Lipitor is a medication used to lower cholesterol levels in the body. According to Drug Patent Watch [1], Lipitor is a brand name for atorvastatin, which is a member of the statin class of drugs. Statins are known to have potential side effects, and muscle strains are one of them.

Muscle strains or muscle damage are possible side effects of taking Lipitor, as mentioned by the Mayo Clinic [2]. The symptoms of muscle strains include muscle pain, tenderness, and weakness. Patients may also experience swelling, bruising, or redness in the affected area. In some cases, the muscle pain may be severe and lead to muscle breakdown, which can cause kidney damage.

A study published in PubMed [3] suggests that patients who experience muscle strains while taking Lipitor may also experience an increase in creatine kinase (CK) levels. CK is an enzyme that is released into the bloodstream when muscle damage occurs. Therefore, an increase in CK levels may indicate muscle damage.

In conclusion, muscle strains are a possible side effect of taking Lipitor, and the symptoms include muscle pain, tenderness, and weakness. Patients may also experience swelling, bruising, or redness in the affected area, and an increase in CK levels may indicate muscle damage. It is important to speak with a healthcare provider if any of these symptoms occur while taking Lipitor.

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://pubmed.ncbi.nlm.nih.gov/37019582/