OBJECT DRUGS

• Mifepristone (Korlym)

PRECIPITANT DRUGS

Enzyme Inhibitors:

• Amiodarone (Cordarone, etc.)
• Amprenavir (Agenerase)
• Aprepitant (Emend)
• Atazanavir (Reyataz)
• Boceprevir (Victrelis)
• Ceritinib (Zykadia)
• Cobicistat (Stribild)
• Conivaptan (Vaprisol)
• Cyclosporine (Neoral, etc.)
• Darunavir (Prezista)
• Delavirdine (Rescriptor)
• Diltiazem (Cardizem, etc.)
• Dronedarone (Multaq)
• Grapefruit
• Imatinib (Gleevec)
• Indinavir (Crixivan)
• Lapatinib (Tykerb)
• Nelfinavir (Viracept)
• Ritonavir (Norvir)
• Saquinavir (Invirase)
• Telaprevir (Incivek)
• Verapamil (Isoptin, etc.)

Comment:

Inhibitors of CYP3A4 may increase the serum concentrations of mifepristone. The product information for mifepristone states that strong CYP3A4 inhibitors should be used only with "extreme caution" in patients on mifepristone.

Class 2: Use only if Benefit Felt to Outweigh Risk

• Use Alternative:
• Calcium channel blockers: Calcium channel blockers other than diltiazem and verapamil are unlikely to inhibit the metabolism of mifepristone.
• Grapefruit: Orange juice does not appear to inhibit CYP3A4.
• Circumvent/Minimize: In patients receiving strong CYP3A4 inhibitors the product information states that the mifepristone dose should be no higher than 300 mg daily.
• Monitor: Monitor for altered mifepristone effect if CYP3A4 inhibitors are initiated, discontinued, or changed in dosage. Adjustments in mifepristone dosage may be necessary.