OBJECT DRUGS

Antipsychotics, Atypical:

• Aripiprazole (Abilify, etc.)
• Brexpiprazole (Rexulti)
• Clozapine (Clozaril, etc.)
• Iloperidone (Fanapt)
• Lurasidone (Latuda)
• Olanzapine (Zyprexa, etc.)
• Quetiapine (Seroquel, etc.)
• Risperidone (Risperdal, etc.)
• Ziprasidone (Geodon)

PRECIPITANT DRUGS

Enzyme Inhibitors: (CYP3A4)

• 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.)
• Grapefruit
• Imatinib (Gleevec)
• Indinavir (Crixivan)
• Lapatinib (Tykerb)
• Lomitapide (Juxtapid)
• Mifepristone (Korlym)
• Nefazodone
• Nelfinavir (Viracept)
• Ritonavir (Norvir)
• Saquinavir (Invirase)
• Telaprevir (Incivek)
• Verapamil (Isoptin, etc.)

Comment:

These antipsychotics are metabolized by CYP3A4; drugs that inhibit CYP3A4 may increase antipsychotic serum levels. Most of these antipsychotics have multiple pathways of elimination (see CYP2D6 inhibitors, below), and the magnitude of the interactions is likely to vary substantially depending on the specific pair of drugs, and the specific patient characteristics.

Class 3: Assess Risk & Take Action if Necessary

• Consider Alternative: Use an alternative to the enzyme inhibitor if possible.
• Calcium channel blockers: Calcium channel blockers other than diltiazem and verapamil are unlikely to inhibit CYP3A4.
• Grapefruit: Orange juice does not appear to inhibit CYP3A4.
• Antipsychotic: Paliperidone (Invega) is not metabolized by CYP3A4 and could be considered as an alternative.
• Circumvent/Minimize: The manufacturer recommends that the dose of aripiprazole or be reduced to one-half the usual dose if CYP3A4 inhibitors or CYP2D6 inhibitors are added. If the inhibitor is then discontinued, they recommend that the aripiprazole dose be increased to the usual dosage.
• Monitor: Be alert for altered effect of the antipsychotic if CYP3A4 inhibitors are started, stopped, or changed in dosage.