Itraconazole and Quetiapine interaction
Itraconazole and Quetiapine: both prescribing labels describe 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 Itraconazole (Tolsura) label · effective 2025-04-23
Antipsychotics, Anxiolytics and Hypnotics Alprazolam Aripiprazole Buspirone Diazepam Haloperidol Midazolam (IV) Quetiapine Ramelteon Risperidone Suvorexant Monitor for adverse reactions.
From the Quetiapine (SEROQUEL XR) label · effective 2026-04-10
• Concomitant use of strong CYP3A4 inhibitors: Reduce quetiapine dose to one‑sixth when coadministered with strong CYP3A4 inhibitors (e.g., ketoconazole, ritonavir) ( 2.5 , 7.1 , 12.3 )
Quetiapine exposure is increased by the prototype CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, indinavir, ritonavir, nefazodone, etc.) and decreased by the prototype of CYP3A4 inducers (e.g., phenytoin, carbamazepine, rifampin, avasimibe, St.
CYP3A4 inhibitors: Coadministration of ketoconazole, a potent inhibitor of cytochrome CYP3A4, resulted in significant increase in quetiapine exposure.
The dose should be reduced to one‑sixth of the original dose in patients coadministered with a strong CYP3A4 inhibitor [see Dosage and Administration (2.5) and 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.