Lipitor is a medication that is used to lower cholesterol levels in the body. It is important to monitor liver function while taking Lipitor, as the medication can cause liver damage in rare cases. The guidelines for Lipitor liver checks are outlined by the FDA and are based on clinical studies.

According to the FDA, liver function tests should be performed before starting Lipitor and periodically thereafter. The frequency of liver function tests should be based on the patient's individual risk factors, such as age, underlying liver disease, and other medications they may be taking. If a patient experiences symptoms of liver damage, such as fatigue, loss of appetite, or yellowing of the skin or eyes, liver function tests should be performed immediately.

The FDA has also issued a safety communication regarding important safety label changes for cholesterol-lowering statin drugs, including Lipitor. The updated label includes information about the potential for liver damage and the need for liver function tests. The label also includes information about the potential for muscle damage and the need to monitor for muscle pain or weakness.

According to a study published in the National Library of Medicine, liver function tests should be performed at baseline and at 12 weeks after starting Lipitor. If liver function tests are normal at 12 weeks, they can be repeated every six months thereafter. If liver function tests are abnormal, Lipitor should be discontinued and further evaluation should be performed.

In summary, the guidelines for Lipitor liver checks include performing liver function tests before starting the medication and periodically thereafter based on individual risk factors. If a patient experiences symptoms of liver damage, liver function tests should be performed immediately. The updated label for Lipitor includes information about the potential for liver damage and the need for liver function tests. Liver function tests should be performed at baseline and at 12 weeks after starting Lipitor, and every six months thereafter if tests are normal. If liver function tests are abnormal, Lipitor should be discontinued and further evaluation should be performed.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.fda.gov/drugs/drug-safety-and-availability/fda-drug-safety-communication-important-safety-label-changes-cholesterol-lowering-statin-drugs
[3] https://www.ncbi.nlm.nih.gov/books/NBK430779/