Drug interactions
Morphine + Protriptyline
Severity: Moderate
Morphine and Protriptyline: 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
Protriptyline adds to the sedative and respiratory depressant effects of morphine. Tricyclic antidepressants combined with opioids also carry a rare risk of serotonin syndrome, and may increase anticholinergic effects such as constipation and urinary retention.
What this interaction means in plain words
Morphine and Protriptyline 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.
Why it happens
Additive CNS depression plus potential additive serotonergic effects from reuptake inhibition.
What to do
Monitor for sedation, respiratory depression and signs of serotonin toxicity such as agitation, tremor, hyperthermia and clonus. Start with low doses and titrate cautiously.
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
Frequently asked questions
Can I take Morphine with Protriptyline?
MediHelp rates the interaction as moderate. Morphine and Protriptyline 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. Protriptyline adds to the sedative and respiratory depressant effects of morphine. Tricyclic antidepressants combined with opioids also carry a rare risk of serotonin syndrome, and may increase anticholinergic effects such as constipation and urinary retention.
How serious is the interaction between Morphine and Protriptyline?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for sedation, respiratory depression and signs of serotonin toxicity such as agitation, tremor, hyperthermia and clonus. Start with low doses and titrate cautiously.
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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