Lipitor is a brand name for atorvastatin, a medication used to lower cholesterol levels in the blood. According to [1], some of the common side effects of taking Lipitor include headache, muscle pain, joint pain, nausea, diarrhea, and constipation. However, these side effects are usually mild and go away on their own.

More serious side effects of Lipitor include liver problems, muscle damage, and an increased risk of developing type 2 diabetes. Patients taking Lipitor should contact their doctor immediately if they experience any of the following symptoms: dark urine, yellowing of the skin or eyes, unexplained muscle pain, tenderness, or weakness, fever, or fatigue. These symptoms may indicate liver problems or muscle damage, which can be serious and require immediate medical attention.

According to [2], some people may also experience allergic reactions to Lipitor, which can cause symptoms such as difficulty breathing, swelling of the face, lips, tongue, or throat, and hives. Patients who experience any of these symptoms should seek medical attention immediately.

It is important to note that not everyone who takes Lipitor will experience side effects. However, patients should be aware of the potential risks and benefits of the medication before taking it. Patients should also discuss any concerns or questions about Lipitor with their doctor or pharmacist.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.nhs.uk/medicines/atorvastatin/side-effects-of-atorvastatin/
[3] https://www.drugwatch.com/lipitor/side-effects/