Lipitor (atorvastatin) is a medication used to lower cholesterol levels in the blood. The dosage of Lipitor may need to be adjusted based on several factors.

According to DrugPatentWatch [1], the recommended starting dose of Lipitor is 10-20 mg once daily. The dose may be increased up to 80 mg once daily depending on the patient's response and tolerance. The patient's age, gender, race, and other medical conditions may also influence the dosage adjustment.

The American Academy of Family Physicians [2] suggests that the dosage of Lipitor should be individualized based on the patient's response to therapy and lipid levels. The goal of therapy is to achieve target lipid levels, which may require dosage adjustments. The patient's medical history, medication history, and other risk factors for cardiovascular disease should also be considered when determining the appropriate dosage.

Medscape [3] notes that the dosage of Lipitor may need to be adjusted in patients with renal impairment. The recommended starting dose is 10 mg once daily in patients with moderate to severe renal impairment, and the maximum recommended dose is 20 mg once daily. Lipitor is not recommended in patients with end-stage renal disease who require dialysis.

In summary, the dosage of Lipitor may need to be adjusted based on the patient's response to therapy, lipid levels, medical history, medication history, risk factors for cardiovascular disease, and renal function. It is important for healthcare providers to individualize the dosage of Lipitor to achieve target lipid levels and minimize the risk of adverse effects.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.aafp.org/pubs/afp/issues/2007/0515/p1487.html
[3] https://reference.medscape.com/drug/lipitor-atorvaliq-atorvastatin-342446