Drug interactions
Amitriptyline + Chlorpheniramine
Severity: Moderate
Amitriptyline and Chlorpheniramine: 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 cause sedation and have anticholinergic properties. Combined use can cause marked drowsiness, dry mouth, urinary retention, constipation and confusion, and chlorpheniramine is partly metabolised by CYP2D6, which amitriptyline can inhibit.
What this interaction means in plain words
Amitriptyline and Chlorpheniramine 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.
Amitriptyline belongs to Central Nervous System; Chlorpheniramine belongs to Respiratory.
Why it happens
Additive H1-receptor antagonism, CNS depression and muscarinic blockade.
What to do
Avoid in older patients where possible and consider a non-sedating antihistamine. Counsel about drowsiness and driving.
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 Amitriptyline
- Amitriptyline + Isocarboxazid Contraindicated
- Amitriptyline + Methylene blue Contraindicated
- Amitriptyline + Phenelzine Contraindicated
- Amitriptyline + Pimozide Contraindicated
- Amitriptyline + Procarbazine Contraindicated
- Amitriptyline + Safinamide Contraindicated
Other interactions of Chlorpheniramine
Frequently asked questions
Can I take Amitriptyline with Chlorpheniramine?
MediHelp rates the interaction as moderate. Amitriptyline and Chlorpheniramine 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 cause sedation and have anticholinergic properties. Combined use can cause marked drowsiness, dry mouth, urinary retention, constipation and confusion, and chlorpheniramine is partly metabolised by CYP2D6, which amitriptyline can inhibit.
How serious is the interaction between Amitriptyline and Chlorpheniramine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid in older patients where possible and consider a non-sedating antihistamine. Counsel about drowsiness and driving.
What other medicines interact with Amitriptyline?
MediHelp also lists interactions of Amitriptyline with, for example, Isocarboxazid, Methylene blue, Phenelzine. The full list is on the Amitriptyline page.
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