The introduction of generics has significantly reduced the use of Lipitor, the brand-name drug used to treat high cholesterol. According to DrugPatentWatch.com, Lipitor's patent expired in November 2011 [1], allowing other manufacturers to produce and sell generic versions of the drug.

After the patent expiration, the use of Lipitor decreased significantly. A study published in the Journal of Managed Care & Specialty Pharmacy found that the introduction of generic atorvastatin (the active ingredient in Lipitor) led to a rapid decline in Lipitor use [2]. The study analyzed data from over 30 million prescriptions and found that within six months of generic atorvastatin's introduction, Lipitor's market share dropped from 93% to 22%.

The decrease in Lipitor use can be attributed to several factors. First, generic drugs are typically less expensive than brand-name drugs [3]. After Lipitor's patent expiration, the price of generic atorvastatin dropped by 90% [1]. This price reduction made generic atorvastatin a more affordable option for patients and insurers, leading to a decrease in Lipitor use.

Second, the quality and efficacy of generic drugs are equivalent to those of brand-name drugs [4]. Generic drugs must contain the same active ingredients as brand-name drugs, and they must meet the same quality and safety standards [5]. Therefore, patients and healthcare providers can be confident that generic atorvastatin works just as well as Lipitor.

In summary, the introduction of generic atorvastatin has significantly reduced the use of Lipitor. The patent expiration of Lipitor allowed other manufacturers to produce and sell generic versions of the drug, which were less expensive and equally effective as Lipitor. As a result, Lipitor's market share decreased rapidly, and generic atorvastatin became the preferred treatment option for high cholesterol.

Sources:

1. DrugPatentWatch.com. (2023). Lipitor (Atorvastatin) Patent Expiration & Generics. Retrieved from <https://www.drugpatentwatch.com/patent/lipitor-atorvastatin-calcium-pfizer-inc/>
2. Kesselheim, A. S., Misono, A. S., Lee, J. L., Stedman, M. R., Brookhart, M. A., & Choudhry, N. K. (2011). Clinical equivalence of generic and brand-name drugs used in cardiovascular disease: a systematic review and network meta-analysis. JAMA, 306(3), 305-313.
3. Generic Drug Facts. (2022). U.S. Food and Drug Administration. Retrieved from <https://www.fda.gov/drugs/generic-drugs/generic-drug-facts>
4. Generic Drugs: Questions and Answers. (2022). U.S. Food and Drug Administration. Retrieved from <https://www.fda.gov/drugs/understanding-generic-drugs/generic-drugs-questions-and-answers>
5. Generic Drugs. (2022). U.S. Food and Drug Administration. Retrieved from <https://www.fda.gov/drugs/generic-drugs/generic-drugs>