Lipitor is a brand name for the drug atorvastatin, which is a type of statin used to lower cholesterol levels in the blood. Statins work by inhibiting the enzyme HMG-CoA reductase, which is responsible for producing cholesterol in the liver. Lipitor is indicated for the treatment of high cholesterol and prevention of cardiovascular disease [1].

Platelet aggregation is the process by which platelets in the blood clump together to form a clot. This is an important mechanism for preventing excessive bleeding after injury. However, excessive platelet aggregation can lead to the formation of blood clots in the arteries, which can cause heart attacks and strokes [2].

There is limited information available on the effects of Lipitor on platelet aggregation. One study published in the journal Circulation found that atorvastatin had no significant effect on platelet aggregation in patients with stable coronary artery disease [2]. Another study published in the journal Platelets found that atorvastatin reduced platelet aggregation in patients with type 2 diabetes and dyslipidemia [3].

Overall, the available evidence suggests that Lipitor may have a limited effect on platelet aggregation. However, more research is needed to fully understand the effects of atorvastatin on platelet function. Patients taking Lipitor should be monitored for any changes in platelet aggregation, particularly if they have a history of bleeding disorders or are taking other medications that affect platelet function [1].

Sources:
[1] DrugPatentWatch - Lipitor: https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] Circulation - Effects of atorvastatin on platelet aggregation and platelet-derived microparticles in patients with stable coronary artery disease: a randomized, placebo-controlled, double-blind crossover study: https://www.ahajournals.org/doi/10.1161/01.cir.0000047060.60595.cc
[3] Platelets - Atorvastatin reduces platelet aggregation and improves hemostatic function in hypercholesterolemic patients with and without diabetes: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3776183/