Drug interactions
Amitriptyline + Dextromethorphan
Severity: Moderate
Amitriptyline and Dextromethorphan: 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
Combining dextromethorphan with amitriptyline may increase serotonergic activity and raise the risk of serotonin syndrome. Amitriptyline can also inhibit CYP2D6 modestly, increasing dextromethorphan exposure.
What this interaction means in plain words
Amitriptyline and Dextromethorphan 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; Dextromethorphan belongs to Respiratory.
Why it happens
Additive serotonergic effects, plus CYP2D6 inhibition reducing dextromethorphan clearance.
What to do
Use standard antitussive doses for short periods and monitor for agitation, tremor, hyperreflexia, sweating and fever. Choose a non-serotonergic cough suppressant if symptoms appear.
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 Dextromethorphan
- Dextromethorphan + Isocarboxazid Contraindicated
- Dextromethorphan + Linezolid Contraindicated
- Dextromethorphan + Phenelzine Contraindicated
- Dextromethorphan + Rasagiline Contraindicated
- Dextromethorphan + Safinamide Contraindicated
- Dextromethorphan + Selegiline Contraindicated
Other interactions of Amitriptyline
- Amitriptyline + Isocarboxazid Contraindicated
- Amitriptyline + Methylene blue Contraindicated
- Amitriptyline + Phenelzine Contraindicated
- Amitriptyline + Pimozide Contraindicated
- Amitriptyline + Procarbazine Contraindicated
- Amitriptyline + Safinamide Contraindicated
Frequently asked questions
Can I take Amitriptyline with Dextromethorphan?
MediHelp rates the interaction as moderate. Amitriptyline and Dextromethorphan 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. Combining dextromethorphan with amitriptyline may increase serotonergic activity and raise the risk of serotonin syndrome. Amitriptyline can also inhibit CYP2D6 modestly, increasing dextromethorphan exposure.
How serious is the interaction between Amitriptyline and Dextromethorphan?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use standard antitussive doses for short periods and monitor for agitation, tremor, hyperreflexia, sweating and fever. Choose a non-serotonergic cough suppressant if symptoms appear.
What other medicines interact with Dextromethorphan?
MediHelp also lists interactions of Dextromethorphan with, for example, Isocarboxazid, Linezolid, Phenelzine. The full list is on the Dextromethorphan page.
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