See the DrugPatentWatch profile for lipitor

Based on the information available, it can be observed that Lipitor, a medication produced by Pfizer to lower cholesterol, faced generic competition after its patent expiration in November 2011 [1]. Atorvastatin is the active ingredient in Lipitor and is now available as a generic drug [1].

According to DrugPatentWatch.com, Lipitor had annual sales of around $10.7 billion in the year before its patent expiration [2]. Post-patent, the revenue of Lipitor has significantly decreased due to the availability of cheaper generic alternatives [1].

In contrast, generic atorvastatin has experienced substantial growth in the market. According to IQVIA Institute for Human Data Science, generic atorvastatin captured 85% of the total atorvastatin prescriptions within six months of Lipitor's patent expiration [3].

Although the exact revenue figures for Pfizer's Lipitor post-patent are not readily available, it is clear that the introduction of generic atorvastatin has led to a considerable decline in Lipitor's revenue. Meanwhile, generic atorvastatin has experienced rapid growth due to its affordability and availability [1][3].

In summary, Lipitor's post-patent revenue has significantly decreased compared to the revenue generated before the patent expiration. On the other hand, generic atorvastatin has seen substantial growth in the market due to its affordability and wide availability [1][2][3].

Sources:
[1] https://www.drugpatentwatch.com/news/2012/05/22/lipitor-loses-patent-protection-and-generic-atorvastatin-hits-the-market/
[2] https://www.drugpatentwatch.com/drugs/lipitor
[3] https://www.iqvia.com/insights/the-iqvia-institute/reports/medicine-use-and-spending-in-the-us-review-of-2017-outlook-to-2022