OBJECT DRUGS

• Alfuzosin (Uroxatral)

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)
• Lomitapide (Juxtapid)
• Mifepristone (Korlym)
• Nelfinavir (Viracept)
• Ritonavir (Norvir)
• Saquinavir (Invirase)
• Telaprevir (Incivek)
• Verapamil (Isoptin, etc.)

Comment:

Alfuzosin is primarily metabolized by CYP3A4, and these agents are inhibitors of CYP3A4. The alfuzosin labeling states that combined use of alfuzosin with potent CYP3A4 inhibitors is contraindicated. Although not all of these drugs have equal potency as CYP3A4 inhibitors, they all would be expected to produce substantial increases in alfuzosin plasma concentrations.

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 significantly inhibit the metabolism of alfuzosin.
• Grapefruit: Orange juice does not appear to inhibit CYP3A4.
• Monitor: If alfuzosin is used with a CYP3A4 inhibitor, monitor blood pressure for evidence of hypotension. Placing the patient in the supine position or additional measures (intravenous fluids, vasopressors) may be necessary if hypotension occurs.