Does Fomepizole Interact with Phenytoin?
Fomepizole and Phenytoin have a unknown drug interaction according to U.S. FDA drug labeling data. Reciprocal interactions may occur through cytochrome P450 system effects, though not studied. The mechanism involves cytochrome p450 system modulation. Patients taking both medications should consult their healthcare provider before starting, stopping, or changing the dosage of either drug. This information is based on official FDA drug labeling sourced from OpenFDA and the NIH National Library of Medicine.
- Severity
- Unknown
- Fomepizole Class
- Antidote
- Phenytoin Class
- Anti-epileptic Agent
- Management
- Consult your pharmacist
- Data Source
- U.S. FDA via OpenFDA
How This Interaction Works
The interaction between Fomepizole and Phenytoin occurs because cytochrome p450 system modulation. Clinically, this means reciprocal interactions may occur through cytochrome p450 system effects, though not studied.
What To Tell Your Doctor or Pharmacist
If you are taking Fomepizole and your doctor is considering prescribing Phenytoin (or vice versa), make sure to:
- Inform your doctor and pharmacist of all current medications, including over-the-counter drugs and supplements
- Ask whether the benefits of combining these medications outweigh the risks for your specific situation
- Ask what symptoms to watch for that would indicate the interaction is causing problems
- Never stop or change either medication without first consulting your healthcare provider