Lipitor (atorvastatin) is a medicine that can lower your levels of cholesterol therefore reducing the risk of developing more dangerous health conditions. Lipitor must never be used by pregnant women as it has been reported to cause birth defects in unborn babies. Always make sure you talk to your health care provider if there is a chance you may get pregnant during the treatment and see what can be done to protect your child. Your doctor must be informed of any medical conditions you have, such as diabetes, underactive thyroid, kidney disease, muscle disorder, history of liver disease, or any other conditions of that kind, as they may affect the dose you are prescribed. There may be some drugs that can interact with Lipitor - make sure you know them all and are aware of the fact any medicine you may be taking at the moment can be on of meds that cause interactions, such as niacin, erythromycin, HIV or AIDS medication, cancer medicines, Clomid, steroids, and antifungal medication. Lipitor can sometimes cause mild side effects, and the following ones are possible: bloating, mild nausea, skin rash, constipation, heartburn, itching, stuffy nose, headache, and stomach upset.