Drug interactions
Rifampin + Zonisamide
Severity: Moderate
Rifampin and Zonisamide: 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
Rifampin induces CYP3A4 and reduces zonisamide exposure, which may reduce anticonvulsant efficacy and risk breakthrough seizures.
What this interaction means in plain words
Rifampin and Zonisamide 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.
Why it happens
Induction of CYP3A4 increasing zonisamide clearance.
What to do
Monitor seizure control and consider increasing the zonisamide dose or checking levels. Reduce the dose again if rifampin is discontinued.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Rifampin and Zonisamide, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
Other interactions of Zonisamide
- Zonisamide + Zuranolone Major
- Acetazolamide + Zonisamide Moderate
- Amisulpride + Zonisamide Moderate
- Amobarbital + Zonisamide Moderate
- Apalutamide + Zonisamide Moderate
- Asenapine transdermal + Zonisamide Moderate
Frequently asked questions
Can I take Rifampin with Zonisamide?
MediHelp rates the interaction as moderate. Rifampin and Zonisamide 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. Rifampin induces CYP3A4 and reduces zonisamide exposure, which may reduce anticonvulsant efficacy and risk breakthrough seizures.
How serious is the interaction between Rifampin and Zonisamide?
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 seizure control and consider increasing the zonisamide dose or checking levels. Reduce the dose again if rifampin is discontinued.
What other medicines interact with Zonisamide?
MediHelp also lists interactions of Zonisamide with, for example, Zuranolone, Acetazolamide, Amisulpride. The full list is on the Zonisamide page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
