Lipitor, also known as atorvastatin, is a medication used to treat high cholesterol levels and reduce the risk of heart attack and stroke [1]. While Lipitor is generally well-tolerated, it may cause side effects in some people [2]. The most common side effects of Lipitor include muscle and joint pain, diarrhea, constipation, and nausea [3]. Some people may also experience headache, insomnia, or a rash.

In rare cases, Lipitor may cause more serious side effects such as liver problems, muscle damage, and a condition called rhabdomyolysis, which can cause kidney damage [2]. It is important to contact a doctor immediately if any of these symptoms occur.

Lipitor may also interact with other medications, including some antibiotics, antifungal medications, and medications used to treat HIV and hepatitis C [3]. It is important to inform a doctor of all medications being taken before starting Lipitor.

In conclusion, while Lipitor is generally well-tolerated, it may cause side effects in some people. The most common side effects include muscle and joint pain, diarrhea, constipation, and nausea. In rare cases, more serious side effects may occur, such as liver problems, muscle damage, and rhabdomyolysis. It is important to contact a doctor immediately if any of these symptoms occur [2][3].

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