Ketoconazole and Venlafaxine interaction
Ketoconazole and Venlafaxine: the Venlafaxine prescribing label 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 Venlafaxine (Venlafaxine Hydrochloride) label · effective 2025-01-31
Ketoconazole: Increase in venlafaxine and O-desmethylvenlafaxine AUC and C max .
Ketoconazole: A pharmacokinetic study with ketoconazole 100 mg b.i.d. with a single dose of venlafaxine 50 mg in extensive metabolizers (EM; n=14) and 25 mg in poor metabolizers (PM;n=6) of CYP2D6 resulted in higher plasma concentrations of both venlafaxine and O-desmethylvenlafaxine (ODV) in most subjects following administration of ketoconazole.
Concomitant use of CYP3A4 inhibitors and venlafaxine may increase levels of venlafaxine and ODV.
Therefore, caution is advised if a patient’s therapy includes a CYP3A4 inhibitor and venlafaxine concomitantly.
CYP3A4 Venlafaxine did not inhibit CYP3A4 in vitro .
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.