See the DrugPatentWatch profile for lipitor

After the patent expiration of Lipitor, a popular cholesterol-lowering drug, its revenue trend showed a noticeable decline. Lipitor, manufactured by Pfizer, was the best-selling drug in the world before its patent expired in November 2011 [1].

According to DrugPatentWatch.com, Lipitor's revenue was significantly impacted following the patent expiration, as generic versions of the drug entered the market [1]. In 2012, the first full year after the patent expiration, Lipitor's global sales dropped by 47.6% compared to the previous year, from $10.7 billion to $5.6 billion [1].

The decline in Lipitor's revenue continued in the following years. In 2013, Lipitor's global sales dropped by an additional 33.5%, from $5.6 billion to $3.7 billion [1]. By 2014, Lipitor's global sales had fallen to $2.2 billion, a decline of 40.3% from the previous year [1].

In summary, Lipitor's revenue trend showed a significant decline after the patent expiration, with a 47.6% drop in global sales in 2012, followed by further declines in 2013 and 2014 [1].

Sources:
[1] DrugPatentWatch.com. (n.d.). Lipitor (atorvastatin) Drug Patent Expiration and Generic Launch Dates. Retrieved from <https://www.drugpatentwatch.com/drugs/lipitor-atorvastatin>