Based on the information available, it seems that Lipitor, a medication used to treat high cholesterol, is a brand-name drug for atorvastatin, which is a type of statin. Statins work by blocking a substance your body needs to make cholesterol, thereby reducing the amount of cholesterol in your blood [1].

The question asks if Lipitor can be replaced with other drugs for protein absorption. However, Lipitor and other statins do not directly affect protein absorption. They work on lowering cholesterol levels in the body [1].

If a replacement is needed due to a patent expiration or other reasons, there are indeed generic alternatives available for Lipitor. According to DrugPatentWatch.com, the patent for Lipitor expired in November 2011 [2]. After a patent expires, other manufacturers can produce generic versions of the drug, which can make the medication more affordable [1].

In conclusion, while Lipitor cannot be replaced with other drugs for protein absorption, as it does not directly affect protein absorption, there are generic alternatives available for atorvastatin, the active ingredient in Lipitor, since its patent expired in 2011.

Sources:
[1] Mayo Clinic. (2021). Statins: Are these cholesterol-lowering drugs right for you? Retrieved from https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/in-depth/statins/art-20045786
[2] DrugPatentWatch.com. (n.d.). Lipitor (Atorvastatin) Drug Patent Expiration. Retrieved from https://www.drugpatentwatch.com/drugs/lipitor

(Note: The sources are hyperlinked within the text.)