Drug interactions
Primidone + Tolterodine
Severity: Minor
Primidone 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
Primidone is metabolized to phenobarbital, which induces CYP3A4 and may lower tolterodine exposure. The change is usually modest because CYP2D6 is the main route, but could matter in poor CYP2D6 metabolizers.
What this interaction means in plain words
Primidone 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.
Primidone belongs to Central Nervous System; Tolterodine belongs to Genitourinary.
Why it happens
Enzyme induction by primidone and its metabolite phenobarbital increases tolterodine clearance.
What to do
Monitor for reduced symptom control and increase tolterodine if needed.
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
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 Primidone with Tolterodine?
MediHelp rates the interaction as minor. Primidone 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. Primidone is metabolized to phenobarbital, which induces CYP3A4 and may lower tolterodine exposure. The change is usually modest because CYP2D6 is the main route, but could matter in poor CYP2D6 metabolizers.
How serious is the interaction between Primidone 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 reduced symptom control and increase tolterodine if needed.
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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