Lipitor (atorvastatin) is a medication that is used to lower cholesterol levels in the blood. According to the National Health Service (NHS) [3], the dosage of Lipitor should be determined by a doctor based on individual patient needs and medical history. The recommended starting dose of Lipitor is usually 10mg or 20mg once daily, taken at any time of the day. The dosage can be increased if necessary, but this decision should be made by a doctor based on the patient's response to the medication and any potential side effects.

Drug Patent Watch [1] provides information on the patent status of Lipitor, but does not offer any guidance on dosage. However, a study published in the National Center for Biotechnology Information (NCBI) [2] suggests that the dosage of Lipitor should be increased cautiously and only when necessary. The study recommends monitoring the patient's response to the medication and adjusting the dosage accordingly. The study also suggests that a lower dosage of Lipitor may be effective for some patients, and that a higher dosage may increase the risk of side effects.

In summary, the dosage of Lipitor should be determined by a doctor based on individual patient needs and medical history. The recommended starting dose is usually 10mg or 20mg once daily, taken at any time of the day. The dosage can be increased if necessary, but this decision should be made by a doctor based on the patient's response to the medication and any potential side effects. It is important to monitor the patient's response to the medication and adjust the dosage accordingly. A lower dosage may be effective for some patients, and a higher dosage may increase the risk of side effects.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4354082/
[3] https://www.nhs.uk/medicines/atorvastatin/how-and-when-to-take-atorvastatin/