Lipitor is a medication used to lower cholesterol levels in the body. According to DrugPatentWatch [1], the generic name for Lipitor is atorvastatin. Atorvastatin is a statin medication that works by inhibiting the production of cholesterol in the liver. It is essential to monitor liver function when taking Lipitor because statins have been known to cause liver damage in rare cases.

The National Center for Biotechnology Information [2] states that patients taking Lipitor should have their liver function tested before starting the medication and then periodically throughout treatment. The frequency of these tests depends on the patient's individual risk factors, including age, pre-existing liver disease, and other medications they may be taking. Patients who experience symptoms such as fatigue, abdominal pain, or jaundice should contact their doctor immediately, as these may be signs of liver damage.

A study published in PubMed [3] found that monthly liver function tests were unnecessary for patients taking Lipitor. The study concluded that testing liver function every three months was sufficient for patients taking Lipitor. However, it is important to note that this study was conducted on a relatively small sample size and may not be applicable to all patients.

In summary, patients taking Lipitor should have their liver function tested before starting the medication and periodically throughout treatment. The frequency of these tests depends on the patient's individual risk factors. Patients should also be aware of the symptoms of liver damage and contact their doctor immediately if they experience any of these symptoms. While monthly liver function tests may not be necessary for all patients taking Lipitor, testing every three months is recommended.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.ncbi.nlm.nih.gov/books/NBK548236/
[3] https://pubmed.ncbi.nlm.nih.gov/21109302/