OBJECT DRUGS
Calcium Channel Blockers:
- Amlodipine (Norvasc)
- Bepridil (Vascor)
- Diltiazem (Cardizem, etc.)
- Felodipine (Plendil)
- Isradipine (DynaCirc, etc.)
- Nicardipine (Cardene, etc.)
- Nifedipine (Procardia, etc.)
- Nimodipine (Nimotop)
- Nisoldipine (Sular)
- Nitrendipine (Baypress)
- Verapamil (Isoptin, etc., etc.)
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)
- Dronedarone (Multaq)
- Grapefruit
- Indinavir (Crixivan)
- Lomitapide (Juxtapid)
- Mifepristone (Korlym)
- Nelfinavir (Viracept)
- Ritonavir (Norvir)
- Saquinavir (Invirase)
- Telaprevir (Incivek)
- Verapamil (Isoptin)
Comment:
Calcium channel blockers (CCBs) are metabolized by CYP3A4, so CYP3A4 inhibitors may substantially increase their serum concentrations. Not all combinations of CCBs and CYP3A4 inhibitors have been studied; assume they interact until proven otherwise. Note, however, that the magnitude of interaction can vary considerably depending on the CCB involved. For example, felodipine undergoes extensive first pass metabolism by CYP3A4 and is markedly affected by CYP3A4 inhibition, while amlodipine undergoes considerably less first pass metabolism by CYP3A4 and is much less affected by CYP3A4 inhibition. For example, grapefruit juice substantially increases felodipine concentrations, but has minimal effects on amlodipine.
Class 3: Assess Risk & Take Action if Necessary
- Monitor:If alternatives are not appropriate, consider reducing CCB dose and monitor for altered CCB response if inhibitor is initiated, discontinued, or changed in dosage.