Lipitor is a medication used to lower cholesterol levels in the blood. According to Drug Patent Watch [1], the active ingredient in Lipitor is atorvastatin, which works by blocking the enzyme responsible for producing cholesterol in the liver. While Lipitor is generally considered safe, it can cause side effects, including muscle weakness, in some patients.

According to the Mayo Clinic [2], muscle weakness is a potential side effect of statins, including Lipitor. However, the Mayo Clinic notes that muscle weakness is typically a temporary side effect that goes away once the medication is discontinued. In rare cases, statins can cause a more serious condition called rhabdomyolysis, which can lead to permanent muscle damage.

A study published in the Journal of Clinical Lipidology [3] found that muscle symptoms, including weakness, were the most common side effect reported by patients taking statins. However, the study also found that the vast majority of patients who experienced muscle symptoms were able to continue taking statins without any long-term muscle damage.

In conclusion, while Lipitor can cause muscle weakness as a side effect, it is typically a temporary condition that goes away once the medication is discontinued. In rare cases, statins can cause permanent muscle damage, but this is a very uncommon occurrence. Patients who experience muscle weakness while taking Lipitor or any other statin should speak with their doctor to determine the best course of action.

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/