leading to potential side effects such as muscle pain, liver damage, and kidney failure [2][3]. Other foods to avoid when taking Lipitor include high-fat meals, alcohol, and excessive amounts of caffeine, as they can also interfere with the absorption and effectiveness of the drug [3]. It is important to talk to a healthcare provider or pharmacist about any concerns or questions regarding the use of Lipitor and its potential interactions with food or other medications [2].

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.healthline.com/health/drugs/lipitor-interactions
[3] https://www.renown.org/blog/foods-to-avoid-when-taking-heart-medications