Drug interactions
Posaconazole + Venlafaxine
Severity: Moderate
Posaconazole 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
Posaconazole may raise venlafaxine exposure, although venlafaxine is cleared mainly by CYP2D6 with CYP3A4 as a minor route. Higher levels could increase serotonergic, cardiovascular and blood pressure effects. Posaconazole also prolongs the QT interval, and venlafaxine has been linked to QT effects in overdose.
What this interaction means in plain words
Posaconazole 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.
Posaconazole belongs to Anti Fungals; Venlafaxine belongs to Central Nervous System.
Why it happens
Posaconazole inhibits CYP3A4, a minor metabolic pathway for venlafaxine, and both drugs may have additive QT effects.
What to do
Monitor blood pressure, heart rate and signs of serotonin toxicity, and obtain an ECG if other QT-prolonging risk factors are present. Reduce the venlafaxine dose if adverse effects emerge.
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 Posaconazole
- Artemether + Posaconazole Contraindicated
- Avanafil + Posaconazole Contraindicated
- Cobimetinib + Posaconazole Contraindicated
- Conivaptan + Posaconazole Contraindicated
- Dihydroergotamine intranasal + Posaconazole Contraindicated
- Dihydroergotamine + Posaconazole 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 Posaconazole with Venlafaxine?
MediHelp rates the interaction as moderate. Posaconazole 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. Posaconazole may raise venlafaxine exposure, although venlafaxine is cleared mainly by CYP2D6 with CYP3A4 as a minor route. Higher levels could increase serotonergic, cardiovascular and blood pressure effects. Posaconazole also prolongs the QT interval, and venlafaxine has been linked to QT effects in overdose.
How serious is the interaction between Posaconazole 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: Monitor blood pressure, heart rate and signs of serotonin toxicity, and obtain an ECG if other QT-prolonging risk factors are present. Reduce the venlafaxine dose if adverse effects emerge.
What other medicines interact with Posaconazole?
MediHelp also lists interactions of Posaconazole with, for example, Artemether, Avanafil, Cobimetinib. The full list is on the Posaconazole page.
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