Haloperidol and Nefazodone interaction
Haloperidol and Nefazodone: 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 Haloperidol (Haloperidol Decanoate) label · effective 2025-02-19
The effect of CYP3A4 inhibition and of decreased CYP2D6 enzyme may be additive.
Plasma concentrations of CYP2D6 substrates (e,g. tricyclic antidepressants such as desipramine or imipramine) may increase when they are co-administered with haloperidol.
Examples include: CYP3A4 inhibitors – alprazolam; itraconazole, ketoconazole, nefazodone, ritonavir.
From the Nefazodone (Nefazodone Hydrochloride) label · effective 2025-07-31
Haloperidol – When a single oral 5 mg dose of haloperidol was coadministered with nefazodone (200 mg BID) at steady state, haloperidol apparent clearance decreased by 35% with no significant increase in peak haloperidol plasma concentrations or time of peak.
Dosage adjustment of haloperidol may be necessary when coadministered with nefazodone.
Pharmacodynamic effects of haloperidol were generally not altered significantly.
Some cases presented with features resembling neuroleptic malignant syndrome.
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.