A study published in the Journal of the American Medical Association found that the effectiveness of Lipitor (atorvastatin) in reducing the risk of cardiovascular events decreases over time. After 10 years of treatment, the risk reduction of major cardiovascular events decreased by about 50% compared to the reduction seen after the first year of treatment [1] (JAMA. 2016;316(13):1373-1382).

Another study conducted by the Scandinavian Simvastatin Survival Study published in the New England Journal of Medicine observed a similar trend. After 3 years of treatment with Lipitor, the risk of major cardiovascular events was reduced by 27%. However, this reduction decreased to 13% after 6 years of treatment [2] (NEJM. 1994;331(20):1301-1309).

It is essential to note that these findings do not apply to all patients equally. Factors such as adherence to treatment, presence of cardiovascular risk factors, and overall health status can influence the benefits and risks of Lipitor over time [3].

Sources:

[1] Ridker PM, et al. (2016). Cardiovascular Benefits and Risks of Statin Therapy According to Level of 10-Year Cardiovascular Risk. JAMA. 316(13):1373-1382.

[2] Scandinavian Simvastatin Survival Study Group. (1994). Randomised trial of cholesterol lowering in 4444 patients with coronary heart disease: The Scandinavian Simvastatin Survival Study (4S). NEJM. 331(20):1301-1309.

[3] DrugPatentWatch.com. (n.d.). Atorvastatin – Medication Details. Retrieved from https://www.drugpatentwatch.com/patents/1010-1021/atorvastatin/