Lipitor is a brand name for atorvastatin, a medication used to treat high cholesterol. According to Drug Patent Watch [1], Lipitor is one of the most commonly prescribed drugs in the United States. However, like all medications, it may cause side effects. One of the most common side effects of Lipitor is muscle pain or weakness, also known as myopathy.

The Mayo Clinic [2] states that muscle pain or weakness is a potential side effect of statins, including Lipitor. The article explains that statins work by reducing the production of cholesterol in the liver, which can lead to a decrease in the production of a substance called coenzyme Q10 (CoQ10). CoQ10 is important for muscle function, and a deficiency can lead to muscle pain and weakness.

A study published in the American Journal of Cardiovascular Drugs [3] investigated the relationship between statins and muscle-related side effects. The study found that myopathy is a rare side effect of statins, occurring in less than 1% of patients. However, the risk of myopathy increases with higher doses of statins, and certain factors such as age, gender, and genetics may also increase the risk.

In conclusion, muscle pain or weakness is a potential side effect of Lipitor, but it is relatively rare, occurring in less than 1% of patients. The risk of myopathy increases with higher doses of the medication and certain individual factors. Patients taking Lipitor should be aware of this potential side effect and report any muscle-related symptoms to their healthcare provider.

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/