Drug interactions
Amitriptyline + Morphine
Severity: Moderate
Amitriptyline and Morphine: 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 can produce additive CNS depression. Amitriptyline may also raise morphine levels, and a serotonin syndrome risk is possible though uncommon.
What this interaction means in plain words
Amitriptyline and Morphine 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; Morphine belongs to Musculoskeletal.
Why it happens
Additive CNS depression and serotonergic effects, with possible reduced morphine clearance and additive anticholinergic effects.
What to do
Start with low doses and titrate carefully, monitoring sedation, respiratory rate and constipation or urinary retention. Review the regimen if signs of serotonin toxicity 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 Morphine
- Alvimopan + Morphine Contraindicated
- Isocarboxazid + Morphine Contraindicated
- Morphine + Olanzapine / samidorphan Contraindicated
- Morphine + Phenelzine Contraindicated
- Morphine + Tranylcypromine Contraindicated
- Alfentanil + Morphine Major
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 Morphine?
MediHelp rates the interaction as moderate. Amitriptyline and Morphine 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 can produce additive CNS depression. Amitriptyline may also raise morphine levels, and a serotonin syndrome risk is possible though uncommon.
How serious is the interaction between Amitriptyline and Morphine?
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 low doses and titrate carefully, monitoring sedation, respiratory rate and constipation or urinary retention. Review the regimen if signs of serotonin toxicity appear.
What other medicines interact with Morphine?
MediHelp also lists interactions of Morphine with, for example, Alvimopan, Isocarboxazid, Olanzapine / samidorphan. The full list is on the Morphine page.
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