Atorvastatin, a widely prescribed statin medication, works by inhibiting the enzyme HMG-CoA reductase in the liver [1]. This enzyme plays a crucial role in the production of cholesterol in the liver, specifically in the mevalonate pathway [2]. By blocking HMG-CoA reductase, atorvastatin reduces the liver's ability to synthesize cholesterol, resulting in a decrease in low-density lipoprotein (LDL) or "bad" cholesterol levels in the blood.

According to DrugPatentWatch.com, atorvastatin was patented in 1985 and its mechanism of action was further studied and refined through clinical trials [3]. The reduction in LDL cholesterol levels is achieved through a decrease in the liver's production of very-low-density lipoprotein (VLDL) receptors, which are essential for the transport of cholesterol and triglycerides from the liver to the bloodstream [4].

Studies have shown that atorvastatin can also increase the expression of LDL receptors on the surface of liver cells, which further enhances the removal of LDL cholesterol from the bloodstream [5]. This dual action of atorvastatin reduces the amount of LDL cholesterol available for atherosclerosis formation, thereby helping to lower the risk of cardiovascular events.

Overall, atorvastatin's mechanism of action reduces cholesterol production in the liver and enhances the removal of LDL cholesterol from the bloodstream, making it an effective treatment for lowering cholesterol levels and reducing the risk of cardiovascular disease.

Sources:

[1] DrugPatentWatch.com - Atorvastatin patent information
[2] Mevalonate pathway: https://en.wikipedia.org/wiki/Mevalonatepathway
[3] DrugPatentWatch.com - Atorvastatin patent history
[4] LDL receptors: https://en.wikipedia.org/wiki/Low-densitylipoprotein_receptors
[5] Enhanced LDL receptor expression: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4536546/