Drug interactions
Ganaxolone + Phenytoin
Severity: Major
Ganaxolone and Phenytoin: major 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
Phenytoin can lower ganaxolone concentrations through CYP3A4 induction, potentially reducing seizure control in CDKL5 deficiency disorder. Ganaxolone labeling advises avoiding moderate and strong CYP3A4 inducers.
What this interaction means in plain words
Ganaxolone and Phenytoin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Ganaxolone belongs to Central Nervous System; Phenytoin belongs to Central Nervous System.
Why it happens
Phenytoin induces CYP3A4, accelerating ganaxolone metabolism.
What to do
Avoid the combination where possible. If unavoidable, consider increasing the ganaxolone dose within the maximum for the patient's weight and monitor seizure frequency and sedation.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Phenytoin
- Artemether / lumefantrine + Phenytoin Contraindicated
- Bictegravir + Phenytoin Contraindicated
- Cabotegravir + Phenytoin Contraindicated
- Doravirine + Phenytoin Contraindicated
- Elbasvir / grazoprevir + Phenytoin Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Phenytoin Contraindicated
Other interactions of Ganaxolone
Frequently asked questions
Can I take Ganaxolone with Phenytoin?
MediHelp rates the interaction as major. Ganaxolone and Phenytoin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Phenytoin can lower ganaxolone concentrations through CYP3A4 induction, potentially reducing seizure control in CDKL5 deficiency disorder. Ganaxolone labeling advises avoiding moderate and strong CYP3A4 inducers.
How serious is the interaction between Ganaxolone and Phenytoin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where possible. If unavoidable, consider increasing the ganaxolone dose within the maximum for the patient's weight and monitor seizure frequency and sedation.
What other medicines interact with Phenytoin?
MediHelp also lists interactions of Phenytoin with, for example, Artemether / lumefantrine, Bictegravir, Cabotegravir. The full list is on the Phenytoin page.
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