Does Sulfadiazine Interact with Indomethacin?
Sulfadiazine and Indomethacin have a moderate drug interaction according to U.S. FDA drug labeling data. Indomethacin may displace sulfonamides from plasma albumin and increase concentrations of free drug in plasma. The mechanism involves displacement of sulfonamides from plasma albumin. 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
- Moderate
- Sulfadiazine Class
- Sulfonamide Antibacterial
- Indomethacin Class
- Nonsteroidal Anti-inflammatory Drug
- Management
- Monitor for effects
- Data Source
- U.S. FDA via OpenFDA
How This Interaction Works
The interaction between Sulfadiazine and Indomethacin occurs because displacement of sulfonamides from plasma albumin. Clinically, this means indomethacin may displace sulfonamides from plasma albumin and increase concentrations of free drug in plasma. This is classified as a moderate interaction. While it may not require stopping either medication, your healthcare provider should be aware you are taking both so they can monitor for potential effects and adjust treatment if necessary.
What To Tell Your Doctor or Pharmacist
If you are taking Sulfadiazine and your doctor is considering prescribing Indomethacin (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