Drug interactions
Paroxetine + Promethazine
Severity: Moderate
Paroxetine 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
Paroxetine is a strong CYP2D6 inhibitor and promethazine is partly metabolized by CYP2D6, so promethazine levels may increase. This may enhance sedation, anticholinergic effects and QT-related risk.
What this interaction means in plain words
Paroxetine 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.
Paroxetine belongs to Central Nervous System; Promethazine belongs to Respiratory.
Why it happens
Inhibition of CYP2D6-mediated promethazine metabolism by paroxetine.
What to do
Use the lowest effective promethazine dose and monitor for sedation, anticholinergic effects and palpitations. Consider an alternative antihistamine if effects are troublesome.
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 Paroxetine
- Isocarboxazid + Paroxetine Contraindicated
- Methylene blue + Paroxetine Contraindicated
- Paroxetine + Phenelzine Contraindicated
- Paroxetine + Pimozide Contraindicated
- Paroxetine + Procarbazine Contraindicated
- Paroxetine + Selegiline Contraindicated
Frequently asked questions
Can I take Paroxetine with Promethazine?
MediHelp rates the interaction as moderate. Paroxetine 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. Paroxetine is a strong CYP2D6 inhibitor and promethazine is partly metabolized by CYP2D6, so promethazine levels may increase. This may enhance sedation, anticholinergic effects and QT-related risk.
How serious is the interaction between Paroxetine 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: Use the lowest effective promethazine dose and monitor for sedation, anticholinergic effects and palpitations. Consider an alternative antihistamine if effects are troublesome.
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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