Lipitor (atorvastatin) is a medication used to treat high cholesterol levels and reduce the risk of heart disease [2]. According to the American Academy of Family Physicians, the starting dose of Lipitor is typically 10 to 20 mg once daily, with a maximum dose of 80 mg per day [3]. However, the appropriate dosage may vary depending on the patient's age, medical history, and other factors [3].

Drug Patent Watch indicates that the dosage of Lipitor can be adjusted based on the patient's response to treatment and the presence of certain medical conditions [1]. For example, patients with severe kidney disease may require a lower dose of Lipitor to prevent side effects [1]. Additionally, patients taking certain medications that interact with Lipitor may require a dosage adjustment [1].

Medscape also notes that the dosage of Lipitor may need to be adjusted in patients with liver disease, as the medication is metabolized in the liver [2]. In patients with mild to moderate liver disease, the starting dose of Lipitor should be 10 mg per day, with a maximum dose of 20 mg per day [2]. In patients with severe liver disease, Lipitor should be used with caution and at the lowest effective dose [2].

In conclusion, the appropriate dosage of Lipitor may vary depending on the patient's medical history and response to treatment. Patients with certain medical conditions, such as kidney or liver disease, may require a lower dose of Lipitor to prevent side effects. It is important for patients to discuss their medical history and any medications they are taking with their healthcare provider to determine the appropriate dosage of Lipitor.

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