Drug interactions
Deutetrabenazine + Promethazine
Severity: Moderate
Deutetrabenazine and Promethazine: 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 drugs cause sedation, and deutetrabenazine can cause depression and somnolence. Promethazine can prolong the QT interval, whereas deutetrabenazine has little QT effect at recommended doses, but the risk rises with other risk factors.
What this interaction means in plain words
Deutetrabenazine and Promethazine 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.
Deutetrabenazine belongs to Central Nervous System; Promethazine belongs to Respiratory.
Why it happens
Additive CNS depression; possible additive QT prolongation, and dopamine blockade by promethazine may add to parkinsonism.
What to do
Monitor sedation and mood. Obtain an ECG and correct electrolytes if QT risk factors are present.
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 Promethazine
- Cabergoline + Promethazine Contraindicated
- Dopamine + Promethazine Contraindicated
- Ibutilide + Promethazine Contraindicated
- Pimozide + Promethazine Contraindicated
- Promethazine + Thioridazine Contraindicated
- Alfentanil + Promethazine Major
Other interactions of Deutetrabenazine
- Deutetrabenazine + Isocarboxazid Contraindicated
- Deutetrabenazine + Linezolid Contraindicated
- Deutetrabenazine + Phenelzine Contraindicated
- Deutetrabenazine + Rasagiline Contraindicated
- Deutetrabenazine + Safinamide Contraindicated
- Deutetrabenazine + Selegiline Contraindicated
Frequently asked questions
Can I take Deutetrabenazine with Promethazine?
MediHelp rates the interaction as moderate. Deutetrabenazine and Promethazine 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 drugs cause sedation, and deutetrabenazine can cause depression and somnolence. Promethazine can prolong the QT interval, whereas deutetrabenazine has little QT effect at recommended doses, but the risk rises with other risk factors.
How serious is the interaction between Deutetrabenazine and Promethazine?
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 sedation and mood. Obtain an ECG and correct electrolytes if QT risk factors are present.
What other medicines interact with Promethazine?
MediHelp also lists interactions of Promethazine with, for example, Cabergoline, Dopamine, Ibutilide. The full list is on the Promethazine page.
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