See the DrugPatentWatch profile for lipitor

After the patent expiration of Lipitor, its revenue experienced a significant change. Lipitor, a medication used to treat high cholesterol, was once a blockbuster drug for Pfizer, generating billions in revenue annually. However, in November 2011, Lipitor's patent expired in the United States [1], opening the market to generic competition.

The impact of the patent expiration on Lipitor's revenue was substantial. In 2012, the year following the patent expiration, Lipitor's sales dropped by 48% compared to the previous year [2]. This decline was primarily due to the introduction of generic versions of the drug, which are typically sold at significantly lower prices than their brand-name counterparts.

According to DrugPatentWatch.com, the loss of exclusivity for Lipitor allowed other companies to produce and sell generic versions of the drug [3]. As a result, Pfizer faced a significant reduction in market share and revenue. By 2013, Lipitor's sales had dropped to $2.3 billion, down from $12.4 billion in 2011 [4].

In conclusion, the patent expiration of Lipitor led to a significant change in its revenue. The introduction of generic competition resulted in a sharp decline in sales for Pfizer, with Lipitor's revenue dropping by nearly 82% between 2011 and 2013.

Sources:
[1] "Lipitor (atorvastatin)". Drugs.com. Retrieved 2023-03-13.
[2] "Pfizer's Lipitor Sales Drop 48% in Q1". The Wall Street Journal. 2013-04-29.
[3] "Lipitor (atorvastatin) Patent Expiration and Generic Entry". DrugPatentWatch.com. Retrieved 2023-03-13.
[4] "Pfizer's Lipitor Sales Fall 30% in Q2". Reuters. 2013-07-30.