Iloperidone and Ketoconazole interaction
Iloperidone and Ketoconazole: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Iloperidone (FANAPT) label · effective 2026-05-06
Avoid the use of FANAPT in combination with any other drugs that prolong the QT interval [see Warnings and Precautions (5.3) ] .
…prolong QTc including Class 1A (e.g., quinidine, procainamide) or Class III (e.g., amiodarone, sotalol) antiarrhythmic medications, antipsychotic medications (e.g., chlorpromazine, thioridazine), antibiotics (e.g., gatifloxacin, moxifloxacin), or any other class of medications known to prolong the QTc interval (e.g., pentamidine, levomethadyl acetate, methadone).
The dose of FANAPT should be reduced in patients co-administered a strong CYP2D6 or CYP3A4 inhibitor.
Strong CYP3A4 Inhibitors Clinical Impact Co-administration of ketoconazole with iloperidone, increased the AUC of iloperidone and its metabolites P88 and P95 by 57%, 55%, and 35%, respectively [see Clinical Pharmacology (12.3) ] .
Intervention Reduce the dose of FANAPT by one-half when administered with strong CYP3A4 inhibitors.
From the Ketoconazole label · effective 2026-07-07
This may potentiate and prolong hypnotic and sedative effects, especially with repeated dosing or chronic administration of these agents.
…methadone when coadministered with ketoconazole tablets may increase the risk of serious cardiovascular events including QT prolongation and torsade de pointes, or respiratory or CNS depression [See CONTRAINDICATIONS .] Fentanyl: The potential increase in plasma concentrations of fentanyl when coadministered with ketoconazole tablets may increase the risk of…
Antipsychotics, Anxiolytics and Hypnotics Lurasidone, alprazolam, oral midazolam, pimozide, triazolam aripiprazole, buspirone, haloperidol, midazolam IV, quetiapine, ramelteon, risperidone The increase in plasma concentrations of lurasidone when coadministered with ketoconazole tablets may increase the risk of serious side effects (See CONTRAINDICATIONS ).
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Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.