The sources provided do not offer specific information about the previous dosage of Lipitor. However, they do provide information about the drug itself, its dosages, and clinical studies.

Lipitor is a medication used to treat high cholesterol and prevent cardiovascular disease [1]. The drug is available in various dosages, including 10 mg, 20 mg, 40 mg, and 80 mg [2]. The appropriate dosage for a patient depends on several factors, including age, health status, and other medications being taken [2].

A clinical study published in the New England Journal of Medicine evaluated the effectiveness of Lipitor in reducing the incidence of major cardiovascular events in patients with a history of stroke or transient ischemic attack [3]. The study used a dosage of 80 mg of Lipitor daily, which was found to significantly reduce the risk of cardiovascular events compared to a placebo [3].

In conclusion, while the sources provided do not offer specific information about the previous dosage of Lipitor, they do provide general information about the drug and its dosages. It is important for patients to consult with their healthcare provider to determine the appropriate dosage of Lipitor for their individual needs.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.drugs.com/dosage/lipitor.html
[3] https://www.nejm.org/doi/10.1056/NEJMoa061894