Drug interactions
Darifenacin + Erythromycin
Severity: Moderate
Darifenacin and Erythromycin: 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
Erythromycin raises darifenacin exposure, which may increase anticholinergic effects such as dry mouth, constipation, and blurred vision. Darifenacin is not expected to affect erythromycin meaningfully.
What this interaction means in plain words
Darifenacin and Erythromycin 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.
Darifenacin belongs to Genitourinary; Erythromycin belongs to Anti Bacterial.
Why it happens
Erythromycin inhibits CYP3A4 metabolism of darifenacin.
What to do
Monitor for anticholinergic effects; the darifenacin dose should not exceed 7.5 mg daily with moderate CYP3A4 inhibitors per labeling.
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 Erythromycin
- Conivaptan + Erythromycin Contraindicated
- Dihydroergotamine intranasal + Erythromycin Contraindicated
- Dihydroergotamine + Erythromycin Contraindicated
- Domperidone + Erythromycin Contraindicated
- Dronedarone + Erythromycin Contraindicated
- Droperidol + Erythromycin Contraindicated
Other interactions of Darifenacin
Frequently asked questions
Can I take Darifenacin with Erythromycin?
MediHelp rates the interaction as moderate. Darifenacin and Erythromycin 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. Erythromycin raises darifenacin exposure, which may increase anticholinergic effects such as dry mouth, constipation, and blurred vision. Darifenacin is not expected to affect erythromycin meaningfully.
How serious is the interaction between Darifenacin and Erythromycin?
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 anticholinergic effects; the darifenacin dose should not exceed 7.5 mg daily with moderate CYP3A4 inhibitors per labeling.
What other medicines interact with Erythromycin?
MediHelp also lists interactions of Erythromycin with, for example, Conivaptan, Dihydroergotamine intranasal, Dihydroergotamine. The full list is on the Erythromycin page.
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