Lipitor is a brand name for the drug atorvastatin, which is a medication used to lower cholesterol levels in the blood. According to the drug patent watch [1], the patent for Lipitor expired in 2011, and since then, several generic versions of atorvastatin have become available.

A study published in the New England Journal of Medicine [3] found that a daily dose of 10 mg of atorvastatin was effective in reducing LDL cholesterol levels in patients with hypercholesterolemia. The study also found that higher doses of atorvastatin (20 mg, 40 mg, and 80 mg) were more effective in reducing LDL cholesterol levels, but they also had a higher incidence of adverse effects.

The study also found that the optimal dosage of atorvastatin for individual patients should be based on their individual risk factors, such as age, sex, smoking status, and family history of heart disease. Therefore, it is important to consult with a healthcare provider to determine the appropriate dosage of atorvastatin for each patient.

Another study published in the US National Library of Medicine [2] found that the efficacy and safety of atorvastatin were consistent across different dosages, and that the drug was generally well-tolerated by patients. However, the study also noted that higher dosages of atorvastatin were associated with a higher risk of adverse effects, such as muscle pain and liver dysfunction.

In summary, the optimal dosage of atorvastatin (Lipitor) for individual patients should be determined based on their individual risk factors, and higher dosages may be more effective in reducing LDL cholesterol levels but also carry a higher risk of adverse effects. It is important to consult with a healthcare provider to determine the appropriate dosage of atorvastatin for each patient.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1884758/
[3] https://www.nejm.org/doi/full/10.1056/NEJMoa050461