Drug interactions
Morphine + Paroxetine
Severity: Moderate
Morphine and Paroxetine: 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
Paroxetine is a potent CYP2D6 inhibitor and serotonergic, but morphine is mainly glucuronidated, so a meaningful pharmacokinetic interaction is unlikely. Serotonin syndrome has been reported with opioids and SSRIs, though morphine carries low risk.
What this interaction means in plain words
Morphine and Paroxetine 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.
Morphine belongs to Musculoskeletal; Paroxetine belongs to Central Nervous System.
Why it happens
Additive serotonergic effects are possible; CYP2D6 inhibition has little effect on morphine because glucuronidation is the main pathway.
What to do
The combination can generally be used; monitor for signs of serotonin toxicity, especially after dose increases. Watch for excess sedation and adjust the morphine dose by response.
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 Paroxetine
- Isocarboxazid + Paroxetine Contraindicated
- Methylene blue + Paroxetine Contraindicated
- Paroxetine + Phenelzine Contraindicated
- Paroxetine + Pimozide Contraindicated
- Paroxetine + Procarbazine Contraindicated
- Paroxetine + Selegiline Contraindicated
Frequently asked questions
Can I take Morphine with Paroxetine?
MediHelp rates the interaction as moderate. Morphine and Paroxetine 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. Paroxetine is a potent CYP2D6 inhibitor and serotonergic, but morphine is mainly glucuronidated, so a meaningful pharmacokinetic interaction is unlikely. Serotonin syndrome has been reported with opioids and SSRIs, though morphine carries low risk.
How serious is the interaction between Morphine and Paroxetine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: The combination can generally be used; monitor for signs of serotonin toxicity, especially after dose increases. Watch for excess sedation and adjust the morphine dose by response.
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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