Lipitor (atorvastatin) is a medication used to lower cholesterol levels in the blood. It is important to be aware of other medications that may interact with Lipitor and cause potential side effects or reduce its effectiveness.

According to Drug Patent Watch [1], medications that should be avoided or used with caution when taking Lipitor include cyclosporine, gemfibrozil, fenofibrate, erythromycin, clarithromycin, telithromycin, HIV protease inhibitors, and nefazodone. These medications can increase the concentration of Lipitor in the blood, which can increase the risk of side effects such as muscle pain, weakness, and liver damage.

GoodRx [2] also lists several medications that may interact with Lipitor, including antifungal medications like itraconazole and ketoconazole, as well as certain antibiotics like rifampin and ciprofloxacin. These medications can either increase or decrease the concentration of Lipitor in the blood, which can affect its effectiveness or increase the risk of side effects.

Everyday Health [3] notes that grapefruit juice should also be avoided when taking Lipitor, as it can increase the concentration of the medication in the blood and increase the risk of side effects.

It is important to always inform your healthcare provider of all medications, supplements, and herbal remedies you are taking before starting Lipitor or any other medication. This will help to ensure that there are no potential interactions that could cause harm.

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