Lipitor, a drug produced by Pfizer, is a statin that inhibits HMG CoA reductase [1]. This enzyme plays a crucial role in the production of mevalonate, a precursor for cholesterol synthesis [2]. By inhibiting HMG CoA reductase, Lipitor reduces the body's production of LDL cholesterol, which is often referred to as "bad" cholesterol [1].

The significance of Lipitor's impact on HMG CoA reductase for LDL cholesterol is substantial. High levels of LDL cholesterol are a major risk factor for cardiovascular disease, the leading cause of death globally [3]. Lipitor has been shown to significantly reduce LDL cholesterol levels, thereby lowering the risk of cardiovascular events [1].

According to DrugPatentWatch.com, Lipitor has been a blockbuster drug, with annual sales exceeding $12 billion at its peak [4]. Its patent expired in 2011, leading to the introduction of generic versions [4]. Despite the availability of generics, Lipitor remains widely used due to its efficacy and tolerability profile [1].

In summary, Lipitor's impact on HMG CoA reductase for LDL cholesterol is significant due to its ability to reduce LDL cholesterol levels, thereby lowering the risk of cardiovascular disease. This has led to its widespread use and blockbuster status.

Sources:
[1] Mayo Clinic. (2021). Atorvastatin (Oral Route). Retrieved from https://www.mayoclinic.org/drugs-supplements/atorvastatin-oral-route/description/drg-20063054
[2] National Center for Biotechnology Information. (2021). HMG-CoA reductase. Retrieved from https://www.ncbi.nlm.nih.gov/gene/3058
[3] World Health Organization. (2021). Cardiovascular diseases (CVDs). Retrieved from https://www.who.int/news-room/fact-sheets/detail/cardiovascular-diseases-(cvds)
[4] DrugPatentWatch.com. (2021). Lipitor. Retrieved from https://www.drugpatentwatch.com/drugs/lipitor