Lipitor is a brand name for the drug atorvastatin, which is a medication used to lower cholesterol levels in the blood. According to Healthline [2], Lipitor is typically prescribed to patients who have high cholesterol levels, and it is used to reduce the risk of heart attack, stroke, and other cardiovascular problems.

The dosage of Lipitor is adjusted based on the patient's individual needs and response to the medication. According to Healthline [2], the usual starting dose of Lipitor is 10-20 mg once daily, and the maximum recommended dose is 80 mg once daily. However, the dose may be adjusted based on the patient's age, health status, and other factors.

Drugpatentwatch [1] indicates that Lipitor has been available in the market since 1996, and its patent expired in 2011. After the patent expiration, the generic versions of atorvastatin became available, which are more affordable than the brand-name Lipitor.

It is important to note that Lipitor, like all medications, may have side effects. According to the National Center for Biotechnology Information [3], some of the common side effects of atorvastatin include muscle pain, weakness, and tenderness, liver problems, and digestive problems. Therefore, patients who experience any of these side effects may need to have their dosage adjusted or switch to a different medication.

In summary, Lipitor (atorvastatin) is a medication used to lower cholesterol levels in the blood, and its dosage is adjusted based on the patient's individual needs and response to the medication. The usual starting dose is 10-20 mg once daily, and the maximum recommended dose is 80 mg once daily. The generic versions of atorvastatin are available in the market since the patent expiration in 2011. Patients who experience any side effects may need to have their dosage adjusted or switch to a different medication.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.healthline.com/health/drugs/lipitor-dosage
[3] https://www.ncbi.nlm.nih.gov/books/NBK430779/