Drug interactions
Chlorpromazine + Phenylephrine
Severity: Moderate
Chlorpromazine and Phenylephrine: 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
Chlorpromazine has alpha-adrenergic blocking activity and may blunt the pressor response to phenylephrine, which can matter when treating phenothiazine-induced hypotension. Phenothiazines may also add to arrhythmia risk with sympathomimetics.
What this interaction means in plain words
Chlorpromazine and Phenylephrine 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.
Chlorpromazine belongs to Central Nervous System; Phenylephrine belongs to Respiratory.
Why it happens
Alpha-1 blockade by chlorpromazine antagonizes phenylephrine's vasoconstriction.
What to do
Monitor blood pressure and titrate phenylephrine to effect, as higher doses may be needed. Monitor ECG in patients with arrhythmia risk.
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 Phenylephrine
- Isocarboxazid + Phenylephrine Contraindicated
- Phenelzine + Phenylephrine Contraindicated
- Phenylephrine + Tranylcypromine Contraindicated
- Bromocriptine + Phenylephrine Major
- Cocaine + Phenylephrine Major
- Dihydroergotamine intranasal + Phenylephrine Major
Other interactions of Chlorpromazine
- Chlorpromazine + Dofetilide Contraindicated
- Chlorpromazine + Dronedarone Contraindicated
- Chlorpromazine + Droperidol Contraindicated
- Chlorpromazine + Ibutilide Contraindicated
- Chlorpromazine + Metrizamide Contraindicated
- Chlorpromazine + Panobinostat Contraindicated
Frequently asked questions
Can I take Chlorpromazine with Phenylephrine?
MediHelp rates the interaction as moderate. Chlorpromazine and Phenylephrine 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. Chlorpromazine has alpha-adrenergic blocking activity and may blunt the pressor response to phenylephrine, which can matter when treating phenothiazine-induced hypotension. Phenothiazines may also add to arrhythmia risk with sympathomimetics.
How serious is the interaction between Chlorpromazine and Phenylephrine?
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 blood pressure and titrate phenylephrine to effect, as higher doses may be needed. Monitor ECG in patients with arrhythmia risk.
What other medicines interact with Phenylephrine?
MediHelp also lists interactions of Phenylephrine with, for example, Isocarboxazid, Phenelzine, Tranylcypromine. The full list is on the Phenylephrine page.
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