Lipitor, the brand name for atorvastatin, is a medication used to lower cholesterol levels in the blood [2]. While the medication is primarily used to reduce the risk of heart attack and stroke, it can also cause side effects [2]. According to the Mayo Clinic, some of the common side effects of Lipitor include headache, muscle aches, and nausea [2]. However, the sources provided do not mention any direct effects of Lipitor on sleep stages.

The drug patent watch website provides information on the patent status of Lipitor [1]. The website lists various patents related to Lipitor, but none of them mention any effects of the medication on sleep stages.

Medical News Today provides information on the uses, dosage, and side effects of atorvastatin [3]. The article mentions that the medication can cause sleep problems, such as insomnia or nightmares, but it does not specify whether the medication affects specific stages of sleep [3].

In summary, while Lipitor can cause side effects such as headaches and muscle aches, the sources provided do not mention any direct effects of the medication on sleep stages. However, the medication can cause sleep problems such as insomnia or nightmares [3]. If you are experiencing any sleep problems while taking Lipitor, it is recommended to speak with your healthcare provider.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.mayoclinic.org/drugs-supplements/atorvastatin-oral-route/side-effects/drg-20067003
[3] https://www.medicalnewstoday.com/articles/atorvastatin-oral-tablet