Does Doxazosin Interact with Phenytoin?
Doxazosin and Phenytoin have a minor drug interaction according to U.S. FDA drug labeling data. In vitro data indicate doxazosin has no effect on protein binding of phenytoin. The mechanism involves protein binding interaction. 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
- Minor
- Phenytoin Class
- Anti-epileptic Agent
- Management
- Generally manageable
- Data Source
- U.S. FDA via OpenFDA
How This Interaction Works
The interaction between Doxazosin and Phenytoin occurs because protein binding interaction. Clinically, this means in vitro data indicate doxazosin has no effect on protein binding of phenytoin. This is classified as a minor interaction with generally low clinical significance, though your healthcare provider should still be informed that you are taking both medications.
What To Tell Your Doctor or Pharmacist
If you are taking Doxazosin 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