Drug interactions
Benperidol + Promethazine
Severity: Moderate
Benperidol 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 agents block dopamine receptors and are sedating, so the combination raises the risk of extrapyramidal symptoms, neuroleptic malignant syndrome and excessive drowsiness. Additive QT prolongation is also possible.
What this interaction means in plain words
Benperidol 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.
Why it happens
Additive dopamine D2 antagonism and CNS depression.
What to do
Monitor for rigidity, dystonia, fever and sedation. Consider an ECG if other QT-prolonging risk factors exist.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Benperidol and Promethazine, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Promethazine
- Ibutilide + Promethazine Contraindicated
- Pimozide + Promethazine Contraindicated
- Promethazine + Thioridazine Contraindicated
- Alfentanil + Promethazine Major
- Amiodarone + Promethazine Major
- Amisulpride + Promethazine Major
Frequently asked questions
Can I take Benperidol with Promethazine?
MediHelp rates the interaction as moderate. Benperidol 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 agents block dopamine receptors and are sedating, so the combination raises the risk of extrapyramidal symptoms, neuroleptic malignant syndrome and excessive drowsiness. Additive QT prolongation is also possible.
How serious is the interaction between Benperidol 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 for rigidity, dystonia, fever and sedation. Consider an ECG if other QT-prolonging risk factors exist.
What other medicines interact with Promethazine?
MediHelp also lists interactions of Promethazine with, for example, Ibutilide, Pimozide, Thioridazine. The full list is on the Promethazine page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
