Drug interactions
Morphine + Quinidine
Severity: Minor
Morphine and Quinidine: minor 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
Quinidine inhibits CYP2D6 strongly, but morphine is mostly cleared by glucuronidation, so exposure is not meaningfully increased. Quinidine may inhibit P-glycoprotein and slightly increase central morphine effects.
What this interaction means in plain words
Morphine and Quinidine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Morphine belongs to Musculoskeletal; Quinidine belongs to Anti Parasitic.
Why it happens
Quinidine inhibits CYP2D6 and P-glycoprotein, with limited relevance to morphine disposition.
What to do
No routine dose change is needed; monitor for unusual sedation or respiratory depression.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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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 Quinidine
- Adagrasib + Quinidine Contraindicated
- Arsenic trioxide + Quinidine Contraindicated
- Artemether / lumefantrine + Quinidine Contraindicated
- Chloroquine + Quinidine Contraindicated
- Dofetilide + Quinidine Contraindicated
- Dronedarone + Quinidine Contraindicated
Frequently asked questions
Can I take Morphine with Quinidine?
MediHelp rates the interaction as minor. Morphine and Quinidine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Quinidine inhibits CYP2D6 strongly, but morphine is mostly cleared by glucuronidation, so exposure is not meaningfully increased. Quinidine may inhibit P-glycoprotein and slightly increase central morphine effects.
How serious is the interaction between Morphine and Quinidine?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No routine dose change is needed; monitor for unusual sedation or respiratory depression.
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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