Drug interactions
Chlorpheniramine + Nortriptyline
Severity: Moderate
Chlorpheniramine and Nortriptyline: 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 anticholinergic effects, so together they may cause marked drowsiness, dry mouth, urinary retention and confusion. Chlorpheniramine is also a CYP2D6 inhibitor and may increase nortriptyline levels modestly.
What this interaction means in plain words
Chlorpheniramine and Nortriptyline 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.
Chlorpheniramine belongs to Respiratory; Nortriptyline belongs to Central Nervous System.
Why it happens
Additive H1 antagonism, anticholinergic and CNS depressant effects, with possible weak CYP2D6 inhibition.
What to do
Advise on sedation and driving, and prefer a non-sedating antihistamine, particularly in older adults. Monitor for anticholinergic toxicity.
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 Nortriptyline
- Disopyramide + Nortriptyline Contraindicated
- Dofetilide + Nortriptyline Contraindicated
- Dronedarone + Nortriptyline Contraindicated
- Ibutilide + Nortriptyline Contraindicated
- Isocarboxazid + Nortriptyline Contraindicated
- Methylene blue + Nortriptyline Contraindicated
Other interactions of Chlorpheniramine
Frequently asked questions
Can I take Chlorpheniramine with Nortriptyline?
MediHelp rates the interaction as moderate. Chlorpheniramine and Nortriptyline 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 anticholinergic effects, so together they may cause marked drowsiness, dry mouth, urinary retention and confusion. Chlorpheniramine is also a CYP2D6 inhibitor and may increase nortriptyline levels modestly.
How serious is the interaction between Chlorpheniramine and Nortriptyline?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Advise on sedation and driving, and prefer a non-sedating antihistamine, particularly in older adults. Monitor for anticholinergic toxicity.
What other medicines interact with Nortriptyline?
MediHelp also lists interactions of Nortriptyline with, for example, Disopyramide, Dofetilide, Dronedarone. The full list is on the Nortriptyline page.
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