Lipitor (atorvastatin) is a prescription medication used to treat high cholesterol and triglyceride levels in the blood. It is essential to know the possible interactions of Lipitor with other medications to avoid any harmful effects.

According to Drug Patent Watch [1], some of the most common drug interactions with Lipitor include:

- Antibiotics: Certain antibiotics like erythromycin, clarithromycin, and telithromycin can increase the risk of muscle damage when taken with Lipitor.
- Antifungal medications: Azole antifungal medications like itraconazole, ketoconazole, and voriconazole can increase the risk of muscle damage when taken with Lipitor.
- Antiviral medications: Some antiviral medications like ritonavir and lopinavir/ritonavir can increase the risk of muscle damage when taken with Lipitor.
- Other cholesterol-lowering medications: Taking Lipitor with other cholesterol-lowering medications like gemfibrozil can increase the risk of muscle damage.
- Immunosuppressants: Immunosuppressants like cyclosporine can increase the risk of muscle damage when taken with Lipitor.
- Heart medications: Certain heart medications like digoxin and diltiazem can increase the risk of muscle damage when taken with Lipitor.

GoodRx [2] also lists some of the common drug interactions with Lipitor, including:

- Grapefruit juice: Drinking grapefruit juice can increase the levels of Lipitor in the blood, which can increase the risk of side effects.
- Birth control pills: Certain birth control pills can increase the levels of Lipitor in the blood, which can increase the risk of side effects.
- Blood thinners: Taking Lipitor with blood thinners like warfarin can increase the risk of bleeding.

WebMD [3] adds that alcohol and niacin can also interact with Lipitor, and it is important to avoid or limit alcohol consumption while taking Lipitor. Niacin can increase the risk of muscle damage when taken with Lipitor.

It is crucial to inform your doctor about all the medications, supplements, and vitamins you are taking before starting Lipitor to avoid any potential interactions. Your doctor may need to adjust the dose of Lipitor or change your medication regimen to avoid any harmful effects.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.goodrx.com/atorvastatin/interactions
[3] https://www.webmd.com/drugs/2/drug-3330/lipitor-oral/details