Lipitor (atorvastatin) is a medication used to lower cholesterol levels in the blood. According to the drug patent watch [1], the standard starting dose of Lipitor is 10 mg per day, and the maximum dose is 80 mg per day. However, the dose may need to be adjusted based on individual patient factors, such as age, kidney function, and other medications being taken.

Medscape [2] recommends that the initial dose of Lipitor be based on the patient's baseline LDL cholesterol level and the presence of other risk factors for cardiovascular disease. For example, patients with a baseline LDL cholesterol level of less than 190 mg/dL and no other risk factors may be started on a lower dose of 10-20 mg per day, while patients with a higher baseline LDL cholesterol level and other risk factors may be started on a higher dose of 40-80 mg per day.

The dose of Lipitor may also need to be adjusted in patients with liver or kidney disease. According to the National Center for Biotechnology Information [3], patients with severe kidney disease may need to start with a lower dose of Lipitor and have their dose adjusted based on their response to the medication. Patients with liver disease may also need to start with a lower dose and have their liver function monitored regularly while taking the medication.

In conclusion, the starting dose of Lipitor is typically 10 mg per day, and the maximum dose is 80 mg per day. However, the dose may need to be adjusted based on individual patient factors, such as age, kidney function, and other medications being taken. The initial dose should be based on the patient's baseline LDL cholesterol level and the presence of other risk factors for cardiovascular disease. Patients with liver or kidney disease may need to start with a lower dose and have their dose adjusted based on their response to the medication. It is important to consult with a healthcare provider before making any changes to the dose of Lipitor.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://reference.medscape.com/drug/lipitor-atorvaliq-atorvastatin-342446
[3] https://www.ncbi.nlm.nih.gov/books/NBK430779/