Drug interactions
Primidone + Topiramate
Severity: Moderate
Primidone and Topiramate: 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
Both drugs are anticonvulsants that cause sedation, dizziness and cognitive slowing, so combining them can increase these effects. Primidone is also an enzyme inducer that may modestly lower topiramate exposure, so seizure control and tolerability can both change.
What this interaction means in plain words
Primidone and Topiramate 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 belongs to Central Nervous System; Topiramate belongs to Central Nervous System.
Why it happens
Additive CNS depression, plus primidone (via phenobarbital) induction of enzymes that metabolize topiramate.
What to do
Monitor sedation, cognition and seizure frequency when starting, stopping or changing doses, and titrate topiramate to clinical effect. Counsel patients about driving and alcohol.
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 Topiramate
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 Topiramate?
MediHelp rates the interaction as moderate. Primidone and Topiramate 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. Both drugs are anticonvulsants that cause sedation, dizziness and cognitive slowing, so combining them can increase these effects. Primidone is also an enzyme inducer that may modestly lower topiramate exposure, so seizure control and tolerability can both change.
How serious is the interaction between Primidone and Topiramate?
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 sedation, cognition and seizure frequency when starting, stopping or changing doses, and titrate topiramate to clinical effect. Counsel patients about driving and alcohol.
What other medicines interact with Topiramate?
MediHelp also lists interactions of Topiramate with, for example, Benzhydrocodone / acetaminophen, Buprenorphine long-acting, Buprenorphine subdermal implant. The full list is on the Topiramate page.
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