Drug interactions
Promethazine + Sunitinib
Severity: Moderate
Promethazine and Sunitinib: 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 can prolong the QT interval, and the combination may raise the risk of torsades de pointes, especially with electrolyte disturbances or cardiac disease.
What this interaction means in plain words
Promethazine and Sunitinib 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.
Promethazine belongs to Respiratory; Sunitinib belongs to Oncology.
Why it happens
Additive QT interval prolongation.
What to do
Obtain a baseline ECG and correct potassium and magnesium before and during therapy. Consider an alternative antiemetic if QTc becomes prolonged.
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
- Ibutilide + Promethazine Contraindicated
- Pimozide + Promethazine Contraindicated
- Promethazine + Thioridazine Contraindicated
- Alfentanil + Promethazine Major
- Amiodarone + Promethazine Major
- Amisulpride + Promethazine Major
Other interactions of Sunitinib
- Adagrasib + Sunitinib Major
- Amiodarone + Sunitinib Major
- Amisulpride + Sunitinib Major
- Anagrelide + Sunitinib Major
- Apalutamide + Sunitinib Major
- Arsenic trioxide + Sunitinib Major
Frequently asked questions
Can I take Promethazine with Sunitinib?
MediHelp rates the interaction as moderate. Promethazine and Sunitinib 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 can prolong the QT interval, and the combination may raise the risk of torsades de pointes, especially with electrolyte disturbances or cardiac disease.
How serious is the interaction between Promethazine and Sunitinib?
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 correct potassium and magnesium before and during therapy. Consider an alternative antiemetic if QTc becomes prolonged.
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.
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