Lipitor (atorvastatin) is a medication used to lower cholesterol levels in the blood. According to Drugs.com [2], it can be taken with or without food, and at any time of the day. However, taking Lipitor at night may be more effective in lowering cholesterol levels than taking it in the morning [2]. This is because the body naturally produces more cholesterol at night, and taking Lipitor at night can help to block the production of cholesterol more effectively [2].

It is important to note that Lipitor can interact with other medications, so it is essential to consult a healthcare provider before taking it with other medications [3]. According to Drug Patent Watch [1], Lipitor has several drug interactions, including interactions with medications such as cyclosporine, gemfibrozil, and rifampin. These interactions can increase the risk of side effects or reduce the effectiveness of Lipitor [1].

In conclusion, Lipitor can be taken at any time of the day, but taking it at night may be more effective in lowering cholesterol levels. However, it is crucial to consult a healthcare provider before taking Lipitor with other medications, as it can interact with several drugs [1][2][3].

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.drugs.com/medical-answers/does-lipitor-work-better-if-you-take-it-at-night-416127/
[3] https://www.khealth.com/learn/high-cholesterol/when-to-take-atorvastatin-morning-or-night/