After reviewing the available information, it is generally recommended to take Lipitor, a medication used to treat high cholesterol, with a meal. According to the drug's official patient information leaflet provided by the U.S. Food and Drug Administration (FDA) [1], Lipitor can be taken at any time of the day but should be taken with a meal or immediately after a meal. This recommendation is based on the drug's mechanism of action and its potential interactions with food.

Lipitor, also known as atorvastatin, is a type of drug called a statin, which works by reducing the amount of cholesterol produced by the liver. When taken with food, particularly a meal that contains some fat, the absorption of Lipitor is increased, leading to higher levels of the drug in the bloodstream [2]. This can enhance the drug's effectiveness in lowering cholesterol levels.

Additionally, taking Lipitor with food can help reduce the risk of gastrointestinal side effects such as nausea, diarrhea, and abdominal pain [1]. However, it is important to note that taking Lipitor with grapefruit or grapefruit juice should be avoided, as it can increase the levels of the drug in the body and increase the risk of side effects [1].

In conclusion, based on the available information from the FDA, it is recommended to take Lipitor with a meal to enhance its absorption and effectiveness, as well as to reduce the risk of gastrointestinal side effects. However, it is important to consult with a healthcare provider for personalized advice on taking Lipitor and other medications.

Sources:
[1] U.S. Food and Drug Administration. (2016). Lipitor (atorvastatin) tablets, for oral use.
<https://www.accessdata.fda.gov/drugsatfda_docs/label/2016/20205s093lbl.pdf>
[2] DrugPatentWatch. (n.d.). Lipitor (atorvastatin) drug patent insights, expiry dates & analysis.
<https://www.drugpatentwatch.com/drugs/lipitor>