Nefazodone and Voriconazole interaction
Nefazodone and Voriconazole: 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 Nefazodone (Nefazodone Hydrochloride) label · effective 2025-07-31
…Astemizole, Cisapride, and Pimozide Interactions Terfenadine, astemizole, cisapride, and pimozide are all metabolized by the cytochrome P450 3A4 (CYP3A4) isozyme, and it has been demonstrated that ketoconazole, erythromycin, and other inhibitors of CYP3A4 can block the metabolism of these drugs, which can result in increased plasma concentrations of parent drug.
Similarly, there were no changes in the pharmacokinetic parameters of nefazodone or HO-NEF; however, the mean AUC levels of the nefazodone metabolites mCPP and triazole-dione increased by 3 to 6 fold and 1.3 fold, respectively.
There were also no changes in the pharmacokinetics of nefazodone or its triazole-dione metabolite, but the AUC and C max of mCPP increased by 44% and 48%, respectively, while the AUC of HO-NEF decreased by 19%.
When the two drugs were coadministered, there were no changes in the steady-state pharmacokinetics of either lithium, nefazodone, or its metabolite HO-NEF; however, there were small decreases in the steady-state plasma concentrations of two nefazodone metabolites, mCPP and triazole-dione, which are considered not to be of clinical significance.
Similar reductions in the C max and AUC of HO-NEF were also observed (85% and 94%), while the reductions in C max and AUC of mCPP and triazole-dione were more modest (13% and 44% for the former and 28% and 57% for the latter).
From the Voriconazole label · effective 2026-06-02
Other HIV Protease Inhibitors (CYP3A4 Inhibition) In Vivo Studies Showed No Significant Effects of Indinavir on Voriconazole Exposure In Vitro Studies Demonstrated Potential for Inhibition of Voriconazole Metabolism (Increased Plasma Exposure) No dosage adjustment in the voriconazole dosage needed for concomitant administration with indinavir.
Prednisolone and other corticosteroids (CYP3A4 Inhibition) In Vivo Studies Showed No Significant Effects of voriconazole on Prednisolone Exposure Not Studied In Vitro or In Vivo for Other Corticosteroids, but Drug Exposure Likely to be Increased No dosage adjustment for prednisolone when concomitantly administered with voriconazole [see Clinical Pharmacology…
Other HIV Protease Inhibitors (CYP3A4 Inhibition) In Vivo Studies Showed No Significant Effects on Indinavir Exposure No dosage adjustment for indinavir when concomitantly administered with voriconazole.
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.