Lipitor is a brand name for the drug atorvastatin, which is used to lower cholesterol levels in the blood. According to the Mayo Clinic [2], some of the side effects of statins, including Lipitor, can include muscle pain, liver damage, and an increased risk of bleeding. However, the risk of bleeding associated with statins is generally considered to be low.

A study published in 2007 by Reuters [3] found that Lipitor could increase the risk of bleeding and stroke in patients who had previously suffered a hemorrhagic stroke. The study analyzed data from over 2,000 patients and found that those taking Lipitor had a higher risk of recurrent bleeding strokes compared to those taking a placebo. However, the study noted that the overall risk of bleeding strokes was still relatively low.

DrugPatentWatch [1] provides information on the patent status of Lipitor but does not directly address the question of whether Lipitor increases bleeding risk.

In conclusion, while there is some evidence to suggest that Lipitor may increase the risk of bleeding and stroke in certain patients, the overall risk is considered to be low. Patients taking Lipitor should discuss any concerns about side effects with their healthcare provider.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/in-depth/statin-side-effects/art-20046013
[3] https://www.reuters.com/article/us-cholesterol-stroke/lipitor-ups-risk-of-bleeding-stroke-study-idUSWBT00804520071212