March 1, 2012
Facts About Statins and Protease Inhibitors
The U.S. Food and Drug Administration (FDA) is issuing updated recommendations concerning drug-drug interactions between drugs for human immunodeficiency virus (HIV) or hepatitis C virus (HCV) known as protease inhibitors and certain cholesterol-lowering drugs known as statins. Protease inhibitors and statins taken together may raise the blood levels of statins and increase the risk for muscle injury (myopathy). The most serious form of myopathy, called rhabdomyolysis, can damage the kidneys and lead to kidney failure, which can be fatal.
The labels for both the HIV protease inhibitors and the affected statins have been updated to contain consistent information about the drug-drug interactions. These labels also have been updated to include dosing recommendations for those statins that may safely be co-administered with HIV or HCV protease inhibitors (see Statin Dose Limitations below).
Healthcare professionals should refer to the current drug labels for protease inhibitors and statins for the latest recommendations on prescribing these drugs.
Patients should contact their healthcare professional if they have any questions or concerns about taking protease inhibitors and statins.
The results from a drug-drug interaction study with atorvastatin and lopinavir/ritonavir that were previously in the atorvastatin label have not yet been validated. Therefore, these results have been removed from the label and the dose cap of atorvastatin 20 mg when co-administered with lopinavir/ritonavir has also been removed. Pending validation of the study, healthcare professionals should use caution when co-administering atorvastatin with lopinavir/ritonavir and use the lowest necessary dose of atorvastatin.
Lovastatin and simvastatin are sensitive in vivo cytochrome P450 3A4 (CYP3A4) substrates. Therefore, strong CYP3A4 inhibitors are predicted to significantly increase lovastatin and simvastatin exposures. A literature review indicates that itraconazole, a strong CYP3A4 inhibitor, increases lovastatin exposure up to 20-fold, and the drug interaction appears to result in rhabdomyolysis.1 Itraconazole increases simvastatin exposure up to 13-fold. Hence, other CYP3A4 inhibitors, including ketoconazole, posaconazole, erythromycin, clarithromycin, telithromycin, nefazodone, human immunodeficiency virus (HIV) protease inhibitors, and the hepatitis C virus (HCV) protease inhibitors boceprevir and telaprevir, are also expected to significantly increase lovastatin and simvastatin exposures. Therefore, concomitant administration of lovastatin and simvastatin with HIV protease inhibitors or HCV protease inhibitors (boceprevir and telaprevir) is contraindicated.
The HIV protease inhibitor combinations lopinavir/ritonavir and atazanavir/ritonavir increase rosuvastatin exposure up to 3-fold. For these combinations, the dose of rosuvastatin should be limited to 10 mg.
|Statin Dose Limitations|
|Statin||Interacting Protease Inhibitor(s)||Prescribing Recommendation|
||Use with caution and use with the lowest atorvastatin dose necessary|
||Do not exceed 20 mg atorvastatin daily|
||Do not exceed 40 mg atorvastatin daily|
|Fluvastatin||No data available|
||No dose limitations|
||No dose limitations|
||Limit rosuvastatin dose to 10 mg once daily|
HIV = human immunodeficiency virus