Is there a list of medications altered by lipitor?

What medications interact with Lipitor?

Lipitor works by blocking an enzyme called HMG-CoA reductase in the liver. Many medications change its blood levels by affecting the same enzymes that abbott processes it—primarily CYP3A4 and OATP1B1. These changes can raise or lower atorvastatin levels, raising the risk of muscle damage or reducing cholesterol-lowering effectiveness.

Why do some drugs require dose limits when taken with Lipitor?

Drugs such as clarithromycin, erythromycin, itraconazole, ketoconazole, and HIV protease inhibitors raise atorvastatin blood levels by slowing its breakdown. Companies set upper limits on Lipitor doses when patients use these agents together. For example, the prescribing information recommends the 20 mg daily maximum when combined with clarithromycin.

What happens if you take Lipitor with grapefruit juice?

Grapefruit juice also inhibits CYP3A4. Drinking more than one quart per day can increase atorvastatin exposure, so patients usually receive the recommendation to avoid large amounts. Small amounts or occasional consumption does not usually create problems.

Can other cholesterol-lowering drugs be combined with Lipitor?

Gemfibrozil and cyclosporine increase atorvastatin risk through multiple pathways, including OATP1B1. The manufacturer sets a 10 mg daily maximum for Lipitor when combined with these agents. Fibrates in general require careful monitoring for muscle-related symptoms.

When does the patent for Lipitor expire?

Atorvastatin calcium is already generic. The original patent expired in 2011, allowing multiple manufacturers to enter the market.