Cimetidine and Iloperidone interaction
Cimetidine and Iloperidone: the Iloperidone prescribing label describes an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Iloperidone (FANAPT) label · effective 2026-05-06
The dose of FANAPT should be reduced in patients co-administered a strong CYP2D6 or CYP3A4 inhibitor.
Table 7: Clinically Important Drug Interactions with FANAPT Strong CYP2D6 Inhibitors Clinical Impact Coadministration of fluoxetine with iloperidone increased exposure (area under curve, [AUC]) of iloperidone and its metabolite P88, by about 2- to 3- fold, and decreased the AUC of its metabolite P95 by one-half [see Clinical Pharmacology (12.3 , 12.5) ] .
Intervention Reduce the dose of FANAPT by one-half when administered with strong CYP2D6 inhibitors.
When a strong CYP2D6 inhibitor is withdrawn from the combination therapy, the iloperidone dose should be returned to the previous level [see Dosage and Administration (2.4) ] .
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) ] .
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
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.