Drug interactions
Promazine + Venlafaxine
Severity: Moderate
Promazine 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
Promazine, a phenothiazine, can prolong the QT interval, and venlafaxine may add to this effect. Promazine also has CYP2D6 inhibition potential, which may raise venlafaxine levels.
What this interaction means in plain words
Promazine 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.
Why it happens
Additive QT prolongation, with possible CYP2D6 inhibition raising venlafaxine exposure.
What to do
Obtain a baseline ECG and monitor QTc and electrolytes, particularly in patients with cardiac risk factors. Monitor for venlafaxine adverse effects such as increased blood pressure.
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 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 Promazine with Venlafaxine?
MediHelp rates the interaction as moderate. Promazine 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. Promazine, a phenothiazine, can prolong the QT interval, and venlafaxine may add to this effect. Promazine also has CYP2D6 inhibition potential, which may raise venlafaxine levels.
How serious is the interaction between Promazine 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: Obtain a baseline ECG and monitor QTc and electrolytes, particularly in patients with cardiac risk factors. Monitor for venlafaxine adverse effects such as increased blood pressure.
What other medicines interact with Venlafaxine?
MediHelp also lists interactions of Venlafaxine with, for example, Isocarboxazid, Methylene blue, Phenelzine. The full list is on the Venlafaxine page.
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