Lipitor, also known as atorvastatin, is a medication used to lower cholesterol levels in the blood. However, it can have side effects, including muscle damage. According to Mayo Clinic [2], statins, including Lipitor, can cause muscle pain, soreness, and weakness, which can be a sign of muscle damage. The muscle damage can be severe, leading to a condition called rhabdomyolysis, which can cause kidney damage and even death in rare cases.

The exact mechanism by which statins cause muscle damage is not fully understood, but it is believed to be related to the way they affect the production of energy in the muscles [3]. Statins like Lipitor inhibit an enzyme called HMG-CoA reductase, which is involved in the production of cholesterol in the liver. However, this enzyme is also involved in the production of a molecule called coenzyme Q10 (CoQ10), which is essential for the production of energy in the muscles. When statins inhibit HMG-CoA reductase, they also decrease the production of CoQ10, which can lead to muscle damage.

According to Drug Patent Watch [1], Pfizer, the manufacturer of Lipitor, has acknowledged the potential for muscle damage and has included a warning about it in the drug's label. The label advises patients to report any unexplained muscle pain, tenderness, or weakness to their doctor immediately.

In conclusion, Lipitor can cause muscle damage, including muscle pain, soreness, weakness, and in rare cases, rhabdomyolysis. The exact mechanism by which this occurs is not fully understood, but it is believed to be related to the way statins affect the production of energy in the muscles. Patients taking Lipitor should be aware of the potential for muscle damage and report any symptoms to their doctor immediately [2][3][1].

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/in-depth/statin-side-effects/art-20046013
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2949584/