Drug interactions
Darifenacin + Primidone
Severity: Moderate
Darifenacin and Primidone: 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
Primidone is metabolized to phenobarbital, which induces CYP3A4 and can reduce darifenacin concentrations. This may decrease control of overactive bladder symptoms.
What this interaction means in plain words
Darifenacin and Primidone 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; Primidone belongs to Central Nervous System.
Why it happens
CYP3A4 induction by primidone and its phenobarbital metabolite increases darifenacin clearance.
What to do
Monitor for reduced efficacy and adjust the darifenacin dose or choose an alternative if symptoms worsen.
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 Darifenacin
Other interactions of Primidone
- Lorlatinib + Primidone Contraindicated
- Lurasidone + Primidone Contraindicated
- Primidone + Ranolazine Contraindicated
- Primidone + Sofosbuvir-velpatasvir-voxilaprevir Contraindicated
- Primidone + Voriconazole Contraindicated
- Abiraterone + Primidone Major
Frequently asked questions
Can I take Darifenacin with Primidone?
MediHelp rates the interaction as moderate. Darifenacin and Primidone 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. Primidone is metabolized to phenobarbital, which induces CYP3A4 and can reduce darifenacin concentrations. This may decrease control of overactive bladder symptoms.
How serious is the interaction between Darifenacin and Primidone?
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 reduced efficacy and adjust the darifenacin dose or choose an alternative if symptoms worsen.
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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