Drug interactions
Chlorpromazine + Cyproheptadine
Severity: Moderate
Chlorpromazine and Cyproheptadine: 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 have sedative and anticholinergic properties, so combined use can cause marked drowsiness, impaired psychomotor performance and anticholinergic effects such as dry mouth, constipation and urinary retention. Older patients are particularly vulnerable.
What this interaction means in plain words
Chlorpromazine and Cyproheptadine 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; Cyproheptadine belongs to Respiratory.
Why it happens
Additive CNS depression through histamine H1 blockade and additive anticholinergic activity.
What to do
Start with lower doses and monitor for oversedation and anticholinergic toxicity. Advise patients to avoid driving and alcohol.
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 Cyproheptadine
- Cyproheptadine + Isocarboxazid Contraindicated
- Cyproheptadine + Phenelzine Contraindicated
- Cyproheptadine + Tranylcypromine Contraindicated
- Alfentanil + Cyproheptadine Major
- Belladonna and opium + Cyproheptadine Major
- Benzhydrocodone / acetaminophen + Cyproheptadine 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 Cyproheptadine?
MediHelp rates the interaction as moderate. Chlorpromazine and Cyproheptadine 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 have sedative and anticholinergic properties, so combined use can cause marked drowsiness, impaired psychomotor performance and anticholinergic effects such as dry mouth, constipation and urinary retention. Older patients are particularly vulnerable.
How serious is the interaction between Chlorpromazine and Cyproheptadine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Start with lower doses and monitor for oversedation and anticholinergic toxicity. Advise patients to avoid driving and alcohol.
What other medicines interact with Cyproheptadine?
MediHelp also lists interactions of Cyproheptadine with, for example, Isocarboxazid, Phenelzine, Tranylcypromine. The full list is on the Cyproheptadine page.
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