Drug interactions
Citalopram + Promethazine
Severity: Moderate
Citalopram 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
Citalopram is a QT-prolonging SSRI and promethazine may also prolong the QT interval, so combined use may raise the risk of arrhythmia. Promethazine may also inhibit CYP2D6 weakly and has rarely been linked with serotonergic or neuroleptic-type reactions.
What this interaction means in plain words
Citalopram 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.
Citalopram belongs to Central Nervous System; Promethazine belongs to Respiratory.
Why it happens
Additive QT prolongation and possible additive serotonergic and dopaminergic effects.
What to do
Monitor ECG in patients with cardiac risk factors or electrolyte disturbances, and keep citalopram within recommended dose limits. Watch for agitation, tremor, hyperthermia or rigidity.
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 Citalopram
- Cisapride + Citalopram Contraindicated
- Citalopram + Dronedarone Contraindicated
- Citalopram + Escitalopram Contraindicated
- Citalopram + Isocarboxazid Contraindicated
- Citalopram + Methylene blue Contraindicated
- Citalopram + Phenelzine Contraindicated
Frequently asked questions
Can I take Citalopram with Promethazine?
MediHelp rates the interaction as moderate. Citalopram 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. Citalopram is a QT-prolonging SSRI and promethazine may also prolong the QT interval, so combined use may raise the risk of arrhythmia. Promethazine may also inhibit CYP2D6 weakly and has rarely been linked with serotonergic or neuroleptic-type reactions.
How serious is the interaction between Citalopram 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 ECG in patients with cardiac risk factors or electrolyte disturbances, and keep citalopram within recommended dose limits. Watch for agitation, tremor, hyperthermia or rigidity.
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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