Ketoconazole and Trazodone interaction
Ketoconazole and Trazodone: 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…
From the Trazodone (RALDESY TM) label · effective 2026-09-01
The use of RALDESY Should be avoided in patients with known QT prolongation or in combination with other drugs that are inhibitors of CYP3A4 (e.g., itraconazole, clarithromycin, voriconazole), or known to prolong QT interval including Class 1A antiarrhythmics (e.g., quinidine, procainamide) or Class 3 antiarrhythmics (e.g., amiodarone, sotalol), certain antipsychotic…
CYP3A4 Inhibitors: Consider RALDESY dose reduction based on tolerability ( 2.5 , 7 ).
Strong CYP3A4 Inhibitors Clinical Impact: The concomitant use of RALDESY and strong CYP3A4 inhibitors increased the exposure of trazodone compared to the use of RALDESY alone.
Intervention: If RALDESY is used with a potent CYP3A4 inhibitor, the risk of adverse reactions, including cardiac arrhythmias, may be increased and a lower dose of RALDESY should be considered [see Dosage and Administration (2.5) , Warnings and Precautions (5.3) ].
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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.