Which specific drugs worsen lipitor's impact on the liver?

Drugs that raise Lipitor levels and risk liver stress

Lipitor (atorvastatin) relies on the CYP3A4 enzyme to break it down. Drugs that inhibit this enzyme keep higher amounts of Lipitor in the body and increase the chance of liver enzyme elevations or more serious liver injury.

What happens if you take these drugs with Lipitor

Certain antifungal agents such as itraconazole and voriconazole, the antibiotic clarithromycin, the antidepressant nefazodone, and HIV protease inhibitors all inhibit CYP3A4. When taken together with Lipitor, they can triple or quadruple Lipitor levels, raising the risk of liver toxicity. Patients taking any of these should ask their doctor about dose adjustments or alternative treatments.

Why are companies challenging this patent?

No companies are challenging the Lipitor compound patent itself because it has already expired. Companies have instead targeted secondary patents on specific formulations and salt forms, but those rights are now finished as well.

When does exclusivity expire?

Lipitor's basic compound patent expired in 2011. Subsequent formulation patents held by Pfizer have also expired. Generic atorvastatin is widely available now.

Who makes generic Lipitor?

Multiple manufacturers produce generic atorvastatin. The main producers include Teva, Mylan, and Dr. Reddy's.