Does Diazepam Interact with Terfenadine?
Diazepam and Terfenadine have a unknown drug interaction according to U.S. FDA drug labeling data. Diazepam may interfere with metabolism of terfenadine, a CYP3A4 substrate, leading to potential drug-drug interaction. The mechanism involves cyp3a4 substrate 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
- Unknown
- Diazepam Class
- Benzodiazepine
- Management
- Consult your pharmacist
- Data Source
- U.S. FDA via OpenFDA
How This Interaction Works
The interaction between Diazepam and Terfenadine occurs because cyp3a4 substrate interaction. Clinically, this means diazepam may interfere with metabolism of terfenadine, a cyp3a4 substrate, leading to potential drug-drug interaction.
What To Tell Your Doctor or Pharmacist
If you are taking Diazepam and your doctor is considering prescribing Terfenadine (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