Ketoconazole and Ziprasidone interaction
Ketoconazole and Ziprasidone: 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
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 ).
From the Ziprasidone (Geodon) label · effective 2025-01-13
…drugs, ziprasidone is contraindicated: • in patients with a known history of QT prolongation (including congenital long QT syndrome) • in patients with recent acute myocardial infarction • in patients with uncompensated heart failure Pharmacokinetic/pharmacodynamic studies between ziprasidone and other drugs that prolong the QT interval have not been performed.
An additive effect of ziprasidone and other drugs that prolong the QT interval cannot be excluded.
QT Prolongation and Risk of Sudden Death Ziprasidone use should be avoided in combination with other drugs that are known to prolong the QTc interval [see Contraindications (4.1) and Drug Interactions (7.4) ] .
Ketoconazole Ketoconazole, a potent inhibitor of CYP3A4, at a dose of 400 mg QD for 5 days, increased the AUC and Cmax of ziprasidone by about 35-40%.
In the second phase of the study, the effect of ziprasidone on QTc length was not augmented by the presence of a metabolic inhibitor (ketoconazole 200 mg twice daily).
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.