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

Antimicrobials:

• Ciprofloxacin (Cipro, etc.)
• Clarithromycin (Biaxin, etc.)
• Erythromycin (E-Mycin, etc.)
• Fluconazole (Diflucan)
• Itraconazole (Sporanox, etc.)
• Ketoconazole (Nizoral, etc.)
• Posaconazole (Noxafil)
• Quinupristin (Synercid)
• Telithromycin (Ketek)
• Troleandomycin (TAO)
• Voriconazole (Vfend)

Comment:

These antipsychotics are metabolized by CYP3A4; these antimicrobials inhibit CYP3A4, and may increase antipsychotic serum levels.

Class 3: Assess Risk & Take Action if Necessary

• Consider Alternative:
• Azole Antifungals:Itraconazole and ketoconazole are potent inhibitors of CYP3A4; fluconazole appears weaker, but in larger doses it also inhibits CYP3A4.
• Macrolides:Unlike erythromycin, clarithromycin and troleandomycin, azithromycin (Zithromax) and dirithromycin* do not appear to inhibit CYP3A4. (*not available in US)
• Telithromycin: The use of azithromycin (Zithromax) or a quinolone antibiotic other than ciprofloxacin may be considered.
• Paliperidone (Invega) is not metabolized by CYP3A4 and could be considered as an alternative.
• Circumvent/Minimize: The manufacturer recommends that the dose of aripiprazole be reduced to one-half the usual dose if CYP3A4 inhibitors are added. If the CYP3A4 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. Due to the long half-lives of some of these drugs, the onset and offset of these interactions may take 1-2 weeks.