Does Modafinil Interact with Phenytoin?
CDI records a moderate classification for Modafinil and Phenytoin. The stored summary is: Elimination may be prolonged by modafinil with resultant higher systemic exposure. Dose adjustment may be necessary when used concomitantly. The mechanism involves inhibition of cyp2c19 metabolic enzymes. Patients taking both medications should consult their healthcare provider before starting, stopping, or changing the dosage of either drug. This record was extracted from drug labeling through openFDA. NIH/NLM RxNorm is used for drug identities. The summary and severity classification are CDI's processed information, not a verbatim source quotation. Product, route, and patient circumstances matter.
- Severity
- Moderate
- Modafinil Class
- Sympathomimetic-like Agent
- Phenytoin Class
- Anti-epileptic Agent
- Management
- Monitor for effects
- Data Source
- U.S. FDA via OpenFDA
Recorded Mechanism
Inhibition of CYP2C19 metabolic enzymes
What To Tell Your Doctor or Pharmacist
If you are taking Modafinil 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
- Ask whether any dosage adjustments are needed
- Never stop or change either medication without first consulting your healthcare provider