Drug interactions
Chlorpheniramine + Orphenadrine
Severity: Moderate
Chlorpheniramine and Orphenadrine: 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 anticholinergic and sedating properties. Together they may cause pronounced drowsiness, dry mouth, urinary retention, constipation and confusion, especially in older adults.
What this interaction means in plain words
Chlorpheniramine and Orphenadrine 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.
Why it happens
Additive antimuscarinic and CNS depressant effects.
What to do
Monitor for anticholinergic toxicity and sedation, using lower doses in elderly patients. Choose a non-sedating antihistamine where possible.
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 Chlorpheniramine
Frequently asked questions
Can I take Chlorpheniramine with Orphenadrine?
MediHelp rates the interaction as moderate. Chlorpheniramine and Orphenadrine 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 anticholinergic and sedating properties. Together they may cause pronounced drowsiness, dry mouth, urinary retention, constipation and confusion, especially in older adults.
How serious is the interaction between Chlorpheniramine and Orphenadrine?
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 for anticholinergic toxicity and sedation, using lower doses in elderly patients. Choose a non-sedating antihistamine where possible.
What other medicines interact with Chlorpheniramine?
MediHelp also lists interactions of Chlorpheniramine with, for example, Belladonna and opium, Benzhydrocodone / acetaminophen, Brexanolone. The full list is on the Chlorpheniramine page.
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