Drug interactions
Fluconazole + Venlafaxine
Severity: Moderate
Fluconazole and Venlafaxine: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Both agents have been associated with QT prolongation, and fluconazole may raise venlafaxine levels by inhibiting its metabolism. Together this may increase the risk of arrhythmia, particularly in patients with other QT risk factors.
What this interaction means in plain words
Fluconazole and Venlafaxine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Fluconazole belongs to Anti Fungals; Venlafaxine belongs to Central Nervous System.
Why it happens
Additive QT prolongation, with fluconazole inhibiting CYP2D6/CYP3A4-mediated venlafaxine metabolism.
What to do
Check ECG and electrolytes at baseline and during co-therapy in patients with cardiac risk factors. Monitor blood pressure and adverse effects of venlafaxine, and reduce the dose if they occur.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Fluconazole
- Dihydroergotamine intranasal + Fluconazole Contraindicated
- Dihydroergotamine + Fluconazole Contraindicated
- Dofetilide + Fluconazole Contraindicated
- Domperidone + Fluconazole Contraindicated
- Dronedarone + Fluconazole Contraindicated
- Erythromycin + Fluconazole Contraindicated
Other interactions of Venlafaxine
- Isocarboxazid + Venlafaxine Contraindicated
- Methylene blue + Venlafaxine Contraindicated
- Phenelzine + Venlafaxine Contraindicated
- Procarbazine + Venlafaxine Contraindicated
- Rasagiline + Venlafaxine Contraindicated
- Safinamide + Venlafaxine Contraindicated
Frequently asked questions
Can I take Fluconazole with Venlafaxine?
MediHelp rates the interaction as moderate. Fluconazole and Venlafaxine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Both agents have been associated with QT prolongation, and fluconazole may raise venlafaxine levels by inhibiting its metabolism. Together this may increase the risk of arrhythmia, particularly in patients with other QT risk factors.
How serious is the interaction between Fluconazole and Venlafaxine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check ECG and electrolytes at baseline and during co-therapy in patients with cardiac risk factors. Monitor blood pressure and adverse effects of venlafaxine, and reduce the dose if they occur.
What other medicines interact with Fluconazole?
MediHelp also lists interactions of Fluconazole with, for example, Dihydroergotamine intranasal, Dihydroergotamine, Dofetilide. The full list is on the Fluconazole page.
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