Isoniazid and Nefazodone interaction
Isoniazid and Nefazodone: the Nefazodone prescribing label flags 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 Nefazodone (Nefazodone Hydrochloride) label · effective 2025-07-31
Severe hyperthermia and seizures, sometimes fatal, have been reported in association with the combined use of tricyclic antidepressants and MAOIs.
…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.
Potential for Interaction with Monoamine Oxidase Inhibitors In patients receiving antidepressants with pharmacological properties similar to nefazodone in combination with a monoamine oxidase inhibitor (MAOI), there have been reports of serious, sometimes fatal, reactions.
These reactions have also been reported in patients who have recently discontinued that drug and have been started on an MAOI.
These reactions have also been reported in patients who have recently discontinued these drugs and have been started on an MAOI.
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.