Lipitor (atorvastatin) is a medication used to lower cholesterol levels in the blood. The recommended dosage of Lipitor varies depending on the patient's age, gender, medical history, and other medications they are taking.

According to Drugs.com [2], the usual starting dose of Lipitor is 10-20 mg once daily, and the maximum dose is 80 mg once daily. However, the dose may need to be adjusted based on the patient's response to the medication and other factors such as kidney function.

It is important to note that Lipitor may interact with other medications, which can affect its efficacy and safety. For example, some medications may increase the risk of muscle damage when taken with Lipitor, while others may decrease the effectiveness of Lipitor in lowering cholesterol levels [3]. Therefore, it is important to inform the prescribing physician of all medications, including over-the-counter drugs and supplements, that the patient is taking.

Medscape [3] recommends that the dosage of Lipitor should be adjusted when used in combination with certain medications such as cyclosporine, clarithromycin, itraconazole, and protease inhibitors. For example, when Lipitor is taken with cyclosporine, the dose of Lipitor should not exceed 10 mg once daily. Additionally, the use of Lipitor with gemfibrozil should be avoided due to an increased risk of muscle damage.

In conclusion, the recommended dosage of Lipitor depends on various factors and may need to be adjusted based on the patient's response to the medication and other medications they are taking. It is important to inform the prescribing physician of all medications the patient is taking to avoid potential drug interactions.

Sources:
[2] https://www.drugs.com/dosage/lipitor.html
[3] https://reference.medscape.com/drug/lipitor-atorvaliq-atorvastatin-342446