Does Fentanyl Transdermal Interact with Phenytoin?
CDI records a major classification for Fentanyl Transdermal and Phenytoin. The stored summary is: CYP3A4 inducer; concomitant use can decrease plasma concentration of fentanyl, resulting in decreased efficacy or withdrawal syndrome. Stopping inducer may increase fentanyl levels causing serious respiratory depression. The mechanism involves cyp3a4 induction. 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
- Major
- Fentanyl Transdermal Class
- Opioid Agonist
- Phenytoin Class
- Anti-epileptic Agent
- Management
- Close medical supervision required
- Data Source
- U.S. FDA via OpenFDA
Recorded Mechanism
CYP3A4 induction
What To Tell Your Doctor or Pharmacist
If you are taking Fentanyl Transdermal 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 how frequently you should be monitored while these are co-prescribed
- Ask whether any dosage adjustments are needed
- Never stop or change either medication without first consulting your healthcare provider