Drug interactions
Lonafarnib + Zonisamide
Severity: Moderate
Lonafarnib 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
Lonafarnib is a strong CYP3A inhibitor and can raise exposure to drugs cleared partly by CYP3A4, including zonisamide. Higher zonisamide levels may increase dose-related adverse effects such as somnolence, dizziness, cognitive slowing and metabolic acidosis.
What this interaction means in plain words
Lonafarnib 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.
Lonafarnib belongs to Miscellaneous; Zonisamide belongs to Central Nervous System.
Why it happens
Lonafarnib inhibits CYP3A4, which is a main route of zonisamide metabolism, reducing its clearance.
What to do
Monitor for CNS adverse effects and consider a zonisamide dose reduction if toxicity appears. Check bicarbonate and zonisamide response when lonafarnib is started or stopped.
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 Zonisamide
- Zonisamide + Zuranolone Major
- Acetazolamide + Zonisamide Moderate
- Amisulpride + Zonisamide Moderate
- Amobarbital + Zonisamide Moderate
- Apalutamide + Zonisamide Moderate
- Asenapine transdermal + Zonisamide Moderate
Other interactions of Lonafarnib
- Alfuzosin + Lonafarnib Contraindicated
- Amobarbital + Lonafarnib Contraindicated
- Apalutamide + Lonafarnib Contraindicated
- Bosentan + Lonafarnib Contraindicated
- Carbamazepine + Lonafarnib Contraindicated
- Clarithromycin + Lonafarnib Contraindicated
Frequently asked questions
Can I take Lonafarnib with Zonisamide?
MediHelp rates the interaction as moderate. Lonafarnib 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. Lonafarnib is a strong CYP3A inhibitor and can raise exposure to drugs cleared partly by CYP3A4, including zonisamide. Higher zonisamide levels may increase dose-related adverse effects such as somnolence, dizziness, cognitive slowing and metabolic acidosis.
How serious is the interaction between Lonafarnib 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 for CNS adverse effects and consider a zonisamide dose reduction if toxicity appears. Check bicarbonate and zonisamide response when lonafarnib is started or stopped.
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.
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