Lipitor and Crestor are both statins, which are drugs that help lower cholesterol levels in the body. According to the sources provided, Lipitor was more commonly prescribed than Crestor in the past, but this trend has shifted in recent years.

According to Drug Patent Watch [1], Lipitor (atorvastatin) was first approved by the FDA in 1996 and became the best-selling drug in the world by 2006. However, its patent expired in 2011, and since then, several generic versions of the drug have become available, leading to a decrease in its sales.

On the other hand, Crestor (rosuvastatin) was approved by the FDA in 2003 and has been marketed as a more potent statin than Lipitor. Medical News Today [2] reports that Crestor has been shown to lower LDL cholesterol levels by up to 63%, compared to Lipitor's 39%.

Despite Crestor's advantages, Lipitor still held a larger market share in the past due to its earlier availability and lower cost. However, SingleCare [3] notes that in recent years, Crestor has become more widely prescribed due to its efficacy and the availability of generic versions of Lipitor.

In conclusion, while Lipitor was more commonly prescribed than Crestor in the past, the trend has shifted in recent years, and Crestor is now prescribed more frequently due to its efficacy and the availability of generic versions of Lipitor.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.medicalnewstoday.com/articles/drugs-lipitor-vs-crestor
[3] https://www.singlecare.com/blog/crestor-vs-lipitor/