Lipitor (atorvastatin) is a medication used to lower cholesterol levels in the blood. According to the sources provided, there are several medications that should be avoided while taking Lipitor.

Firstly, it is important to note that grapefruit and grapefruit juice should be avoided while taking Lipitor as they can increase the risk of side effects. Additionally, Lipitor should not be taken with certain antibiotics, such as erythromycin and clarithromycin, as well as antifungal medications like itraconazole and ketoconazole, as they can increase the levels of Lipitor in the blood and increase the risk of side effects [2].

Furthermore, certain medications used to treat HIV/AIDS, such as indinavir, nelfinavir, ritonavir, and saquinavir, should also be avoided while taking Lipitor as they can increase the levels of Lipitor in the blood and increase the risk of side effects [3].

Other medications that should be used with caution while taking Lipitor include blood thinners like warfarin, as well as other cholesterol-lowering medications like gemfibrozil and niacin. It is important to discuss all medications, including over-the-counter drugs and supplements, with a healthcare provider before starting Lipitor to avoid any potential interactions [1].

In conclusion, Lipitor should not be taken with grapefruit or grapefruit juice, certain antibiotics and antifungal medications, and certain medications used to treat HIV/AIDS. It is also important to use caution when taking blood thinners and other cholesterol-lowering medications while taking Lipitor. Patients should always consult with their healthcare provider before starting Lipitor or any other medication to avoid potential interactions.

Sources:
[1] https://www.everydayhealth.com/drugs/lipitor
[2] https://www.goodrx.com/atorvastatin/interactions
[3] https://www.drugpatentwatch.com/p/tradename/LIPITOR