SIDE EFFECTS OF ATORVASTATIN: Like all medications, atorvastatin (brand name Lipitor) can cause side effects. The most common side effects of atorvastatin are usually mild and may include: Headache Muscle aches and pains Abdominal pain or bloating Nausea or vomiting Diarrhea or constipation Skin rash Insomnia Some people may also experience more serious side effects. If you experience any of the following symptoms, you should contact your healthcare provider immediately: Unexplained muscle pain, tenderness, or weakness Fever or flu-like symptoms Dark-colored urine or yellowing of the skin or eyes (jaundice) Severe stomach pain Allergic reactions such as hives, swelling of the face, lips, tongue, or throat