Drug interactions
Darifenacin + Morphine
Severity: Minor
Darifenacin and Morphine: 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
Darifenacin inhibits CYP2D6 only modestly, and morphine is cleared mainly by glucuronidation rather than CYP2D6, so a meaningful pharmacokinetic change is not expected. Both drugs can slow gut motility, so constipation or urinary retention may be additive.
What this interaction means in plain words
Darifenacin and Morphine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Darifenacin belongs to Genitourinary; Morphine belongs to Musculoskeletal.
Why it happens
Morphine is not significantly CYP2D6-dependent; the main overlap is additive anticholinergic and opioid effects on gut and bladder function.
What to do
No dose change is needed for the pharmacokinetic aspect. Monitor for constipation and urinary retention and treat them as they arise.
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 Darifenacin
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 Darifenacin with Morphine?
MediHelp rates the interaction as minor. Darifenacin and Morphine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Darifenacin inhibits CYP2D6 only modestly, and morphine is cleared mainly by glucuronidation rather than CYP2D6, so a meaningful pharmacokinetic change is not expected. Both drugs can slow gut motility, so constipation or urinary retention may be additive.
How serious is the interaction between Darifenacin and Morphine?
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 dose change is needed for the pharmacokinetic aspect. Monitor for constipation and urinary retention and treat them as they arise.
What other medicines interact with Darifenacin?
MediHelp also lists interactions of Darifenacin with, for example, Atazanavir, Bethanechol, Clarithromycin. The full list is on the Darifenacin page.
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