Lipitor is a brand name for atorvastatin, which is a medication used to lower cholesterol levels in the body. According to the sources provided, there are several known side effects of Lipitor/atorvastatin.

Common side effects of atorvastatin include muscle and joint pain, headache, diarrhea, and constipation. Some patients may also experience nausea, vomiting, and abdominal pain. These side effects are usually mild and go away on their own after a short period of time [2].

In rare cases, atorvastatin can cause serious side effects such as liver damage, muscle breakdown, and a rare but serious condition called rhabdomyolysis. Rhabdomyolysis is a condition in which muscle fibers break down and release their contents into the bloodstream, which can lead to kidney damage or failure [2].

Other potential side effects of atorvastatin include memory loss, confusion, and high blood sugar levels. However, these side effects are rare and usually occur in patients who are already at risk for these conditions [3].

It is important to note that not everyone who takes atorvastatin will experience side effects. The benefits of taking the medication to lower cholesterol levels generally outweigh the risks of side effects for most patients [2].

In conclusion, while Lipitor/atorvastatin is generally well-tolerated, there are several known side effects that patients should be aware of. Common side effects include muscle and joint pain, headache, diarrhea, and constipation, while rare but serious side effects include liver damage, muscle breakdown, and rhabdomyolysis. Patients who experience any unusual symptoms while taking atorvastatin should contact their healthcare provider immediately [2][3].

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.nhs.uk/medicines/atorvastatin/side-effects-of-atorvastatin/