Ketoconazole and Ranolazine interaction
Ketoconazole and Ranolazine: 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 Ketoconazole label · effective 2026-07-07
QT Prolongation and Drug Interactions Leading to QT Prolongation Coadministration of the following drugs with ketoconazole is contraindicated: dofetilide, quinidine, pimozide, lurasidone, cisapride, methadone, disopyramide, dronedarone, ranolazine.
…contraindicated with ketoconazole tablets: methadone, disopyramide, dronedarone, ergot alkaloids such as dihydroergotamine, ergometrine, ergotamine, methylergometrine, irinotecan, lurasidone, oral midazolam, alprazolam, triazolam, felodipine, nisoldipine, ranolazine, tolvaptan, eplerenone, lovastatin, simvastatin and colchicine (see PRECAUTIONS: Drug Interactions ).
Coadministration of the following drugs with ketoconazole is contraindicated: dofetilide, quinidine, pimozide, lurasidone, cisapride, methadone, disopyramide, dronedarone, ranolazine.
Dihydropyridines: Concomitant administration of ketoconazole tablets may cause several-fold increases in plasma concentrations of dihydropyridines Cardiovascular Drugs, Miscellaneous ranolazine aliskiren, bosentan Ranolazine: The potential increase in plasma concentrations of ranolazine when coadministered with ketoconazole tablets may increase the risk of serious…
From the Ranolazine (ASPRUZYO SPRINKLE) label · effective 2025-01-29
ASPRUZYO Sprinkle is contraindicated in patients: Taking strong inhibitors of CYP3A [see Drug Interactions (7.1)] Taking inducers of CYP3A [see Drug Interactions (7.1)] With liver cirrhosis [see Use in Specific Populations (8.6)] Strong CYP3A inhibitors (e.g., ketoconazole, clarithromycin, nelfinavir) (4, 7.1)
Effects of Other Drugs on Ranolazine Strong CYP3A Inhibitors Concomitant use of ASPRUZYO Sprinkle with strong CYP3A inhibitors, including ketoconazole, itraconazole, clarithromycin, nefazodone, nelfinavir, ritonavir, indinavir, and saquinavir is contraindicated [see Contraindications (4), Clinical Pharmacology (12.3)].
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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.