Drug interactions
Quinacrine + Tolterodine
Severity: Minor
Quinacrine and Tolterodine: 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
Quinacrine may inhibit CYP2D6, which could raise tolterodine levels and increase anticholinergic effects. Evidence is limited and the effect is likely small because CYP3A4 offers an alternative pathway. Both drugs may also affect cardiac repolarization.
What this interaction means in plain words
Quinacrine and Tolterodine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Possible CYP2D6 inhibition by quinacrine reducing tolterodine metabolism.
What to do
Monitor for anticholinergic adverse effects and consider ECG monitoring if other QT-prolonging risk factors are present.
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 Tolterodine
Frequently asked questions
Can I take Quinacrine with Tolterodine?
MediHelp rates the interaction as minor. Quinacrine and Tolterodine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Quinacrine may inhibit CYP2D6, which could raise tolterodine levels and increase anticholinergic effects. Evidence is limited and the effect is likely small because CYP3A4 offers an alternative pathway. Both drugs may also affect cardiac repolarization.
How serious is the interaction between Quinacrine and Tolterodine?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for anticholinergic adverse effects and consider ECG monitoring if other QT-prolonging risk factors are present.
What other medicines interact with Tolterodine?
MediHelp also lists interactions of Tolterodine with, for example, Clarithromycin, Clozapine, Cobicistat. The full list is on the Tolterodine page.
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