Lipitor (atorvastatin) is a medication used to lower cholesterol levels in the blood. The dosage of Lipitor varies depending on the patient's condition and response to treatment. According to Drugs.com [3], the recommended starting dose of Lipitor for most adults is 10-20 mg per day, taken once daily. The maximum recommended dose is 80 mg per day, but this high dose is usually reserved for patients with severe hypercholesterolemia or who have not achieved their desired cholesterol levels with lower doses. The dosage of Lipitor may need to be adjusted based on the patient's age, liver function, and other medications they are taking. Medscape [2] notes that the dosage of Lipitor should be reduced in patients with liver disease or who are taking certain medications that can increase the risk of side effects. Additionally, the dosage of Lipitor may need to be adjusted in elderly patients or those with kidney disease. Patients should always follow their doctor's instructions regarding the dosage and duration of Lipitor treatment. It is important to note that Lipitor should not be taken during pregnancy or while breastfeeding [2].

Sources:
[2] Medscape. Atorvastatin (Rx). https://reference.medscape.com/drug/lipitor-atorvaliq-atorvastatin-342446
[3] Drugs.com. Atorvastatin Dosage. https://www.drugs.com/dosage/atorvastatin.html