Lipitor is a brand name for the drug atorvastatin, which is used to lower cholesterol levels and reduce the risk of heart attack and stroke. According to the sources provided, none of them mention the last time Lipitor was taken as it is a medication that is still currently being prescribed and taken by patients.

The first source, Drug Patent Watch [1], provides information about the expiration date of the Lipitor patent, which expired in 2011. This means that other pharmaceutical companies are able to produce and sell generic versions of atorvastatin.

The second source, Drugs.com [2], provides information about the optimal time to take Lipitor. It suggests that taking Lipitor at night may be more effective in reducing cholesterol levels than taking it during the day. This is because the body produces more cholesterol at night, so taking Lipitor before bed may help to inhibit its production.

The third source, Mayo Clinic [3], provides information about the proper use of atorvastatin. It recommends taking the medication at the same time each day, with or without food, and following the prescribed dosage. It also advises patients to continue taking atorvastatin even if they feel well, as high cholesterol often has no symptoms.

In conclusion, while the sources provided do not mention the last time Lipitor was taken, they do provide information about the medication's patent expiration, optimal timing for taking it, and proper use. It is important for patients to follow their doctor's instructions and continue taking atorvastatin as prescribed to effectively manage their cholesterol levels and reduce their risk of heart attack and stroke.

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.mayoclinic.org/drugs-supplements/atorvastatin-oral-route/proper-use/drg-20067003