Lipitor is a medication that belongs to a class of drugs known as statins, which are used to lower cholesterol levels in the blood. According to the National Health Service (NHS) [2], liver function tests are usually recommended before starting treatment with statins and then repeated after 3 months. After that, tests may be repeated every 12 months or more frequently if there are concerns about liver function or if there are changes in the patient's health that may affect liver function. The NHS [3] also states that regular liver function tests are important when taking statins to ensure that the medication is not causing any harm to the liver.

However, it is important to note that the frequency of liver function tests may vary depending on the individual patient's medical history and overall health. Patients with pre-existing liver conditions or those who are taking other medications that may affect liver function may require more frequent monitoring. It is also important to inform your healthcare provider if you experience any symptoms such as abdominal pain, yellowing of the skin or eyes, or dark urine, as these may be signs of liver problems.

In summary, liver function tests are recommended before starting treatment with Lipitor and then repeated after 3 months. After that, tests may be repeated every 12 months or more frequently if there are concerns about liver function or changes in the patient's health. However, the frequency of liver function tests may vary depending on the individual patient's medical history and overall health. It is important to inform your healthcare provider if you experience any symptoms of liver problems while taking Lipitor.

Sources:
[2] https://www.nhs.uk/conditions/statins/considerations/
[3] https://www.nhsinform.scot/tests-and-treatments/medicines-and-medical-aids/types-of-medicine/statins