Lipitor, also known as atorvastatin, is a medication used to lower cholesterol levels in the blood. According to DrugPatentWatch [1], Lipitor works by blocking an enzyme in the liver that produces cholesterol. Joint pain is a common side effect of statins, including Lipitor, as stated by GoodRx [2]. However, it is unclear whether Lipitor can worsen joint pain. According to DrugWatch [3], joint pain is a possible side effect of Lipitor, but it is not listed as a common or serious side effect. It is important to note that joint pain can have many causes, and it is not always clear whether a medication is the cause. If you are experiencing joint pain while taking Lipitor, it is recommended to speak with your doctor to determine the cause and explore potential treatment options.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.goodrx.com/classes/statins/joint-pain
[3] https://www.drugwatch.com/lipitor/side-effects/